基于电流行波的微电网保护策略

针对微电网的故障电流小、潮流双向性等特性,提出了适合微电网的保护策略并进行了仿真。传统的基于过电流的电网保护技术对于微电网的保护受到一定限制,因而需要对新的技术进行探索。在对这些因素分析的基础上,提出了微电网的保护策略:通过小波变换对电流行波进行分析判断故障位置,母线电压确定故障发生与否及扰动电压判断故障类型。利用SVPWM控制原理在Matlab/Simulink中使用SimPowerSystems搭建微电网的模型,并对孤岛运行模式下微电网不同的故障类型进行仿真分析,仿真结果表明所提出的保护策略在孤岛运行的方式下是有效的。

Protection scheme of microgrid based on current traveling wave

Based on the characteristics of microgrid, for example small fault current, the bidirectional powerflow, etc, a protection scheme is proposed and simulated. The traditional protection scheme based on overcurrent has some restrictions on the microgrid protection, thus a novel protection needs to be explored. Based on the analysis of the above factors, a microgrid protection scheme is proposed. Wavelet transform is used in analyzing current traveling waves to identify faulted location, the bus bar voltages are used to determine whether a fault happened or not, and disturbance voltages are used to determine fault types. A microgrid model is established using SVPWM with SimPowerSystems in Matlab/Simulink, and different faults in the islanded microgrid are simulated, and the result shows that the proposed protection is valid in an islanded operating mode.