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3
votes
1answer
34 views

add run capacitor to capacitor start motor to increase efficiency

Can I add a run capacitor to a capacitor start motor to increase its efficiency? I remember doing this 20 years ago and the run current dropped 20% or so, but I didn't measure the power consumed. The ...
3
votes
1answer
33 views

Is there any way to use the saturation harmonics to determine the rated voltage of a induction motor?

When the motor is running at no-load, the core eventually saturates as the AC supply voltage is increased. Therefore, harmonics will be present in the AC supply current waveform . I suspect that the ...
0
votes
0answers
16 views

Why is the voltage more in case of same polarity during a polarity test of induction motor?

I was performing experiment in the lab of my university. The experiment was supposed to be performed on a squirrel cage induction motor. But I performed it on a three phase slip ring I.M with its ...
0
votes
0answers
18 views

How do I calculate the number of turns per slot on a stator?

I am in the process of winding a split phase permanent capacitor motor running 1/3 at ~1720 RPM 120V 60Hz. It features 4 poles and 24 slots on the stator. The motor had 18 AWG magnet wire. I am ...
0
votes
0answers
31 views

Calculating the value of external resistors on an induction motor

I have been given part of a question to answer; "Calculate the external resistors needed so that the motor develops 100kW @ 500rpm", with the various other values that will apply. I've calculated the ...
0
votes
2answers
28 views

Minimal power circuit for recupating three phase motor drive on DC

A thee phase motor (like an asynchronous motor or an brushless DC motor) can be driven from DC power by using a half bridge on every of the three phases (for example by six FETs) if I'm right. What ...
2
votes
1answer
68 views

Would you help me understand the design of this induction motor?

I need to understand the design of a single phase induction motor (I think it is a permanent split capacitor motor). The motor works on three different speeds. It has 8 poles as shown in figure. ...
0
votes
4answers
82 views

Ways to estimate the rated current of an induction motor without nameplate

I am looking at ways to find the rated current of the motor without the nameplate data. Methods for rated voltage has been found. Assuming that we have the rated voltage, what would be some ways or ...
0
votes
1answer
90 views

Designing a brushless DC motor:

I watched a DIY video recently on building a brushless DC motor. Can someone demonstrate for me how to calculate the max torque & max rpm of that motor based on the components that are used in ...
0
votes
1answer
103 views

Why starting current in star-delta starter becomes 1/√3 times that of DOL starter?

I have seen this statement in a question paper. I was asked to prove it but I can not find the logic.
-1
votes
1answer
170 views

Starting torque of an induction motor

The starting torque of an induction motor increases with increasing rotor resistance. However, we know that, with increasing rotor resistance, rotor current will reduce, and hence rotor flux will ...
0
votes
1answer
80 views

What is the synchronous speed of single phase induction machine from 2 phases of 3 phase machine in parallel?

If I take all three windings of a three phase induction machine and put them in series, it acts as a single phase induction machine with three times the number of poles. This scheme is used to perform ...
2
votes
2answers
62 views

Interface for Induction Motor

I'm trying to make a board for controlling a reversible single phase induction motor. The board simply needs to be able to turn on/off the motor and control the direction. My understanding is that ...
0
votes
1answer
47 views

Sensorless Drive

for my general electrical course I participated lab work about sensorless induction motor but for one part it requires to plot graph, I did not understand how to create this graph.Can you help me ...
0
votes
3answers
110 views

What motor type is better suited for instant torque supply

I am working in a robotics project and I am looking way to make my robot "dash" as soon as possible. Therefore I need to have a quite high acceleration for a brief time. To be more specific, I am ...
1
vote
1answer
229 views

Tips to find the rated voltage of the induction motor without nameplate data

I am doing a project in which I need to find the parameters without nameplate data of the induction motor. I am looking into finding a way/method to find the rated voltage of motor. Can I get any ...
1
vote
0answers
15 views

Microchip MCHV reference design Ic Ia IBus current waveforms

I have built a Microchip MCHV board (ACIM Inverter based driver) from the schematics on the MCHV user manual. ...
1
vote
4answers
130 views

What type of motor should be used to handle a static torque (blocked shaft)?

For the purpose of DIY robotics, I would like to have an electric motor, which is best for providing torque while not rotating. I imagine my robot will maintain a static balanced torque while ...
3
votes
3answers
139 views

Why are induction motors controlled with a constant V/f?

It seems that induction motors are always controlled using a constant ratio of voltage over frequency. Why is that? Take the classic torque-speed characteristic curve - varying the frequency shifts it ...
0
votes
1answer
276 views

Do the power ratings on the nameplate of an AC motor indicate electrical or mechanical power?

A 6 pole 3-phase AC induction motor is delta-connected and has the following rated values on its nameplate: Frequency: 50 Hz Power: 22 kW   30 hp RPM: 970 \$\cos \phi\$ (power factor): 0.80 Primer ...
-1
votes
0answers
28 views

How does a multiphase induction machine works? [closed]

A simple AC Motor with single/three phase induction machine can generate EMF and thus the current. If it is so, then how a multiphase induction machine, means no of phases greater than 3 works?
1
vote
2answers
109 views

AC Motor torque simulation

I am trying to do a simulation on the start up speed to a system powered by an AC motor. As part of this I am trying to find a mathematical torque/speed curve that I can use. I expect a curve that ...
2
votes
1answer
417 views

Skew angle in squirrel cage induction motor

The rotor in the squirrel cage induction motor are shorted end to end by aluminium bars; however the are placed parallel at a certain skew angle. Wikipedia states that "The conductors are often ...
0
votes
4answers
988 views

Induction motor electrical and mechanical angle

How do we reach the relation between mechanical angle(\$\theta m\$) and electrical angle(\$\theta e\$) as: \$\theta e = (P/2)\theta m\$ ? ; where P is the number of poles.
1
vote
1answer
81 views

Braking of Motors

Is an induction motor delivering or drawing mechanical power in the braking region? . according to the torque slip curve of an Induction motor,torque is positive and the motor continue to rotate in ...
-2
votes
2answers
465 views

Starting current of an induction motor

How to calculate the Starting current of an induction motor if I have the power in kilo watts and the voltage? I have looked up formulas , but I got confused. I calculated the full load current by ...
-1
votes
1answer
88 views

Does “crawling” absent incase of slip-ring induction motor?

In case of wound rotor induction motor no. of stator & rotor pole must be same otherwise the motor will not operate. Please can anybody explain the physical reason behind it. As the no. of stator ...
2
votes
1answer
625 views

What does it mean if an AC motor has two voltage ratings?

On my AC motor nameplate, it says V230/400 (delta/star). I imagine this means that it is compatible with both voltages, but what allows it to do this? How will the performance change for each?
0
votes
0answers
72 views

Variable frequency drive power transistor selection

I'm designing a variable frequency drive for a single-phase induction motor driving a water pump. The motor power is 1.3 kW, it has 2 windings with resistance of 1.5/3 Ohms. My local electrical grid ...
1
vote
0answers
107 views

Determine active and reactive power from voltage and current over time in a three phase motor

How does one calculate active and reactive power from a set of data containing voltage-time and current-time pairs if the waves are not sinusoidal? I understand that apparent power in an induction ...
2
votes
3answers
153 views

Estimating power usage of idle motor

I would like to calculate the power usage of an idle motor. The motor drives state a power usage of approx 8-10% of full load. Would it simply be the case of taking 8-10% of the motor's power rating ...
0
votes
2answers
2k views

Identifying windings of a single phase induction motor

How can I identify the main and auxiliary windings of a single phase induction motor which has only three terminals (1.Red, 2. Yellow & 3. Black) out of the device? How to connect capacitor and ...
0
votes
1answer
3k views

Correct wiring for 3 wire single phase motor

I have a single phase 3 wires ( + ground ) submersible pump , I need to understand the correct wiring what type of motor is this and is the capacitor important ? the previous owner was not using this ...
2
votes
1answer
54 views

Determine power rating of induction motor

I got a 1-phase induction motor (230v/50hz) that was taken from a tile cutting saw that I planned to use in a home made disc sander, the labeling on the machine says it's a 600W motor but the motor ...
0
votes
1answer
41 views

Why sinusoidally varying torque in induction machine not visible

We know that torque in an induction machine varies as \$k\times[\cos(2wt)+\cos(\beta)]\$ but we don't feel it. Why it's so?
1
vote
2answers
194 views

Calculate rotor slip without knowing synchronous speed

I am given the rated values of a squirrel cage induction motor: A 300hp, 2300V, 3‐phase, 60Hz squirrel‐cage induction motor turns at a full‐load speed of 590r/min. What is the approximate value ...
-1
votes
1answer
123 views

How is low starting torque of asynchronous AC motors addressed when driving elevators?

Long before variable frequency drives became popular elevators were often driven by dual-speed asynchronous AC motors. Switching speeds was done by changing the number of poles (which is done by ...
0
votes
1answer
112 views

High Voltage Triac Control

I'm trying to control a universal motor run from a 240V power supply using a micro-controller. There is a existing PCB that uses a potentiometer to vary the speed that I am trying to replace. I've ...
0
votes
0answers
52 views

Design of PWM controller for Wound Rotor Induction Motor

I want to make a controller for Wound Rotor Induction Motor in which effective external resistance on rotor side is varied by changing the duty cycle(PWM controller) with the help of a chopper.What ...
0
votes
1answer
72 views

Multi-speed control of cage Induction Motor

Good day All. KIndly help me to find that why slip (s) is subtracted from synchronous speed (Ns) to get value for actual speed of Induction motor in "Separate-Winding Motor" case( a method for ...
0
votes
2answers
278 views

resistive braking for induction motor?

It occurred to me that since single-phase AC induction motors can act as generators, it might be possible to brake an induction motor with a resistive load. The basic idea is that when you want to ...
-1
votes
3answers
203 views

Are DC induction motors possible?

Forgive me if I am asking something absurd, I really do not understand much about electric motors. After reading the answers of Why does a Tesla car use an AC motor instead of a DC one? , I got ...
-1
votes
3answers
155 views

Two induction motors are made, one 50hz one 60hz, other specs are same. Which one is larger in size? [closed]

All other specs are same. Only difference is operating frequency.
0
votes
1answer
749 views

Shaded Pole motor - change RPM by relative change to windings

I've got a small shaded pole motor (C-type) that I'm cannibalizing for use in a project, but the current RPM is too high. I don't want to spend the effort to build a micro-controller to run it. Is ...
1
vote
4answers
3k views

Is Power consumed by a motor under various load conditions constant?

Does a motor (dc /Induction/Synchronous ) consumes more power when operating at higher load than when operating at some lower load? Or power consumption remains constant/same in both cases? What I ...
0
votes
3answers
2k views

Power and control 3 phase ac induction motors with dc source

Background So we are making a drive system to be used in a medium sized catamaran. The catamaran will use two water-jets powered by two 3 phase 380v ac induction motors. The entire system will be ...
5
votes
2answers
267 views

converting induction motor winding to reluctance motor winding

I want to build simple reluctance motor for education purpose. I have couple of small 3 Phase AC Induction motor with 24 slot stator lap winded for 4 pole design. I want to convert it to reluctance ...
0
votes
3answers
2k views

Identify coils end in 3 phase AC induction motor for star-delta configuration

In general if I look at a 3 phase AC motor outlet wires there are six wires that comes out of motor, three of them are marked to show coils end and other three are not marked which show coils other ...
0
votes
2answers
840 views

Driving single phase induction motors on three phase inverter

I like to drive a small (150W) single phase induction motor by an existing three phase inverter by removing the capacitor and just connecting the two windings to the inverter in an incomplete triangle ...
0
votes
1answer
214 views

Equivalent circuit of a three phase induction motor

So, i know that a equivalent circuit of a single phase of a three phase induction motor is just like a transformer equivalent circuit when it is at standstill. When, however, it is rotating the ...