Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [synchronous-motor]

The tag has no usage guidance.

-3
votes
0answers
17 views

Synchronous motor efficiency [closed]

A 50 kW synchronous motor is tested by driving it by another motor. When the excitation is not switched on, the driving motor takes 800 W. When the armature is short-circuited and the rated armature ...
-1
votes
0answers
22 views

Accuracy issues with a Synchro

I have a Gertsch Synchro Standard, similar to this one: And I am trying to accurately measure angle by monitoring the Voltage outputs S3-S1, S2-S1, & S3-S2, as guided in this document ...
0
votes
1answer
41 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 ...
0
votes
1answer
36 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?
0
votes
2answers
155 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 ...
0
votes
1answer
413 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 ...
2
votes
3answers
496 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 ...
0
votes
2answers
265 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 ...
1
vote
1answer
76 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.
0
votes
0answers
263 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 ...
1
vote
0answers
377 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 ...
2
votes
2answers
7k 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 ...
-4
votes
1answer
69 views

Speed voltage variation in alternators

What happens to the terminal voltage of synchronous generator if we change the speed ?
0
votes
1answer
3k views

Calculate electromagnetic torque of synchronous motor?

I usually use this formula $$P=Tω=Τ\frac{2π}{60}n$$ where n is revolutions per minute and P is the power depending on the occasion. Since we have to deal with a synchronous motor we have to use ...
0
votes
1answer
86 views

Control of a Permanent Magnet Synchronous Machine (PMSM)

I'm trying to control the speed of a PMSM in the simulation software PSIM. Now, I have learned that in a Synchronous Machine the steady-state speed is directly proportional to the frequency of the ...
0
votes
1answer
96 views

Gas/Steam turbine for power generation

I have a question regarding the electricity generation using either steam or gas turbine. After the process of gas or steam accrues and the turbine rotates. the turbine which is connected to the ...
1
vote
2answers
255 views

Can over-excited synchronus motor operate on lagging power factor?

All of the Electric Machines literature I'm using states that over-excited (back emf E> supply voltage V) synchronus motor will operate on leading power factor (one of them states that it may also ...
0
votes
2answers
803 views

How does this increase the torque of a synchronous motor?

I'm studying from Wildi's textbook on electrical machines and I came across the following on starting a synchronous motor: "To limit the voltage induced in the rotor windings during the starting of ...
0
votes
0answers
39 views

Control AC Sync. Motor by Blocking AC Cycles

I have an AC synchronous centrifugal water pump that I would like to control the speed of. The main goal is to slowly start the pump and ramp up to full speed over about 60 seconds. I believe this ...
0
votes
2answers
85 views

d-q-frame-currents. What and where are they in PMSM?

I am doing a course in power electronics. We discuss a lot about Iq and Id, when we are talking about a three phase system and electric motors. I like to visualize things to make them more ...
0
votes
1answer
1k views

How is this synchronous AC gear motor being reversed?

I just disassembled the shifter assembly in a washing machine. It uses a synchronous 120VAC gear motor. The motor says "CW/CCW Z.P." It has two leads for the AC power and no other inputs. I ...
0
votes
2answers
843 views

Why does a synchronous motor run at synchronous speed if we reduce excitation to zero?

It is stated in the textbook I'm studying that if we reduce the excitation current after the rotor has reached synchronous speed , its speed will remain constant even if the excitation current becomes ...
2
votes
2answers
2k views

Why does stator current increase with increasing load in a synchronous motor?

Isn't the current, coming from the 3-phase source of the stator, constant? We don't change the source, so how does the current change? Is a voltage induced because of the magnetic field of the rotor? ...
2
votes
1answer
120 views

Which is the physical insight behind the widely approved 'space vector' notation used in the analysis of the dynamic model of electric machines?

When approaching the study of electric machines in transient condition, it is customary to discard the real physical vector quantities like magnetic field and magnetic induction and to define fake ...
1
vote
1answer
615 views

Armature and field mmf axes in synchronous machines

In the book "Electrical Machines and Technology" by J.Hindmarsh, in the chapter about synchronous machines, it stated that for the machine to develop a uniform torque, the armature and field mmf axes ...
-2
votes
1answer
134 views

Modification of a 3 phase AC motor [closed]

There is a permanent-magnet synchronous motor with an external rotor that I want to explore and possibly modify. To do this I need some answers to my simple question: For a given shape of stator ...
0
votes
1answer
217 views

ACB vs Contactor for synchronous generators

I've been told by an experienced electrical engineering colleague that it is preferred to use an ACB rather than a contactor for making and breaking the connection to a synchronous generator, but he ...
0
votes
1answer
154 views

Reversing a small synchronous gearmotor

it's been difficult to find the answer to this problem I have. My project is based on home automation. I need to control the direction of the rotation and if possible the torque of an AC synchronous ...
0
votes
1answer
685 views

Speed of Synchronous motor determined by frequency, but how about current?

The speed of a permanent magnet synchronous motor is determined by n = 120f/p where f is frequency, n is speed in rpm and p is number of poles. p is fixed in a motor so changing the frequency ...