The invention provides a digital
single cycle method control
active power filter based on
delay compensation, belonging to the field of
digital control. The implementation of the filter comprises the following steps: (1) detecting load current and using a
harmonic calculation method to calculate
harmonic current ilha, ilhb, and ilhc, (2) detecting three-phase
power supply voltage ea, eb and ec and DC side
capacitance voltage Udc, and inputting the three-phase
power supply voltage and the DC side
voltage into a DSP(
digital signal processor) for sampling, (3) inputting the above sampling value into a
single cycle control module to calculate the duty ratio of a switch tube, and (4) multiplying the calculated duty ratio with the cycle register value of a
timer in the DSP, taking the result as the value of a comparison register, controlling the DSP to generate a PWM
signal, controlling the switch-on and switch-off of a switch in a converter, turning on a switch device when the PWM
signal is high level, turning off the switch device when the PWM
signal is low level, and thus generating compensation current. According to the
active power filter, the
delay effect of the
active power filter can be effectively reduced.