A Fuzzy Technique for Voltage Control During Parallel Operation between In-plant Generation and Utility

One of the important criteria from the viewpoint of the industrial consumer is to maintain a satisfactory voltage level at relevant terminals. The voltage levels along the distribution feeders must be kept within standardized values in both design and operation stages. Parallel operation between local gas turbine generation and utility source in industrial plants has to consider the two control schemes of utility transformer on load tap changer and generator AVR. The correct choice of the two control schemes setting is the key for proper parallel operation to avoid the generator reverse operation as load to the utility. The present paper deals with a fuzzy technique for voltage profile control and parallel operation between local gas turbine generation and utility source in industrial plants. The fuzzy technique designed to monitor continuously the paralleling of gas turbine driven generator and grid (through power transformer with on load tap changing (OLTC)). The targets during parallel operation on the common bus-bars between the two sources are to keep voltage within standard tolerances by utility power transformer (OLTC) regulation, and the generator AVR to maintain the desired power factor. The developed system checks the power swing between generator exciter and transformer tap changer. The developed system discusses the sudden increase in load on the utility supply subsequent to local gas turbine driven dropping as well. It determines the percentage of loading sharing. The developed system has been applied on one of Enppi projects for United Gas Derivative Company (owned by British Petroleum and Gasco) at Port Said, Egypt. The developed system has been revised successfully by both the international and the national companies.