Intelligent system applications to power quality assessment

Summary form only given. In this study, we have investigated the feasibility of qualitative reasoning (QR) or model based reasoning for power quality assessment. QR depends on the ´first principles´ of the physical system. In the context of power quality, the first principles are models of the physical behavior of distribution feeders and their protective devices. The cause-effect relations between a disturbance and its resulting power quality problems need to be established. Quantitative behavior such as exact power flows and voltage magnitudes are not as important when the primary purpose is to determine the cause. In this presentation, examples are used to illustrate the QR method developed in our study. Our QR method is based on generalized power rules. The software prototype is developed in Microsoft Visual C++, which includes the qualitative reasoning method. The prototype makes use of the object-oriented programming techniques in conjunction with intelligent system concepts