Direct-current transformer input voltage balance control method based on model prediction

Abstract

The invention discloses a direct current transformer input voltage balance control method based on model prediction, and belongs to the field of direct current converter control, and the method comprises the steps: calculating an input voltage reference value Vinref through the input voltage vinj (k) of each DAB module in a k-th switching period; using the input total current iin(k), the output voltage vo(k) and the output load current io(k) to predict an input voltage vinj(k + 1) and an output voltage voo(k + 1) in the (k + 1)-th switching period; calculating a target function J and an intermediate parameter Pj of each DAB module by using a difference value between vinj(k + 1) and Vinref and a difference value between voo(k + 1) and Voref; when the control objective function J is minimized, determining per unit output power puj(k) of each DAB module based on the Pj; and selecting phase shift angles D1, D2 and D3 by using the per-unit output power puj (k), so the input voltage of each DAB module tracks the input voltage reference value. According to the invention, a PI controller is not needed, the input voltage balance of each DAB module on the series input side is realized from the parameters of the circuit, and the reliable operation of the ISOP cascade converter is ensured.

Description

technical field [0001] The invention belongs to the field of DC converter control, and more specifically relates to a model-based prediction-based DC transformer input voltage equalization control method. Background technique [0002] In the field of high-power DC conversion, due to the limited capacity of a single converter and the limited voltage stress and current stress of power switching devices, it cannot meet the power requirements of the system. The modular series-parallel combination scheme can effectively increase the power level of the DC transformer, reduce the voltage and current stress of the power switching device, and enhance the fault tolerance of the system; at the same time, in the modular series-parallel combination scheme, the characteristics of the converter itself have been improved. reserve. In recent years, the combination scheme of Input Series and Output Parallel (ISOP) is often used in the field of DC conversion. [0003] The ISOP cascade system...

AI Technical Summary

Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a DC transformer input voltage equalization control method, device and control system based on model prediction. The input voltage of each DAB module on the input side is balanced to ensure the reliable operation of the ISOP cascaded converter, thereby solving the technical problem of poor control stability of the existing DC converter

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