基于无功优化的DFIG并网电力系统OSC-OPF算法

Oscillatory Stability Constrained Optimal Power Flow Algorithm Based on Reactive Power Optimization for DFIG Integrated Power System

双馈感应发电机(DFIG)与同步发电机(SG)间动态交互,影响系统阻尼振荡能力。由于系统状态矩阵由SG和DFIG参数决定,推导振荡模式对受控参数灵敏度的难度增加。针对含DFIG的电力系统,为量化无功调节对阻尼振荡的控制效果,提出阻尼比对SG无功出力灵敏度的解析表达。引入最小阻尼比约束,提出基于无功优化的振荡稳定约束最优潮流(OSC-OPF)模型。根据OSC-OPF拉格朗日乘子,提出稳定约束下网损对SG无功容量的灵敏度。仿真结果证实,所提模型有助于降低风电系统网损并改善其阻尼振荡能力。

The dynamic interaction of synchronous generators(SGs) and doubly-fed induction generators(DFIGs) changes the damping oscillation capability of the system. The system state matrix is decided by the parameters of the SGs and the DFIGs,which increases the difficulty of deriving the sensitivity of the oscillation modes to the control parameters. For the power system with the DFIGs, to quantify the control effect of reactive power adjustment on damping oscillation, the analytical expression of the sensitivity of the damping ratio to the reactive power output of the SGs is proposed. By introducing the constraint of the minimum damping ratio, the oscillatory stability constrained optimal power flow(OSC-OPF) model based on reactive power optimization is proposed. According to the Lagrange multiplier of the OSC-OPF, the sensitivity of the power loss to the reactive power capacity of the SGs under the stability constraint is proposed. The simulation results show that the proposed model helps to reduce the power loss and improve the damping capability of the wind power system.