改进整数变量辨识方法在机组组合问题中的应用

如何辨识待定整数变量,是机组组合问题中的难点,为此在综合考虑机组不同出力水平对成本的影响、系统时段耦合、系统备用以及网络安全等约束的情况下,提出了待定整数变量辨识方法.首先对各线性化目标函数进行安全约束机组组合松弛计算,根据所得结果按给定规则确定所有在全时段机组状态出现启停的机组集合,有效缩小了机组组合的寻优空间.在不影响最优解的前提下,利用负荷曲线特异性截取技术,加速了待定整数集合识别过程,提高了计算效率.算例结果验证了该方法的有效性

Application of the Improved Method to Identify Integer Variables in Unit Commitment

It is a difficult point in unit commitment problem to identify integer variables,therefore under the situation of taking the influences of different output levels of units on generation cost,ramping constraints,system capacity reserve and security constraints of power network into account a method to identify the undetermined integer variables is proposed.Firstly,relaxation calculation of security-constrained unit commitment for each linearized objective function is performed,and based on the calculation results and according to the given rule the unit sets in which the start-up/stop of units occur within the whole time intervals are determined to effectively downsize the search space of unit commitment.Under the presupposition that the optimal solution is not affected,the identification process of undetermined integer sets is accelerated by use of load curve specifically truncated(LCST) to improve the computational efficiency.The effectiveness of the proposed method is verified by results of IEEE 9-machine 30-bus system and IEEE 54-machine 118-bus system.