Dual-Loop Continuous Control Set Model Predictive Control for a High-Voltage and High-Power Energy Storage System

In this article, a dual-loop continuous control set model predictive control (CCS-MPC) method is proposed for high-voltage and high-power energy storage system (ESS) based on dc dynamic voltage regulator (dc-DVR). Different from the conventional control method, the proposed control method uses a cascade dual-model-predictive control for the inner and outer control loops. The mathematical model of ESS is established. The inner-loop MPC controller is based on the inductance characteristic equation, which is used to control the inductance current of dc-DVR. The outer-loop MPC controller is based on the capacitance characteristic equation, which is used to control the output voltage to track the reference value. In this proposal, the parameters of the inner-loop and outer-loop MPC controllers are updated at each control cycle to improve the robustness to load changes and parameter uncertainties. In addition, the proposed method is combined with interleaved parallel control. It not only realizes the current balance between the parallel phases of dc-DVR, but also reduces the voltage and current ripple. Several advantages can be highlighted such as fixed switching frequency, short output voltage dynamic adjustment time, and robustness to system parameter mismatch. The proposed method is verified by an experiment platform.