| 1. |
- Verma, Pranjal Pragya, et al.
(författare)
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Bayesian Nash Equilibrium in Electricity Spot Markets : An Affine-Plane Approximation Approach
- 2022
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Ingår i: IEEE Transactions on Control of Network Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 2325-5870. ; 9:3, s. 1421-1434
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Tidskriftsartikel (refereegranskat)abstract
- This article proposes a system of stochastic mixed complementarity problems (MCP) for calculating the Bayesian Nash equilibrium (BNE) in an electricity spot market. The generators submit strategic multilevel price-offer functions under incomplete information about their rivals' marginal cost. This strategic multilevel price offering of each generator is modeled as a standard stochastic bilevel program which is then reformulated as its equivalent MCP. The merger concept is employed and formulated to model multilevel price-offer functions. We then propose the BNE-MCP model which solves the stochastic MCP models of all generators together. A scenario reduction technique is also developed to accurately model the wind and demand uncertainty in the proposed BNE-MCP model. The proposed BNE-MCP model is carefully studied on two illustrative examples. The modified IEEE 14-, 30-, and 57-node systems are also examined in our article.
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| 2. |
- Molzahn, Daniel K., et al.
(författare)
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A Survey of Distributed Optimization and Control Algorithms for Electric Power Systems
- 2017
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Ingår i: IEEE Transactions on Smart Grid. - : Institute of Electrical and Electronics Engineers (IEEE). - 1949-3053 .- 1949-3061. ; 8:6, s. 2941-2962
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Tidskriftsartikel (refereegranskat)abstract
- Historically, centrally computed algorithms have been the primary means of power system optimization and control. With increasing penetrations of distributed energy resources requiring optimization and control of power systems with many controllable devices, distributed algorithms have been the subject of significant research interest. This paper surveys the literature of distributed algorithms with applications to optimization and control of power systems. In particular, this paper reviews distributed algorithms for offline solution of optimal power flow (OPF) problems as well as online algorithms for real-time solution of OPF, optimal frequency control, optimal voltage control, and optimal wide-area control problems.
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| 3. |
- Morales-España, Germán, 1982-, et al.
(författare)
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Robustified Reserve Modelling for Wind PowerIntegration in Ramp-Based Unit Commitment
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper proposes a “robustified” network-constrained Unit Commitment (UC) formulation as an altern-ative to the robust and stochastic UC formulations under windgeneration uncertainty. The formulation draws a clear distinctionbetween power-capacity and ramp-capability reserves to deal withwind production uncertainty. These power and ramp require-ments can be obtained from wind forecast information. The modelis formulated under the ramp-based scheduling approach, whichschedules power-trajectories instead of the traditional energy-blocks and takes into account the inherent startup and shutdownpower trajectories of thermal units. These characteristics allowa correct representation of unit’s ramp schedule which definetheir ramp availability for reserves. The proposed formulationsignificantly decreases operation costs if compared to traditionaldeterministic and stochastic UC formulations while simultan-eously lowering the computational burden. The operation costcomparison is made through 5-min economic dispatch simulationunder hundreds of out-of-sample wind generation scenarios.
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| 4. |
- Varawala, Lamia, et al.
(författare)
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A generalised approach for efficient computation of look ahead security constrained optimal power flow
- 2023
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Ingår i: European Journal of Operational Research. - : Elsevier BV. - 0377-2217 .- 1872-6860.
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Tidskriftsartikel (refereegranskat)abstract
- We consider a generalised comprehensive Look-ahead Security-constrained Optimal Power Flow (LASCOPF) formulation under the N−1 contingency criterion over multiple dispatch intervals. We observe that the number of decision variables varies quadratically with the number of intervals. To improve scalability, we propose a reduced LASCOPF formulation for which the number of decision variables varies only linearly. We extend these formulations to the N−k contingency criterion. For reduced LASCOPF we observe that the number of decision variables varies with the number of k-permutations of contingencies. To improve scalability, we propose a formulation that is further reduced to vary only with the number of k-combinations. Also, we show that our formulations can be extended simply to model recovery from the corresponding outages. Furthermore, we present LASCOPF under the N−1 contingency criterion using DC and AC power flow under generator contingencies. We prove that, barring borderline cases, solving the reduced formulation is equivalent to solving the comprehensive formulation. We extend these results to the N−k contingency criterion. Finally, we present numerical results on the IEEE 14 bus, IEEE 30 bus and IEEE 300 bus test cases, and the 1354 bus part of the European power system using AC power flow to demonstrate the computational advantage of the reduced formulations under the N−1 and N−2 contingency criteria.
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| 5. |
- Varawala, Lamia, et al.
(författare)
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A Scalable Formulation for Look-Ahead Security-Constrained Optimal Power Flow
- 2022
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Ingår i: IEEE Transactions on Control of Network Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 2325-5870. ; 9:1, s. 138-150
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Tidskriftsartikel (refereegranskat)abstract
- We consider the look-ahead security-constrained optimal power flow (LASCOPF) problem under transmission line and generator contingencies. We first formulate LASCOPF under the N - 1 contingency criterion (LASCOPF(1)) using the dc power flow model. We observe that the number of decision variables in the comprehensive formulation increases quadratically with the number of look-ahead intervals, T, making the problem infeasible to solve for large T. To overcome this, we propose the reduced LASCOPF problem (LASCOPF-r(1)) in which the number of decision variables increases only linearly with T. Thereafter, we prove that, barring borderline cases, if LASCOPF(1) is feasible then the optimal solutions of LASCOPF(1) and LASCOPF-r(1) are equivalent. We then extend our results to the N - k contingency criterion (LASCOPF-ru(k)) for any collection of k contingencies, and we prove that the ordering of the contingencies does not affect the optimal solution. We then illustrate LASCOPF(1) on a simple 2-bus 2-generator system. We show the numerical benefits of the proposed LASCOPF-r(1) formulation on the IEEE 118-bus, the IEEE 300-bus, and the 2383-bus Polish systems.
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| 6. |
- Viola, Luigi, et al.
(författare)
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Ancillary services in power system transition toward a 100% non-fossil future: Market design challenges in the United States and Europe
- 2024
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Ingår i: Electric power systems research. - : Elsevier BV. - 0378-7796 .- 1873-2046. ; 236
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Forskningsöversikt (refereegranskat)abstract
- The expansion of variable generation has driven a transition toward a 100% non-fossil power system. New system needs are challenging system stability and suggesting the need for a redesign of the ancillary service (AS) markets. This paper presents a comprehensive and broad review for industrial practitioners and academic researchers regarding the challenges and potential solutions to accommodate high shares of variable renewable energy (VRE) generation levels. We detail the main drivers enabling the energy transition and facilitating the provision of ASs. A systematic review of the United States and European AS markets is conducted. We clearly organize the main ASs in a standard taxonomy, identifying current practices and initiatives to support the increasing VRE share. Furthermore, we envision the future of modern AS markets, proposing potential solutions for some remaining fundamental technical and market design challenges.
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| 7. |
- Zografos, Dimitrios, et al.
(författare)
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Frequency Response Assessment: Parameter Identification of Simplified Governor Response Models Using Historic Event Data
- 2020
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Ingår i: Cigre Science & Engineering. - : CIGRE (International Council on Large Electric Systems). - 2426-1335. ; 17, s. 150-167
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Tidskriftsartikel (refereegranskat)abstract
- With a growing share of inverter-interfaced generation in modern power systems, synchronous inertia is declining. This leads to faster frequency drop after large generation trip events. During low inertia conditions, frequency containment reserves might not be sufficient to arrest frequency before it reaches the threshold for underfrequency load shedding. It is therefore be-coming increasingly important for system operators to be able to assess frequency response in near real time. In contrast to detailed models, simplified models offer short simulation times and their parameters can be accurately identified and adapted to changing system conditions in near real time. In this paper, the parameters of governor response models are identified by minimizing the er-ror residuals between the simulation models' and the actual sys-tem's measured active power response. This is accomplished by using historic event data from two system operators: the Electric Reliability Council Of Texas (ERCOT) and the Swedish Svenska kraftnät (Svk). Then, the respective frequency response models are simulated to assess frequency response. The results show that, despite their simplicity, the models provide a very good fit com-pared to the actual response. The models of ERCOT and Svk are examined; however, a similar approach can be employed to repre-sent the frequency response of other power systems.
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