Performance Investigation of Synchronized Three-Phase AC Chopper-Based Controller for Small Hydrogeneration Systems

Abstract

This article presents the design, development, and performance analysis of a three-phase synchronized ac chopper (SynACC)-based controller for small hydrogeneration systems. The three-phase SynACC-based controller is used to control the voltage and frequency of a three-phase self-excited induction generator (SEIG)-based small hydropower generation system. The SynACC-controlled dump load is connected at the point of common coupling across the consumer load that controls the system frequency and voltage using instantaneous power balancing method. The SynACC-based controller has synchronized the system frequency feedback-based pulsewidth modulated current delivered to the dump load with the SEIG output voltage in order to make the equal instantaneous currents and similar frequency spectrum of current in all the three phases of the dump load circuit. The equal instantaneous currents and similar frequency spectrum of currents in all the three phases of the dump load circuit significantly improve the system stability. That also improves the system efficiency by removing the multiple and fast fluctuating torque generation problem in three-phase SEIG-based small hydrogeneration systems. The SynACC controller improves the system power factor, since it reduces the reactive power demanded by the dump load circuit. The laboratory prototype of the scheme has been developed and detailed mathematical modeling along with the simulation and experimental results are presented in the article to validate the claims. The technique presented in this article may also be used to develop an improved power quality heating furnace system for chemical and process industry applications.