基于混合牵引供电系统的短路稳态计算及保护分析

Short Circuit Steady State Calculation and Protection Analysis Based on Hybrid Traction Power Supply System

针对24脉波整流机组和逆变能馈装置并联耦合的混合牵引供电系统,研究其直流侧短路故障发生时的电流特性,并制定相应的直流侧短路保护整定参数。首先计算了整流机组和能馈装置单独短路情况下的等效参数,并根据叠加定理研究混合牵引供电系统的直流侧短路特性。然后对牵引供电系统继电保护类型及保护整定设计原则进行介绍分析。搭建含逆变能馈装置的混合牵引供电系统仿真模型,对含逆变能馈装置的直流牵引供电系统直流侧近、远端短路进行仿真,验证等效计算结果,根据仿真电流波形设定适合混合牵引供电系统的保护整定参数,判断不同短路距离时启用的保护类型,确定混合牵引供电系统能正确切断电路,保障城市轨道交通系统的安全运行。

For the hybrid traction power supply system with parallel coupling of 24 pulse rectifier unit and inverter energy feed device,the current characteristics of DC side short-circuit fault are studied,and the corresponding DC side short-circuit protection setting parameters are formulated.First,the equivalent parameters of rectifier unit and energy feed device are calculated,and the DC side short-circuit characteristics of hybrid traction power supply system are studied according to the superposition theorem.Then the relay protection types and protection setting design principles of traction power supply system are introduced and analyzed.The simulation model of hybrid traction power supply system with inverter energy feed device is built to simulate the short circuit at the near and far ends of DC side of DC traction power supply system with inverter energy feed device,and the equivalent calculation results are verified.The protection setting parameters of the hybrid traction power supply system are set according to the simulated current waveform,and the protection types enabled at different short-circuit distances are judged.It is determined that the hybrid traction power supply system can cut off the circuit correctly to ensure the safe operation of urban rail transit system.