A Phase Detection Method using Power Handling Capability in Resonant Converters

In resonant converter, controlling phase angle is important as insufficient phase can lead to semi-conductor devices to enter complete or partial hard-switching conditions. This is exceptionally challenging when operating at multi-MHz switching frequency. This paper proposes a concept of calculating phase angle from resonant topology inherent property of power handling capability. A Class-PN resonant converter topology is operated with a series-parallel compensated load at 6.76 MHz. The phase angle is measured using experimental waveforms and compared with calculated values by proposed methodology of using the power handling capability. The proposed methodology calculates phase angle with an error of 3.2-6.6° compared to measurement when the input DC voltage is varied from 180-300 V.