This paper presents a novel configuration of a voltage and frequency (VF) controller for a stand-alone pico hydro power generating system employing an asynchronous generator (IAG). The proposed VF controller is an electronic load controller (ELC), which consists of a three leg insulated gate bipolar junction transistor (IGBT) based voltage source converter (VSC), a DC chopper and an auxiliary load at its DC bus. The neutral terminal for the consumer loads is created using a zigzag transformer. Three leg VSC is connected to the tertiary winding of the zigzag transformer to select the optimum voltage rating of the DC bus. The control algorithm of the VF controller is developed to control the system VF under varying consumer loads. The proposed system is modelled and simulated in MATLAB using Simulink and power system blockset (PSB) toolboxes. Extensive simulation results are presented to demonstrate the capability of the controller as a harmonic eliminator, a load balancer, a neutral current compensator along with VF controller.
Keywords: stand-alone power generation, voltage source converter, VSC, voltage control, frequency control, zigzag transformer, electronic load controller, pico hydro power, asynchronous generators, simulation, harmonic elimination, load balancing, neutral current compensation