Low control frequency control method for high switching frequency inverter

Abstract

The invention discloses a low control frequency control method for a high switching frequency inverter. In each switching period of a control period, the angle of the voltage vector outputted by the high-frequency inverter in a static coordinate system is rotated, the rotation angle is an angle rotated by a dq rotating coordinate system in a switching period, the angle of the output voltage vectoris compensated, and the compensation angle is an angle rotated by the dq rotating coordinate system in a half switching period; and a voltage reference vector of the next switching period in the ABCstatic coordinate system is calculated in each switching period, thereby compensating the delay one-beat characteristic of a PWM wave generator. The control method gives full play to the advantage ofhigh switching frequency, can improve the closeness degree of the output voltage vector of the inverter and the reference voltage vector, improves the sine degree of the output current of the inverter, and remarkably improves the control effect.

Description

technical field [0001] The invention belongs to the field of inverter control, in particular to a low control frequency control method for a high switching frequency inverter. Background technique [0002] Thanks to the development of high-frequency wide bandgap devices-silicon carbide (Silicon Carbide, SiC) devices and gallium nitride (Gallium Nitride, GaN) devices, high-frequency devices can now be used to make high switching frequency inverters (High Switching Frequency Inverter, HSFI) to deal with some occasions that require high frequency drive to improve the control effect, such as using a high switching frequency inverter to control a high frequency permanent magnet synchronous motor (High Frequency Permanent Magnet Synchronous Motor, HFPMSM) can significantly reduce the current ripple. The high switching frequency inverter made of wide bandgap devices can increase the switching frequency to hundreds of kilohertz in small and medium power applications, which is much h...

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Problems solved by technology

[0004] The inventor found through research that the existing inverter control technology with high switching frequency and low control frequency has the following problems: Although the load current ripple can be reduced by relying on high switching frequency, the update frequency of the voltage reference value is only the control frequency , so that the output voltage vector seriously deviates from the reference voltage vector, resulting in severe distortion of the current waveform, and the high switching frequency is not fully utilized

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