同期発電機の内部磁束に基づく負荷飽和特性について

抄録

Magnetic flux in a synchronous generator is saturated by an iron core in magnetic path. Conventionally, saturation characteristics of generator are examined in the case of no-load saturation test and zero power factor test. In these cases, the path of magnetic flux is limitted in d-axis direction. Therefore the saturation characteristics are grasped by measurements of terminal voltages and currents with regarding a generator as a black box. On the other hand, an on-load saturation characteristics have never been discussed in experiment. However, the conventional treatment of saturation characteristics are considered to be reasonable in physical meaning, because the analysis based on conventional assumptions does not contradict their experimental results. In this paper, the on-load saturation characteristics are discussed experimentally based on the experimental results at a generator operating onto an infinite bus system. As results, the harmonic components of air-gap flux density depend only upon the shape of salient rotor at no-load state. As for the tested generator, the saturation characteristics of d-axis component are independent of q-axis component in despite of the existence of q-axis current. Moreover, the on-load saturation characteristics for d-axis current corresponds to the shifted curve of the no-load saturation characteristics by a constant flux components with taking the ratio of field and d-axis current in consideration.