Estimation of Output Voltage for High Speed, Surface Permanent Magnet Generator with Large Air Gap Length

This paper presents a method to estimate the output voltage of a high speed, surface permanent magnet generator with large air gap length at design stage. The output voltage is estimated by the induced electromotive force and the synchronous inductance obtained from the analytical results of the flux linkage using FEM. Also, a method to classify the synchronous inductance per each causing factor is proposed. The air gap leakage inductance is not negligible in a large air gap machine like this generator. The validity of the proposed method has been proved by the measured values of a generator designed by this method, and also the measured values show that the output voltage of the generator is within the permissible range. The method propose in this paper will be an effective tool to design a high speed, surface permanent magnet generator with large air gap length.