Torque observer and extended H∞ filter for sensorless control of permanent magnet generators tested on a wind turbine emulator

This paper presents a discrete time torque observer and an extended H∞ filter to estimate the rotor speed and position in a permanent magnet machine. Those estimated variables are key components of a robust sensorless controller for the machine when it is associated with a wind turbine emulator test-rig. In addition, an iterative maximum power point tracking algorithm is proposed for maximum efficiency of the device. Experimental verification on the laboratory setup is given to demonstrate the correct integration of all the control algorithms.