关键词: 绿电制氢装置, 并网, 离网, 供电稳定性, 储能系统, 调差系数, 微电网频率, 视在功率

Abstract:

During the process of switching from grid connected to off grid of green power hydrogen production, the imbalance of active and reactive power causes frequency and voltage oscillations of the microgrid, and the inverter is overloaded and out of operation. In order to solve these problems, a multi-mode control strategy for energy storage is proposed with the goal of stable operation during hydrogen production grid connected and off grid switching. Firstly, establish the power conversion equation for the energy storage system and analyze the power and frequency regulation relationship of the energy storage controller. Secondly, study the multi-mode switching strategy for energy storage, analyze the key factors for stable off grid switching, and compare the impact of energy storage capacity and controller parameters on the system. Finally, taking a typical green power hydrogen production microgrid as an example, the switching performance under different energy storage capacities and adjustment coefficients is simulated and calculated. The results indicate that the higher the proportion of energy storage capacity, the less apparent power overshoot of energy storage, and the lower the risk of equipment overload. Under the same energy storage capacity, the smaller the adjustment coefficient, the smaller the peak apparent power, and the lower the risk of overload. However, at the same time, it is required that the current overload capacity of the inverter is strong. The adjustment coefficient of 0.20 can meet various operating conditions of grid connection and off grid.

Key words: green power hydrogen production unit, grid connected, off grid, power supply stability, energy storage system, adjustment coefficient, microgrid frequency, apparent power