A stored energy-based control strategy to improve LVRT capability of HRES using PSO & WCA optimized DVR

Abstract

The article presented here utilizes the particle swarm optimization (PSO) and water cycle algorithm (WCA) based dynamic voltage restorer (DVR) to augment the low voltage ride through (LVRT) performance of a hybrid renewable energy system (HRES). Moreover, FACT equipment like the dynamic voltage restorer (DVR) is deployed to boost the quick responsiveness of compensation and good transient performance of HRES. Due to numerous disturbances brought on by WECS' nonlinearity, the best tuning of a PI controller for DVR control is investigated to match the LVRT requirement of the HRES. The design incorporates a battery energy storage system (BESS) that is connected over the DC terminals of the DVR to improve the compensating capabilities by regulating the D-Q axis voltage signal to control the voltage source converter gate signals. In comparison to DVR alone, the suggested technique increases the DC-link voltage and PCC voltage by 44% and 4.6 %, respectively. MATLAB simulation results show that the BESS-enabled PSO DVR performs better in all respect for the compensation of voltage sag and makes the system self-LVRT capable.

A review on the state of the art of dynamic voltage restorer: topologies, operational modes, compensation methods, and control algorithms

“…However, the energy storage device's capacity can become a limiting factor during compensation when the DVR needs to supply real power into the affected line in cases of pre-sag or in-phase conditions. The storage of real power occurs in the DVR's DC connector, which happens to be one of its costlier components [52]. The main goal of the energy optimization technique is achieved when the phasor of the injected voltage is perpendicular to the phasor of the load current.…”

“…When the DVR grid is weak, the auxiliary supply system is employed to boost performance. The energy source can be SMES (Superconducting magnetic energy storage) [49], fly wheel [50], Auxiliary power supply [51], Hybrid energy storage systems [52], super capacitors [53], fuel cell [51] and leadacid for most DVR applications. If the grid is strong, the leftover voltage on the supply or load side is used to deliver needed power to the DVR; an AC/DC/AC converter is employed in this technique [54].…”