In today's world of energy shortage and environmental protection, improving energy efficiency and developing renewable energy have become two important aspects of sustainable development of energy. Wind energy and solar energy have attracted more and more attention and have become the "green energy" with the most large-scale development and application prospects. About 20% of the solar radiation received by the earth is converted into wind energy. If 1% of the total global wind energy is used for power generation, it can meet all energy consumption. Therefore, wind power generation, which is mainly formed by wind energy utilization, and photovoltaic power generation, which is formed by solar energy utilization, have developed rapidly in recent years. my country has abundant wind power resources and solar energy resources. With the recent implementation of various relevant government support policies, China's wind power market and photovoltaic power generation market will be more vibrant.

The export voltage of wind power/photovoltaic generator sets generally used in my country is 690V, which must be boosted to achieve the purpose of long-distance power transmission. In wind farms/photovoltaic farms, cables are generally used to connect generators to special box-type step-up substation to increase the voltage to 40.5kV or 12kV and then send it to the central substation of the wind farm/photovoltaic farm. The central substation then further steps up the voltage and sends it to the power grid. The combination of wind turbine/photovoltaic generator and box-type step-up substation adopts a unit connection of one machine and one transformer. The 40.5 and 12kV wind power special step-up substation and photovoltaic special step-up substation designed and developed by our company are developed to meet this demand.