REDUCTION OF ENERGY LOSSES ON HEATING OIL CIRCUIT BREAKERS 35–110 KV IN JSC «CHERNIGIVOBLENREGO»

Abstract

The analysis of the state of 35–110 kV circuit breakers in the Chernihiv region, which are on the balance sheet of the operator of the distribution system JSC «Chernigivoblenergo», has been carried out. It was shown that the number of circuit breakers that satisfy regulatory documents is only 18.9 % in 35 kV and 2 % in 110 kV power networks. Unfortunately, most of the 35–110 kV circuit breakers in the Chernihiv region are low-oil and bulk-oil type, which required heating during cold meteorological conditions. The article assess the duration of the circuit breakers heating and their drives, depending on the selected set point of the temperature and the averaging interval of the ambient temperature, and the value of technological energy losses. The article considers following ways to reduce technological costs for heating: optimization of the heating control system, replacement of oil circuit breakers with modern vacuum and SF6 circuit breakers, which require lower costs on heating, and applied both above ways. The effectiveness of the above ways was done with apply Net Present Value, which includes not only investments and Net Profit Margin, but also operating costs and Discount Rates. It has been shown that all of the above ways are effective. In particular, the least costly is the modernization of the heating control system, which has payback period is low three years. The payback period for second way to replace all 35–110 kV oil circuit breakers with modern ones at JSC «Chernigivoblenrego» is about 6.5 years, but this way requires large investments. However, this way cannot be done in one year. Therefore effectiveness will be less due to energy losses to operated oil circuit breakers.