介质损耗角的数字化测量

研究了两种介质损耗角的数字化测量方法即过零点时差法和正弦波参数法，分析了影响测量准确度的因素。在研制的介质损耗角在线监测装置中，由８０９８单片机来测量过零点时差以简化电路。从测量结果中扣除电流、电压通道间的附加相位差；多次测量后，剔除异常值，将平均值作为结果给出，以提高测量准确度。对正弦波参数法，研究了基于最小二乘法和基于三角函数正交性的两种算法，仿真试验说明正弦波参数法具有较高的准确度。据此研制的绝缘参数测量仪的试验结果说明，其性能是满意的。

Study on digital measurements for dielectric loss angle

Two digital methods for measuring dielectric loss angle: one based on time delaybetween zero points and the other based on parameters of sinusoidal wave were investigatedand the factors which could influence the measuring accuracy were analyzed. In the developed on line monitoring device for measuring dielectric loss angle, in order to simplify thecircuits a single chip computer 8098 is used to measure the time delay between zero points.For raising the accuracy, the attached phase angle difference between current channel andvoltage channel should be deducted from the measuring result; 100 measurements were concluded in one measuring process, after the unusual data were abandoned the average valueswere taken as the measuring results. The algorithms based on the least mean square errorsand the orthogonality of trigonometric functions respectively were studied and the computersimulation experiments showed that the method based on parameters of sinusoidal wave wasmore accurate. An instrument for measuring insulation parameters was developed and theexperiment results showed its performance was satisfied.