考虑了电力系统和天然气系统之间存在燃气发电机和电机驱动压缩机的耦合，建立了电 － 气混合系统安全约束最优能量流计算模型。模型以混合系统的总运行成本，即燃煤发电机组发电消耗燃煤的成本和天然气网从气源消耗天然气的成本之和为目标函数，同时考虑了电力系统和天然气系统中多个 N-1 故障的安全约束。首先，通过计及电力系统和天然气系统间交易的影响，对原优化模型的目标函数进行分离，并采用一阶泰勒级数展开，分别实现了对燃气发电机和电机驱动压缩机的耦合特性方程的线性化，使得可采用同步型交替方向乘子法 (ADMM) 对安全约束最优能量流计算模型进行分布式求解; 然后采用 GAMS 软件中的 CONOPT 求解器分别对电力系统和天然气系统的最优能量流进行求解; 最后以修改的 IEEE39 节点电力系统与比利时 20 节点天然气系统构成的电 － 气混合系统为例，对所提出的模型和求解算法的正确性和有效性进行了验证，计算结果表明所提出的模型和求解算法正确有效。

A security-constrained optimal energy flow calculation model for integrated power and gas energy sys-tems (IPGES) was established，considering the coupling of gas generators and motor driven compressors between power system and natural gas system． The model takes the total operating cost of the IPGES，that is，the sum of the cost of coal consumption by coal-fired generating units and the cost of natural gas consumption by gas sources of natural gas networks，as the objective function，and the security constraints of multiple N-1 contingencies in power systems and natural gas systems were considered． Firstly，the objective function of the original optimization model was divided by considering the influence of the transaction between the power network and the natural gas network．And the coupling equations of the gas generators and the motor-driven compressors were linearized by the first-order Taylor series expansion，respectively． Thus makes it possible to use the synchronous alternating direction multipli-er method (ADMM) for distributed solution of security-constrained optimal energy flow calculation model． Then the CONOPT solver in GAMS software was used to solve the optimal energy flow of power system and natural gas
system，respectively． Finally，the modified IEEE-39 bus power system and Belgium 20-bus natural gas system were taken as an example to validate the proposed model and solution algorithm． The results show that the proposed model and algorithm are correct and effective．