Position Sensorless Control of a Reluctance Synchronous Wind Generator Drive with an LC Inverter Filter

Abstract-A control structure for an inverter-fed high speed reluctance synchronous generator wind energy conversion system is proposed and investigated in this article. The novel combination of an LC inverter output filter and a hybrid position sensorless control method is used to ensure robustness and reliability of the system. The proposed LC inverter filter and position sensorless control method also allows the inverter unit to be stationed in the tower base instead of in the nacelle. With the LC filter, sinusoidal machine terminal voltages and reduced electromagnetic interference (EMI) from the tower supple cables are ensured. A new estimation method is developed to minimize current and voltages sensors in the drive system with the LC filter, whereby the machine's stator quantities are estimated, requiring only parameter knowledge of the LC filter. The proposed hybrid position sensorless control algorithm uses the estimated stator quantities to estimate the rotor position. A high-frequency injection position sensorless control method is used at low speeds. The frequency of the high-frequency injection voltage is chosen close to the resonance frequency of the filter and machine model to amplify the high-frequency current response. Excellent dynamic performance of the proposed control drive system is obtained from a 9.6-kW laboratory reluctance synchronous generator drive system.