Control of standalone asynchronous generator driven by uncontrolled pico hydro turbine

This paper presents a simple and effective neural-network based electronic load controller (ELC) for standalone asynchronous generator driven by an hydro turbine. This proposed ELC uses least mean square (LMS) algorithm for estimation of reference source currents. The ELC consists of a auxiliary load, chopper switch on the de bus of a three-leg current controlled voltage source converter (VSC) and a non-isolated zigzag transformer is used to convert the three-phase three-wire system into three-phase four-wire and acts as a neutral current compensator. The proposed ELC controls the terminal voltage along with constant frequency and also provides load balancing. The ELC for an asynchronous generator system is developed using digital signal processor and test results are presented to demonstrate the effectiveness of the ELC for asynchronous generator system feeding three-phase four-wire consumer loads.