Secondary voltage control of single phase induction generator operated in small scale picohydro power plant at off-grid area

The usage of monoblock single phase electric water pump for small-scale electric power generation at the off-grid area is beneficial in terms of cost, ease of construction, availability of spare parts and in terms of reliability. The problem found is the difficulty to maintain the output voltage and frequency of single-phase induction motor when operated as an electric induction generator especially during fluctuation of the load due to the un-linearity behaviour of the induction machine. The common way to control voltage and frequency is applying electronic load controller by adjusting dummy load power to compensate the fluctuation of the real load. This research proposes additional secondary voltage control on the system by adjusting the capacitance value of the capacitor connected to the auxiliary winding in order to compensate the fluctuation of the output voltage.