Transient process control method and system for dual-active-bridge series resonant converter

Abstract

The invention discloses a transient process control method and system for a dual-active-bridge series resonant converter, and belongs to the field of direct-current converter control. Comprising the steps that when a transmission power instruction of the converter suddenly changes in the kth switching period, the difference between the transmission power Pk of the converter in the kth switching period and the transmission power Pk-1 of the previous switching period is obtained to obtain delta P, the size of the delta P and the minimum power instruction difference Pset of the transient process is judged, and if a transient event occurs, according to the phase shifting ratio, the difference Pset of the transmission power Pk of the converter in the kth switching period is judged to be smaller than the difference Pset of the transmission power Pk-1 of the converter in the previous switching period. And calculating the intermediate phase shift ratio of the rising edge and the falling edge of the lagging voltage in the kth switching period, performing modulation according to a transient driving modulation control method, and then recovering the steady-state phase shift ratio Dk from the (k + 1) th switching period to finish the transient process at the end of the kth switching period. Oscillation of inductive current and resonant capacitor voltage in the sudden change process of a power instruction can be eliminated, stable and rapid transition between two power levels is achieved in one switching period, and the dynamic performance of the converter is improved.

Description

technical field [0001] The invention belongs to the field of DC converter control, and more particularly, relates to a transient process control method and system for a dual active bridge series resonant converter. Background technique [0002] With the rapid development of new energy power generation and energy Internet, DC transformers have received extensive attention from scholars and have become a research hotspot in the field of power electronics in recent years. A dual bridge series resonant converter (DBSRC) has the advantages of electrical isolation, bidirectional energy flow, and high power density. In addition, due to the existence of the resonant tank, the current waveform of the resonant converter is close to a sine wave, which is easy to realize soft switching and the current stress of the switch tube is small. Therefore, it is currently one of the most applied and studied DC transformer topologies. [0003] In actual operation, due to the variability and int...

AI Technical Summary

Problems solved by technology

However, a detailed mathematical description of this process has not yet been established, so it is impossible to estimate the overcurrent and overvoltage conditions and duration of the transient process

Images