Electronic load controller of a micro-hydro generator for stand-alone operation

This study presents the development of an electronic system for load control of a single-phase permanent magnet synchronous generator which operates in stand-alone mode. Considering that the generator input power is kept constant, the control system goal is to ensure that the generator output power is also kept constant, even if changes in the user load consumption occur. A switched binary-weighted ballast load is connected in parallel to the user load. It is composed of six resistors connected in series. These resistors will absorb the power not used by the user. A power electronic switch is connected in parallel to each ballast load resistor. Each switch is triggered in integer cycles. The on/off combination of these switches provides 64 options of equivalent resistances that vary linearly.