A Bidirectional Converter Stabilization Control Strategy for Novel Power Systems

Abstract

With the increasing proportion of photovoltaic (PV) and other new energy in the grid, it is foreseeable that the future grid will become novel power systems with photovoltaic and other new energy as the main energy source. However, due to the volatility and randomness of PV power generation, making the grid prone to become unstable. By connecting the PV generation and storage devices to the DC bus, the grid instability caused by the use of PV generation can be effectively attenuated. Based on this, this paper applies dual-bridge series resonant DC/DC converter (DB-SRC) to the connection of PV and energy storage devices to DC bus, and proposes a minimum current stress control strategy under single side dual phase shift control, which can select the optimal internal and external shift angles based on the voltage gain and the actual output power. Meanwhile, in order to improve the dynamic characteristics and reduce the current stress of the converter, this paper combines the minimum current stress control strategy with the model predictive control strategy and proposes a model predictive control based on the minimum current stress (MPC-MCS). This method reduces the impact of circuit parameters on the MPC while improving the dynamic characteristics of the converter and reducing current stress, ensuring the accuracy of the controller output at steady state.