A new control method of permanent magnet generator for maximum power tracking in wind turbine application

This paper discusses a new and simple control method for maximum power tracking in a variable speed wind turbine by using a step-up dc-dc converter. The output voltage of permanent magnet generator is connected to a fixed dc-link through a three-phase rectifier and the dc-dc converter. A maximum power-tracking algorithm calculates the speed command that corresponds to maximum power output of the turbine. The dc-dc converter uses this speed command to control the output power of the permanent magnet generator, such that the speed of generator tracks the command speed. A current regulated PWM voltage source inverter maintains the output voltage of dc-dc converter at a fixed value by balancing the input and output power to the dc-link. In addition, the inverter can improve power factor and inject a current with very low harmonic distortion into the utility grid. The generating system has potentials of high efficiency, good flexibility, and low cost.