Modeling and control of variable speed wind turbine with permanent magnet synchronous generator

Abstract

This paper derives all necessary equations which require for modeling of PMSG. The generator model is established in the dq-synchronous rotating reference frame. A MATLAB/Simulink simulation has been developed using 8.5 KW permanent magnet synchronous generator. In this paper maximum power point tracking (MPPT) controller for variable speed wind turbine is proposed. Maximum power which a wind turbine can deliver at a certain wind speed depends upon certain optimum value of speed at which the shaft rotates. Only at optimum speed we can have efficient use of equipment and available energy source. In order to control a wind turbine with Permanent Magnet Synchronous Generator (PMSG), a set of full-scale back-to-back voltage converter is used. The back-to-back converters are connected through a DC-link capacitor. The capacitor decouples the two converters, allowing separate controls being applied to each converter for simplicity. The control systems are separated into generator-side controller and grid-side controller. In this arrangement, the generator-side converter controls the operation of the generator and the network-side converter controls the DC link voltage by exporting active power to the network.