Final Report Summary - UMBRELLA (Toolbox for Common Forecasting, Risk assessment, and Operational Optimisation in Grid Security Cooperations of Transmission System Operators (TSOs))
Executive Summary:
Transmission system operators (TSOs) are facing new challenges in day-to-day grid operation and operational planning. The security issues affecting the pan-European electricity transmission system are becoming more and more challenging due to:
• The growing contribution of less predictable and more variable renewable energy sources (RES);
• The need for the coordination of controllable devices such as phase-shifting transformers (PSTs), high-voltage direct-current (HVDC) lines and flexible alternating-current transmission systems (FACTSs);
• Partially controllable electricity demand;
• The increasing difficulty of building new transmission lines;
• The gradual integration of national markets into one common European electrical energy market;
• Market mechanisms not covering certain aspects of system security, leading to high deviations between scheduled and physical flows in terms of time, direction and volume.
As a consequence meteorological forecasting errors may lead to unforeseen violations of operating limits and trigger cascading outages in stressed-system situations. These new constraints, but also new opportunities, result in more complex operational planning and transmission system operation, take the system closer to its operational limits, cause remedial actions to be taken more frequently in order to relieve congestion and, as a result, make it necessary to revise operational rules and procedures. To be fully efficient, emerging Regional Security Cooperation Initiatives (RSCIs) need a new generation of tools to allow the different TSOs to increase coordination and react more quickly to the growing complexity of operational planning and system operation.
Hence, nine TSOs(1) from Central and Central- Eastern Europe, organised within their RSCI named TSO Security Cooperation (TSC), have joined forces with five universities (2) and one research institute (3) to to provide a coordinated solution to these increasing challenges in their target area. This research and development project, entitled “Innovative tools for the future coordinated and stable operation of the pan-European electricity transmission system” (UMBRELLA), is supported by the European Union as part of its Seventh Framework Programme (FP7). To cope with the above mentioned challenges
TSOs at first have to find an answer to the question: What will be the upcoming system state? This requires the modelling of uncertainties related to RES, load forecasting deviations and intraday trades. In this regard, the UMBRELLA Toolbox goes beyond state of the art by not just looking at one forecast. Instead, a wide range of deviations from the forecast and their probabilities are assessed by applying advanced deterministic and probabilistic methods.
Risk-based security assessment will allow the TSOs to answer the question whether the system will be secure. This includes a comparison of the well-known N-1 criterion with risk-based security criteria, taking into account both the probability of occurrence and the severity of outages, cascades and violations of operational limits. Additionally, the UMBRELLA Toolbox is capable of assessing additional operational costs that are the consequences of forecast deviations.
The complexity of congestion management in transmission systems is growing due to an increase in the amount of congestion and the number of available remedial measures. The enhanced optimal power flow (EOPF) algorithm developed may relieve TSOs’ workload significantly by using deterministic or probabilistic optimisation algorithms that take both uncertainty and risk measures into account.
The UMBRELLA Optimisation Framework aims to provide optimal topological and redispatch measures as well as the curtailment of RES infeed and load-shedding measures by taking into account numerous objectives, such as regulatory restrictions, the cost of redispatch and other factors, ranging from day-ahead operational planning to close-to-real-time operation.
The developed modules are synthesised in the UMBRELLA Toolbox. By testing the UMBRELLA Prototype on historical test cases (TCs), the general functionalities of the UMBRELLA Toolbox have been validated and key performance indicators (KPIs) attest the improvement achieved. The applied test system of nine TSOs’ control areas includes some 7000 nodes, approx. 3000 branches and around 1400 transformers of which 46 are phase-shifters. Some modules are tested using test systems of the Institute of Electrical and Electronics Engineers (IEEE). For the implementation and further exploitation of the UMBRELLA Toolbox within RSCIs, a stepwise approach is proposed.
As an result of the UMBRELLA and iTesla projects, a set of recommendations is provided for stakeholders such as regulators, policymakers, TSOs and the European Network of Transmission System Operators for Electricity (ENTSO-E) to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange so that the innovative software tools developed can be applied by TSOs and within RSCIs
1) Amprion GmbH (Germany), Austrian Power Grid AG (Austria), CEPS (Czech Republic), Elektro-Slovenija (Slovenia), PSE S.A. (Poland), swissgrid (Switzerland), TenneT TSO B.V. (Netherlands), TenneT TSO GmbH (Germany; Coordinator) and TransnetBW GmbH (Germany)
2 ) Delft University of Technology (Netherlands), Graz University of Technology (Austria), ETH Zurich (Switzerland), RWTH Aachen (Germany) and University of Duisburg-Essen (Germany)
3 )FGH Forschungsgemeinschaft für elektrische Anlagen und Stromwirtschaft e.V. (Germany)
Project Context and Objectives:
Motivation and Summary
As part of the fight against climate change, the European Union is aiming to decarbonise its economy. An important aspect is to replace fossil-fuel-based electricity generation with RES such as wind and solar power. Therefore, European energy markets as well as energy grids have to be fit for renewables.
Figure 1: RES increase, based on Germany’s grid development plan 2025, 2015 version
As can be seen from the data compiled in the latest available version of the German grid development plan6 (Figure 1), German RES capacity is expected to grow, even in the most conservative scenario, by more than 50% between 2013 and 2025. Other EU countries are expected to undergo similar developments—partly time- delayed—over the coming years given the EU’s ambitions for the so-called Energy Union.
In order to ensure the secure and stable operation of the transmission grid, TSOs predict the load and corresponding generation at a regional level, including forecasts for RES infeed and according to market outcomes the conventional power generation. They also aim at considering load-flow deviations caused by intraday market trades, power plant and grid equipment outages and volatile consumption. Based on these predictions, in the second step of their daily process the TSOs analyse where congestion may occur by taking into account the given capacity and availability of power lines, transformers and other grid elements.
The interconnected transmission grid in Continental Europe is severely stressed as a result of the insufficient harmonisation of regulatory frameworks and market rules in the various countries. More and more frequently in the congestion management process, TSOs identify severe overloading of grid elements by loop flows or transit flows, and this has a major influence on further decision making. Having collected the necessary operational data, TSOs take the available operational measures, such as changes to the network topology and flow-control device settings, to manage power flows within the capability of existing networks. If congestion cannot be relieved by such measures, counter-trade and redispatch have to be considered and implemented. As these measures are expensive and affect the market outcome they need to be kept to a minimum. For all the necessary remedial measures to be available in good time, TSOs aim to establish the most reliable forecast process possible. Operational planning can then take place one day in advance on the basis of those forecasts. This entire process is named the Day-Ahead Congestion Forecast (DACF).
Short-term analysis is also constantly undertaken in the form of a so-called rolling Intraday Congestion Forecast (IDCF). This takes place from hours in advance until the end of the day, and monitors and tracks the actual development of the system state. It allows favouring less costly measures and delays the adoption of costly measures until they are guaranteed to be needed.
Figure 2: Example TenneT Germany: Wind deviation from forecast
However, the growing proportion of electricity generated by intermittent RES, as well as increasing market-based cross-border flows and related physical flows, are nowadays leading to a significant increase in the uncertainty surrounding the generation of forecasts and the related power flow in the grid.
This is a difficult challenge to face, as the trans- mission grid is not designed for this purpose and the construction of new power lines will take a number of years. Furthermore, new storage technologies have not yet reached industrial maturity or economic viability.
Figure 3: TenneT Germany, PV forecast deviation: fog forecasted, but not occurred (deviation 6000 MW to DACF; 3000 MW to updated forecast)
Especially if wind infeed arrives earlier or later than expected or even falls short of or overshoots the forecasted level of infeed (Figure 2), the load flows in the grid can differ considerably from the predictions. Forecast deviations for PV installations have similar critical effects if fog or clouds unexpectedly shield them from solar radiation or, on the contrary, allow for more infeed than initially expected (Figure 3).
Currently, the DACF, short-term and real-time forecasts are merely deterministic. Uncertainty is considered only implicitly, by means of security margins. As such uncertainty grows due to the increase in volatile RES infeed and intraday electricity market trades, however, the classic deterministic approach for each single control area is no longer sufficient. As can be seen from the example of TenneT, the rise of RES generation capacity (Figure 1) goes hand in hand with the soaring number of TSO interventions needed (Figure 4) to safeguard transmission system operation. Concurrently with this, the incidents to be dealt with by the TSOs will continue to increase in number as well as in duration. Furthermore, European electricity market integration is leading to an increase in the scale of unscheduled cross- border flows, which also require even better multilateral coordination between different TSOs. As most of the uncertain processes involved are taking place on lower voltages in the distribution grid, TSOs can observe only the aggregated behaviour of these processes on the high-voltage grid, which makes it difficult to collect data and to derive relevant information from them.
These challenges reveal the need for automated and multilaterally optimised methods to safeguard the operation of the transmission system and to make optimal use of the existing grid capacity.
Figure 4: Incidents with counter-measures in the control area of TenneT Germany
(excluding voltage/reactive power problems)
As a consequence of these trends, meteorological forecasting errors may lead to unforeseen violations of operating limits and trigger cascading outages in stressed-system situations. Especially in mainland Central Europe as a synchronous area with pre-existing large RES generation facilities, the difference between actual physical flows and market exchanges in the Central Europe synchronous area can be very substantial in time, direction and volume. These new constraints, but also new opportunities, result in more complex operational planning and transmission system operation, take the system closer to its operational limits, cause remedial actions to be taken more frequently in order to relieve congestion and, as a result, make it necessary to revise operational rules and procedures.
Against this backdrop, the tools for security assessment that are currently available and established will no longer be suitable for TSOs to make the right decisions. To be fully efficient, emerging Regional Security Cooperation Initiatives (RSCIs) need a new generation of tools to allow the different TSOs to increase coordination and react more quickly to the growing complexity of operational planning and system operation. In search of a holistic approach to the aforementioned TSOs’ challenges, nine TSOs (1) from Central and Central- Eastern Europe, organised within their RSCI, named TSC, have joined forces with five universities (2) and one research institute (3) to investigate advanced deterministic and probabilistic methods beyond the state of the art to provide a coordinated solution to these increasing challenges for their control areas (Figure 5).
Figure 5: Target area and participants of the UMBRELLA FP7 R&D project
This research and development project, entitled “Innovative tools for the future coordinated and stable operation of the pan-European electricity transmission system” (UMBRELLA), is supported by the European Union as part of its Seventh Framework Programme (FP7).
Forecasting and uncertainty
TSOs at first have to find an answer to the question: What will be the upcoming system state? This requires the modelling of uncertainties related to RES and load forecasting deviations. Such deviations could be traded in the intraday markets.
This will lead to changes of load flows that need to be anticipated by the TSOs. In addition, deviations that cause load flows into neighbouring control areas have to be regarded as well. In this regard, the UMBRELLA Toolbox goes beyond state of the art by not just looking at one forecast. Instead, a wide range of deviations from the forecast and their probabilities are assessed by applying newly developed methods.
Risk assessment
To allow the system operator to make use of the numerous possible scenarios for the upcoming future, new methods to perform risk-based security assessment must be developed. Such risk assessment will allow the TSOs to answer the question whether the system will be secure. This includes a comparison of the well-known N-1 criterion with risk-based security criteria, taking into account both the probability of occurrence and the severity of outages, cascades and violations of operational limits. Additionally, the UMBRELLA Toolbox is capable of assessing additional operational costs that are the consequences of forecast deviations.
Optimisation
Once upcoming system states are known and their severity is assessed, system operators can undertake actions in order to ensure system security. Here, the need for coordination and modern, automated software tools is evident: the complexity of congestion management in transmission systems is growing due to an increase in the amount of congestion and the number of available remedial measures. The enhanced optimal power flow (EOPF) algorithm developed here may relieve TSOs’ workload significantly by using deterministic or probabilistic optimisation algorithms that take both uncertainty and risk measures into account.
The UMBRELLA Optimisation Framework aims to provide optimal topological and redispatch measures as well as the curtailment of RES infeed and load-shedding measures by taking into account numerous objectives, such as regulatory restrictions, the cost of redispatch and other factors, ranging from day-ahead operational planning to close-to-real-time operation. This allows remedial measures with long activation times, such as thermal power plants, to be activated well in advance.
Since the methodology used for the probabilistic forecast of the future use of the new system is based on a statistical model, it is important to compile, validate and maintain historical data with which to build the statistical backbone of the system. Based on this methodology, a number of potentially critical scenarios for the future use of system developments can be identified.
UMBRELLA Toolbox
The developed modules for improved forecasting, optimisation and risk-based assessment are synthesised in the UMBRELLA Toolbox, which offers users the flexibility to apply either individual parts or the complete set of functionalities. The effectiveness of the Toolbox has been demonstrated in tests using the UMBRELLA Prototype, which comprises most of the developed methods. By testing the UMBRELLA Prototype on historical test cases (TCs), the general functionalities of the UMBRELLA Toolbox have been validated and key performance indicators (KPIs) attest to the improvement achieved. The applied test system of nine TSOs’ control areas includes some 7000 nodes, approx. 3000 branches and around 1400 transformers of which 46 are phase-shifters. Some modules are tested using test systems of the Institute of Electrical and Electronics Engineers (IEEE). For the implementation and further exploitation of the UMBRELLA Toolbox within RSCIs, a stepwise approach is proposed.
As an additional result of the UMBRELLA and iTesla (4) projects, a set of recommendations is provided for stakeholders such as National Regulatory Authorities (NRAs), policymakers, TSOs and the European Network of Transmission System Operators for Electricity (ENTSO-E) to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange so that the innovative software tools developed can be applied by TSOs and within RSCIs. The report concludes with a description of the prerequisites for the safe operation of the pan-European transmission system, including the provision of data of the necessary quality and quantity.
1 Amprion GmbH (Germany), Austrian Power Grid AG (Austria), CEPS (Czech Republic), Elektro-Slovenija (Slovenia), PSE S.A. (Poland), swissgrid (Switzerland), TenneT TSO B.V. (Netherlands), TenneT TSO GmbH (Germany; Coordinator) and TransnetBW GmbH (Germany)
2 Delft University of Technology (Netherlands), Graz University of Technology (Austria), ETH Zurich (Switzerland), RWTH Aachen (Germany) and University of Duisburg-Essen (Germany)
3 FGH Forschungsgemeinschaft für elektrische Anlagen und Stromwirtschaft e.V. (Germany)
4 Innovative Tools for Electrical System Security within Large Area (iTesla)
Project Results:
Please refer to the core part of the attached deliverable D1.3
Potential Impact:
In the framework of the UMBRELLA Project a dedicated innovative toolbox was developed to support TSOs’ and RSCIs’ future efforts to ensure grid security. The UMBRELLA Toolbox includes:
• The simulation of uncertainty caused by market activities and Renewable Energy Sources (RES).
• A deterministic and probabilistic optimisation framework for corrective actions to cope with simulated risks on different timescales and increasing system complexity; the aim of this is to reduce the total cost of uncertainty while also increasing system security and transmission capacity.
• Risk-based assessment tools for anticipated system states with and without corrective actions.
The tools developed are synthesised in the UMBRELLA Toolbox, which offers users the flexibility of applying either individual modules or the complete set of functionalities. The individual software tools are extensively tested using IEEE test systems based on the historical datasets of the nine TSOs’ target area through a decentralised approach. Thus, the concept of the individual methods, as well as the UMBRELLA Toolbox Prototype that combines them, is proven by applying them to historical Test Cases (TCs), such as the cold snap on 8 February 2012 and the stressed-grid situation which arose on 22 August 2012.
The tests performed by the TSOs with the support of the universities and research institutes show that the UMBRELLA Toolbox is able to:
• calculate remedial actions to ensure the safe and reliable operation of the transmission network; and
• give the operator additional information about the range of uncertainty that can be expected.
It is shown that the application of the UMBRELLA Toolbox Optimisation Framework speeds up the current experience-based process significantly by avoiding unnecessary iteration steps, since the conflicting activation of remedial actions by different TSOs is avoided. This gives the operators and operational planners the necessary time to prepare the actual implementation of the proposed remedies.
According to the GRID+ concept, KPIs are evaluated to compare business as usual with the results of the new innovative tools. This reveals the significant progress brought about by the new tools. Besides a considerable improvement in the security of system operation, the recovery of overall UMBRELLA Project can be expected within one month when the UMBRELLA Toolbox functionalities are applied.
Further development of the Toolbox and a parallel dry run are currently being prepared by the TSC initiative. This will enable TSOs to identify optimal settings for the Toolbox in order to implement it in daily operational planning processes as well as in real-time operation.
As the envisaged exploitation of the UMBRELLA Toolbox shall be embedded in established information systems, the extension and harmonisation of data exchanges is crucial. A stepwise approach is proposed for the implementation of the UMBRELLA Toolbox by TSOs and RSCIs to overcome the challenges on the path from research to the industrialisation of the UMBRELLA Toolbox. Thus, the adaptation of processes and the introduction of the new CGMES data format can go hand in hand with the gradual introduction of the related tools.
As a result of the UMBRELLA and iTesla projects, a set of recommendations is provided for stakeholders such as regulators, policymakers, TSOs and ENTSO-E to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange for the application of the new software tools.
Impact
In order to test the toolbox prototype, three test cases TC1 (2/2012), TC2 (8/2012), and TC3 (3/2013) have been selected, covering seasonal aspects, e.g. different current limits of transmission lines and different infeed scenarios for RES. The historic test cases always resemble stressed-grid situations, which required a significant amount of remedial actions, such as topological measures and redispatch, in order to ensure the safe and reliable operation of the transmission system. The test cases cover the whole day in order to be able to test the time coupled optimisation, which is quite relevant for power plant start up or shut down decisions.
After defining the TCs, the toolbox prototype was tested and evaluated. For this purpose, the TC datasets had to be checked and adjusted by the TSOs. Model corrections to ensure the quality of the datasets and model improvements to check the different remedial actions were implemented manually and compared with the results of the toolbox prototype’s optimisation functions. The probabilistic results (see figure Impact 1) were compared with the operational experience of all participating TSOs.
Fig. Impact 1: The probabilistic functionality of the UMBRELLA Toolbox provides additional insight in the possible system development
To investigate whether the UMBRELLA Optimisation Framework of the prototype toolbox is able to improve the daily business of TSOs significantly and whether it would be relatively easy to integrate it into current processes, the assessment of results is carried out in detail. For the sake of simplicity, we refer to the optimisation functionalities simply as “the Optimiser”.
In the Base Case, TSOs implemented model corrections in the datasets in order to achieve a common starting point for further evaluation. The Classic Approach represents the datasets after each TSO has implemented its remedial actions manually, as usually performed during the daily DACF process. The Modern Approach represents the datasets after the Optimiser has implemented remedial actions in an automated manner. The degrees of freedom for the Optimiser were (at least) the set of topological measures from the Classic Approach as well as redispatch and available PST tap changes.
As can be observe in the figure Impact 2, after only one run of the Optimiser the overloads are resolved and the transmission grid works close to its operational limits. This means an improvement for system security and a minimisation of costs, since the maximum of 100% loading in the N-1 case is achieved faster and more consistent than with the manual approach. It is shown that the application of the UMBRELLA Toolbox Optimisation Framework speeds up the current experience-based process significantly by eliminating unnecessary iteration steps, since the conflicting activation of remedial actions by different TSOs is avoided. These major points give the operators and operational planners the necessary time to prepare the actual implementation of the proposed remedies. Hence, it can be concluded that system security can be improved significantly with the optimisation methods developed within the UMBRELLA Project.
Fig. Impact 2: The UMBRELLA Toolbox Optimisation Framework renders advantages with regard to accuracy as well as costs of spent operation time, redispatch and stress on grid equipment
One objective of the UMBRELLA optimisation framework is to keep the security of supply at least at the current level and at the same time reducing the overall costs of security related measures by determining the remedial measures in a coordinated way across the whole transmission system. The optimisation algorithm gives priority to less costly remedial actions and tries to relieve congestion in the most efficient way.
In general, the optimisation algorithm managed to reduce the amount of redispatch. This is because it considers the combined relieving of multiple congestions with globally available remedial measures. While there is barely any advantage in situations with very little congestion, the Optimiser becomes extremely beneficial in the case of a large number of redispatch measures. This is particularly evident by the situation with the largest number of redispatch measures in the Classic Approach, namely the 12:30 timestamp in TC2. The amount of redispatch estimated in the Classic Approach for this timestamp is 2770 MW. Meanwhile, the Optimiser achieves a less critical system state, with a redispatch of just 1204 MW, which means a 57% reduction in redispatch volume. This can bring a significant benefit for the reduction of costs for the TSOs’ daily operation, which ultimately results in an increased social welfare.
To give an impression of the financial impact of this effect, let’s have a look at an example: In 2015 Redispatch costs in Germany amounted to approximately one billion Euros. A reduction of only 10 % by use of the UMBRELLA optimisation framework, which is far below the actual test case results, would recover the overall UMBRELLA project costs within one month.
Furthermore, assuming that the optimizer saves approximately two hours of manual work per day and assuming an average salary of a TSO operator of approx. 100€/h, for all nine UMBRELLA-TSOs the toolbox is able to save over 650 k€ per year when using the deterministic optimizer instead of the iterative manual approach, thus only by relieving TSO-personnel from daily routine. Taking into account all ENTSO-E TSOs this amount is growing to round about 3 M€ per year.
The introduction of uncertainty margins (which are necessary to avoid N-1 violations,) leads to a decrease in available transmission capacity and thus to a higher cost. To assess this cost increase, we introduce a new metric, the cost of uncertainty, which measures the increase in operational costs which arise due to forecast uncertainty.
The cost of uncertainty is positive, meaning that the TSO generally has to pay a higher operational cost to secure the system against uncertainty. However, the additional costs can be significantly reduced by the use of the analysed R&I methods. Especially in the case of flexible use of reserves, the saving potential in uncertainty costs compared with business as usual reaches up to 2.3 %.
Another aspect, which is quiet difficult to quantify, is the beneficial effect of the toolbox to reduce the risk of major system disturbances, in the worst case a blackout of the European electricity system and the speedup of system restoration. Since the toolbox proposes remedial actions, quantifies uncertainty and accounts for a quantified risk, a general reduction of major system disturbances is to be expected.
To give a specific example we can assess the effect of the deterministic optimisation. First of all it gives the operators a set of remedial actions which are the global optimum. This means also a minimisation of switching actions and therefore a closer operation of the transmission system at its predetermined standard switching state. This standard switching state is for the vast majority of system uses cases the best switching state in terms of minimizing losses and maximizing system security. Furthermore it is usually also the best switching state for a grid restoration since it requires only some circuit breaker switching actions and minimises switching actions of disconnectors, since the latter typically tend to be weak spots in the network.
Exploitation
Based on the background to define a toolbox design and to develop a prototype of selected functionalities the following exploitation possibilities are available. All possibilities require some basic functionalities such as load flow calculation and a knowledge transfer which can be done
• by implementing the toolbox design based on published information or
• by transferring the information from foreground owners to third parties or
• by continuing or setting up cooperation with foreground and background owners.
All three possibilities are open for all TSOs. Additional modules from other projects or already existing modules can be integrated as well. It has to be taken into account that the functionalities developed by Umbrella need a wider data base than it is currently used in the operational TSO processes. Data availability and interfaces have to be checked by TSOs.
The TSC already plans a concrete exploitation of the results. The exploitation approach is shown in figure Exploit 1.
Fig. Exploit 1: From Toolbox design to exploitation
TSC TSOs will establish a new consortium with 3rd parties, or employ these parties as service providers. Those 3rd parties can be the foreground owners as well as other parties. A selection of available modules from Umbrella and suitable other projects has to be made by the TSOs. This choice of modules and functionalities depends on the capability to support current processes already carried out by European TSOs (DACF process). The focus of this exploitation is to improve today’s process and to open the process for new deterministic methods and to introduce first probabilistic methods to forecast generation and load uncertainty. Both methods could be introduced without the necessity to set up an entirely new process.
The implementation within the TSC is planned in three steps. The first step is to consider today’s process. Required data and (new) IT-infrastructure has to be defined, recommendations to adapt the existing process have to be set up. The second step consists of several activities like close-to-real-time validation, establishing of an adapted process for data exchange among TSOs, to build (new) IT-infrastructure and a comparison with today’s common operational planning system in a parallel trial run. Those activities will be done in parallel to shorten the time to realise a new process. The third step is the realisation by integration of the new functionalities into the online process based on the visualisation concept.
The overall approach to use all functionalities from Umbrella in the online process is given in figure Exploit 2.
Fig. Exploit 2: Overall approach to implement all functionalities stepwise
Each new function will be implemented in a separate step in order to have a smooth implementation phase. This is crucial to gain the time to test and improve each function for daily operation and to avoid an overload of the operators with the rollout of the new features.
The TSC cooperation will start to integrate the deterministic optimisation as the first step, since this is the easiest to implement and the most wanted feature from perspective of the operators. The currently discussed approach from IT point of view can be seen in figure Exploit 3.
Fig. Exploit 3: Parallel operation and optional later integration into existing software (Confidential)
Further details on Exploitable Foreground see table B2. For Dissemination refer to tables A1 and A2.
List of Websites:
www.e-umbrella.eu
Transmission system operators (TSOs) are facing new challenges in day-to-day grid operation and operational planning. The security issues affecting the pan-European electricity transmission system are becoming more and more challenging due to:
• The growing contribution of less predictable and more variable renewable energy sources (RES);
• The need for the coordination of controllable devices such as phase-shifting transformers (PSTs), high-voltage direct-current (HVDC) lines and flexible alternating-current transmission systems (FACTSs);
• Partially controllable electricity demand;
• The increasing difficulty of building new transmission lines;
• The gradual integration of national markets into one common European electrical energy market;
• Market mechanisms not covering certain aspects of system security, leading to high deviations between scheduled and physical flows in terms of time, direction and volume.
As a consequence meteorological forecasting errors may lead to unforeseen violations of operating limits and trigger cascading outages in stressed-system situations. These new constraints, but also new opportunities, result in more complex operational planning and transmission system operation, take the system closer to its operational limits, cause remedial actions to be taken more frequently in order to relieve congestion and, as a result, make it necessary to revise operational rules and procedures. To be fully efficient, emerging Regional Security Cooperation Initiatives (RSCIs) need a new generation of tools to allow the different TSOs to increase coordination and react more quickly to the growing complexity of operational planning and system operation.
Hence, nine TSOs(1) from Central and Central- Eastern Europe, organised within their RSCI named TSO Security Cooperation (TSC), have joined forces with five universities (2) and one research institute (3) to to provide a coordinated solution to these increasing challenges in their target area. This research and development project, entitled “Innovative tools for the future coordinated and stable operation of the pan-European electricity transmission system” (UMBRELLA), is supported by the European Union as part of its Seventh Framework Programme (FP7). To cope with the above mentioned challenges
TSOs at first have to find an answer to the question: What will be the upcoming system state? This requires the modelling of uncertainties related to RES, load forecasting deviations and intraday trades. In this regard, the UMBRELLA Toolbox goes beyond state of the art by not just looking at one forecast. Instead, a wide range of deviations from the forecast and their probabilities are assessed by applying advanced deterministic and probabilistic methods.
Risk-based security assessment will allow the TSOs to answer the question whether the system will be secure. This includes a comparison of the well-known N-1 criterion with risk-based security criteria, taking into account both the probability of occurrence and the severity of outages, cascades and violations of operational limits. Additionally, the UMBRELLA Toolbox is capable of assessing additional operational costs that are the consequences of forecast deviations.
The complexity of congestion management in transmission systems is growing due to an increase in the amount of congestion and the number of available remedial measures. The enhanced optimal power flow (EOPF) algorithm developed may relieve TSOs’ workload significantly by using deterministic or probabilistic optimisation algorithms that take both uncertainty and risk measures into account.
The UMBRELLA Optimisation Framework aims to provide optimal topological and redispatch measures as well as the curtailment of RES infeed and load-shedding measures by taking into account numerous objectives, such as regulatory restrictions, the cost of redispatch and other factors, ranging from day-ahead operational planning to close-to-real-time operation.
The developed modules are synthesised in the UMBRELLA Toolbox. By testing the UMBRELLA Prototype on historical test cases (TCs), the general functionalities of the UMBRELLA Toolbox have been validated and key performance indicators (KPIs) attest the improvement achieved. The applied test system of nine TSOs’ control areas includes some 7000 nodes, approx. 3000 branches and around 1400 transformers of which 46 are phase-shifters. Some modules are tested using test systems of the Institute of Electrical and Electronics Engineers (IEEE). For the implementation and further exploitation of the UMBRELLA Toolbox within RSCIs, a stepwise approach is proposed.
As an result of the UMBRELLA and iTesla projects, a set of recommendations is provided for stakeholders such as regulators, policymakers, TSOs and the European Network of Transmission System Operators for Electricity (ENTSO-E) to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange so that the innovative software tools developed can be applied by TSOs and within RSCIs
1) Amprion GmbH (Germany), Austrian Power Grid AG (Austria), CEPS (Czech Republic), Elektro-Slovenija (Slovenia), PSE S.A. (Poland), swissgrid (Switzerland), TenneT TSO B.V. (Netherlands), TenneT TSO GmbH (Germany; Coordinator) and TransnetBW GmbH (Germany)
2 ) Delft University of Technology (Netherlands), Graz University of Technology (Austria), ETH Zurich (Switzerland), RWTH Aachen (Germany) and University of Duisburg-Essen (Germany)
3 )FGH Forschungsgemeinschaft für elektrische Anlagen und Stromwirtschaft e.V. (Germany)
Project Context and Objectives:
Motivation and Summary
As part of the fight against climate change, the European Union is aiming to decarbonise its economy. An important aspect is to replace fossil-fuel-based electricity generation with RES such as wind and solar power. Therefore, European energy markets as well as energy grids have to be fit for renewables.
Figure 1: RES increase, based on Germany’s grid development plan 2025, 2015 version
As can be seen from the data compiled in the latest available version of the German grid development plan6 (Figure 1), German RES capacity is expected to grow, even in the most conservative scenario, by more than 50% between 2013 and 2025. Other EU countries are expected to undergo similar developments—partly time- delayed—over the coming years given the EU’s ambitions for the so-called Energy Union.
In order to ensure the secure and stable operation of the transmission grid, TSOs predict the load and corresponding generation at a regional level, including forecasts for RES infeed and according to market outcomes the conventional power generation. They also aim at considering load-flow deviations caused by intraday market trades, power plant and grid equipment outages and volatile consumption. Based on these predictions, in the second step of their daily process the TSOs analyse where congestion may occur by taking into account the given capacity and availability of power lines, transformers and other grid elements.
The interconnected transmission grid in Continental Europe is severely stressed as a result of the insufficient harmonisation of regulatory frameworks and market rules in the various countries. More and more frequently in the congestion management process, TSOs identify severe overloading of grid elements by loop flows or transit flows, and this has a major influence on further decision making. Having collected the necessary operational data, TSOs take the available operational measures, such as changes to the network topology and flow-control device settings, to manage power flows within the capability of existing networks. If congestion cannot be relieved by such measures, counter-trade and redispatch have to be considered and implemented. As these measures are expensive and affect the market outcome they need to be kept to a minimum. For all the necessary remedial measures to be available in good time, TSOs aim to establish the most reliable forecast process possible. Operational planning can then take place one day in advance on the basis of those forecasts. This entire process is named the Day-Ahead Congestion Forecast (DACF).
Short-term analysis is also constantly undertaken in the form of a so-called rolling Intraday Congestion Forecast (IDCF). This takes place from hours in advance until the end of the day, and monitors and tracks the actual development of the system state. It allows favouring less costly measures and delays the adoption of costly measures until they are guaranteed to be needed.
Figure 2: Example TenneT Germany: Wind deviation from forecast
However, the growing proportion of electricity generated by intermittent RES, as well as increasing market-based cross-border flows and related physical flows, are nowadays leading to a significant increase in the uncertainty surrounding the generation of forecasts and the related power flow in the grid.
This is a difficult challenge to face, as the trans- mission grid is not designed for this purpose and the construction of new power lines will take a number of years. Furthermore, new storage technologies have not yet reached industrial maturity or economic viability.
Figure 3: TenneT Germany, PV forecast deviation: fog forecasted, but not occurred (deviation 6000 MW to DACF; 3000 MW to updated forecast)
Especially if wind infeed arrives earlier or later than expected or even falls short of or overshoots the forecasted level of infeed (Figure 2), the load flows in the grid can differ considerably from the predictions. Forecast deviations for PV installations have similar critical effects if fog or clouds unexpectedly shield them from solar radiation or, on the contrary, allow for more infeed than initially expected (Figure 3).
Currently, the DACF, short-term and real-time forecasts are merely deterministic. Uncertainty is considered only implicitly, by means of security margins. As such uncertainty grows due to the increase in volatile RES infeed and intraday electricity market trades, however, the classic deterministic approach for each single control area is no longer sufficient. As can be seen from the example of TenneT, the rise of RES generation capacity (Figure 1) goes hand in hand with the soaring number of TSO interventions needed (Figure 4) to safeguard transmission system operation. Concurrently with this, the incidents to be dealt with by the TSOs will continue to increase in number as well as in duration. Furthermore, European electricity market integration is leading to an increase in the scale of unscheduled cross- border flows, which also require even better multilateral coordination between different TSOs. As most of the uncertain processes involved are taking place on lower voltages in the distribution grid, TSOs can observe only the aggregated behaviour of these processes on the high-voltage grid, which makes it difficult to collect data and to derive relevant information from them.
These challenges reveal the need for automated and multilaterally optimised methods to safeguard the operation of the transmission system and to make optimal use of the existing grid capacity.
Figure 4: Incidents with counter-measures in the control area of TenneT Germany
(excluding voltage/reactive power problems)
As a consequence of these trends, meteorological forecasting errors may lead to unforeseen violations of operating limits and trigger cascading outages in stressed-system situations. Especially in mainland Central Europe as a synchronous area with pre-existing large RES generation facilities, the difference between actual physical flows and market exchanges in the Central Europe synchronous area can be very substantial in time, direction and volume. These new constraints, but also new opportunities, result in more complex operational planning and transmission system operation, take the system closer to its operational limits, cause remedial actions to be taken more frequently in order to relieve congestion and, as a result, make it necessary to revise operational rules and procedures.
Against this backdrop, the tools for security assessment that are currently available and established will no longer be suitable for TSOs to make the right decisions. To be fully efficient, emerging Regional Security Cooperation Initiatives (RSCIs) need a new generation of tools to allow the different TSOs to increase coordination and react more quickly to the growing complexity of operational planning and system operation. In search of a holistic approach to the aforementioned TSOs’ challenges, nine TSOs (1) from Central and Central- Eastern Europe, organised within their RSCI, named TSC, have joined forces with five universities (2) and one research institute (3) to investigate advanced deterministic and probabilistic methods beyond the state of the art to provide a coordinated solution to these increasing challenges for their control areas (Figure 5).
Figure 5: Target area and participants of the UMBRELLA FP7 R&D project
This research and development project, entitled “Innovative tools for the future coordinated and stable operation of the pan-European electricity transmission system” (UMBRELLA), is supported by the European Union as part of its Seventh Framework Programme (FP7).
Forecasting and uncertainty
TSOs at first have to find an answer to the question: What will be the upcoming system state? This requires the modelling of uncertainties related to RES and load forecasting deviations. Such deviations could be traded in the intraday markets.
This will lead to changes of load flows that need to be anticipated by the TSOs. In addition, deviations that cause load flows into neighbouring control areas have to be regarded as well. In this regard, the UMBRELLA Toolbox goes beyond state of the art by not just looking at one forecast. Instead, a wide range of deviations from the forecast and their probabilities are assessed by applying newly developed methods.
Risk assessment
To allow the system operator to make use of the numerous possible scenarios for the upcoming future, new methods to perform risk-based security assessment must be developed. Such risk assessment will allow the TSOs to answer the question whether the system will be secure. This includes a comparison of the well-known N-1 criterion with risk-based security criteria, taking into account both the probability of occurrence and the severity of outages, cascades and violations of operational limits. Additionally, the UMBRELLA Toolbox is capable of assessing additional operational costs that are the consequences of forecast deviations.
Optimisation
Once upcoming system states are known and their severity is assessed, system operators can undertake actions in order to ensure system security. Here, the need for coordination and modern, automated software tools is evident: the complexity of congestion management in transmission systems is growing due to an increase in the amount of congestion and the number of available remedial measures. The enhanced optimal power flow (EOPF) algorithm developed here may relieve TSOs’ workload significantly by using deterministic or probabilistic optimisation algorithms that take both uncertainty and risk measures into account.
The UMBRELLA Optimisation Framework aims to provide optimal topological and redispatch measures as well as the curtailment of RES infeed and load-shedding measures by taking into account numerous objectives, such as regulatory restrictions, the cost of redispatch and other factors, ranging from day-ahead operational planning to close-to-real-time operation. This allows remedial measures with long activation times, such as thermal power plants, to be activated well in advance.
Since the methodology used for the probabilistic forecast of the future use of the new system is based on a statistical model, it is important to compile, validate and maintain historical data with which to build the statistical backbone of the system. Based on this methodology, a number of potentially critical scenarios for the future use of system developments can be identified.
UMBRELLA Toolbox
The developed modules for improved forecasting, optimisation and risk-based assessment are synthesised in the UMBRELLA Toolbox, which offers users the flexibility to apply either individual parts or the complete set of functionalities. The effectiveness of the Toolbox has been demonstrated in tests using the UMBRELLA Prototype, which comprises most of the developed methods. By testing the UMBRELLA Prototype on historical test cases (TCs), the general functionalities of the UMBRELLA Toolbox have been validated and key performance indicators (KPIs) attest to the improvement achieved. The applied test system of nine TSOs’ control areas includes some 7000 nodes, approx. 3000 branches and around 1400 transformers of which 46 are phase-shifters. Some modules are tested using test systems of the Institute of Electrical and Electronics Engineers (IEEE). For the implementation and further exploitation of the UMBRELLA Toolbox within RSCIs, a stepwise approach is proposed.
As an additional result of the UMBRELLA and iTesla (4) projects, a set of recommendations is provided for stakeholders such as National Regulatory Authorities (NRAs), policymakers, TSOs and the European Network of Transmission System Operators for Electricity (ENTSO-E) to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange so that the innovative software tools developed can be applied by TSOs and within RSCIs. The report concludes with a description of the prerequisites for the safe operation of the pan-European transmission system, including the provision of data of the necessary quality and quantity.
1 Amprion GmbH (Germany), Austrian Power Grid AG (Austria), CEPS (Czech Republic), Elektro-Slovenija (Slovenia), PSE S.A. (Poland), swissgrid (Switzerland), TenneT TSO B.V. (Netherlands), TenneT TSO GmbH (Germany; Coordinator) and TransnetBW GmbH (Germany)
2 Delft University of Technology (Netherlands), Graz University of Technology (Austria), ETH Zurich (Switzerland), RWTH Aachen (Germany) and University of Duisburg-Essen (Germany)
3 FGH Forschungsgemeinschaft für elektrische Anlagen und Stromwirtschaft e.V. (Germany)
4 Innovative Tools for Electrical System Security within Large Area (iTesla)
Project Results:
Please refer to the core part of the attached deliverable D1.3
Potential Impact:
In the framework of the UMBRELLA Project a dedicated innovative toolbox was developed to support TSOs’ and RSCIs’ future efforts to ensure grid security. The UMBRELLA Toolbox includes:
• The simulation of uncertainty caused by market activities and Renewable Energy Sources (RES).
• A deterministic and probabilistic optimisation framework for corrective actions to cope with simulated risks on different timescales and increasing system complexity; the aim of this is to reduce the total cost of uncertainty while also increasing system security and transmission capacity.
• Risk-based assessment tools for anticipated system states with and without corrective actions.
The tools developed are synthesised in the UMBRELLA Toolbox, which offers users the flexibility of applying either individual modules or the complete set of functionalities. The individual software tools are extensively tested using IEEE test systems based on the historical datasets of the nine TSOs’ target area through a decentralised approach. Thus, the concept of the individual methods, as well as the UMBRELLA Toolbox Prototype that combines them, is proven by applying them to historical Test Cases (TCs), such as the cold snap on 8 February 2012 and the stressed-grid situation which arose on 22 August 2012.
The tests performed by the TSOs with the support of the universities and research institutes show that the UMBRELLA Toolbox is able to:
• calculate remedial actions to ensure the safe and reliable operation of the transmission network; and
• give the operator additional information about the range of uncertainty that can be expected.
It is shown that the application of the UMBRELLA Toolbox Optimisation Framework speeds up the current experience-based process significantly by avoiding unnecessary iteration steps, since the conflicting activation of remedial actions by different TSOs is avoided. This gives the operators and operational planners the necessary time to prepare the actual implementation of the proposed remedies.
According to the GRID+ concept, KPIs are evaluated to compare business as usual with the results of the new innovative tools. This reveals the significant progress brought about by the new tools. Besides a considerable improvement in the security of system operation, the recovery of overall UMBRELLA Project can be expected within one month when the UMBRELLA Toolbox functionalities are applied.
Further development of the Toolbox and a parallel dry run are currently being prepared by the TSC initiative. This will enable TSOs to identify optimal settings for the Toolbox in order to implement it in daily operational planning processes as well as in real-time operation.
As the envisaged exploitation of the UMBRELLA Toolbox shall be embedded in established information systems, the extension and harmonisation of data exchanges is crucial. A stepwise approach is proposed for the implementation of the UMBRELLA Toolbox by TSOs and RSCIs to overcome the challenges on the path from research to the industrialisation of the UMBRELLA Toolbox. Thus, the adaptation of processes and the introduction of the new CGMES data format can go hand in hand with the gradual introduction of the related tools.
As a result of the UMBRELLA and iTesla projects, a set of recommendations is provided for stakeholders such as regulators, policymakers, TSOs and ENTSO-E to foster the necessary harmonisation of the legal, regulatory and operative framework as well as to allow data exchange for the application of the new software tools.
Impact
In order to test the toolbox prototype, three test cases TC1 (2/2012), TC2 (8/2012), and TC3 (3/2013) have been selected, covering seasonal aspects, e.g. different current limits of transmission lines and different infeed scenarios for RES. The historic test cases always resemble stressed-grid situations, which required a significant amount of remedial actions, such as topological measures and redispatch, in order to ensure the safe and reliable operation of the transmission system. The test cases cover the whole day in order to be able to test the time coupled optimisation, which is quite relevant for power plant start up or shut down decisions.
After defining the TCs, the toolbox prototype was tested and evaluated. For this purpose, the TC datasets had to be checked and adjusted by the TSOs. Model corrections to ensure the quality of the datasets and model improvements to check the different remedial actions were implemented manually and compared with the results of the toolbox prototype’s optimisation functions. The probabilistic results (see figure Impact 1) were compared with the operational experience of all participating TSOs.
Fig. Impact 1: The probabilistic functionality of the UMBRELLA Toolbox provides additional insight in the possible system development
To investigate whether the UMBRELLA Optimisation Framework of the prototype toolbox is able to improve the daily business of TSOs significantly and whether it would be relatively easy to integrate it into current processes, the assessment of results is carried out in detail. For the sake of simplicity, we refer to the optimisation functionalities simply as “the Optimiser”.
In the Base Case, TSOs implemented model corrections in the datasets in order to achieve a common starting point for further evaluation. The Classic Approach represents the datasets after each TSO has implemented its remedial actions manually, as usually performed during the daily DACF process. The Modern Approach represents the datasets after the Optimiser has implemented remedial actions in an automated manner. The degrees of freedom for the Optimiser were (at least) the set of topological measures from the Classic Approach as well as redispatch and available PST tap changes.
As can be observe in the figure Impact 2, after only one run of the Optimiser the overloads are resolved and the transmission grid works close to its operational limits. This means an improvement for system security and a minimisation of costs, since the maximum of 100% loading in the N-1 case is achieved faster and more consistent than with the manual approach. It is shown that the application of the UMBRELLA Toolbox Optimisation Framework speeds up the current experience-based process significantly by eliminating unnecessary iteration steps, since the conflicting activation of remedial actions by different TSOs is avoided. These major points give the operators and operational planners the necessary time to prepare the actual implementation of the proposed remedies. Hence, it can be concluded that system security can be improved significantly with the optimisation methods developed within the UMBRELLA Project.
Fig. Impact 2: The UMBRELLA Toolbox Optimisation Framework renders advantages with regard to accuracy as well as costs of spent operation time, redispatch and stress on grid equipment
One objective of the UMBRELLA optimisation framework is to keep the security of supply at least at the current level and at the same time reducing the overall costs of security related measures by determining the remedial measures in a coordinated way across the whole transmission system. The optimisation algorithm gives priority to less costly remedial actions and tries to relieve congestion in the most efficient way.
In general, the optimisation algorithm managed to reduce the amount of redispatch. This is because it considers the combined relieving of multiple congestions with globally available remedial measures. While there is barely any advantage in situations with very little congestion, the Optimiser becomes extremely beneficial in the case of a large number of redispatch measures. This is particularly evident by the situation with the largest number of redispatch measures in the Classic Approach, namely the 12:30 timestamp in TC2. The amount of redispatch estimated in the Classic Approach for this timestamp is 2770 MW. Meanwhile, the Optimiser achieves a less critical system state, with a redispatch of just 1204 MW, which means a 57% reduction in redispatch volume. This can bring a significant benefit for the reduction of costs for the TSOs’ daily operation, which ultimately results in an increased social welfare.
To give an impression of the financial impact of this effect, let’s have a look at an example: In 2015 Redispatch costs in Germany amounted to approximately one billion Euros. A reduction of only 10 % by use of the UMBRELLA optimisation framework, which is far below the actual test case results, would recover the overall UMBRELLA project costs within one month.
Furthermore, assuming that the optimizer saves approximately two hours of manual work per day and assuming an average salary of a TSO operator of approx. 100€/h, for all nine UMBRELLA-TSOs the toolbox is able to save over 650 k€ per year when using the deterministic optimizer instead of the iterative manual approach, thus only by relieving TSO-personnel from daily routine. Taking into account all ENTSO-E TSOs this amount is growing to round about 3 M€ per year.
The introduction of uncertainty margins (which are necessary to avoid N-1 violations,) leads to a decrease in available transmission capacity and thus to a higher cost. To assess this cost increase, we introduce a new metric, the cost of uncertainty, which measures the increase in operational costs which arise due to forecast uncertainty.
The cost of uncertainty is positive, meaning that the TSO generally has to pay a higher operational cost to secure the system against uncertainty. However, the additional costs can be significantly reduced by the use of the analysed R&I methods. Especially in the case of flexible use of reserves, the saving potential in uncertainty costs compared with business as usual reaches up to 2.3 %.
Another aspect, which is quiet difficult to quantify, is the beneficial effect of the toolbox to reduce the risk of major system disturbances, in the worst case a blackout of the European electricity system and the speedup of system restoration. Since the toolbox proposes remedial actions, quantifies uncertainty and accounts for a quantified risk, a general reduction of major system disturbances is to be expected.
To give a specific example we can assess the effect of the deterministic optimisation. First of all it gives the operators a set of remedial actions which are the global optimum. This means also a minimisation of switching actions and therefore a closer operation of the transmission system at its predetermined standard switching state. This standard switching state is for the vast majority of system uses cases the best switching state in terms of minimizing losses and maximizing system security. Furthermore it is usually also the best switching state for a grid restoration since it requires only some circuit breaker switching actions and minimises switching actions of disconnectors, since the latter typically tend to be weak spots in the network.
Exploitation
Based on the background to define a toolbox design and to develop a prototype of selected functionalities the following exploitation possibilities are available. All possibilities require some basic functionalities such as load flow calculation and a knowledge transfer which can be done
• by implementing the toolbox design based on published information or
• by transferring the information from foreground owners to third parties or
• by continuing or setting up cooperation with foreground and background owners.
All three possibilities are open for all TSOs. Additional modules from other projects or already existing modules can be integrated as well. It has to be taken into account that the functionalities developed by Umbrella need a wider data base than it is currently used in the operational TSO processes. Data availability and interfaces have to be checked by TSOs.
The TSC already plans a concrete exploitation of the results. The exploitation approach is shown in figure Exploit 1.
Fig. Exploit 1: From Toolbox design to exploitation
TSC TSOs will establish a new consortium with 3rd parties, or employ these parties as service providers. Those 3rd parties can be the foreground owners as well as other parties. A selection of available modules from Umbrella and suitable other projects has to be made by the TSOs. This choice of modules and functionalities depends on the capability to support current processes already carried out by European TSOs (DACF process). The focus of this exploitation is to improve today’s process and to open the process for new deterministic methods and to introduce first probabilistic methods to forecast generation and load uncertainty. Both methods could be introduced without the necessity to set up an entirely new process.
The implementation within the TSC is planned in three steps. The first step is to consider today’s process. Required data and (new) IT-infrastructure has to be defined, recommendations to adapt the existing process have to be set up. The second step consists of several activities like close-to-real-time validation, establishing of an adapted process for data exchange among TSOs, to build (new) IT-infrastructure and a comparison with today’s common operational planning system in a parallel trial run. Those activities will be done in parallel to shorten the time to realise a new process. The third step is the realisation by integration of the new functionalities into the online process based on the visualisation concept.
The overall approach to use all functionalities from Umbrella in the online process is given in figure Exploit 2.
Fig. Exploit 2: Overall approach to implement all functionalities stepwise
Each new function will be implemented in a separate step in order to have a smooth implementation phase. This is crucial to gain the time to test and improve each function for daily operation and to avoid an overload of the operators with the rollout of the new features.
The TSC cooperation will start to integrate the deterministic optimisation as the first step, since this is the easiest to implement and the most wanted feature from perspective of the operators. The currently discussed approach from IT point of view can be seen in figure Exploit 3.
Fig. Exploit 3: Parallel operation and optional later integration into existing software (Confidential)
Further details on Exploitable Foreground see table B2. For Dissemination refer to tables A1 and A2.
List of Websites:
www.e-umbrella.eu
Verwandte Dokumente
- final1-figure-3-example-pv-forecast-deviation.pdf
- final1-figure-1-res-increase-.pdf
- final1-impact_fig_2.pdf
- final1-figure-4-incidents-with-counter-measures.pdf
- final1-exploitation_fig_1.pdf
- final1-figure-5-umbrella-target-and-participants.pdf
- final1-exploitation_fig_2.pdf
- final1-figure-2-example-wind-deviation-from-forecast.pdf
- final1-umbrella-project-final-report-web.pdf
- final1-impact_fig_1.pdf
