Transient Stability Improvement based on Optimal Generation Rescheduling for the Fault Duration

摘要

This paper presents an approach to solve the online transient stability constrained power generation using improved particle swarm optimization (IPSO) technique based on transient energy function (TEF). Transient stability constrained power generation is formulated as a nonlinear optimization problem subject to load flow equations, power system capacity requirements and power system transient stability behavior. The objective is to determine the proper generation rescheduling (GR) during the disturbances in order to improve the system security by increasing the critical clearing time (CCT) and minimize system losses as well. The idea of coherent behavior of generators is used to find a new generation configuration with better transient stability margin. The calculation in the proposed method is simple and direct. The generation rescheduling depends only on the original generation and inertia constants of the machines, and their rotor speeds at the fault clearing time. In this work, The TEF method is used to check the dynamic security levels throughout the system by analyzing all credible three phase faults with single line outages. IPSO is used to determine the most suitable generation coordination that maintain acceptable security levels and improve system transient stability. The proposed approach using IPSO provides a fast and accurate tool to enhance system transient stability. The effectiveness of the method is tested and illustrated on WSCC three-generator, nine-bus system and New England ten-generator, 39-bus system.