基于Matlab的变压器差动保护闭环仿真研究

Study on closed-loop simulation of transformer differential protection based on Matlab

应用Matlab建立了微机保护仿真系统,并对不同原理的变压器差动保护进行了仿真和比较。仿真系统采用积木式结构,根据微机保护的实现原理构建模块,实现保护的闭环仿真,对保护的动作过程进行分析。以变压器差动保护为例,研究比较了常规比率差动、复式比率差动、故障分量比率差动元件的工作原理,分析了二次谐波、波形对称原理识别励磁涌流的方法,构建了相应的保护模块并进行了仿真和比较。仿真结果说明仿真系统可考核保护的各元件判据、动作定值、动作逻辑和分析特殊故障条件下保护内部元件的动作特性,实现保护动作全过程的闭环仿真。

A closed- loop simulation system of microcomputer- based protective relay is developed on Matlab,with which the transformer differential protections of different principles are simulated and compared. The system adopts modular structure and the modules are built according to operational principles to realize the closed- loop simulation of protections and the analysis of protective processes. With the transformer differential protection as an example,the operational principles of conventional ratio,compound ratio and fault component ratio differential protections are compared, the exciting inrush detection methods of second harmonic and waveform symmetry are analyzed, based on which the corresponding protection modules are built for simulation and comparison. The simulative results indicate that,the system can be used to examine the criteria, settings and action logic,study the operating characteristics of internal protective components under specific operating conditions,and realize the closed-loop simulation of entire protection process.