The Sensorless Control Of Permanent Magnetic Synchronous Motor (PMSM)

AC servo drive system play an important role in the current industrial control technology, one of which is the permanent magnet servo system is often employed in the high technology fields, such as precision machinework and aerospace. In the permanent magnet motor control technology research, sensorless control is a hot spot, this paper is developed in this background.This paper first introduces the structure of the permanent magnet motor. Because the structure decides the nature and the nature decides the uses. Then explained the basic thought of the vector control of the permanent magnet motor, as currently the basic control method of the permanent magnet motor, it is the basis of the research on the pace. Then, provide the mathematical model of the permanent magnet synchronous motor, with which the electromagnetic relation of the motor can be operated into mathematical equations. In order to analysis the dynamic characteristics of the motor better, the mathematical model in this paper is given under the dqO coordinates. Based in the motor mathematical model, this paper introduces several common sensorless control methods, including flux estimation method, the sliding-mode observer method and high frequency injection method.Take TMS320F28335 as the core control chip, the author made digital motor controller protype. The controller provides current and voltage detection circuits for position estimate algorithm, and contains the over-current and over-voltage protection circuits. Use the Infinon production FP75R12KT3 IPM module as the main inverter circuit, and contrapose it design the PWM drive and protection circuit. In order to do the research conveniently, we installed rotating transformer on the motor's none-shaft extension for measurement of motor rotor's actual position as contrast reference. In the hardware system also joined the SCI and CAN bus module as a function expansion. In order to debug more efficiently, we use a D/A converter with which the controller can output out a simulation waveform of internal calculation variables. As the hardware circuit was built, the author writes the software control procedures for the test of motor control without rotor position sensor.The experiments of this paper are base on a 1.5 KW surface mounting permanent magnet synchronous motor. The author completed the whole controller manufacturing, commissioning, and set up the related device. Experiments show that, the sensorless vector control system estimate position angle accurately, achieve good dynamic performance, high precision, and can be put into practical use.