A Simple Sensorless Current Sharing Control for Input-Parallel Output-Parallel Dual Active Bridge Converters

The circuit parameters mismatches of input-parallel output-parallel (IPOP) dual active bridge (DAB) converter modules will cause power imbalances of the system. To solve this problem, this paper presents a simple sensorless current sharing control based on dual-phase-shift (DPS) modulation method. First, the full process operation mode of IPOP DAB is analyzed. Then, the power balance mechanism of the IPOP DAB converter is discussed, and a sensorless current sharing control method is proposed. The core principle of the proposed method is based on the perturbation algorithm to estimate the parameter mismatches of each DAB cell. Once the parameter mismatches are known, the phase shifts that achieve current sharing are calculated. The implementation scheme based on CAN Bus is given, and sensitivity and stability analysis of the proposed method are conducted. Finally, the simulation and experimental results verify the effectiveness of the proposed control strategy.