Simulation Model of an Asynchronous Machine with Wound Rotor in Matlab Simulink

The article presents a three-phase mathematical model of asynchronous machine with wound rotor based on differential equations. The equations are resolved with respect to the derivatives of flux linkages. The description of the computer program in the Matlab Simulink that implements the model and allows to simulate transients of the asynchronous motor is present. A simulation model of a three-phase asynchronous machine with wound rotor, which allows to investigate static and dynamic operating ranges when power converters are connected to the rotor circuit has been obtained. The results of approbation of the obtained simulation model in the Matlab Simulink environment and experimental research of asynchronous engine with wound rotor, driving into the asynchronous-valve cascade, are presented. The results of experimental studies of the asynchronous machine under sinusoidal voltage using a stand based on the asynchronous-valve cascade, and comparison of the oscillograms obtained with simulation results of the proposed model are presented. The comparison of experimental and calculated oscillograms of the current of the investigated asynchronous motor can be concluded on satisfactory accuracy of the proposed model and the possibility of its application for modeling and analysis of asynchronous electric drives

Development of a Method and Algorithm for Inhibiting an Automatic Transfer Switch of the Circuit Breaker for a Sustained Short-Circuit

Circuit breakers with automatic transfer switches (ATS) are designed in such a way that when the voltage disappears during a short-circuit (SC) in the ring network line, the ATS device is triggered. At the same time, its switch is turned on at short-circuit, then it is turned off with acceleration. Even a shortterm switching on of the automatic transfer switch for a sustained short-circuit leads to emergency situations [1,2]. The electrical equipment of the ring network spare line is exposed to high emergency short-circuit currents, and the consumers powered by the spare transformer are turned off. It is possible to minimize and eliminate the damages caused by the above mentioned cases by inhibiting the switching on of the circuitbreaker of the automatic transfer switch