Patent ID: 11894782
Assignee: SANTAK ELECTRONIC (SHENZHEN) CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A Pulse Width Modulation (PWM) method for a Cascaded H-bridge (CHB) converter, wherein each phase of the CHB converter connected to a three-phase AC power supply is provided with n CHB rectifier circuits, where n is greater than 1, and each CHB rectifier circuit is provided with a first AC input terminal, a second AC input terminal, a positive DC output terminal, a negative DC output terminal, four power transistors connected to form a H-bridge structure, and a DC bus capacitor,
the PWM method comprising the steps of:
S1, generating a pair of sinusoidal signals with a phase difference of 180 degrees as a first reference waveform and a second reference waveform, and generating n carrier signals having sequentially decreasing levels and equal amplitudes to correspond to the n H-bridge rectifier circuits, respectively, wherein the levels of the n carrier signals are cascaded to fill the amplitude of a unipolar voltage half cycle of the reference waveform; and
S2, determining PWM signals for controlling the corresponding H-bridge rectifier circuits based on each reference waveform and each of the n carrier signals, and controlling, by n groups of the PWM signals, the power transistors in the n H-bridge rectifier circuits to switch on and off.