Optimization Planning Method of Distributed Generation Based on Steady-State Security Region of Distribution Network

Distributed wind and photovoltaic (PV) power generation are boosting in China. The wide integration of these generators into the distribution network leads to the risk of branch overload and bus voltage violation. To cope with the above risk, some peak output of wind turbines and PV equipment may be curtailed. Although curtailment measure leads to the increase of wind and PV power generation cost, more wind and PV electricity can be integrated into distribution network. In order to balance the power supply cost and the penetration rate of wind and PV electricity, the principle of economic consumption is introduced. Then an optimization planning method considering wind and PV electricity curtailment measure is proposed, and a fast model solving method based on distribution network steady-state security region is proposed. The main work is as follows. Firstly, a maximum and minimum optimization planning model is established. The maximum optimization refers to the maximum consumption of renewable energy electricity during the operation scheme formulating. The minimum optimization refers to choosing the planning scheme with the lowest power supply cost. Secondly, steady-state security region of distribution network is used to solve the optimization model quickly. To the maximum optimization, the model is transformed into a linear programming model with the help of the security region linear expression in power injection space. To the minimum optimization, an initial solution formulation method based on the redundancy information of the system operation state is given, by which the initial solution is close to the final solution. Finally, a case study of the IEEE 33-bus system is carried out and proves the effectiveness of the method. It is found that under the principle of economic consumption, the penetration rate of renewable energy electricity can be effectively improved when suitable renewable electricity curtailment measure is taken