基于改进熵的风光储互补并网系统优化运行

摘要

High-capacity wind-solar-battery hybrid power system provides a referable generating mode for high permeability intermittent energy connected to grid in the future. Compared with separate photovoltaic or wind power generation, the hybrid wind-solar-battery power generation system can make up the defect of uneven distribution of natural resource based on the complementary characteristics of wind and solar resources. Configuring energy storing device with appropriate capacity to stabilize fluctuation, the output power is managed uniformly by energy management system to realize the wind power and solar energy’s storage and release, and decrease the output power fluctuation. A measurement index is proposed based on improved entropy which is developed in the index of traditional standard deviation. Battery’s charge-discharge power in every moment is scheduled in a cycle to make the output power minimum. A case study is presented to verify that the index of improved entropy’s valley-to-peak is smaller than the situation of simply considering the standard deviation, and the fluctuation is small, so the spinning reserve capacity is reduced.%大容量风光储联合发电系统为未来高渗透率间歇性能源并网发电提供了一个可参考的发电模式，利用风电和太阳能时间上的互补性，弥补了风电和光伏独立系统在自然资源分布不均的缺陷，再配置适当容量的储能设备来平抑波动，通过风光储能量管理系统的统一调度管理，实现对随机性较大的风能与太阳能的存储与释放，使其输出功率波动减小。在传统的以标准差为指标衡量系统波动性基础上，提出基于改进数学熵的衡量指标，在运行周期内优化调度每时刻蓄电池充放电功率，使得输出功率波动性最小。算例表明基于标准差基础上的改进数学熵的衡量指标比单纯的考虑标准差时的峰谷差更小，波动性更小，从而减少系统旋转备用容量。