微机变压器变比及联结组别标号测量装置的研制

Development of measurement device of voltage ratio and connection-group code of transformer by microcomputer

针对三相变压器变比及联结组别标号试验中连接线较多 ,测试过程复杂 ,测量结果不直观等问题 ,介绍了一种能同时自动测量变压器的变比及联结组别标号的测量装置。该装置采用单片机进行数据处理与控制 ,变比测量电路设计采用双电压表法的原理 ,利用高精度A/D转换器进行模 -数转换 ,通过微机测量电压 ,并计算变比值 ;联结组别标号的测量采用相位表法的原理 ,在三相变压器的初级加三相交流电压 ,检测初级和次级线电压的相位差 ,从而判定联结组别标号。试验表明 ,该装置测量过程自动化 ,测量结果数字化 ,且测量准确度高 ,使用方便。

Aiming at the problems of three phase transformers voltage ratio and connection group code test, such as more connecting wires, complex test process and the test result not being audio visual, a micro computer based measurement, data processing and control system was successfully developed. This device only employing single phase power supply can at the same time automatically measure the voltage ratio and connection group and the test result can directly be displayed in digital. In the voltage ratio circuit design, the principle of two voltage meter method is adopted, a high precision A/D transformer is used and a microcomputer is employed to measure voltage and calculate the voltage ratio values. In the connection group code circuit design, the principle of phase meter method is employed, i.e. adding a three phase A.C. voltage on the primary coil to detect the phase difference between primary and second coils, and thus the value of connection group code may be judged. Experimental test shows that this system possesses the advantatges of good anti disturbed ability, high test precision and easy operation.