Study on load balancing of low and medium voltage supply and distribution system for nuclear island fire fighting based on genetic algorithm

In order to ensure the safety of nuclear power plant nuclear island, the high power equipment of nuclear island fire fighting will have emergency startup situation, which leads to transient load surge and causes uneven load distribution problem. To this end, a new type of low and medium voltage power supply and distribution system for nuclear power plant island fire fighting is designed. The problem of instantaneous load surge is mitigated by three power sources: the main power source, the backup power source and the redundant power source. A modular radial network topology and a ring DC distribution network structure are used to design the system power supply and distribution. Taking the minimum number of power supply lines and the lowest average value of line load ratio as the objectives, the optimization objective function of low-voltage power supply and distribution is constructed, and the objective function is solved by changing the allocation position of a certain load through the genetic algorithm, so as to realize the uniform distribution of loads. The results show that the FTLBD of the designed system is higher than 0.80, the load balancing effect is better, and there is a strong load balancing ability when coping with power supply line failure.