PQ Improvement for SEIG Based Standalone Hydroelectric Generation System With UPQC

The integration of unified power quality conditioner (UPQC) with self-excited induction generator (SEIG) based standalone hydroelectric power generation (HPG) having backup of bidirectional battery and single stage solar photovoltaic (SSSPV) is presented in this paper with the feature of power quality enhancements. When the SEIG is operated at varying loading conditions, or when its frequency varies, the power quality problems arise in this standalone system. Hence, these power qualities issues are mitigated by incorporating a UPQC device, having two separate voltage source converters (VSCs) with same DC points. Irrespective of any variation in voltage generated, the harmonics free with fixed amplitude voltage at the load terminals are regulated by the series connected VSC of UPQC. Furthermore, the current qualities are enhanced by parallel (shunt) connected VSC and improved the source side power factor, harmonics in the source currents, and reactive power, etc., simultaneously with enhancement of voltage quality. An enhanced generalized integrator (EGI) control scheme is used for extraction of fundamental signals for the nonlinear load currents waveform. These fundamentals are further used for generation of the reference and switching pulses for both VSCs. The effectiveness of PQ improvement under a variety of circumstances are analyzed and the source currents and load voltages both adhere to IEEE-519 standard.