变电站容量和DG置信容量概率规划

针对基于主变“N-1”安全准则或给定容量比确定变电站容量存在的问题,采用概率规划方法,基于总费用最小建立了涉及DG的变电站容量优化简化模型:目标函数考虑了变电站容量投资和停电损失费用;约束为相关配电网规划导则中推荐的主变容量及其组合。其中,通过多场景概率分析法建立了DG的多状态出力模型;提出了较小供电区域内一般仅需对不同类型DG状态进行组合来考虑分布式电源出力的相关性。考虑到实际变电容量的离散性,模型采用枚举法进行求解。基于模型求解获得的变电站优化容量,定义了两类DG变电置信容量,将传统的DG变电置信容量评估转换成了基于变电站优化容量的DG变电置信容量计算。算例表明了概率规划对于变电站容量选择的意义以及DG对变电站容量的替代作用。

Probabilistic Planning of Substation Capacity and Capacity Credit of Distribution Generators

To solve the problem of determining substation capacities based on main transformer "N-1" safety guidelines or given capacity-load ratio, a simplified model of substation capacity optimization involving DG is established based on minimum total cost by using a probabilistic planning method. The objective function considers the investment of substation capacity and the cost of outage loss. Constrains include the recommended capacity of main transformer and its combination in relevant distribution network planning guidelines. The multi-state output model of DGs is established by multi-scenario probability analysis method, and the correlation of DGs output is considered only by combining different types of DGs states in a small power supply area. The model is solved by enumeration method considering the discreteness of the actual transformer capacity. Two types of DG substation capacity credit are defined based on the optimal capacity of substation obtained by solving the model, therefore the traditional evaluation problem is transformed into the calculation of DG substation capacity credit based on the optimal substation capacity. The numerical examples show the significance of probabilistic substation capacity planning and the substitution effect of DGs for substation capacities.