Constant Current Fault-Tolerant Buck Type Interleaved DC-DC Converter for Battery Charging Applications

DC-DC converters are used in the variety of industrial processes, one of which is the battery charging for electric vehicles (EVs). Since, these converters are more prone to switch faults and to guarantee reliable operation fault tolerant converters are used. The paper presents the design of a 2.2 kW fault-tolerant interleaved buck converter. Additionally, it suggests an algorithm that can identify any switch defect within one switching cycle and adjust the gains to distribute the entire current equally among the healthy legs to provide constant current. In order to have the least amount of ripple in the output voltage and output current, it also updates the phase shift of healthy legs using phase selector. A PI control is implemented along with fault tolerant control which not only avoids sharp overshoots and undershoots but also input disturbances and load variation by adjusting the duty of each leg. The proposed scheme has been analyzed and simulated in MATLAB SIMULINK.