Development of Battery Cascade High-Voltage Charging Power Supply Based on Time-Sequence Encoding

A megawatt-level high-voltage charging power supply suitable for fast and cyclic charging of pulse capacitors is developed to meet the requirements of electromagnetic launch devices. Batteries are used as energy storage units to meet outdoor application environments. The low-voltage cascade topology is used as the charging circuit, which achieves high voltage through the series connection of low-voltage repetitive battery modules. The control strategy of time-sequence encoding is adopted to control the activation time of each battery module. In addition, a method for eliminating reverse voltage of pulse capacitors is proposed, which can convert reverse energy into charging energy. The power supply consists of 16 battery modules, with the peak power of 5.5 MW, the output voltage of 0–7 kV, the average charging current of 800 A, the charging rate of 2 MJ/s, the charging efficiency is 95.5%, and the ability to cyclic charging for more than ten times. The power supply is verified through simulation and experiments, and the results prove that the output capability meets the design specifications, and the reverse voltage can be eliminated, which also helps improve the charging rate.