Initial orientation and sensorless starting strategy of Wound-Rotor Synchronous Starter/Generator

This paper proposes a sensorless control method for Wound-Rotor Synchronous Starter/Generator (WSSG) in starting process. It is necessary to identify the initial rotor position when uses sensorless control method to start-up AC machines. However, during the process of initial orientation the excitation current of the main generator contains severe pulsating components, which leads to the ineffectiveness of traditional position estimating methods. In order to improve the accuracy of estimation results, the specified transient pulse signal voltage injection and the associated signal processing method are propose in this paper. In starting process, the square-wave-type voltage signal injection method, which capably of eliminates the interference of pulsating excitation current and enhancing the dynamic performance of the system, is used in the starting process to acquire the rotor position by demodulating the induced high-frequency stator current. Experimental results proved the effectiveness and accuracy of the propose method.