Output Voltage Drop and Input Current Ripple Suppression for the Pulse Load Power Supply Using Virtual Multiple Quasi-Notch-Filters Impedance

To balance the instantaneous power difference between the pulsed output power and the constant input power of the pulse load power supply (PLPS), an active capacitor converter (ACC), which can compensate the pulsed current, is connected in parallel with the output of the dc-dc converter in the PLPS. In this article, based on the Fourier decomposition results of the load current, it is evident that the square waves have significant harmonic content. Hence, to provide the lower impedance at the frequencies of the high content harmonics in the load current, a virtual impedance that consisted of the multiple quasi-notch-filters is proposed to be in parallel at the port of the ACC for the suppression of output voltage drop and input current ripple. The virtual parallel impedance is implemented by the output voltage feedforward control of the ACC. The design considerations of the virtual parallel impedance are presented to ensure the stability of the PLPS. Finally, a synchronous rectifier buck converter with a bidirectional buck/boost converter is tested at the pulse repetition frequency of 100-300 Hz and the pulse duty cycle of 0.15 to verify the validity of the proposed control scheme.

Automated summary

In order to balance the power difference between the pulsed output power and the constant input power in the pulse load power supply (PLPS), an active capacitor converter (ACC) is connected to the output of the dc-dc converter. A virtual impedance consisting of multiple quasi-notch-filters is proposed to provide lower impedance at the frequencies with high harmonic content in the load current, and it is implemented by the output voltage feedforward control of the ACC. The validity of the proposed control scheme is verified through experiments with a synchronous rectifier buck converter.