西安电网主网电压等级为330/110 kV，电网发展初期300 MW级机组均要求接入330 kV电网。随着城市集中负荷的发展、电网的不断加强，上述机组接入原则已不能完全适应电网发展的要求。以西安西郊热电厂2×350 MW机组接入系统方案研究为例，分析了受端电网负荷中心城区300 MW级机组分层分区接入110 kV电网的可行性、合理性以及技术上需要满足的条件。

The voltage grade of main Xian power grid is 330/110 kV. In the initial development stage of power grid, the 300 MW grade generation units are all required to interconnect to 330 kV power grid. However, with the development of the urban load and power grid, the connection principle is not adaptive to the development of power grid completely. Therefore, taking the connection to power system of 2×350 MW generation units in Xian west suburb thermal power plant as an example, the feasibility, rationality and essential technology conditions are analyzed for the 300 MW grade generation unit connecting to 110 kV power grid by the sub-layer and sub-area way.