计及储能运行特性的独立型交直流混合微网优化调度

针对独立型交直流混合微网提出了计及储能运行特性的优化调度模型。由于储能损耗与荷电状态(SOC)之间呈现非线性关系,为准确计算储能损耗成本并简化优化模型的求解,首先提出利用一次函数近似表示储能的非线性损耗特性。储能的始末SOC会影响其充放电能力,考虑将初始SOC作为优化变量以搜寻最优值,提高微网运行的经济效益。然后,算例分析表明所提储能损耗模型的准确性较高,优化问题转化为二次规划后求解速度快。优化初始SOC能够最大化发挥储能转移电量的能力,减少独立微网的弃风、弃光及切负荷现象。最后,分析结果验证了优化调度模型的合理性和有效性。

Optimal Scheduling for Independent AC/DC Hybrid Microgrid Considering Operation Characteristics of Energy Storage

An optimal scheduling model for independent AC/DC hybrid microgrid considering operation characteristics of energy storage(ES)is proposed. Due to the nonlinear relationship between ES loss and state of charge(SOC), a method using linear functions to approximate the nonlinear characteristics of ES loss is raised in order to calculate ES loss cost accurately and solve the optimal model simply. Initial/final SOC of ES can affect its charging and discharging capability, thus initial SOC acts as an improved variable to search the optimal value, which can improve the economic benefits of microgrid operation. Then, a case study shows that proposed ES loss model is more accurate and the solution is accelerated after transforming the optimal problem into a quadratic programming problem. Optimization of initial SOC can maximize the ability of transferring electricity for ES, and reduce the phenomena of abandoning wind/solar energy and shedding loads in isolated microgrid. Finally, results verify the rationality and validity of the optimal scheduling model.