Research On Steady Characteristic About Doubly Salient Permanent Magnet Motor

Doubly Salient Permanent Magnet (DSPM) motor system is a kind of controllable variable-speed system, and it was proposed in last 90's along with the development of power electronics and permanent materials. Vast researches have been done on the kind of motor by many scholars from various countries. And various kinds of structure for the motor are proposed, including Doubly Salient Electromagnetic (DSEM) motor.On the base of existing conclusions about Doubly Salient Motor, the steady characteristics and correlative factors of the motor system are investigated thoroughly in this text by the methods of both theory analysis and experiment test.First, a introduction about the structure of the concerned Doubly Salient Motor is given. Meanwhile, the composition of the motor system is also given while the motor works as a starter. A mathematics model for Doubly Salient Permanent Magnet motor is constructed from the view of conversation of energy. On the base of linear disposal for permanent magnetic flux, some control strategies are put forward such as control mode I, angular advance control mode and control mode II. And for each strategy, corresponding one-order constant coefficient nonlinear differential equations are given. And all these are the bases of a more advanced research for Doubly Salient Motor.Due to 12/8 poles Doubly Salient Permanent Magnet motor, planar Finite Element Method (FEA) is applied to analyze the magnetic field inside the motor. And a series of static characteristics are investigated, such as field distribution, air gap magnetic density, field flux, inductance, static torque. On the bases of FEA results and one-order constant coefficient nonlinear differential equations, a steady analysis method for the motor system's running steadily is proposed. And a primary research work has been done on some steady characteristics of the system, such as phase current, field flux, inductance, voltage, output torque. All these are verified by some tests applied on prototype.By applying the method composed of theory analysis, simulation and test verification, some researches have been done on unload characteristic, torque-current characteristic, revolving speed-voltage characteristic and mechanism characteristic of the motor system. Meanwhile, various control modes of the system are analyzed. All these researches provide some references for the motor's application.