VECTORIAL METHOD FOR MEASUREMENT OF SHORT-CIRCUIT LOOP IMPEDANCE IN NETWORK WITH OPERATING LOAD

摘要

This paper is concerned with the measurement of short-circuit loop impedance in electrical low voltage network with operating loads. The paper discusses and analyzes the influence of the operating network load on the accuracy of loop impedance measurement when are use classical instruments and methods. The results of analysis indicate that the effect of the operating load is significant especially when the measurement point is close to the induction motors. The paper presents the new vectorial method for measurement loop impedance in which the influence of operating loads on measurement result is eliminated. The relations are derived for determining the values of magnitude loop impedance Z and its orthogonal component resistance R and reactance X.