Comparative analysis of IEEE 112-B and IEC 34-2 efficiency testing standards using stray load losses in low voltage three-phase, cage induction motors

Author(s):  
A.T. de Almeida ◽  
F.T.E. Ferreira ◽  
J.F. Busch ◽  
P. Angers
2020 ◽  
Vol 11 ◽  
pp. 11-17
Author(s):  
Gabriel Nicolae Popa ◽  
Corina Maria Diniș

Low-voltage three-phase induction motors are most often used in industrial electric drives. Electric motors must be protected by electric and/or electronic devices against: short-circuit, overloads, asymmetrical currents, two-phase voltage operation, under-voltage, and over-temperature. To design the electronic protection currents, voltages and temperature must be measured to determine whether they fall within normal limits. The electronic protection was design into low capacity PLC. The paper presents the designs and analysis of complex electronic protection for general purpose low-voltage three-phase induction motors. The electronic protection has Hall transducers and conversion electronic devices for AC currents to DC voltages, AC voltages to DC voltage, temperature to DC voltage, a low capacity PLC, switches, motor’s power contactors, and signalling lamps has been developed. Experiments with complex electronic protection, for different faults are presented. The proposed protection has the advantages of incorporating all usual protections future for the low-voltage three-phase induction motors.


2020 ◽  
Vol 21 (1) ◽  
pp. 1-8
Author(s):  
Yesenia Reyes Severiano ◽  
Jesús Aguayo Alquicira ◽  
Susana Estefany De León Aldaco ◽  
Luis Mauricio Carrillo Santos

Currently, induction motors are widely used in industry because have a high potential for the efficiency improvement. Therefore, a topic of interest to the industry is to reduce the energy consumption of induction motors, as they represent almost half of the total electrical energy consumption in the world. The energy consumption of electric motors can be reduced by using motors that are more efficient and by using power converters to feed the motors, thereby enabling accurate control according to the load. The function of the power converter is to modify the intrinsic characteristics of the induction motor (speed and torque). There are different topologies of the power converter commonly called inverter for induction motors. An inverter requires a modulation strategy for its operation, there are several modulation strategies that are used in the induction converter-motor assembly. This paper presents the comparative analysis of the influence of the phase disposition modulation (PD-PWM) strategy with different modulation indices, on parameters related to the output signal of a seven-level cascaded multilevel inverter as well as on the nominal working conditions of a three-phase induction motor.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7130
Author(s):  
Marcel Torrent ◽  
Balduí Blanqué

This work shows the results obtained from studying the influence of equivalent circuit resistances on three-phase induction motors. The stator resistance, rotor resistance, and iron losses resistance affect the different motor operating variables (output power, current, speed, power factor, starting ratios, and maximum torque). These influences have been quantified, paying particular attention to the losses affected and their impact on efficiency. The study carried out does not apply optimization techniques. It evaluates the different influences of the equivalent circuit’s different resistances on its operation by evaluating applicable constructive modifications concerning available motors. The work has been limited to three-phase induction motors up to 50 kW and low voltage, with the nominal powers of the selected motors being 0.25 kW, 1.5 kW, 7.5 kW, 22 kW, and 45 kW. The tools used to carry out the study are analyzing the equivalent circuit and the simulation of the electromagnetic structure using a finite-element program. The variations proposed in each resistance for all the motors studied is not purely theoretical, as it is based on applying feasible constructive modifications, appropriately analyzed and simulated. These modifications are the variation of the conductor diameter in the stator coils, the change of the section of the rotor cage, and the selection of different ferromagnetic steel types.


Sign in / Sign up

Export Citation Format

Share Document