Experimental testing of an isolated micro-grid supplied by two micro hydro power plants

This paper presents the experimental testing of a control strategy for the parallel operation of two micro hydro power plants (MHPPs) on an islanded micro-grid (MG). The two MHPPs are equipped with constant-speed turbines that drive induction generators (IG). The proposed control system is a combination between a voltage source inverter (VSI) and a dump load (DL). The VSI operates at constant frequency, thus stabilizing the MG frequency. The voltage regulation is accomplished by the DL, by dissipating the exceeding active power. Experimental tests are performed to highlight the control system response to significant transitory regimes such as the connection of the second generator to the MG or a large load being suddenly switched on and off.