Abstract In addition to the reliability of power supply quality of electricity consumers are one of the most important characteristics of the electrical systems. It has a significant impact on the efficiency of electrical receivers and the technical and economic performance electric networks. In the modern developed networks providing quality indicators of energy acceptable for consumers, requires significant cost of funds and materials, as well as the collection and processing of more information. This explains the importance of the questions of power quality in the complex problem of the design and operation of electrical systems. If the provision in the electrical systems normalized values of the frequency is mainly due to the balance of active capacity and characteristics of the appropriate equipment on the electrical stations, the quality of the voltage at the consumer is determined mainly by cost distribution networks. For consumer’s rural areas referred to the costs are most of the total production costs and electricity transmission, so questions quality assurance voltage networks always were in the focus of research, design, and operational organizations. Particular attention these questions acquire at present in connection with the rapid growth of electricity consumption in agriculture and the relevant development of rural networks. The huge positive effect electrification to fully manifest only when consumers are delivered electricity is quite high quality. Reduction of the quality of significantly impairs performance electrical receivers and leads to marked electro receivers damage.