正序电压坐标和零序电压测量

零序电压是一个矢量，有大小及方向。在有中性点的系统中，用正序电压作参考坐标，进行零序电压测量，又用几何作图的方法，得出零序电压矢量图，在中性点没有引出的系统中，测出三相线电压，得正序电压坐标作参考，以三相电压作图，或者是计算得出零序电压矢量值，方法简单实用。

Positive-Sequence Voltage Coordinate & Zero-Sequence Voltage Measurement

Zero-sequerence voltage is a vector with size and di rection.In the system with a neutral point,zero-se-quence voltage is measured by using positive-se quence voltage as a reference coordinate and zero-se quence voltage vector diagram is drawn by geometric method.In a system where a neutral point fails to be led,three-phase line volt-age is measured and positive-sequence voltage vector is got for reference.It is a simple and practicable way to obtain the value of zero-sequence voltage vector by drawing with three-phase voltage or by calculation.