Mitigation Strategies for Low-Voltage and Transformer Overload Issues in Mountainous Area Distribution Network

Due to the massive integration of distributed photovoltaic systems, seasonal production activities, holidays, and temperature changes, the seasonal overload and low voltage problems of transformers in mountainous area distribution networks are particularly prominent, seriously affecting the stable and reliable supply of electricity. Considering that the problem only occurs seasonally, traditional methods such as increasing capacity and adding distribution transformers have problems such as low equipment utilization and high investment. Therefore, how to ensure normal power supply and stable operation of distribution transformers during seasonal peak load periods with limited investment is an urgent problem to be solved. This article first analyzes the characteristics of overload and low voltage problems in the distribution transformers of a regional power grid. Then, a method of installing fans on distribution transformers was proposed to ensure their safe and stable operation under short-term overload conditions. Secondly, in response to the low voltage problem caused by a long power supply radius, low-voltage AC/DC hybrid technology has been adopted to solve the problems of high cost and limited improvement effect on long-distance line voltage through traditional mitigation strategies. Finally, the feasibility and economy of the mitigation strategies proposed in this article were verified through a regional power grid project.