Enhancing Event-Driven Load Shedding by Corrective Switching With Transient Security and Overload Constraints

Abstract

Sudden loss of bulk power generation will result in significant power shortage and power flow redistribution, which may lead to insecurity and/or stability problems. Under this condition, load shedding (LS) and corrective line switching (CLS) can be used to guarantee a reliable electricity supply. However, at present, the above two procedures are implemented separately, which may deteriorate each other and cause unnecessary load loss. To address this issue, a coordination optimization method is proposed to coordinate event-driven LS and CLS for enhancing power system security and stability as well as reducing LS amount simultaneously. A two-loop integrated algorithm is designed to solve the constrained optimization problem, which takes the transient frequency/voltage deviation and overload capacity of the transmission lines as constraints. In the inner loop, iterative optimization of the LS for frequency/voltage security is achieved based on linearized sensitivity analysis, and then step-by-step summation is employed to get the LS amount for alleviating overload. Neighbor search is used in the outer loop to coordinate event-driven LS and CLS so as to optimize the total LS amount. The effectiveness of the proposed method is validated in a modified IEEE 39 bus test system and an industrial power system. The results show that the proposed scheme can decrease the LS amount without improve the transient security while maintaining the transient security and alleviating overload.

Extending SFR model to incorporate the influence of thermal states on primary frequency response

“…In addition, the periodic calculation and update, e.g. in 5–30 min, are effective ways to further reduce the burdens of real‐time calculation and data transmission, considering the relatively slow change of the power system operation state [28, 29]. In the proposed approach, the calculation and update of most coefficients are also carried out periodically.…”

Multi‐objective coordinated dispatch of high wind‐penetrated power systems against transient instability

“…Event‐driven corrective control, also named emergency control (EC), is executed instantly after contingencies to make timely enhancement on system dynamic performance [24]. As a form of EC, emergency demand response (EDR) or emergency load shedding (ELS) can immediately shed loads after contingency to effectively stabilise the post‐contingency system [23, 25–27]. Xu et al [23] presented a method for optimisation of ELS under transient stability constraints, and demonstrated its capabilities on large‐scale power systems.…”

“…Yang et al [26] proposed a real‐time EC scheme, which utilises the measurement data from PMUs, a system reliable instability index and real‐time critical machines identification algorithm to achieve the optimal accuracy and efficiency. Shi et al [27] presented a coordinated EC method, which adopted a two‐layer algorithm to coordinate between ELS and corrective line switching (CLS) measures to enhance system post‐disturbance transient security and reduce ELS amounts.…”

Improved Correction Strategy for Power Flow Control Based on Multi-Machine Sensitivity Analysis

“…The superiority of this model was validated by comparing its robustness and performance to that of conventional routing based on the shortest-path model; however, it relied too much on grid measurement systems. A coordinated optimization method was proposed to coordinate event-driven LS and corrective line switching (CLS), reducing the LS amount by linearized sensitivity analysis in [32]. In [33], the potential of lines was measured to simultaneously reduce overloads and prevent new ones, based on the power shift sensitivities of overloaded lines and the time required to complete the adjustment.…”