一种通用电子式互感器数字接口的研究与实现

Study on Digital Interface of ETA/ETV and Its Implementation

电子式电流/电压互感器(ETA/ETV)与继保设备的合并单元(MU)的数字接口一直没有明确的规范,为方便ETA/ETV与各厂家的MU接口,考察了国内电力设备二次厂家MU的数字输入输出格式后提出了一种通用的电子式互感器与MU的数字接口方法。该方法采用复杂可编程逻辑器件(CPLD)作为核心处理器件,能够方便地实现各种数字输出的ETA/ETV与MU的接口。接口转换系统与四方公司MU的配合实验结果验证了接口方法和系统软硬件设计的正确性,可以运用在实际的一次互感器和二次设备接口的场合。

Since there is no verbose specification for communication between electronic transformers and MU, a general method has been brought forward. This method adopts an Altera MAX II series CPLD as a CPU, which is simply to use, low cost, and high performance. The device can receive data of electronic transformers, format the data following the request of the MU, and send the processed data to it. The data format that the MU received is consisted with sync signal, data signal, status signal and CRC identifying code, exactly. The IEC advices that the clock of electronic transformers will be given by MU, which is also the design trend. But obviously the challenge will not be easily met, especially for different vendors of the primary and secondary devices, So in many circumstances, electronic transformers and MU have their clock systems respectively. Our design follows this pattern. But using the clock of MU is also valid and it＇s maintained in our system. We consider our design as a general method just because we should never change the hardware structure of our interface board for different MUs and electronic transformers in common use, just need to change the software a little instead. This device connects electronic transformers and MU properly and succinctly. A chamber experiment has been taken in the lab of ourselves to examine and certify the design method and the whole device system, and the test result appears that the method is very correct and robust,and is very suitable for implementation and popularization.