中文摘要：

为降低大规模风电场群对电网爬坡速率的需求,研究水电站配合燃气电站共同缓解风电时段间波动的问题。定义出力波动频率作为系统输出波动性的衡量指标以避免较为保守的容量配置结果,进而建立考虑出力波动频率的风- 水-燃气系统随机最优设计模型,利用风电波动的概率密度函数,优化水电调节速率及燃气电站额定功率,使得水电调节成本、燃气电站建设成本及期望燃料费用最小。为有效求解该模型,设计马尔可夫稳态分析方法,得到了出力波动频率及期望燃料费用的解析计算式。结果表明：当水电站提供一定调节能力时,为风电场配备其装机容量12%左右的燃气电站可以96%的概率实现联合出力无波动且成本增加不大;稳态方法求解时间短且精度较高。

英文摘要：

In order to reduce the ramping capacity required by large-scale wind farms, both hydro and gas station were used to mitigate the stochastic fluctuation of wind power. Fluctuation frequency was defined as the index of joint output fluctuation, and was used to avoid capacity redundancy. Mathematical model of wind-hydro-gas system design was established with fluctuation frequency. Hydro regulation rate and gas station capacity were co-optimized with the objective of hydro regulation cost, gas investment cost and expected fuel cost minimization using the probability density function of wind power fluctuation. Markovian steady-state analysis was proposed to solve efficiently. Analytical expressions of fluctuation frequency and expected fuel cost were obtained. Numerical results show： when a certain hydro regulation rate is provided, the non-fluctuation frequency can achieve 96% with a little cost increment and a gas station capacity of about 12% wind farm capacity; the proposed steady-state analysis method is fast and accurate.