A low control frequency control method for high switching frequency inverters

Abstract

The invention discloses a low control frequency control method for a high switching frequency inverter. In each switching cycle of a control cycle, the angle of the voltage vector output by the high frequency inverter in the static coordinate system is rotated, and the rotation angle is is the angle rotated by the dq rotating coordinate system in one switching cycle, and compensates the angle of the output voltage vector. The compensation angle is the angle rotated by the dq rotating coordinate system in half a switching cycle; the next one is calculated in each switching cycle The voltage reference vector of the switching cycle in the ABC stationary coordinate system, thereby compensating the one-beat delay characteristic of the PWM wave generator. This control method gives full play to the advantages of high switching frequency, can increase the closeness of the inverter output voltage vector to the reference voltage vector, increase the sine degree of the inverter output current, and significantly improve 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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