配电变压器容量测试仪的研制

分析了配电变压器容量测试的必要性,提出了一种基于单片机W77E58的配电变压器容量微机化测试方法,详细介绍了通过变压器短路试验进行配电变压器容量测试的算法原理。硬件电路以W77E58为核心,外扩必要的外围电路,采用锁相环技术和多通道A/D转换器,解决了多路电压、电流信号的同步整周期采样问题,提高了测试精度。在软件算法上灵活运用模糊判据,提高了容量测试的精确性。实际应用表明,该仪器具有很高的测试精度,容量测试准确率达99%。

Development of Capacity Measuring Instrument for Distribution Transformer

The necessity of capacity testing for distribution transformer is analyzed and a new measurement method based on W77E58 is introduced. The paper demonstrates the algorithmic principle on capacity testing for distribution transformer. A method of hardware solution using phase-locked loop and simultaneous sampling A/D chip is presented, to resolve the AC sampling for multiple voltage and current signals, and furthermore to improve the testing precision. A new fuzzy principle is applied in the software algorithm to enhance the testing accuracy. The practical application shows that the accuracy rate of capacity testing by this instrument is up to 99%.