The Impact Of The Electric Loads On Voltage And Current Of The Grid

Harmonic and voltage sag are two important researches in electric power system, one side, it has great change in the structure of electric system load at present, a lot of late-model electric-electronic equipments pour large amount of harmonics when them were installed into system, another side, the induction motor start is one of the main causes voltage sag for the moment. Therefore, jumping into an electric load's causing damage and effects on the electric system safety operation and works regularly is increasing regarded highly.In this article, as for above two problems, the operation regularity of nonlinear load was onto grid impacts on voltage and current is researched under two kinds conditions of having background harmonic and having no it. The voltage sag causing by throwing an induction motor starts onto grid when it carring idler or half-load or full-load were compared, and the transient state waveform of PCC voltage is respectively observed by simulate as inductance and capacitance was thrown onto grid during the moment of voltage sag happening, the average voltage sag (impact) strength data have been defined to analyze quantitatively the voltage wave causing by two kind of loads.