Coordination of Multiple Flexible Resources Considering Virtual Power Plants and Emergency Frequency Control

Abstract

High-voltage direct current (HVDC) blocking disturbance leads to large power losses in the receiving-end power grid, and the event-driven emergency frequency control (EFC) is an important measure to prevent large frequency deviation. By aggregating controllable distributed energy resources (DERs) on the demand side, a virtual power plant (VPP) could quickly reduce its power and can be a new fast response resource for EFC. Considering both the VPP and the traditional control resources, this paper proposes an optimized EFC strategy coordinating multiple resources for the receiving-end power grid with multi-infeed HVDC. The approximate aggregation model of the VPP response process is constructed, based on which the EFC strategy, aiming at minimizing the total control cost while meeting constraints on rotor angle stability and frequency deviation security, is proposed. The electromechanical transient simulation combined with particle swarm optimization (PSO) is utilized to solve the model, and parallel computation is utilized to accelerate the solving process. The effectiveness of the proposed EFC strategy is verified by a provincial receiving-end power grid with multi-infeed HVDC. The detailed simulation results show that VPP could dramatically reduce the control cost of EFC while maintaining the same stability margin.

Optimal Cluster Scheduling of Active–Reactive Power for Distribution Network Considering Aggregated Flexibility of Heterogeneous Building-Integrated DERs

“…The authors use a constraint space-superposition method based on Minkowski Sum to seek the maximal inner cube constraints for the virtual synchronous machine of a heat pump cluster [19]. Moreover, the authors in [20] developed a day-ahead optimal scheduling model based on the generalized virtual battery model to determine the energy schedule and reserve capacity of electric vehicles and air conditioning. Additionally, a flexibility assessment can represent the abundance of flexible resources in a distribution network and has been comprehensively investigated with the insufficient ramping resource expectation index [21], the network flexibility index [22], the technical uncertain scenario flexibility index [23], and the technicaleconomic uncertainty scenario flexibility index [24].…”