A Single-Switch Bidirectional AC Chopper-Based Electronic Load Controller for Pico Hydropower System

This paper proposed a simple electronic load controller (ELCr) for a pico hydropower system. The electronic load controller is used to regulate the output power of hydropower generators, thereby maintaining the output voltage and frequency at desired values. Conventionally, the diode bridge rectifier with IGBT ELCr is used in pico hydropower. However, it injects harmonics into the system. The phase regulation technique also suffers from harmonics and is limited by the timing accuracy of the trigger pulse. Hence a single-switch bidirectional AC chopper (SSBAC) - based ELCr is proposed. This SSBAC ELCr uses a single IGBT per phase to switch voltage and current bi-directionally to the dump load. From the simulation studies, the SSBAC ELCr produced excellent voltage regulation with low order harmonics at a value of 3.21%. The SSBAC ELCr maintained the generator's torque constant and provided a balanced distribution of power in each phase.