1400

In this paper, a cascaded DCSST is used. By adopting PWM control to the front stage, the active control of the input terminal of DAB is realized, which makes the voltage matching of the two ports of DAB and reduces the system loss.On the other hand, due to the inevitable factors such as manufacturing process and equipment aging, module parameters do not match, which will lead to the failure of voltage equalization control to achieve power balance.On this basis, the virtual impedance is introduced into the control loop, and the output impedance of a single module is changed without changing the output characteristics of the whole system, so as to suppress the circulation and achieve a good power balance effect.