Control of production operations is one of the most cost-effective methods to improve energy efficiency in production lines. Although many research efforts have been devoted to utilizing production control to boost production energy efficiency, it is not clear how production dynamics change in reaction to the energy saving operations, which is important to capture energy saving opportunities. In this paper, an optimal energy saving control method based on N-policy is introduced to reduce the system energy consumption while only slightly decreasing productivity. A Markov chain model is established to interpret the dynamics of serial production lines with N-policy. The analytical formulas of production rate and energy consumption are derived. Then, an energy-efficient control model is formulated to balance the productivity and energy consumption. For two-machine production lines, the monotonicity property of the model is proved, and the analytical N-policy is derived. For longer production lines, an adaptive genetic algorithm is utilized to solve the energy-efficient control model. Case studies validate the effectiveness of the proposed optimal energy saving control method.

控制生产操作是提高生产线能源效率的最经济有效的方法之一。尽管许多研究工作致力于利用生产控制来提高生产能效，但尚不清楚生产动态如何响应节能操作而发生变化，这对于抓住节能机会很重要。本文介绍了一种基于N策略的最优节能控制方法，可以在降低系统能耗的同时仅略微降低生产率。建立了马尔可夫链模型来解释具有N策略的批量生产线的动态。推导了生产率和能耗的解析公式。然后，建立了节能控制模型以平衡生产率和能耗。对于两机生产线，证明了该模型的单调性，并推导了解析的N策略。对于更长的生产线，采用自适应遗传算法求解节能控制模型。案例研究验证了所提出的最佳节能控制方法的有效性。