A new exact equivalent circuit of the medium voltage three-phase induction motor

Abstract

This paper proposes a new equivalent circuit for medium voltage and great power induction motors considering the more complete information given by the manufacturer. A methodology for obtaining the parameters of the equivalent circuit is presented, having this circuit the advantage of allowing the electrical calculation of all the power losses and the realization of the power balance. It is an achievement of this work a new way of calculating and representing the additional losses using a resistance located in the rotor circuit. Then, three types of losses are considered as a part of a power balance: the conventional or joule effect variable losses, the constant losses, and the additional losses. The proposed method is straight and non-iterative. It was applied to a case study motor of 6000 V and 2500 kW located at the Maximo Gomez Power Plant in Cuba.

A universal model of three-phase asynchronous motors for electrical power system analysis

“…That is, a 6000 V, 2500 kW, 60 Hz, 2-pole medium voltage motor which drives the feed pump with a variable torque load of a power plant. Figures 3 and 4 show the active and reactive power as a function of voltage, considering both the universal model and the exact equivalent circuit solution obtained in [20]. To demonstrate the model's validity as a function of frequency, Figure 5 compares the characteristic obtained with the universal model and that obtained from the equivalent circuit of [20].…”

“…To validate the model, the data of [20] are used. That is, a 6000 V, 2500 kW, 60 Hz, 2-pole medium voltage motor which drives the feed pump with a variable torque load of a power plant.…”

“…Figures 3 and 4 show the active and reactive power as a function of voltage, considering both the universal model and the exact equivalent circuit solution obtained in [20]. To demonstrate the model's validity as a function of frequency, Figure 5 compares the characteristic obtained with the universal model and that obtained from the equivalent circuit of [20]. As can be seen in Figures 3, 4, and 5, the errors are less than 6% for the admissible voltage values (±10%).…”

“…This method requires knowledge of the parameters of the circuit, which almost any manufacturer does not offer. This makes it necessary to model the TAM to use other software to calculate these parameters [18]− [20] or to incorporate it into the electrical network analysis software [21].…”

MATLAB/Simulink modeling of electric motors operating with harmonics and unbalance

“…These power quality issues significantly affect the operational behavior of the EMs [13], [14]. Due to the energetic importance of EMs, it is crucial to develop simulation models that allow analyzing the effects of power quality on electrical and mechanical parameters and the efficiency of EMs [15]. Some studies that develop simulation models for the analysis of EMs.…”