Power quality is a very important part to achieve the good quality of the supply. Power quality is defined as the in all electrical networks or any grids its giving perfect along with pure sinusoidal wave form and free noise without any disturbance. To improve the power quality we need some analyzes and research on power quality disturbance perfectly. According to this paper mainly identify the power quality disturbance and harmonic disturbances by changing the short term voltage a little movements. Mainly the wave will analyzed through the four transform equations.. The simulation results and the theoretical analysis show that the model in this paper could simulate the voltage change and harmonic disturbance well, which can provide data and basis for detection and identification of PQ and further control measures. © 2019, Blue Eyes Intelligence Engineering and Sciences Publication. All rights reserved.