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This paper describes a novel line-start type selfexcited wound-field synchronous motor with three-phase concentrated winding stator. The unique feature of this proposed motor is that it accelerates by obtaining the starting torque from the slip frequency at the time of starting, and at the time of synchronous pull-in, it is driven synchronously with utilizing the second order space harmonic as the field magnetization power. This driving principle was verified by performing a load test using the prototype with two types of load, fan load and eddy current brake load. Consequently, the synchronization based on the proposed drive principle could be demonstrated on the actual machine, and the line-start characteristics of the proposed motor have been clarified.

This paper describes a novel line-start type self-excited wound-field synchronous motor with three-phase concentrated winding stator. The unique feature of this proposed motor is that it accelerates by obtaining the induction torque from the slip frequency at the time of starting, and at the time of synchronous pull-in, it is driven synchronously with the second order space harmonic as the field magnetization power. First, the operation principle and the magnetic circuit design topologies will be described. Then, the prototype for principle verification and experimental setup will be revealed. Next, the result of evaluating the no-load synchronization pull-in characteristics in actual machine evaluation is reported.

This study clarifies experimentally the effect of the secondary conductor bar on line-start characteristics in a line-start type self-excited wound-field synchronous motor. This motor is based on a brushless wound-field synchronous motor having a rotor winding connected to a diode rectifier circuit. And it has a secondary conductor bar that is independently connected at a pitch of one pole, without end-ring. First, the operation principle of the proposed motor and its magnetic circuit design are described, and then the details of the prototype for principle verification are clarified. Next, when the combination of the connecting of the secondary conductor bar is changed, an experiment of line-starting characteristics and measured rotor field current is demonstrated. Consequently, it was clarified that the influence on the synchronous pull-in, speed ripple, and rotor field current.