Questions tagged [synchronous-motor]

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Effects of decreasing the field voltage of a synchronous machine

I am running a simulation of a synchronous machine in matlab and I have some behaviour I cant quite grasp my head around. The machine is running as a motor with only about 20% of its maximum load, ...
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49 views

Number of poles used for calculating synchronous speed

I am a bit confused in the formula used to determine the synchronous speed \$N_S\$. Following is the formula used to determine the speed: \$N_S = \frac{120f}{p}\$ Now for a 6 pole motor there are some ...
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84 views

What happens when adding a load on a synchronous generator?

When a single synchronous generator is operated alone adding a load on a synchronous generator the following happens: Adding inductive loads, |Eo| will increase, however, δ will not vary. Adding ...
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19 views

Delta connected synchronous motor current

My question is why would the answer be wrong if I apply the same formula i.e. Which will give the value of the line current to be IL = 86.3 A SOURCE: Power System Analysis John J. Grainger and ...
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39 views

overexcited generators and motors supply reactive power

I know that an overexcited synchronous motor has a leading power factor. But an overexcited synchronous generator has a lagging power factor. However, as shown in the attached page it says that ...
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24 views

synchronous generator speed

Isn't a synchronous generator speed fixed at synchronous speed regardless of the load? In the question the synchronous generator has different speed why? Reference: Electrical Machines, Drives, and ...
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43 views

What is the effect of stator magnetic flux on the rotor of Synchronous motor?

I get that the stator is fed 3 phase supply and the rotor is fed a dc supply. And it reaches a stage where the constant flux by dc current in rotor and the rotating magnetic flux by ac current in the ...
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38 views

Is the orthogonal spacing of dq axis of AC motor with respect to electrical or mechanical angle?

In FOC of AC machines, we try to align the stator flux to Q axis and maximize the value. The idea behind this logic is when rotor flux and stator flux are orthogonal, we generate max flux. But is the ...
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1answer
53 views

What is the standard procedure to design a Synchronous Machine?

I have Modelled an IPMSM based on the innovative idea i got. I have also decided on the rating of the machine, torque to be produced, Required Rated RPM, but after this i have so much doubt. whether ...
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82 views

Is the current in the correct direction in this image describing a one phase generator?

The dot on the left is current going towards us according to the image. But if the magnet is rotating counter clockwise while the conductor is stationary (which is same as magnet being stationary ...
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1answer
40 views

Synchro with 1 phase grounded

I have been doing some research into synchros and I know the base equations from to determine the voltage difference between phases. Those equations can be used to determine the angular position from ...
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141 views

Relation between torque angle, power angle and power factor

Considering a synchronous generator, is there a relation between power angle (angle between V terminal and V induced), torque angle (difference between rotor flux and stator flux) and power factor(...
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41 views

Steady State speed of rotor in following doubly excited system

I'm trying to analyse following system - A three phase armature winding on stator and on rotor field winding and both stator and rotor are cylindrical . And armature winding is connected to a three ...
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1answer
37 views

Copper loss of a synchronous motor at a particular load

Imagine I'm driving a 50KW synchronous motor of full load current of 10A as a generator using a motor. Assume the driving motor losses to be negligible. Am I right about the following statements? When ...
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2answers
105 views

Electrical frequency of motor with different stator and rotor poles

I know the formula to find electrical frequency when we have RPM and rotor poles of a synchronous machines which is f=RPM/60*pole pairs. I think the assumption here is that the number of rotor poles ...
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1answer
62 views

Explanation of v curve of sync machine

I am trying to understand the v curve of synchronous machine. Particularly, the point that changing field current can put the machine in leading or lagging mode. I am trying to get an explanation to ...
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318 views

Tesla Model S inverter DC bus voltage

I was recently researching about this Telsa electric car inverters where i found one intresting thing. Usually in the voltage source inverter the DC bus voltage will be around 600 to 650 V considering ...
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1answer
63 views

How to find the 120 degree phase angle in a single layered lap winding of a synchronous machine?

Ok, so I have a 4 pole synchronous machine with 24 slots meaning each slot has a phase difference of 30 degree with respect to each other. 1)That means pole pitch is 180 degree for a full pitched ...
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120 views

PMSM failure modes? Winding apparently not shorted

(This may look like a repair question, but I'm actually interested in how the simplest kind of motor failed) This is the stator of a permanent-magnet single-phase motor from a washing machine drain ...
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1answer
48 views

Rotating rectifier waveform

I am testing a circuit which is used in a synchronous motor rotor excitation. I am testing the part when the rotor is stationary and the motor stator has a rotating magnetic field, in that case it ...
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2answers
257 views

Motors in symmetrical fault analysis

In three phase symmetrical fault motors(Induction and Synchronous) become generators(I guess because of the inertia). When do I take in consideration of the motors? Do I even need take them in ...
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1answer
488 views

What happens to the Real and Reactive power when I increase the excitation current in a 3-Phase Synchronous Generator?

Basically my doubt is, for the same load, why does the Real power remain constant when I increase the excitation current?
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369 views

What will happen if the prime mover driving synchronous machine is accidentally disconnected?

What happens to a synchronous machine connected to an infinite grid, acting as a generator, when its prime mover fails i.e. when mechanical input at the shaft reduces to 0? I'm assuming that the ...
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1answer
96 views

Understanding of torque constant and efficiency of a permanent magnet motor from datasheet

I am trying to understand the efficiency of the following permanent magnet synchronous motor Motor Datasheet (note we are using the medium voltage model), and its relationship with the input voltages ...
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1answer
85 views

PMSM Rotor Design. Are these terms equivalent?

I'm working on a project with a PMSM. As I go through the literature I come across the following terms and wanted to make sure that I am getting right which ones are synonyms. Surface-mounted PM = ...
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1answer
812 views

Electrical equivalence and Difference between Flux and Torque in AC motors

For AC motors, Synchronous and Asynchronous ones, are these two linked together or different quantities, namely magnetic flux and torque? Also if I want to measure these quantities electrically then ...
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237 views

Controlling the reactive current of an PMSM in an open loop setting

for my master thesis I'm investigating the EMI of a 3-phase inverter, wich drives a PMSM. The inverter's structure is the common 3-Phase DC/AC Voltage Source Inverter and it uses EPC2020 GaN ...
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1answer
185 views

Adding an additional motor to a load

You have a 500kVA load with a power factor of 0.6 lag. You add an additional synchronous motor with an input of 80kW and max power factor of 0.8 leading. Determine the reactive power and the overall ...
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25 views

Medium Voltage Synchronous Motor Protection [duplicate]

How is the wound field of a medium voltage synchronous motor protected from voltage surges? We do know that the stator is protected from surges by either one of the following: 1. RC Snubber Circuit 2. ...
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1answer
86 views

Which way should this capacitor go on this circuit?

Which way should this capacitor go on this AC Hysteresis Synchronous motor circuit? Which terminal is CCW and which is CW?
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2answers
151 views

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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167 views

About how to extract back EMF from SMO(sliding mode observer), maybe I need a doctor for this question

The equations of PMSM on alpha-beta frame(2 fixed coordinate systems) are like this, ...
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102 views

Tips for designing a permanent magnet synchronous generator?

I'm currently working on designing a permanent magnet synchronous generator for one of my personal projects and I'm having trouble getting a voltage I am satisfied with. My goal is to get around 4-6 V ...
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1answer
322 views

Under no load condition,what will be the angle between the induced voltage and the supply voltage in synchronous motor?

Can anyone explain what will be the angle between induced voltage and supply voltage in synchronous voltage under no load condition?
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1k views

Synchronous motor high starting current

I have Danaher Motion SS451 (120V, 60 Hz, Single Phase, 72 RM, page 10 in manual below) synchronous motor that was consistently blowing a 3 amp fuse. I replaced it with 5 amp slow-blow fuse and ...
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384 views

Modeling scalar control of PMSM

I have met with a scalar control algorithm for a permanent magnet synchronous motor. I haven´t heard about it before so I decided to develop a dynamic model to further analyze this control algorithm. ...
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2answers
2k views

Permanent magnet synchronous motor (PMSM) equivalent circuit

I am trying to model a PMSM (permanent magnet synchronous motor) in LTspice and in order to do so I need to form an equivalent circuit. Through some research I believe the circuit should be formed in ...
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1answer
416 views

Synchronous Motor Leading Power Factor

I am looking for an explanation for the fact that over excited synchronous motor has leading power factor. If induced voltage due to the rotor is greater that the supply voltage, wouldn't that being a ...
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1answer
444 views

Does the rotation speed of a synchronous machine affect the voltages induced?

We know that synchronous generator are the go to for power generation. They essentially need an excitation current for the rotor and an external force to rotate it. This would induce a voltage in the ...
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1answer
51 views

Increase rotational velocity of synchronous motor

I recently got my hands on a Philips PM8110 (a single pen recorder which is basically an analog printer for voltages) which sadly provides paper with a velocity of 8 cm/hour. Although this would ...
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1answer
288 views

What are the d and q axes for induction machine?

What are the d and q axes for an induction machine (physical meaning)? I understand them for a synchronous machine but how are they defined for an IM?
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2answers
731 views

What is the connection of this synchronous motor?

so yeah I took this picture of the terminal box of the synchronous motor we're cleaning. I can't distinguish what is wye or delta when it's shown like this. what are the indications that a connection ...
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1k views

Formulas for AC Synchronous motors

I have this questions: At what frequency must a 4-pole motor be supplied so that its synchronous speed is 1200 rev/min? The nameplate of a standard 50 Hz induction motor quotes full load speed as ...
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3answers
1k views

Does the continuous power-to-weight ratio of electric motors decrease with size?

Background: According to the DEP overview section of this NASA paper, aviation companies are interested in distributed electric propulsion (DEP) because the scale-agnostic power-to-weight ratio of ...
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3answers
771 views

How does line impedance of a BLDC motor relate to the RPM of its rotor?

I am curious about the impedance of the three phase BLDC motor when it is in operation. If the speed of the rotor of a BLDC motor is proportional to the frequency of the three phase current, and the ...
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1answer
126 views

Why the shape of rotor-poles of salient pole synchronous machines are designed as sinusoidal in shape?

I knew that this is done to eliminate harmonics. But I couldn't get its reason. So I am confused whether my conclusion was right or wrong.
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424 views

Electrical Machine Design: Why do open slots are allowed in synchronous machine while they are avoided in Inductio Machine

Why do open slots are allowed in stator and rotor of synchronous machine while they are avoided in stator of Induction Machine? Because flux from stator to rotor (IM) and from rotor to stator (in SM ...
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720 views

When are positive-sequence and negative-sequence equivalent impedance the same?

One of the topics we covered in an introduction to power systems class was using zero/positive/negative sequence networks to analyze faults in networks. For many problems, this requires setting up ...
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2answers
11k views

What is the "field-weakening" operation?

I'm studying brushless and induction motors, in my studying material "field-weakening operation" and "field-weakening region" are often cited without an explanation. As far as I understood is a method ...
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98 views

Speed voltage variation in alternators

What happens to the terminal voltage of synchronous generator if we change the speed ?