周期性变工况条件下异步电机节能机理和节能途径

Energy Saving Theory and Approach for Asynchronous Motor Under the Periodically Variable Running Condition

对于周期性变工况运行的异步电机,调速难以保证负荷的周期性,使调压节能成为优选方案,又考虑到效率的概念不适合于发电工况的能耗分析,因此以总损耗最小为目标研究调压节能的机理,并对比分析多种节能途径。按照不变损耗和可变损耗新的划分方式得到相应的损耗计算方法;据此,根据给定的转矩曲线,能方便地得到总损耗最小所对应的最优电压曲线,进而提出由现场在线可测输入量求得各种工况下最优电压的方法。对包括断续供电节能在内的几种动态节能途径进行了综合讨论和对比,通过对典型周期性变工况的抽油机电动机的仿真和实测,分析了几种节能途径的效果和适用性。

For motors working on periodically variable running condition, the speed regulation approach is difficult to ensure periodicity so that the voltage regulation became a preferable scheme. Since the concept of efficiency is not appropriate for the loss analysis of generating running condition of generation, the minimum total loss is taken as the optimal objective for voltage regulation method which is analyzed and contrasted with several other energy saving approaches. First the new total losses calculation method is implemented by means of the classification of variable loss and invariable loss. Hereby, the optimal voltage curve corresponding to the minimum total losses could be conveniently obtained according to the given torque curve. Then the calculation and implementing method for optimal voltage under every running condition are put forward by use of on-line measured field input quantities. Finally, Several energy saving approaches including for intermittent power supply are comprehensively discussed and compared with the optimal voltage curve. The simulation and field test on beam pump unit show the effect and applicability of these approaches.