2024-05-13 Share: FOC - SVPWM

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Motor vector control FOC realizes dynamic current control through the conversion of the rotor coordinate system. Several links of realization, phase current → Park(Ialpha/Ibeta) → Clarke(Iq/Id) → current PID(target Iq/Id) → reverse Park(Valpha/Vbeta) → SVPWM → PWM duty cycle.

When the modulation harmonic is a sine wave, the output voltage amplitude does not change. The modulation harmonic is sin(t)+1/6sin(3t), the magnification of the sine wave is 1.155 times (2/√3( sin(t)+1/6sin(3t)) ⇐ 1). Moreover, because the phase difference of the three phases of the motor is 120, the third harmonics on the line voltage will cancel each other out.
Because of the hardware switching characteristics of the Inverter three-phase full bridge, it is divided into 6 areas for control. The remaining two switch states are 000 and 111. The SVPWM corresponding to the 6 areas is:
Convert to each PWM and ADC sampling period domain,
ADC sampling and feedback control are performed every cycle. The sampling point can be overflow or CC4 trigger. It is necessary to calculate whether the ADC sampling cycle is sufficient. Using complementary PWM, the dead time of the upper and lower tubes is related to the hardware.