Abstract

The article discusses the interrelated electromechanical processes in asynchronous machines when testing by the loading-back method with energy recovery in the network. We analyze a system of two asynchronous machines connected by a common shaft, in which one machine operates as an engine with the voltage supply of increased frequency from the frequency converter and the external machine operates as a network generator. Electromechanical processes in machines have an influence on each other. We have carried out the simulation of electromechanical processes in the motors with allowance for several factors—namely, different degrees of saturation of magnetic cores, torque equalization, and the change in parameters of the windings when changing the operating mode with a nonsinusoidal voltage supply to the asynchronous motor from the frequency converter. A modeling technique with mutual matching of the electromagnetic field models of machines through the relationship of torques on the shaft, based on system minimization of the electromagnetic energy functionals has been presented. The results of simultaneous numerical calculations of interrelated electromagnetic fields in machines and electromechanical processes have been presented. The calculations of electromechanical processes and the characteristics of an asynchronous motor–generator system with a common shaft, mutual load and energy recovery in the network have been performed. The results of experimental studies of a two-machine unit are presented, confirming the theoretical results. It is established that the application of the calculation technique with direct computing the interrelated electromagnetic fields in the engine and generator with allowance for the electromagnetic torque on the shaft provides an error of no more than 7% compared with the experiment.

中文翻译：

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网络中采用能量回收的后备式方法分析异步电机的测试过程中的机电过程

摘要

本文讨论了通过网络中的能量回收的装回方法进行测试时异步电机中相互关联的机电过程。我们分析了一个由公共轴连接的两台异步电机的系统，其中一台电机作为发动机运行，并由变频器提供增加的频率，而外部电机作为网络发电机运行。机器中的机电过程会相互影响。我们对电动机中的机电过程进行了仿真，并考虑了多个因素，即磁芯的饱和度不同，转矩均衡，以及在通过变频器向异步电动机提供非正弦电压的情况下更改运行模式时绕组的参数变化。基于电磁能量功能的系统最小化，提出了一种通过轴上转矩关系相互匹配机器电磁场模型的建模技术。提出了在机器和机电过程中相互关联的电磁场的同时数值计算结果。进行了机电过程的计算以及具有公共轴，互负载和网络中能量回收的异步电动发电机系统的特性。给出了两机单元的实验研究结果，确认理论结果。可以确定的是，直接计算发动机和发电机中相关电磁场并允许轴上电磁转矩的计算技术的应用与实验相比，误差不超过7％。