A Method For Suppressing A Speed Fluctuation, A Control Apparatus And A Compressor Control System

A control apparatus of a permanent magnet synchronous motor, comprising:

• an obtaining module, configured to obtain a target speed and a feedback speed of the permanent magnet synchronous motor, to obtain a fluctuation speed of the permanent magnet synchronous motor according to the target speed and the feedback speed, and to obtain a q-axis inductance and a permanent magnet flux linkage of the permanent magnet synchronous motor;
• a q-axis compensation current calculating module, configured to perform a speed loop PI adjusting on the fluctuation speed to obtain a q-axis reference current, to obtain a q-axis target voltage according to the q-axis reference current, the target speed, the fluctuation speed and the permanent magnet flux, and to perform a PI control on a q-axis actual voltage according to the q-axis target voltage to obtain a q-axis compensation current;
• a d-axis compensation current calculating module, configured to obtain a d-axis target voltage according to the q-axis reference current, the q-axis compensation current, the target speed, the fluctuation speed and the q-axis inductance, and to perform a PI control on a d-axis actual voltage according to the d-axis target voltage to obtain a d-axis compensation current;
• a q-axis current compensation module, configured to superpose the q-axis compensation current and the q-axis reference current to perform a feedforward compensation on a q-axis current;
• a d-axis current compensation module, configured to superpose the d-axis compensation current and the d-axis reference current to perform a feedforward compensation on a d-axis current.

A compressor control system, comprising a control apparatus of a permanent magnet synchronous motor, wherein the control apparatus comprises:

• an obtaining module, configured to obtain a target speed and a feedback speed of the permanent magnet synchronous motor, to obtain a fluctuation speed of the permanent magnet synchronous motor according to the target speed and the feedback speed, and to obtain a q-axis inductance and a permanent magnet flux linkage of the permanent magnet synchronous motor;
• a q-axis compensation current calculating module, configured to perform a speed loop PI adjusting on the fluctuation speed to obtain a q-axis reference current, to obtain a q-axis target voltage according to the q-axis reference current, the target speed, the fluctuation speed and the permanent magnet flux, and to perform a PI control on a q-axis actual voltage according to the q-axis target voltage to obtain a q-axis compensation current;
• a d-axis compensation current calculating module, configured to obtain a d-axis target voltage according to the q-axis reference current, the q-axis compensation current, the target speed, the fluctuation speed and the q-axis inductance, and to perform a PI control on a d-axis actual voltage according to the d-axis target voltage to obtain a d-axis compensation current;
• a q-axis current compensation module, configured to superpose the q-axis compensation current and the q-axis reference current to perform a feedforward compensation on a q-axis current;
• a d-axis current compensation module, configured to superpose the d-axis compensation current and the d-axis reference current to perform a feedforward compensation on a d-axis current.