Potential Evaluation Method of 220kV Line Transmission Capacity Considering Regional Power Supply Ability

To solve the contradiction between the continuous growth of demand for transmission capacity and the difficulty of constructing a new transmission line, it is necessary to accelerate the improvement of power grid transmission capacity and release the transmission capacity of important transmission sections and lines of the backbone power grid. In this paper, the limit transmission capacity of the transmission line based on the security control current in the regional power grid is calculated first. The power flow of the bayonet transmission line of the regional power grid under normal operation mode is calculated by considering the limited transmission capacity. Next, the power flow sensitivity of the key transmission lines in the regional power grid is calculated based on the existing power supply mode and load level. Then, according to the power flow sensitivity of the key transmission line and the load rate of the lines under normal operation mode, the maximum power supply capacity of the regional power grid is calculated when the key lines are used as the power supply capacity bayonet factor. Finally, an evaluation index is defined to evaluate the necessity of potential exploitation of the transmission capacity for different transmission lines. The effectiveness and adaptability of the proposed method are verified by a practical power grid.