Research on Model Predictive Control Strategy of Three-level Dual-Active Bridge DC-DC Converter

A model predictive control strategy for Zero Voltage Switching (ZVS) was proposed for the mid-point clamp three-level dual Active Bridge (DAB) DC-DC converter. Through the switching conduction mode of the three-level DAB converter, the working conditions of the inductor current in each mode are analyzed, and the range of zero-voltage turn-on of all switches of the three-level DAB under single phase shift (SPS) modulation is derived. The spatial equation of state is established according to each mode, the purpose of fast response is achieved through the cost function, and finally the predictive control strategy of the three-level DAB model with zero voltage turn-on is obtained discretically. Simulation results show that the output voltage of the control strategy can be quickly stabilized under the load mutation condition when the converter realizes the zero voltage opening of all open tubes, which not only reduces the loss of the switch tubes, but also makes the system have faster dynamic response ability.