The Research Of100kW Bidirectional Power Storage Converter Based On Digital Control

Chemical battery energy storage system becomes a brand new method to overcome the existing problems of power supply and to achieve sustainable development of the power grid, due to the development of large-capacity battery energy storage technology. It will effectively promote the development and utilization of renewable energy. Converter is the key element of the energy storage system. It's Responsible for energy storage battery charging and the task of power back to the power grid. The performance of the converter control system is directly related to the stability, accuracy and response speed of the whole energy storage system. Therefore, it has great theoretical and practical significance to do deep research on the energy storage converter.This paper presents a digital control program of the energy storage bi-directional converter based on the controller architecture of DSP and FPGA. The main topology of bi-directional converter was established based on the PEBB module. The working principle of the AC/DC active rectifier and the DC/DC buck-boost module was analyzed. Active rectifier control strategy and interleaved DC/DC converter control strategies based on the SVPWM algorithm was described in details. The main circuit of the converter system was designed and the SEMIKRON IGBT module was chosen as the power device of the main circuit. The parameters of the input-output filter inductors and capacitors, the AC filter, and other peripheral circuits were determined. The control system of the converter was designed, including hardware control circuits and software control circuits. Detailed analysis was done according to modules functions. DSP main control program and FPGA auxiliary control program were written. Real-time communication between hypogynous-machine and host computer was realized based on RS232communication protocol. AC/DC active rectifier and DC/DC conversion experiment platform was built and the validation experiments of rectifier, inverter, buck and boost were completed. On this basis, a bi-directional energy storage cabinet with a rated power of100kW was assembled, and high-power long-time test in the power grid was completed, obtaining good electrical performance parameters.Test result shows that the designed100kW bi-directional energy storage converter is stable, with the characteristics of little output voltage-current ripple, large power factor, and high conversion efficiency. It has good electrical performance.