An Identification Algorithm of Relay Protection Parameter for Flexible High-Voltage Direct Current Transmission Lines Under Synchronous Sampling

Abstract

Relay protection device is a protection device when the flexible DC transmission line is long and leads to line failure. Therefore, in order to ensure the reliable identification of relay protection parameters, an identification algorithm of relay protection parameter for flexible DC transmission line under synchronous sampling is proposed. By calculating the relay protection parameters based on synchronous sampling, the algorithm obtains the positive sequence parameters and zero sequence parameters of flexible DC transmission line’s relay protection, and uses the matrix beam algorithm to identify the positive sequence parameters and zero sequence parameters, so as to obtain the subsynchronous oscillation modal parameters. In order to improve the identification effect, the extended particle swarm optimization algorithm is used to optimize the identification results. The test results show that the algorithm has the feasibility of relay protection parameter identification and the calculation function of positive sequence parameters and zero sequence parameters of relay protection device. It can reliably identify the current change and the change results of positive sequence parameters and zero sequence parameters with minimal identification error.