Research On Dual Half-bridge Bi-directional DC-DC Converter Based On PWM Plus Phase-shift Control

With the development of human civilization and industrilization, the resources on earth arebecoming depleted. To solve this problem, people focus on new resources and its technology. As animportant part of energy storage system, bi-directional DC-DC converter has wide applications in newenergy fields. Traditional bi-directional DC-DC converter based on phase-shift control for vehicleadopts clamping capacitors to realize the zero-voltage switching of power transistors. However, as aresult of the instability of the accumulator, the amplitude of input and output voltage of the dualhalf-bridge phase-shift control bi-directional DC-DC converter does not match, then the current of thetransformer leakage inductance increased significantly.To solve this problem, a technology of PWM plus phase-shift control is proposed in this paper.With this method, the dismatch of input and output voltage of the dual half-bridge phase-shift controlbi-directional DC-DC converter can be solved. Firstly, the operating principle of the bi-directionalDC-DC converter based on phase-shift control is analyzed. For the disadvantage of phase-shift control,PWM plus phase-shift control method is discussed. Then the parameters of the main circuit aredesigned. Based on this design, devices such as the soft start, PWM plus phase-shift control are addedto the design. Next, the simulation based on SABER is carried out. After the simulation, a device ofdual half-bridge bi-directional DC-DC converter based on PWM plus phase-shift control is built.Experiment results show that PWM plus phase-shift control method can match amplitude of input andoutput voltage well, and have a good performance in the control of the dual half-bridge bi-directionalDC-DC converter. The proposed technology has good appication perspective.