Interleaved Operation of Conventional PWM Control in a Buck-Boost Active Balancing Circuit

Efficient charge balancing is essential for enhancing the life of a Li-ion battery pack. This paper introduces an interleaved square PWM control, in addition to the conventional PWM for the buck-boost active charge balancing architecture. Thereby, it reduces the RMS values of the battery currents, and consequently, the losses associated with the same. Further, the proposed scheme reduces the time required for charge balancing. Therefore, the proposed approach would help in substantially improving the life of the battery. Simulations are carried out on a 28 V, 20 AH battery pack using a battery model developed from experimental data to validate the control scheme.