非正弦不对称三相三线电路负载侧相电压的定义与测量

对非正弦不对称三相三线电路，如何恰当地定义负载侧的相电压并能方便地测量一直未有明确的统一认识。本文从研究三相三线电路中相电压与线电压的关系着手，根据外部等效的思想。来定义三相三线电路负载侧的相电压。按此定义的相电压恒满足ｕ，＋“ｂ＋“ｃ＝０，并可方便地通过三相电压互感器或直接依据负载侧的线电压来唯一确定负载侧的相电压。

The Definition and Messurement of Loa d''''s Phase Voltagesin Non-Sinusoidal Unsymmetrical 3-Phase 3-Wire System

t is not clear and definite, up to now, how to properly define and easily measure the load;s phase voltages in non-sinusoidal unsymmetrical 3- phase 3 -wire system. Starting with the study of relation between the phase voltages and the line voltages on both source and load sides in 3- phase 3-wire system and according the external equivalence, this paper gives the clear definition of the loads phase volt-age in non-sinusoidal unsymmetrical system. Based on the definition, the sum of the 3 phase voltages is always equal to zero or and it is easy to uniquely determine or measure the loads phase voltages by the normal 3-phase PT or directly by measuring the loads line voltages.