On the Characteristics of the Cycloconverter-type Commutatorless Motor (Compared with the induced-voltage commutation-type commutatorless motor)

摘要

As the induced-voltage commutation-type commutatorless motor (DC-CLM) depends on only its armature induced-voltage commutation of thyristors, in the starting, it sometimes fails in commutation. While the DC-CLM, the cycloconverter-type commutatorless motor (AC-CLM) has both the source and induced-voltage commutation, and it scarcely fails in commutation, therefore the latter is more reliable. This paper describes the comparison of the steady state characteristics of AC and DC CLM, based on the experiments and the following results are obtained. 1. In the speed control of the CLM, the voltage control scheme is better than the field control scheme. In the comparison of speed regulation, DC-CLM is superior to AC-CLM. 2. Although armature reaction is nearly the same for both AC and DC-CLM, the former has larger commutation angle and much harmonics, and therefore the load limit is narrower than the latter. 3. In the comparison of efficiency of both machines, AC-CLM is inferior to the DC-CLM. It seems that this is caused by the torque due to the harmonics.