Operating Reserves and Variable Generation

Ela, Erik; Milligan, Michael; Kirby, Brendan

doi:10.2172/1023095

Cited by 315 publications

(220 citation statements)

References 44 publications

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“…A general conclusion of several recent studies addressing power systems with variable generation technologies is the need of dynamic reserve requirements depending on the system operating conditions. Transmission system operators should use the information available to establish those operating conditions involving high or low levels of risk, and then schedule operating reserves accordingly [29]. Because keeping the same requirements for PV units all times of the day and all days of the year would make no sense from any point of view, a reasonable criterion is to require FFR only at some hours of the year, based on a specific security criterion, for example, based on the PV penetration level.…”

Section: Discussion Regarding Frequency-related Grid Requirements Formentioning

confidence: 99%

Fast Frequency Response Capability of Photovoltaic Power Plants: The Necessity of New Grid Requirements and Definitions

2014

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Abstract:In recent years, only a small number of publications have been presented addressing power system stability with the increased use of large-scale photovoltaic (PV) generation around the world. The focus of these publications was on classical stability problems, such as transient and small signal stability, without considering frequency stability. Nevertheless, with increased PV generation, its effects on system frequency response during contingencies can no longer be ignored, especially in the case of weakly interconnected networks or isolated power systems. This paper addresses the impacts of large scale PV generation on the frequency stability of power systems. The positive effects of deloaded PV power plants (PV-PPs) able to support system frequency recovery during the initial seconds after major contingencies are also examined. Because this type of frequency support is not covered by current definitions, a new terminology is proposed that includes the frequency response of inertia-less generation units immediately after major power imbalances. We refer to this type of frequency support as fast frequency response (FFR). Finally, a discussion is also presented regarding the applicability and pertinence of frequency-related grid requirements for PV-PPs in the case of real power systems. The investigation is based on the isolated power system of northern Chile. The obtained results indicate that in the case of major power imbalances, no significant effects arise on the system frequency response until PV penetration levels exceed approximately 20%. From a system security perspective, the problems arise for PV penetration levels of OPEN ACCESSEnergies 2014, 7 6307 approximately 50%, in which case, the frequency response capability in PV-PPs would be justified during certain hours of the year.

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Section: Discussion Regarding Frequency-related Grid Requirements Formentioning

confidence: 99%

Fast Frequency Response Capability of Photovoltaic Power Plants: The Necessity of New Grid Requirements and Definitions

2014

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“…The reserve demand in these markets is exogenously specified by the Transmission System Operator, which opens up a number of different ad-hoc criteria, see e.g. Ela et al (2011). 2. To clear the forward market using stochastic programming (Birge & Louveaux, 2011), which allows modeling future balancing needs and costs in a probabilistic framework, thus yielding the day-ahead energy dispatch that minimizes the expected system operating costs.…”

Section: Introductionmentioning

confidence: 99%

Electricity market clearing with improved scheduling of stochastic production

Morales

Zugno

Pineda

2014

European Journal of Operational Research

106

122

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In this paper, we consider an electricity market that consists of a day-ahead and a balancing settlement, and includes a number of stochastic producers. We first introduce two reference procedures for scheduling and pricing energy in the day-ahead market: on the one hand, a conventional network-constrained auction purely based on the least-cost merit order, where stochastic generation enters with its expected production and a low marginal cost; on the other, a counterfactual auction that also accounts for the projected balancing costs using stochastic programming. Although the stochastic clearing procedure attains higher market efficiency in expectation than the conventional day-ahead auction, it suffers from fundamental drawbacks with a view to its practical implementation. In particular, it requires flexible producers (those that make up for the lack or surplus of stochastic generation) to accept losses in some scenarios. Using a bilevel programming framework, we then show that the conventional auction, if combined with a suitable day-ahead dispatch of stochastic producers (generally different from their expected production), can substantially increase market efficiency and emulate the advantageous features of the stochastic optimization ideal, while avoiding its major pitfalls.A two-node power system serves as both an illustrative example and a proof of concept. Finally, a more realistic case study highlights the main advantages of a smart day-ahead dispatch of stochastic producers.Dear Editor of European Journal of Operational Research, Today's electricity market design is the result of adapting traditional practices, such as unit commitment, economic dispatch or contingency analysis, to a competitive structure. These practices were conceived in view of a generation mix mostly formed by dispatchable power plants, and are now to be revisited so that stochastic producers can enter the competition in a fair and efficient manner.In this line, researchers have recently advocated a market-clearing mechanism that co-optimizes the forward (day-ahead) and the anticipated real-time energy dispatches using stochastic programming. Even though, ideally, this mechanism attains maximum market efficiency, it results in an energy-only market settlement that requires flexible producers to accept economic losses for some realizations of the stochastic production, which raises concerns on its practical applicability.Starting from this point, this paper shows that, if stochastic production is conveniently scheduled in the day-ahead market, the conventional settlement of this market can notably approach the behavior of the stochastic ideal, while sidestepping its theoretical drawbacks. To this end, we construct a bilevel programming formulation that determines the optimal value of stochastic production that should be considered to clear the day-ahead market under the conventional settlement.We firmly believe that this research work could positively contribute to your Journal. We thank you in advance for considering this...

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“…Finally, tertiary reserve assists in the replacement of primary and secondary reserves that were used for the outage of elements in the system. The typical time-response is 10 seconds for the primary reserve and, 10 to 30 minutes for the secondary and tertiary reserves, respectively [23].…”

Section: Reserve System Requirementsmentioning

confidence: 99%

Nodal user’s demand response based on incentive based programs

González-Cabrera

Gutiérrez-Alcaraz

2017

J. Mod. Power Syst. Clean Energy

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This paper describes a practical approach to identify nodal price compensation payment for nodal consumers willing to reduce their energy consumption (consumers' demand response). The implementation of a nodal reliability service pricing is based on contingency assessment of N -2 order for transmission lines. A representative annualized demand curve is used to reflect the system's operation condition by seasons. Such curve is used to access the nodal reliability impact trough a whole year in order to determine back-payments (incentive payment) to users for service interruption. The IEEE_RTS 24 nodes system is used to implement the proposed approach.

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Operating Reserves and Variable Generation

Cited by 315 publications

References 44 publications

Fast Frequency Response Capability of Photovoltaic Power Plants: The Necessity of New Grid Requirements and Definitions

Fast Frequency Response Capability of Photovoltaic Power Plants: The Necessity of New Grid Requirements and Definitions

Electricity market clearing with improved scheduling of stochastic production

Nodal user’s demand response based on incentive based programs

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