Questions tagged [induction-motor]

Induction motors are alternating current motors with rotors that are energized by induction. They are available with power ratings ranging from about 1/500 Hp (1.5 W) to 30,000 Hp (22MW). They are the dominant type of AC motor used in most of that power range. Squirrel-cage motors are, by far, the dominant type of induction motor.

401 questions
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Vector Control in Induction Motors

Can vector control in induction motors be considered as power factor correction ? From my researchs, it seemed to me angle between rotor and stator flux is 90 degree when load is purely resistive (...
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What is the equation for mechanical efficiency of a 3 phase induction motor?

I know that mechanical efficiency is n= power output/power input, but I don't know how to find each of those. I have to find the efficiency at full load running speed. I was only given mechanical ...
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Which electrical characteristics of stator and rotor windings influence the mechanical power of a single phase induction motor?

I wish to find the values of resistance, inductance and mutual inductance of stator and rotor windings of a single phase, two poles, capacitor-start, capacitor-run induction motor with 1/2 Hp ...
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Explain the braking and generating regions in a slip torque curve? [closed]

Can you help explain simply, the braking and generating regions in a slip torque curve?
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Torque, Current and Voltage Relationship in Induction Motor

In induction motor, Torque is proportional to square of applied stator voltage (I agree that) but some source says torque is proportional to current. For me something proportional to square of volt ...
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How can I find the slip speed of a slip ring induction motor without knowing the rotor speed (rated RPM)

The Rotor of a 4 pole, 50hz slip ring induction motor has a resistance of 5ohm per phase and inductance of 150mH per phase. Calculate the slip speed at which max torque occurs. I have used Ns = 120f/...
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Find rotor stator loss in a 3 phase delta connected induction motor?

I'm trying to work out stator input power of a 3 phase delta connected induction motor. I have the equation Stator Input Power (P1), where P1= Pm + rotor copper loss + rotor stator loss. I have Pm ...
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Should startup torque be higher in value than full load torque in an induction motor?

I found out values of my 3 phase delta connected induction motor for full load torque, maximum torque and startup torque. My maximum torque was higher than my full load torque, but the thing I'm ...
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torque-speed characteristics of induction motors

I have come across a website which says that zero staor resistance makes the maximum torque constant for different frequencies while keeping v/f ratio constant. And a non-zero stator resistance affect ...
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Cheapest way of rectifying 60hz -> 30hz 120V AC to halve speed of PSC induction motor

I am trying to slow down a PSC motor. (VFD’s are expensive) I can cheaply rectify AC into the following waveform. 2 positive peaks then 2 negative peaks repeating. It would look like pictured. ...
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Torque in a 3-phase delta connected induction motor

I know the equation for torque is T=[m*(N2/N1)^2/2*pi*Ns]*[s*E1^2*R2/R2^2+(s*X2)^2] N2/N1 is the effecting rotor-stator turns ratio. I have it written ...
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Finding value of slip in an 3-phase delta connected induction motor

I know the equation for slip is s= (Ns-Nr/ns)x100 and that to find Ns is Ns= f/p. I have been given ...
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Controlling speed of PSC induction motor (Questions about operating at high slip)

Induction motors typically run synchronous speed since most motor types (CS/CSCR/Permanent Split Phase) have high low-end torques. A PSC motor on the other hand doesn't have much low-end torque. FAN ...
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How can an induction motor be “self starting”

I read that all you need to start an induction motor is to apply the AC voltage, and with time the slippage decreases. How does this happen magnetically? If a rotor, connected to a moderate sized ...
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Relationship of Slip and Angle Between Rotor and Stator Flux for Induction Motor

I know how slip and flux angle individually affect torque of induction motors but I can't understand the relationship between slip and flux angle in terms of torque. Do they both have different effect ...
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Vector Control & Slip

I know slip in induction motor determine the current and torque but the point I want to ask, when controlling with vector control it is said stator and rotor flux is always kept with 90 degrees apart ...
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How to make a conveyor (electric part)

I am going to make a conveyor like this There will be a optic sensor which detects a box. There will be motor (3 phase, 380 V, 1 A, 0.37 kW, 1400 rpm) with gear reduction (coefficient of reduction ...
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why induction motor torque oscillating?

why when start induction motor the torque oscillate before become constant, like the following matlab torque simulation graph .
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Can torque angle of motor be positive?

For any motor text say that, the rotor field follows the stator field with a certain torque angle. And in case of generator, the stator field follows the rotor field with a negative load angle. The ...
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Induction motor equivalent model (abc vs dq)

Why is the equivalent circuit of an induction motor structurally different in abc domain (link) and in dq domain (link)? I mean abc has load modeled as a variable resistance while in dq it is not. ...
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what will happen if the motor that is designed for delta connected in star connection

I have a motor which is designed for 3 phase, 380V. The power rating of motor is 132kw and motor stator winding is connected in delta connection. If I connect the same motor stator winding in star ...
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Relation between torque angle and power factor

What is the relationship between torque angle and power factor for a induction motor? Here is my understanding. Lets say a stator coil produces a magnetic field and the field induces voltage in a ...
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Identifying direction of rotation for a three phase motor, without applying three-phase power

Suppose I have a typical smallish (say, <3kW) three phase induction motor. Likely 400V star-connected, but methods that work with any motor would be preferred. I can ensure that the supply phase ...
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Braking Methods in Induction Motor

When I search on web, I see three types of electrical braking exist for induction motors. 1-Regenerative 2-Dynamic 3-Plugging Regenerative is said to be possible when rotor speed is higher than ...
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Ins on motor wiring diagram

I'm trying to connect a 220 single phase motor, the wiring diagram is on a sticker on the motor. However, I'm not sure what the Brown wire is supposed to be connected to, I think it says "Ins" which I'...
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Brake Resistor in Regenerative Case for Elevator

I am trying to understand the switching pattern of Inverter and the Brake chopper while a 3-phase AC motor is in regenerative mode for example in Elevator case: When its Cabin is full and it is ...
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Speed Current Relationship in İnduction Motors

It is said that speed of an induction motor depends on its frequency and torque depends on current. But I will explain what i cant understand here. Let’s think an induction motor runs with constant ...
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Slip Control vs Constant V/F Control for 3-Phase ACIM

I am trying to understand how is Slip Control different from Constant V/F control. If I need to control the speed of 3-phase ACIM then its slip would obviously change with its rotational speed then ...
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Speed control using direct torque control of induction motor

Is there any steady state error present in speed output at any load in direct torque control of induction motor?
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Induction Machine: What would multiplying the angular electrical frequency of the machine with the electromagnetic torque give?

I understand that multiplying the output torque (load torque or mechanical torque) $T_m$ with the mechanical speed $w_m$ we obtain output power. But what would multiplying the electromagnetic ...
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Orientation of magnetic flux in a induction motor?

1) The rate of change of stator flux creates rotor emf and current which in turn produces rotor flux. What is the relationship between stator flux and rotor flux? In what direction is the rotor flux ...
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Controling a Washing Machine AC Motor Using a Relay

I would like to control the motor of my washing machine using an Arduino. It's an old washing machine with a mechanical controller and an AC motor connected to a 12.5 uF run/start capacitor. According ...
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Frequency of stator current in induction motors

I am learning about induction motors. I have a question about the stator current, especially the rotor induced current. If the rotor rotates at 1-s of sync frequency, then the emf and current ...
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Why does my shaded pole motor barely rotate when driven at 1/2 its rated voltage?

Hello electronics community! I'm attempting to service a shaded pole motor (pictured below) that is used for rotating a cylindrical fan from an electrical heater. The fan stopped rotating and so I ...
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I am doing an experiment that involves loading an asynchronous 50 HZ generator. For the load to consume current it has to be a capacitive load to cause a phase shift between the current and the ...
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FEMM: Calculating Torque of an Induction Motor using the Air Gap Integral and SlidingBand

I am currently working on my Master's Thesis, building an Octave/MATLAB-Program to automatically calculate desired outputs of various induction motors. Since FEMM released the (Anti)-Periodic-Air-Gap-...
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What are differences between neodym motor wheels and copper motors?

I want to learn about electrical wheels, typically used in electric bicycles. But most of information I could find is related to marketing, and nothing on theory. This is probably due to "relative ...
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How to read Torque-Power diagram for an asynchronous motor

I'm sorry if my question is too stupid, but I am not able to correctly understand how to compare the information showed by the torque-power diagram with the motor test data for a 2000W Asynchronous ...
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Use a TRIAC to connect/disconnect a capacitor to a PSC motor

In the image above, we see a PSC motor, with its 3 terminals, connected to a control board. This board has a RUN capacitor always connected to the motor. When the motor has to turn, the board applies ...
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voltage transient protection for MV Motors

What types of transient voltage protection is applied on medium voltage motors and are these types of protection that are applied depended on the type of motor it is e.g Synchronous vs Induction motor?...
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Three-phase induction motor winding terminals

According to the following diagram, when the motor is delta connected as far as I can see: L1 goes into U1; U2 goes into L3 L2 goes into V1; V2 goes into L1 L3 goes into W1; W2 goes into L2 It ...
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3 phase motor change from 440 V to 220 V with diagram question

Some confusion the way my new machine is wired. I bought a sander not hooked up and the guy thought it was wired at 440. I need to set it to 220. The motor says 220/440. I have 220 at my shop with ...
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Trouble to find out the nominal motor current and motor type of a fan from its datasheet

Is there a way to find out what is the nominal current of this fan and what type of single phase induction motor is used?
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A very basic question about VFD output frequency

I know that a VFD's inverter stage creates alternating voltages at a desired frequency for the terminals of a delta induction motor(stator voltage freq.). Normally without a VFD the nominal freq. ...
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Is induction motor's rotor speed or torque change with delta or star connection?

An induction motor's synchronous speed Ns is given as: Ns = frequency * 120 / number of poles This formula is independent of the voltage applied to the windings. On the other hand, I know from ...
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Is it good idea to charge a battery from a starter-capacitor of an AC generator?

Some friends and I took a working electric motor out of an electric lawn mower. We suspect it is a single-phase AC induction motor (correct me if I'm wrong) with a starter capacitor (pictures above). ...
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Chop Saw Inrush Current Limiter?

I have a Dewalt Metal cutting abrasive saw that tends to open a breaker on starting up. It draws 75A on startup tripping the magnetic part of the breaker and opening it. This circuit is only to stop ...
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operating a motor with a undersized vfd

A centrifugal pump requires 21.6 hp to flow 350 gpm at 2800 rpm with a 230/460V, 40 hp, 2-pole (3600 rpm) motor. The VFD available can operate up to a 25 hp motor at 230V, with a maximum output of 68 ...