含DFIG风电场电-气耦合系统的概率连续混合潮流方法及其负荷裕度分析

针对含双馈感应式风机(DFIG)风电场电-气耦合多能流系统的最大负荷裕度及其耦合影响问题，考虑天然气管网的动态特性，建立考虑DFIG稳态模型和能源路由器(EH)的含参连续混合潮流模型；采用随机响应面法(SRSM)拟合DFIG出力，结合预估-校正及电-气系统耦合交替迭代获取电力系统负荷节点的有功功率-电压曲线、天然气系统流量-气压曲线及其负荷裕度期望值；定义电压-负荷、气压-流量灵敏度，可分别跟随电力系统负荷节点有功功率-电压曲线、天然系统气流量-气压曲线的获取，定义电-气耦合环节中天然气系统节点压强-EH节点注入电功率和电力系统节点电压-EH节点天然气注入流量灵敏度，从而定量评估电-气耦合下电力系统、天然气系统和电-气耦合环节的薄弱节点及EH耦合程度。含DFIG风电场的IEEE 14节点电力系统和22节点天然气系统通过11个EH耦合而成的电-气系统的算例仿真结果验证了所提模型、算法和所定义负荷裕度灵敏度指标的正确性和有效性。

Probabilistic continuous hybrid flow method for electricity-gas coupling system integrated with DFIG wind farm and its load margin analysis

Aiming at the problems of the maximum load margin and its coupling effect of the electricity-gas coupling multi-energy flow system integrated with DFIG(Doubly-Fed Induction Generator)-based wind farm, based on the dynamic characteristics of natural gas pipeline network, the continuous hybrid flow models with parameters are established considering DFIG steady-state model and EH(Energy Hub). The SRSM(Stochastic Response Surface Method) is used to fit the output of DFIG, combining prediction-correction and the alternate iteration of electricity-gas coupling system, the active power-voltage curves of the electric po-wer system load nodes, the natural gas flow-gas pressure curves of natural gas system and their expected load margins are obtained. The voltage-load sensitivity and gas pressure-natural gas flow sensitivity are defined, which can be obtained with the active power-voltage curve of the electric power system load node and the natural gas system flow-gas pressure curve of natural gas system respectively. In the electricity-gas coupling link, the sensitivities of natural gas system node pressure-injection electric power of EH node and the electric power system node voltage-natural gas injection flow of EH node are defined, based on which, the EH coupling degree and the weak nodes of electric power system, natural gas system and electricity-gas coupling link can be evaluated quantitatively. Simulative results of the electricity-gas coupling system, coupling with the IEEE 14-bus system with DFIG-based wind farm and the 22-node natural gas system through 11 EHs, verify the correctness and effectiveness of the proposed model, algorithm and the defined load margin sensitivity indexes.