Pole-mounted transformers are key equipment in power systems used for voltage conversion and power distribution, typically installed on 10-15 meter poles. This equipment uses an oil-immersed structure with a capacity range of 50-400 kVA, fixed using a double-pole, equal-height arrangement. Some newer single-tube pole-mounted transformers use a steel pipe pole structure, with an overall height of approximately 5.5 meters. The transformer is integrated with a comprehensive distribution box, with a capacity up to 500 kVA. Its core structure includes high-voltage terminals, insulators, heat dissipation devices, and protective components, and is equipped with protective devices such as vacuum circuit breakers and surge arresters.
This equipment achieves ground-based operation and installation through optimized installation devices (such as lifting platforms and hoisting devices), reducing the risks of working at heights. The State Grid Yijun County Power Supply Company was the first in Shaanxi Province to apply high and low voltage live-line working combined with a mobile transformer substation to achieve 'seamless access' replacement of a 400 kVA transformer. In 2023, the Chengdu Shuangliu Power Supply Company completed the replacement of a 200 kVA transformer using a comprehensive uninterrupted working method. In terms of operation and maintenance, oil level and temperature, and the condition of insulating bushings need to be checked regularly. In special scenarios, live replacement can be carried out using a mobile transformer substation vehicle.
