Space vector modulation based harmonic current compensation system for high-speed permanent magnet motor

Abstract

The invention discloses a space vector modulation based harmonic current compensation system for a high-speed permanent magnet motor. The system comprises a rotor position and speed observation module, a stator phase current harmonic compensation module, a phase current feedback module, a rotation speed PI adjustment module, a current PI adjustment module and an SVPWM (space vector pulse width modulation) conversion output module. The stator phase current harmonic compensation module comprises a harmonic current extraction module, a proportional controller, a harmonic current adjustment module and a harmonic voltage compensation amount calculation module. The harmonic current extraction module extracts phase current harmonics of a permanent magnet synchronous motor in real time by the aid of an adaptive band-pass filter; the proportional controller adjusts the harmonic current and feeds the harmonic current to a current loop; the harmonic current adjustment module and the harmonic voltage compensation amount calculation module are used for calculating harmonic voltage compensation amount on the basis of a mathematical model of the high-speed permanent magnet motor and feeding back to the voltage loop. By the space vector modulation based harmonic current compensation system for the high-speed permanent magnet motor, voltage compensation amount can be calculated accurately, real-time compensation can be realized, phase current waveforms in operation of the permanent magnet synchronous motor can be improved effectively, torques and rotation speed pulses can be reduced, and accordingly operation efficiency, stability and reliability of the motor can be improved.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet synchronous motor control, and more specifically relates to a system for controlling current harmonics during the operation of a high-speed permanent magnet motor. Background technique [0002] A high-speed motor refers to a motor whose speed exceeds 10000r / min. Compared with traditional motors, high-speed permanent magnet synchronous motors have the characteristics of compact structure, small size, high efficiency, high power density, and fast response speed. They have broad applications in the fields of micro gas turbines, high-speed machine tools, blowers, compressors, and molecular pumps. The application prospect is becoming a research hotspot in the international electrotechnical field. During the operation of the permanent magnet synchronous motor, due to the characteristics of the dead time of the switching device of the PWM inverter, the tube voltage drop, and the distortion of t...

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Problems solved by technology

For example, optimize the design of the motor body and improve the sine degree of the air-gap magnetic field distribution, but such methods can only suppress the current harmonics caused by the distortion of the air-gap magnetic field; in view of the nonlinear characteristics of the PWM inverter, the current feedback type voltage compensation method is used. Voltage compensation, but this method can only compensate the 5th and 7th current harmonics caused by the nonlinear characteristics of the PWM inverter; the voltage compensation amount is calculated according to the mathematical model of the permanent magnet motor for voltage compensation, and this method can suppress the The 5th and 7th current harmonics caused by the nonlinear characteristics of the inverter and the distortion of the air gap magnetic field, but some harmonic components have been ignored when the mathematical model is established, and the harmonic current feedback loop has not been added. For the current harmonics of low-speed motors Wave suppression has achieved good results, but for high-speed motors, it will cause large control errors

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