Assessing Voltage Unbalance Conditions in IE2, IE3 and IE4 Classes Induction Motors

Abstract

Brazil has started an energy transition process through more efficient electric motors. The new legislation determining the IE3 Class as the minimum efficiency level in commercial electric motors became valid in August 2019. Currently, four induction motor classes are defined by the IEC 60034-30-1, with the IE4 class being the most efficient, and in the same way, proposals to achieve IE5 efficiency class are available in the market. Considering the upcoming new technologies, it is necessary to know the impact of power systems disturbances in IM's in view of future substitutions. This paper presents a detailed analysis of the impact of different percentages of under and over voltage unbalances on the temperature and performance of electric motors classes IE2, IE3 and IE4. Results show that the IE4 hybrid motor presents non-linear characteristics, being observed this motor shows less dependence on voltage variation, mainly undervoltage unbalance. An analysis of how this phenomenon impacts on the current harmonic distortions in the induction motors operation is also developed through Spearman's correlation matrices. Finally, models that represent the temperature increase of each motor with different voltage unbalance conditions are presented.

Assessing Energy Efficiency and Power Quality Impacts Due to High-Efficiency Motors Operating Under Nonideal Energy Supply

“…Electric motors are also a load sensitive to voltage unbalance, which can also be accompanied by voltage magnitude variations. Studies relating both phenomena and their negative impacts on electric motor's torque, power factor, and efficiency have been presented in [14], [16], [26]- [32].…”

“…The simulation and validation have also been presented in [36], [37], where it is observed how the presence of voltage unbalance results in increases in losses and consequently a reduction in the useful life of the motor. The impact of voltage unbalance and harmonics in the electrical power systems and equipment has been presented in [20], [21], [38]- [40], where equipment malfunction, temperature increases, and reduction of useful life are the most considerable impacts, while those related to the impacts on power quality have been presented in [15], [16], [38].…”

“…FIGURE 5. Cost-benefit-impacts relation for efficient motors: (a)Technical (power quality) and economical comparison for IE2, IE3, and IE4 class motors and (b) quantitative comparison in economic and technical terms[16] …”

Three-Phase Induction Motors Online Protection against Unbalanced Supply Voltages

“…On the other hand, the VUF provides better physical interpretation of the cause of voltage unbalance, and it is more useful in the prediction and analysis of the USV effects on electrical machines. A deep literature review shows that most of the published papers were focused on the study of the USV effects on the IMs performance in terms of speed, torque, current losses, power factor, and efficiency [13,[15][16][17][18][19]. However, the online detection of the USV is not very much reported.…”

Analysis of influencing factors affecting the operational reliability of low-voltage asynchronous electric motors

“…В условиях реальной работы электродвигателей, в зависимости от различных факторов, имеет место значительное отклонение от номинальных режимов эксплуатации. Как показывают исследования и многолетний опыт эксплуатации [3][4][5][6][7][8][9], на срок службы электродвигателей оказывают влияние климатические, электромеханические факторы внешней среды, более 50% электродвигателей работают в условиях, параметры которых значительно отличаются от нормированных по ГОСТ Р 51137-98 «Электроприводы регулируемые асинхронные для объектов энергетики», ГОСТ IEC 60034-1-2014 «Машины электрические вращающиеся. Номинальные значения параметров и эксплуатационные характеристики».…”