Operation of an induction motor supplied by voltage containing subharmonics

2017 ◽  
Vol 1 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Tomasz Drabek
Keyword(s):  
Induction Motor ◽  
Power Supply ◽  
Induction Machine ◽  
Induction Machines ◽  
Positive Sequence ◽  
Rotor Speed ◽  
Phase Voltage ◽  
Negative Sequence ◽  
Three Phase

The paper discusses the effects of the presence of subharmonics (i.e. frequencies lower than the basic 50 Hz) in the voltage supplying the induction machine. Subharmonics in a three-phase grid are the result of the oscillations of peak values of the voltages. In induction machines, this results in the subharmonic and interharmonic currents, the generation of alternating moments, the increase in the rms value of the current of the fundamental harmonic and the oscillations of the rotor speed. In the paper is derived expression on the thermally acceptable load of the motor (by torque and power), in the case of supplying it by three-phase voltage containing a positive sequence of subharmonics. It presented the obstacles to derive the analogical expression for power supply containing a negative sequence of subharmonics.

Operation of an induction motor supplied by voltage with interharmonics

2018 ◽  
Vol 2 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Tomasz Drabek
Keyword(s):  
Induction Motor ◽  
Fundamental Frequency ◽  
Skin Effect ◽  
Induction Machines ◽  
Positive Sequence ◽  
Rotor Speed ◽  
Negative Sequence ◽  
Three Phase ◽  
Total Multiplicity ◽  
Rotor Cage

The paper discusses the effects of interharmonics, i.e. frequencies higher than the fundamental frequency, not being its total multiplicity, in the voltage supplying the induction motor. The emergence of interharmonics in a three-phase grid is mainly the result of the swinging of peak mains voltages. In induction machines, this results in the occurrence of currents with interharmonic and subharmonic frequencies, the generation of alternating moments, the swinging of the rotor speed and the change in the RMS value of the current of the fundamental frequency. The paper explores these phenomena simulation, taking into account the skin effect of currents in the rotor cage. The research was carried out both for interharmonics with a positive sequence of phases as well as for the negative sequence. The paper is a continuation of work [1].

Experimental Analysis on the Operating Performance of Induction Motor with Unbalance Power Supply Conditions

2014 ◽  
Vol 635-637 ◽  
pp. 1404-1407
Author(s):  
Yuan Xing Zhang ◽  
Fei Li ◽  
Ya Li Shen ◽  
Lei Juan Yang ◽  
Jie Li ◽  
...  
Keyword(s):  
Induction Motor ◽  
Power Supply ◽  
Power Efficiency ◽  
Single Phase ◽  
Reactive Power ◽  
Phase Voltage ◽  
Three Phase ◽  
Unbalanced Voltage ◽  
Negative Sequence Current ◽  
Domestic Appliances

Problems of power quality have been increasingly concerned by the researchers, as the domestic appliances we are usually used are single-phase load, which mainly causes the unbalance of three-phase voltage of power supply. If the induction motor is supplied by three-phase unbalanced voltage, the currents, active and reactive power, efficiency, and losses are affected as the negative-sequence current appears, this paper is emphasized on the induction motor’s characteristics when its’ power supply is three-phase unbalanced voltage by experimental research.

scholarly journals A rapid harmonic detection method for grid-connected photovoltaic when three-phase voltage is unbalanced

2021 ◽  
Author(s):  
Tiezhou Wu ◽  
An Wang ◽  
Yawen Xu
Keyword(s):  
Phase Angle ◽  
Detection Method ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Phase Voltage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Negative Sequence ◽  
Three Phase ◽  
Low Pass

Abstract By using power electronic devices, photovoltaic grid-connected power generation may inject harmonics into the power system. As the photovoltaic grid-connected inverter has the same basic structure as the active power filter, so the unified control of the photovoltaic grid and active filtering can be achieved. When the current unified control system compensates harmonics of the grid side, it mainly uses ip-iq harmonic detection method, which is based on instantaneous reactive power theory. When the three-phase voltage is unbalanced, the method has a large voltage phase angle detection error and the signal of the low-pass filter tracking system is long, detection time delay and even failure occur. This paper proposes an improved fast harmonic detection method. When phase deviation or amplitude change occurs to the three-phase voltage, the positive and negative-sequence voltages are simultaneously park transformed. The negative-sequence component is filtered by the current average module to obtain the fundamental amount of the voltage, then the phase angle of the positive-sequence voltage is accurately calculated to improve the harmonic current detection accuracy. Through the study of the integral method, it is found that the least common multiple of each harmonic period can be used as the integral interval, and the integral value is also zero, so the detection delay time is reduced by replacing the low-pass filter with an integration module. The simulation results show that the proposed harmonic detection algorithm can accurately detect harmonics when the three-phase voltage is unbalanced, and about 0.057 s improve the harmonic detection speed compared with the commonly used ip-iq method.

scholarly journals Unbalanced Voltages Impacts on the Energy Performance of Induction Motors

2018 ◽  
Vol 8 (3) ◽  
pp. 1412 ◽  
Author(s):  
Enrique C. Quispe ◽  
Iván D. López ◽  
Fernando J. T. E. Ferreira ◽  
Vladimir Sousa
Keyword(s):  
Induction Motor ◽  
Induction Motors ◽  
Energy Performance ◽  
Positive Sequence ◽  
Negative Sequence ◽  
Voltage Unbalance ◽  
Three Phase ◽  
Motor Load ◽  
Sequence Parameters

<p class="Abstract">This paper presents the results of a study about the effects of unbalanced voltages on the energy performance of three-phase induction motors. The principal contribution of this paper is that presents a detailed analysis of the influence of positive and negative sequence voltage components and the angle between them on several characteristics such as: line currents, losses, efficiency and power factor under different voltage unbalanced conditions. A three-phase induction motor of 3 HP was used as a case study. The results of the investigation show that the positive sequence voltage must be considered together with the voltage unbalance factor (VUF) or percent voltage unbalance (PVU) index to evaluate the performance of the induction motor. It is also shown that the behavior of the motor load influences on the positive sequence parameters next to the voltage, while in the case of negative sequence only influences the negative sequence voltage.</p>

scholarly journals Induction Motor Stator Interturn Short Circuit Fault Detection in Accordance with Line Current Sequence Components Using Artificial Neural Network

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Gayatridevi Rajamany ◽  
Sekar Srinivasan ◽  
Krishnan Rajamany ◽  
Ramesh K. Natarajan
Keyword(s):  
Neural Network ◽  
Fault Detection ◽  
Induction Motor ◽  
Short Circuit ◽  
Positive Sequence ◽  
Negative Sequence ◽  
Three Phase ◽  
Sequence Components ◽  
Negative Sequence Current ◽  
Short Circuit Fault

The intention of fault detection is to detect the fault at the beginning stage and shut off the machine immediately to avoid motor failure due to the large fault current. In this work, an online fault diagnosis of stator interturn fault of a three-phase induction motor based on the concept of symmetrical components is presented. A mathematical model of an induction motor with turn fault is developed to interpret machine performance under fault. A Simulink model of a three-phase induction motor with stator interturn fault is created for extraction of sequence components of current and voltage. The negative sequence current can provide a decisive and rapid monitoring technique to detect stator interturn short circuit fault of the induction motor. The per unit change in negative sequence current with positive sequence current is the main fault indicator which is imported to neural network architecture. The output of the feedforward backpropagation neural network classifies the short circuit fault level of stator winding.

scholarly journals Influence of Single-Phase Voltage Loss and Load Carrying Mode on Mine Drainage Pump Motor in Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Nhu Y DO ◽  
Xuan Cuong NGO
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Mine Drainage ◽  
Torque Ripple ◽  
Positive Sequence ◽  
Phase Voltage ◽  
Negative Sequence ◽  
Copper Loss ◽  
Voltage Loss ◽  
Load Carrying

Mine drainage pump is the most important load in mining which requires high reliabilitywhen operating. Currently, the power supply of a mine drainage pump is connected to the same powerline with many nonlinear loads, and is equipped with power electronic converters, which makes thepower supply nonsinusoidal. During the working process of a mine drainage pump, the load-carryingfactor often changes, and many types of failures occur, among which single-phase voltage loss is themost common problem. In the case of a nonsinusoidal power supply, if a single-phase voltage lossoccurs in different load modes, it will greatly affect the working mode of the mine drainage pumpleading to influences on the working efficiency, the life of the pump, and sometimes it is necessary torecalculate the protection parameters. This paper studies the influence of single-phase voltage loss andload carrying mode on the working mode of mine drainage pump motor in case the of nonsinusoidalpower supply. Research results show that, in the case of nonsinusoidal power supplied with single-phasevoltage loss, copper losses in the rotor and stator circuits increase with increases in voltage totalharmonic distortion (THD) and load-carrying factor, 5th order reverse harmonic increases copper loss inasynchronous motor the most, and higher harmonic components have less effect on copper loss in themotor. At the same time, the speed ripple decreases with the increase of the motor load factor anddecreases in the presence of the 5th order negative sequence harmonic, and increases significantly in thepresence of the 7th order positive sequence harmonic. 5th order negative sequence harmonic increases,the torque ripple increases, while the 7th order positive sequence harmonic reduces the torque ripple inthe case of single-phase voltage loss. The results of the paper will help improve the operationalefficiency of the mine drainage pump in Vietnam's mines.

scholarly journals Experimental Study of Various Parameters during Speed Control of Three-phase Induction Motor Using GPIC and LabVIEW

2021 ◽  
Vol 5 (1) ◽  
pp. 51-62
Author(s):  
Adnan Ahmed ◽  
Abdul Majeed Shaikh ◽  
Muhammad Fawad Shaikh ◽  
Shoaib Ahmed Shaikh ◽  
Jahangir Badar Soomro
Keyword(s):  
Induction Motor ◽  
Induction Motors ◽  
Induction Machine ◽  
Speed Control ◽  
Industrial Applications ◽  
General Purpose ◽  
Three Phase ◽  
Field Programmable ◽  
Input Source ◽  
Open Control

Induction motors are widely used from home to industrial applications. Speed of induction motor plays important role, so to control the speed of induction motor various techniques are adopted and one of these techniques is V/F control, which is adopted in this paper. This technique helps to control the speed in open control system in RPM. Moreover, Control is designed in LabVIEW, it is quite helpful to develop the circuit graphically and code is automatically written in the background to run on Field Programmable Gate Array (FPGA). The aim of this research is to study the impacts on diverse parameters during speed control of three phase induction machine with manipulation of GPIC. Solar technology is used as input source to drive the General-Purpose Inverter Controller (GPIC). Apart of this, impacts of modulation index and carrier frequency influencing the active, reactive and apparent power, temperature and power quality and current overshoot is analysed. MATLAB/Simulink and LabVIEW tools are used for simulation and results along with GPIC, Induction motor and solar panel as hardware.

scholarly journals DESIGN AND SIMULATION OF THREE PHASE FIVE LEVEL AND SEVEN LEVEL INVERTER FED INDUCTION MOTOR DRIVE WITH TWO CASCADED H-BRIDGE CONFIGURATION

2013 ◽  
pp. 29-34
Author(s):  
MANASA S ◽  
BALAJI RAMAKRISHNA S ◽  
MADHURA S ◽  
MOHAN H M
Keyword(s):  
Induction Motor ◽  
Pulse Width Modulation ◽  
Induction Machine ◽  
Poor Quality ◽  
Motor Drive ◽  
Induction Motor Drive ◽  
Voltage Reference ◽  
Multilevel Converters ◽  
Harmonic Elimination ◽  
Three Phase

This paper deals with study of Three phase Five Level and Seven Level inverter fed induction motor drive . Both five level and seven level are realized by cascading two H- bridges. The poor quality of voltage and current of a conventional inverter fed induction machine is due to the presence of harmonics and hence there is significant level of energy losses. The Multilevel inverter is used to reduce the harmonics. The inverters with a large number of steps can generate high quality voltage waveforms. The higher levels can follow a voltage reference with accuracy and with the advantage that the generated voltage can be modulated in amplitude instead of pulse-width modulation. An active harmonic elimination method is applied to eliminate any number of specific higher order harmonics of multilevel converters with unequal dc voltages. The simulation of three phase five and seven level inverter fed induction motor model is done using Matlab/Simulink. The FFT spectrums for the outputs are analyzed to study the reduction in the harmonics.

scholarly journals Reduced-Order Model of Rotor Cage in Multiphase Induction Machines: Application on the Prediction of Torque Pulsations

2020 ◽  
Vol 25 (1) ◽  
pp. 11 ◽  
Author(s):  
Abdelhak Mekahlia ◽  
Eric Semail ◽  
Franck Scuiller ◽  
Hussein Zahr
Keyword(s):  
Induction Machine ◽  
Induction Machines ◽  
Reduced Order Model ◽  
Order Model ◽  
Two Phase ◽  
Reduced Order ◽  
Three Phase ◽  
Torque Pulsations ◽  
Sinusoidal Current ◽  
Rotor Cage

For three-phase induction machines supplied by sinusoidal current, it is usual to model the n-bar squirrel-cage by an equivalent two-phase circuit. For a multiphase induction machine which can be supplied with different harmonics of current, the reduced-order model of the rotor must be more carefully chosen in order to predict the pulsations of torque. The proposed analysis allows to avoid a wrong design with non-sinusoidal magnetomotive forces. An analytical approach is proposed and confirmed by Finite-Element modelling at first for a three-phase induction machine and secondly for a five-phase induction machine.

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