The Application Research Of Vector Inverter In Speed-Regulation System Of Permanent Magnet Synchronous Motor

Since the 70s, the control technology of permanent magnet synchronous motor (PMSM) has been developed rapidly and permanent magnet synchronous motor control system is also more and more used in a variety of industrial fields. In some occasions, there is a phenomenon that permanent magnet synchronous motor even replace the direct current motor.As the development of permanent magnet synchronous motor, the existed problems appear gradually, such as irreversible demagnetization and cost problem. This paper presents a method of vector control in order to adjust the speed of permanent magnet synchronous motor, and gives a compensation method for dead time effect of inverter. The research work as follows:Firstly, this paper presents the topological structure and control method of vector inverter, including rectifier, inverter, constant V/F control theory, vector control theory and direct torque control theory. Secondly, analyses these control theory, establish mathematical model of permanent magnet synchronous motor and give coordinate transformation equation. After building the voltage equation and torque equation of PMSM, stimulate speed control system of PMSM using simulink software. Give the alternate coordinates used by this paper, and simple entails.Then, this paper presents two kinds of frequently-used speed-regulation method, and establishes the model of PMSM, which used space vector pulse width modulation, provide the effectiveness of this modulation.Finally, make some research aiming at compensating dead time, this paper presents the main reason of dead time effect is the output current distortion of inverter, and the output current distortion influence low speed performance of permanent magnet synchronous motor. Aiming at solving this problem, this paper gives a compensation method based on the product of voltage and time. Using this method could reduce the current distortion. From the simulation result, we can see the amplitude of torque triple is smaller, and the control effect is effective.