New constant-frequency current-mode control for power converters, stable for all values of duty ratio, and usable in all four quadrants

摘要

A constant-frequency, current-mode, pulse-width modulator (PWM) for switching power converters is presented. The PWM is stable for any value of the duty ration ( delta ) and is suitable for operation in one to four quadrants of the output current-voltage plane. The control system can be used with most DC-DC power-converter topologies. Due to its unique properties of delta range stability and four-quadrant operation, the control process is particularly useful in DC-AC conversion. The process is clearly advantageous compared to the other current-mode control method, the bang-bang process. It has all the advantages inherent to constant-frequency operation, including the possibility of paralleling different converters without low-frequency beating and the suppression of low-frequency subharmonics in DC-AC conversion.