Current harmonic minimum pulse width modulation switching angle calculation and smooth switching method suitable for permanent magnet driving system

The invention discloses a current harmonic minimum pulse width modulation switching angle calculation and smooth switching method suitable for a permanent magnet driving system, and the method comprises the steps: building a CHMPWM mathematical model of a permanent magnet synchronous motor, solving an optimal switching angle and a suboptimal switching angle in a full modulation ratio range under any carrier wave ratio based on the CHMPWM mathematical model, storing K continuous solutions into a controller, and carrying out the calculation of the optimal switching angle and the suboptimal switching angle. Smooth switching between discontinuous switching angles is achieved by setting a hysteresis switching area and solving a switching phase angle with the minimum torque impact. The problem that current harmonics of the permanent magnet driving system are difficult to be minimum due to the fact that a traditional CHMPWM algorithm ignores the salient pole effect and load characteristics of the motor is solved, sw