Motor driving system based on harmonic observer

Abstract

The invention discloses a motor driving system based on a harmonic observer, which comprises a DC / DC (direct current / direct current) conversion unit, an inverter, a permanent magnet motor, an MCU (microprogram control unit), a harmonic generator and a harmonic observer, wherein the DC / DC conversion unit is connected with a battery; an output end of the DC / DC conversion unit is connected with the inverter; the inverter is connected with the permanent magnet motor; a voltage sensor detects input voltage Vin and output voltage Vo of the DC / DC conversion unit; a current sensor detects output currents ia and ib of the inverter; the harmonic observer observes a rotating speed omega m and a rotor position of the permanent magnet motor; and the harmonic generator is used for generating a high order sinusoidal harmonic signal and injecting the generated harmonic signal into q-shaft voltage. According to the system, a system control effect is improved.

Description

technical field [0001] Generally speaking, the present invention relates to motors, and in particular to a motor drive system based on a harmonic observer. Background technique [0002] Electric vehicles, such as electric cars, are becoming more and more popular. At present, the drive of electric vehicles generally adopts the mode of battery + permanent magnet motor, and the control system adopts open-loop / closed-loop control. For open-loop control, the vehicle (vehicle speed) cannot accurately follow the given, which has been phased out. In the closed-loop control, the speed closed-loop control method is generally adopted at present, which uses the traditional PID regulator to adjust the deviation between the given speed and the actual speed, and controls the output of the inverter according to the adjustment result. With this control method, the system response speed is slow, and overshoot is prone to occur during the adjustment process, and the actual speed vibrates aro...

AI Technical Summary

Problems solved by technology

Mechanical position sensors can achieve high-precision detection of the rotor position, but they are usually expensive and easily limited by environmental conditions, and have disadvantages such as increasing the moment of inertia of the motor rotor, increasing the system volume, and reducing system reliability.

In addition, current electric vehicles generally use a chopper boost (boost) method to boost the output voltage of the battery. This method has large switching tube losses and low power factor.

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