Universal Active Filter With SPV and Battery Support for Standalone Hydroelectric System

The number of sensitive loads that require optimal sinusoidal supply voltages for proper operation has increased because of developments in process control, digital electronics, and power converters. Therefore, it is imperative to develop efficient control strategies to address this issue. In this article, a universal active power filter (UAPF) is incorporated with the standalone hydroelectric system to enhance voltage and current qualities simultaneously. This standalone hydropower system includes an induction generator as a primary source, a battery with a dc–dc converter, and a solar photovoltaic array. The series compensator improves the voltage characteristics. It keeps the harmonics (distortion) free voltage with constant amplitude at the terminals of nonlinear loads, regardless of source voltage variations. Furthermore, UAPF's shunt compensator improves power indices, including power factor, current harmonics, and reactive power. By using an improved low-pass second-order generalized integrator control algorithm, the fundamental elements of nonsinusoidal currents from nonlinear critical loads are estimated. These components are used to generate switching pulses and reference signals, ensuring efficient and effective power quality (PQ) enhancement under various circumstances. Moreover, laboratory prototype validation has ensured the effectiveness in providing PQs of currents and voltages to follow the IEEE std. 519.