Experimental Study on Three Phase Permanent Magnet Synchronous Generator for Pico Hydro Isolated Systems

Permanent magnet synchronous generators (PMSG) are becoming popular for small-scale isolated energy systems due to many advantages like self-started generator, suitable for variable and constant speed applications, high efficiency, good voltage regulation, brushless arrangement, low losses, etc. This paper presents the design aspects of specially designed three-phase PMSG and performance verification for small- scale isolated/off-grid applications. In this study, a constant speed prime mover is used as the emulation of micro/pico-hydro turbine. The prime mover is controlled through a voltage/frequency (V/F) drive and connected to the shaft of the generator and make it run at synchronous speed throughout the operation for the generation of voltage. The micro/pico-hydro systems are equipped with constant speed/power turbines. The load rating is restricted to the rated capacity of the generation in the off-grid mode of operation. In this paper, by understanding the features of the source of generation and load, the three-phase PMSG is specially designed with the help of an industry and experimentally verified the performance for the dedicated loads and found satisfactory within acceptable power quality range.