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• A semi-analytical approach is developed to obtain the BESS power reserve for FFR. • The local minimum power reserve is derived to avoid UFLS under a large contingency. • The proposed method bridges the gap of the trial-and-error approaches. • The effectiveness of the proposed method is validated with an actual network model. • The methodology will advance grid services estimation and battery management. The large-scale renewable energy integration faces a challenge of frequency stability due to low inertia in weak power grids. One solution to mitigate this issue is via the fast frequency response service provided by battery storage systems so that the overall grid response during a large power outage can be improved. The battery power reserve is crucial to ensure the frequency ancillary services provision. However, grid operators currently investigate the contingency reserve of batteries through inefficient processes, such as extensive simulations or trial-and-error methods. Therefore, this paper proposes a semi-analytical methodology to quantitively determine the minimum required battery power reserve for preventing under-frequency load shedding when a severe generation trip occurs. This minimum reserve is derived from the time-variant kinetic energy of a given dispatch case. Case study results of the Mexican network demonstrate that the calculated battery power reserve can provide a cost-effective fast frequency response for a real islanded network. The research outcomes offer valuable insights for battery management and grid ancillary services requirement estimation in the transition to power networks dominated by converter-interfaced renewable energy resources. [ABSTRACT FROM AUTHOR]

• A two-stage security-constrained economic dispatch model is proposed to exploit the inherent grid flexibility. • A joint chance constraints-based method is developed to efficiently utilize dynamic line rating while handling its uncertainty. • The post-outage setpoint adjustments of flexible ac transmission systems are extended from N-1 to N-K contingencies. • Computational tractability is attained by a nested column-and-constraint generation algorithm. Dynamic line rating (DLR) and flexible ac transmission system (FACTS) are two technologies to enhance the utilization of existing transmission lines and exploit the inherent transmission-side flexibility. This paper coordinates DLR and FACTS in a two-stage security-constrained economic dispatch (SCED) model to enhance the power system flexibility in N-K contingency management and reduce operational cost. To utilize DLR while handling its uncertainty, spatial–temporal joint chance constraints (JCCs) are used. A scalable reformulation method for these JCCs is developed, which enables considering the spatial–temporal correlations between DLRs and co-optimizing the DLR utilization with system dispatch. To leverage the flexibility of FACTS, the adjustments of FACTS set points before and after the occurrence of any N-K line outage are modelled. The proposed SCED model is reformulated as a triple-level robust model, which avoids enumerating all possible N-K outages in the SCED model and obtains a more reasonable model size. To handle the presence of binary variables in the lowest level of the robust model, a nested column-and-constraint generation solution structure is designed. Case studies on IEEE 14 and 118-bus systems are conducted to verify the effectiveness of the proposed SCED model. [ABSTRACT FROM AUTHOR]

Abstract: Market power refers to the ability of generators in influencing the energy prices above competitive level to obtain more profits. It may be the cause of transmission congestion that limits transfer capability in an interconnected area. Hence an independent system operator (ISO) must be able to detect the conditions in which market power has been practiced to guarantee a secure competition and economical operation of the electricity market. To cope up with transmission congestion to assess market power, an optimal power flow (OPF) based on shift-factor methodology to find out a new indicator, called congestion-based dynamic dispatch index has been proposed. One of the beneficial feature of the proposed method is the ability to recognise accurately the most potential generator to exercise the market power. A generator bidding scheme represented by financial withheld strategy is then utilised to investigate the dynamic condition of power market. An analysis on the power market performance to identify potential generators in exercising market power is also presented. The results show that transmission congestion condition may be created unnaturally by this particular bidding strategy. It prevents some cheap generators to supply their outputs and allows all more expensive generators within the congested zone to gain more profits at the cost of other market participants. [Copyright &y& Elsevier]