Multioutput DC-DC Converter With Optimal Torque Distribution for Split Drive Electric Vehicle Applications

The demand for electric vehicles (EVs) is growing fast in the recent years due to the increasing energy crisis and environmental concerns. However, the operation of the EVs is limited due to the reduced drive range and lower torque generation. Dedicated motor drive for each wheel can solve these problems. Thus, a multidrive system for EV operation is becoming an important research area. In addition, integrated converter for motor drive can reduce the size and improve the operation further. These converters require wide voltage gain due to significant variations in the voltage of the EV sources. The resonant converters are well-suited for wide voltage applications with soft-switching capabilities. However, achieving significant voltage gain requires a wide frequency range. Thus, this article presents a multiport reconfigurable resonant converter that integrates LLC and LLC-C resonant networks for narrow frequency operation. Moreover, this article proposes a dynamic programming (DP) algorithm to determine the optimal torque distribution between the split motors. Based on the analysis and simulations the torque allocation ensures that the motor operates within the high-efficiency region for different driving cycles due to the DP algorithm. The results are compared with the 50% torque distribution, which shows that the proposed strategy can improve the driving range over 15% . This article includes experimental verifications of the multimotor drive operation.