A Cooperative Game Theory-based Approach to Under-frequency Load Shedding Control

TL;DR

This paper introduces a cooperative game theory-based two-stage load shedding method to enhance frequency stability in power systems, accurately determining load shedding locations and amounts during disturbances.

Contribution

It presents a novel two-stage cooperative game theory approach for precise load shedding in UFLS, improving upon traditional fixed-schedule methods.

Findings

Effective frequency stabilization after disturbances

Precise load shedding locations and amounts identified

Validated on WECC system with RTDS simulations

Abstract

This paper proposes a cooperative game theory-based under-frequency load shedding (UFLS) approach for frequency stability and control in power systems. UFLS is a crucial factor for frequency stability and control especially in power grids with high penetration of renewable energy sources and restructured power systems. Conventional UFLS methods, most of which are off-line, usually shed fixed amounts of predetermined loads based on a predetermined schedule which can lead to over or under curtailment of load. This paper presents a co-operative game theory-based two-stage strategy to effectively and precisely determine locations and amounts of loads to be shed for UFLS control. In the first stage, the total amount of loads to be shed, also referred to as deficit in generation or the disturbance power, is computed using the initial rate of change of frequency (ROCOF) referred to the equivalent inertial center. In the second stage, the Shapley value, one of the solution concepts of cooperative game theory, is used to determine load shedding amounts and locations. The proposed method is implemented on the reduced 9-bus 3-machine Western Electricity Coordinating Council (WECC) system and simulated on Real-time Digital Simulators (RTDS). The results show that the proposed UFLS approach can effectively return the system to normal state after disturbances.