基于混合注入模型的光伏并网潮流计算研究

Research on Power Flow Calculation of Hybrid Injection Model Based on PV Grid-connected Power System

首先提出将光伏电站计入网络参数的潮流计算策略,充分考虑光伏电站及电网的相互影响,通过一次计算同时得到光伏电站、电网两部分的潮流结果。针对光伏电站并入输电网问题,提出光伏电站网络化简策略,减少网络节点增加个数,减小雅克比矩阵增大规模。求解潮流时,提出基于电流/功率混合注入模型的牛顿-拉夫逊(N-R)潮流算法。该算法既继承了常规电流注入模型迭代时,雅克比矩阵PQ节点分块矩阵的非对角元素恒定不变的优点,又降低了雅克比矩阵的规模,节省存储空间。针对混合注入模型的混合坐标问题,提出坐标转换策略,将潮流方程右侧均转换到同一坐标下,使潮流方程变得整齐,程序编写方便。最后,从青海某光伏电站中选出4路光伏阵列并网线路接入IEEE30节点系统,基于其实际参数,进行并网潮流计算,验证了本文算法的可行性。

A power flow calculation strategy with network parameters of PV stations is put forward, the interaction be- tween PV station and power grid is taken into consideration, and power flow results of PV station and power grid are ob- tained through once calculation. As for PV grid-connected power grid, PV station network simplification strategy is proposed to decrease network nodes and to reduce the scale of Jacobian matrix. When solving power flow equations, a N - R power flow calculation algorithm is put forward based on current/power hybrid injection model, which not only inherits the advantage that the non-diagonal elements of PQ node block in Jacobian matrix keeping constant during the iteration of the conventional current injection model, but also reduces Jacobian matrix scale, which save the storage space. By considering of the h.ybrid coordinate issues of hy- brid injection model, a coordinate conversion strategy is presented to convert the right parts of power flow equations to those in same coordinate, which make the power flow e- quations more orderly and more convenient to encode pro- grams. In the end, by taking the IEEE30 system with a 4 PV arrays from a certain PV station in Qinghai is used as exam- ple, power flow calculation is performed based on the actual parameters to the feasibility of proposed algorithm.