梯级水电站期末蓄能最大模型简化求解方法

A Simplified Solution Method for End-of-Term Storage Energy Maximization Model of Cascaded Hydropower Station

摘要: 梯级水电站期末蓄能最大模型求解复杂，采用拉格朗日松弛算法求解时需要对多个时段对应的乘子更新迭代，求解效率较低。本文为降低乘子规模大对模型求解造成的影响，提出了一种简化的求解方法。该方法首先将多个时段梯级总出力约束转换一个约束，利用凝聚函数法将该约束进行近似的转化，并建立只有一个乘子的对偶优化问题。而后采用次梯度法和逐次逼近法对简化后的新问题进行求解。以乌江梯级电站为背景的实例应用表明，提出的方法能有效降低问题复杂度，提高求解效率和求解质量，满足短期优化调度的时效性和实用性要求。

Abstract: The end-of-term storage energy maximization model of cascaded hydropower station is complicated to solve. Using Lagrange relaxation method directly, the solution efficiency is low for it involves the update iteration of large scale multiplier vector. In this paper, a simplified solution method is proposed in order to reduce the impact of the multiplier scale on the solution. The period cascade power constraints are replaced by one constraint. Then the new constraint is further approximated using the aggregate function and a dual optimization problem with only one multiplier is established. The sub-gradient method and successive approximation method are used to solve the new problem. Case study for Wu River cascaded hydropower system shows that the method can effectively reduce problem complexity, improve solution efficiency and solution quality, and satisfy the timeliness and practicality requirements of short-term optimal scheduling.