A control method of sinusoidal pulse width variable carrier for permanent magnet synchronous motor

Abstract

The invention relates to a sinusoidal pulse width variable-carrier control method for a permanent magnet synchronous motor. The method comprises combining a sinusoidal pulse width modulation with third harmonic injection by using a mathematical relationship between the third harmonic and the fundamental voltage to improve a DC voltage utilization rate; and adjusting the phase angle of the three-phase carrier according to the intersection of the modulated waves to eliminate a zero vector, thereby suppressing the common-mode voltage fluctuation of the permanent magnet synchronous motor under thecontrol of the variable carrier. The method has the beneficial effects that during the high-speed operation of the permanent magnet synchronous motor, a space vector pulse width modulation method hasa high DC voltage utilization rate, but may aggravate the high-frequency and low-frequency fluctuation of the common-mode voltage of the motor, and the combination of the sinusoidal pulse width modulation, the third harmonic injection and the variable carrier control reduces the fluctuation of the common-mode voltage of the motor under the premise of ensuring the DC voltage utilization rate.

Description

technical field [0001] The invention belongs to a control method of a permanent magnet synchronous motor, and relates to a variable carrier control method of sinusoidal pulse width of a permanent magnet synchronous motor, in particular to a variable carrier control method using harmonic injection. Background technique [0002] Permanent magnet synchronous motor has the advantages of simple structure, high volume energy density and high compactness, and is widely used in AC servo, aerospace and other fields. Space vector pulse width modulation is a commonly used control method for permanent magnet synchronous motors. This method improves the utilization rate of DC voltage while ensuring the high speed control accuracy of the motor. When using space vector pulse width modulation, the motor common mode voltage has obvious fluctuations. [0003] The three-phase voltage source inverter consists of three groups of six switches. The upper and lower switch tubes of the A, B, and C ...

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Problems solved by technology

[0005] In order to avoid the deficiencies of the prior art, the present invention proposes a permanent magnet synchronous motor sinusoidal pulse width variable carrier control method to solve the common mode voltage fluctuation problem of the permanent magnet synchronous motor under the space vector pulse width modulation method

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