A Case Study on the Current Mode Control of Phase Shifted Full Bridge Converter for the SONAR Based Pulse Power Applications

SONAR transducers that are used for underwater object detection and navigation applications require pulse power in the range of ten to hundreds of kilowatts with variable frequency and amplitude electrical signals. This is typically implemented with several stages of converters at the heart of which is the DC-AC Class-D Power Amplifiers which in turn is supplied by a suitable DC-DC converter such as Phase Shifted Full Bridge (PSFB) converter. The pulse powered operation can be realized by either varying the modulation index or by controlling the input DC source of the Power Amplifier. However, delivering higher power in short bursts of few milliseconds requires precise control of the DC-DC converter transients. Phase Shifted Full Bridge converter is one of the most efficient DC-DC converter that is capable of delivering variable power by varying the phase shifted operation. An attempt is made in this paper to study the performance of various compensators for the PSFB control and thereby arrive at selection and design methodology of suitable compensator as per the application requirement. The PSFB plant model is validated by comparing with the small signal frequency response obtained from the PLECS simulation platform. For the obtained plant model, design and analysis of various compensators is presented and its performance is evaluated through experimental results.