Modeling and control of variable-speed micro-hydropower plant based on Axial-flow turbine and permanent magnet synchronous generator (MHPP-PMSG)

This paper presents a grid connected variable-speed micro hydropower plant, based on a micro Axial-flow turbine (semi-Kaplan) coupled to permanent magnet synchronous generator (MHPP-PMSG); Two back-to-back Voltage Source Inverters are interfacing the generator. The main idea is to show the feasibility and interest of variable speed operation of the considered system. The scope of the presented work is similar to that used for wind and tidal generators. A MPPT algorithm (perturb & Observe) is used for controlling the MHPP-PMSG for optimizing the operating efficiency by finding the optimal rotation speed. PI controllers are used to control the power electronics interface converters and DC-link voltage. The proposed scheme of MHPP-PMSG has been simulated under Matlab Simulink and the results obtained show the benefit of variable speed for micro hydropower.