Permanent magnet synchronous motor control algorithm for improving transient stability of small capacity dc bus capacitor voltage

The invention discloses a permanent magnet synchronous motor control algorithm for improving the transient stability of a small capacity DC bus capacitor voltage. According to the difference between a DC bus voltage and an absolute value of a grid voltage, a given component of a motor direct-axis current is adjusted, the transient stability of the DC bus voltage is improved, and the distortion rate of a grid input current is reduced. A small capacity thin-film capacitor is used for replacing a power factor correction circuit to extend the service life of the entire system. However, the capacitance of the thin-film capacitor is small and the capacitor voltage is susceptible to motor back electromotive force, which results in a series of problems of a high distortion rate of the grid input current and the like. For this reason, the invention adjusts the given component of the direct-axis current based on the difference between the DC bus voltage and the absolute value of the grid voltage, and adopts an internal