Independent voltage and frequency controller for a parallel operated isolated three-phase asynchronous generators

Abstract

This paper presents a voltage and frequency controller (VFC) for parallel operated isolated asynchronous generators (IAGs) in pico and micro hydro systems feeding 3-phase 4-wire loads. The proposed VF controller regulates the system voltage and frequency in decoupled manner through control of reactive and active powers. The controller is a combination of a static compensator (STATCOM) and an electronic load controller (ELC). The STATCOM is used for reactive power compensation for voltage control, load balancing, harmonic elimination and neutral current compensation while an ELC is used for active power control at the terminals of the generators, which in turn keeps the system frequency constant. Modelling of the proposed generating system is carried out in MATLAB-based environment and a set of simulation results are given to demonstrate the performance of the controller in an isolated electrical distribution system using SIMULINK and PSB (Power System Block sets) toolboxes.