AC power with three legs run 120 degrees out of phase

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27 views

Making Star & Delta Networks on Breadboard

I'm almost a noob in forming breadboard circuits. Nonetheless, I need to form a star & a delta circuit (separately) on breadboard, simply with resistors, and a DC voltage source. Could anyone ...
2
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4answers
64 views

What is capacitance required for this 3 phase rectifier

In the diagram above I want to know the value and the rating of the capacitor that should be used for good rectification The Line to Line voltage is 400 , and by relation Vdc =(3√2 VL)/pi=(3√2 x ...
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2answers
58 views

What is the pole frequency of a three-phase LC filter?

Suppose I have this configuration: Assume L1=L2=L3 and C1=C2=C3. What is the pole frequency of this filter? Edit: As mcmiln says, this is not identical to the question here: Cut Off Frequency in ...
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0answers
19 views

Incorrect 3-phase LN Voltage

So I have a circuit which is comprised of two 3-phase generators and one 3-phase load; the only info I have on them is as follows: From there, I was able to figure out the current leaving the first ...
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1answer
36 views

Disagreeing 3-phase power

So this feels like a silly one but I'm absolutely stuck. I'm trying to balance the power between a 3 phase source and two 3 phase loads in parallel. One is a Wye and the other is a Delta: So I ...
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1answer
36 views

Why is inductance negative in this triphase mutual inductor?

Suppose I have a threephase circuit with a mutual inductor on the first and second phase (V2 and V3). One way of solving the circuit (ie finding the phase currents) would be the following: convert the ...
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1answer
47 views

Voltage between AC phase and DC link

Let there be 3-phase rectifier connected to the standard electricity grid with 400V between phases. Measuring voltage between one of the phases (AC) and negative terminal of the rectifier output (DC), ...
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1answer
44 views

Max Current through Neutral in wye-wye 3phase circuit

Assume that you have a wye-wye 3 phase circuit. Each of the 3 phase wires can take a max of X Amps. What is the max current the neutral of the circuit could have? Is it possible for the neutral ...
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2answers
40 views

Hooking up a variable frequency drive

I have a 3-phase blower motor that I am looking to control from a Danfoss VLT 2800 that I purchased on eBay. I am going through the manual and I see this table for the mains connection: . I have in ...
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2answers
149 views

How to wire 3 phase motor to VFD

I am trying to wire a new motor to a variable frequency drive (VFD) and having some trouble figuring out how to wire the motor to the VFD. The motor is a 1 HP, 3-phase, 208-230/460 volts, and I'm ...
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1answer
47 views

Design of three phase thyristor circuit for temperature controller

Circuit is powered by 3 phase, 415 V AC. This is connected to nri halogen tubes to heat a chamber up to 20 kW and 700℃. I have to control temp using delta controller DTA 7272 which will sense ...
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1answer
39 views

Calculating phase currents of an automotive alternator

I have an automotive (3-phase) alternator with peak rated output of 150A at 14V (after rectification, of course). How can I determine phase (AC) currents in this situation?
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1answer
90 views

why the stator frame of a 3-phase generator is made up of cast iron?

I don't have a good knowledge of engineering materials, so please answer the following questions with reasons. Why is the stator frame of a 3-phase generator made up of cast iron? Why is the ...
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1answer
37 views

Symmetrical components: phase voltages

In the following question on symmetrical components, the 11kV of the source is the line-to-line voltage. When using symmetrical components you want to be working with line-to-neutral voltage. Am I ...
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1answer
48 views

How to derive apparent power formula for three phase AC system?

I know that the total power output of a three phase system is √3 EI cosØ Where E and I are the line voltage and line current. Now my question is how can one derive the apparent power equation i.e.. ...
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6answers
436 views

Why do we need to install a power transformer for each high building?

I live in area where many high buildings are being built. Each building is more than 10 floors. A special room is made next to the main entrance or the garage. The room is designed for installing a ...
0
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0answers
43 views

Three Phase Permanent Magnet Rotor Generator Magnetization

I have a three phase permanent magnet rotor synchronous generator. The rotor was recently removed from the machine in order to repair the shaft. The motor when when run at the same speed does not ...
2
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2answers
151 views

Power factor correction for LED lighting on a generator

I'm the electrician for a club that builds an illuminated carnival parade float, and historically we've lit our float using around 10,000 x 40w incandesant lamps powered by a 800kVA 3 phase generator. ...
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1answer
57 views

How to set phase delay for a three phase igbt rectifier

I have a three phase igbt rectifier like so. three phase voltage = 690V. how to set the phase delay and DC link capacitor value(F) to get Vdc = 1070. I have updated the complete simulation with the ...
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1answer
167 views

IGBT vs. SCR rectifier

I simulated three phase rectifier using a thyristor like so: I get the expected result. But if I change the thyristors to IGBTs as shown below, it does not work. Why do these two circuits behave ...
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2answers
80 views

Measuring 400V three phase large consumer power

I need to measure the power consumption of a large (11kW) electrical motor during various stages of operation. I have a few interlinked questions: I'm interested in the power the operator of that ...
4
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2answers
280 views

Why are the letters U, V and W used in AC motors to represent the windings?

I am connecting up an AC motor and was wondering if this labeling system was representative of something? Or just another set of letter like X,Y,Z? I could not find any information regarding this in ...
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1answer
95 views

What is the cause of voltage phase shift in a power system?

What element(s) cause the phasor voltage to shift in a power system? Why does the voltage phase angle increase with distance in a power grid?
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3answers
121 views

A basic question regarding three phase power

I have a very basic question about three phase power. We have a three phase power supply rates as 32A/415V. The line to line voltage has been measured to be 415 V (using a multimeter) and the line to ...
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4answers
133 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 ...
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1answer
2k views

Why does a delta/wye transformer make 30 degrees phase shift ?

I'v heard that a delta/delta or Wye/Wye transformers do not make any phase shift. In delta/wye or wye/delta transformers, There is a 30 degrees phase shift between the primary and secondary coils. So, ...
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2answers
83 views

3 phase VFD/rheostat for motor

I have a 3 phase motor and 3 phase power supply (400V, 50Hz) Currently this motor produces 1.5hp in torque and ~1750rpm. I need it to produce less. My question is: Is the best way to go about this, ...
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4answers
1k views

Why does current flow from the most positive to the most negative in three phase system?

I put the following circuit in a simulator to see how it works. I understood it but I have a question: At the time of the vertical green line, The simulator shows me that the current flows from the ...
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0answers
93 views

How to separate three phase signal in positive dq axis and negative dq axis in MATLAB/Simulink

I want to separate three-phase voltage into two groups positive and negative dq components (ie positive-direct voltage "Vd+", positive-quadrature voltage "Vq+", negative-direct Voltage "Vd-", and ...
2
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0answers
80 views

What will be the effect of putting a single phase load on an open delta transformer secondary?

Suppose I have an open delta transformer, 240 line to line secondary. I have a single phase constant power load I want to apply. I could apply it across either of the 'closed' phases and load that one ...
0
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0answers
29 views

symmetrical components and power conservation?

My understanding of the method of symmetrical components is the following: An unbalanced three phase system (voltages, currents etc.) is split into three balanced sets; zero, positive and negative ...
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2answers
114 views

Using Single-Phase and 3-Phase Equipment?

Let's say I have a single-phase facility and I plug in a piece of 3-phase equipment, what happens? Is it dangerous? Is it less efficient (if so, approximately how many percent less in efficiency)? ...
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1answer
47 views

Three phase balanced transformer network with b-phase fault

100 kVA, 11 kV (delta) : 400 V (wye), Xeq = 0.1 p.u with a neutral to ground connected through Zn = j0.1 (ohm) I have a question where the above transformer is fed by a balanced positive sequence ...
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10answers
8k views

Why three-phase power? Why not a higher number of phases?

Is there a reason, beyond historical reasons, that three phases has become the dominant number of phases? I am aware of the advantages against one phase and two phase, namely the reduced amount of ...
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2answers
2k views

How to wire three phases for 220V?

In Thailand we usually use 3 phases (L1, L2, L3) + Neutral (N) + Ground (PE) with 220V. A machine imported from Taiwan has four connectors: L1, L2, L3 and Ground (connected to the housing). It uses ...
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4answers
3k views

How to change rotation direction of 3-phase electrical machines?

I was taught that if you want to change the direction of a three phase rotating machine that is rotating in forward direction, you interchange the phases. Since the phases has the same features ...
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0answers
76 views

delta-star three-phase transformer for single phase

Can a delta-star three-phase transformer be used with a single-phase supply and load without damaging it? simulate this circuit – Schematic created using CircuitLab Primary: star/wye ...
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1answer
55 views

Question about output current

I've got huge three-phase transformer, primaries are connected in Y configuration, secondaries in Delta, then goes to 6 diode bridge rectifier. Output is about 200 amp 52 VDC. In short, how many ohm ...
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1answer
173 views

Phase Sequencer

I have 3 phase voltages entering into my PIC ADC (3 different channels ) through a voltage down scaling circuit and I have successfully calculated their rms values inside my controller.Know I want to ...
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2answers
141 views

What's a good set of PWM values to make sine waves for a 3 phase motor?

I'm building a synchronous rotating spark gap for a tesla coil. I have a working mcu (Kinetis K64F) driving a 230volt inverter board and it spins a 3 phase synchronous motor. The motor is a ...
0
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2answers
102 views

Calculate a voltage angle offset for a 3-Phase utility meter

I'm trying to analyze and write a program around some data that I was given. The data is a collection of readings from 3 Phase smart meters of an electrical utility. One value in the data that I can ...
2
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2answers
336 views

Will a RCBO 4P trip in case of neutral fault/failure/interrupt/float?

We have 3 phase power supply in my home which is used to power single phase 240V 50 hz appliances with common neutral. (Diagram in the link at the bottom) The only protection we have as of now are ...
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1answer
214 views

Question regarding a resistor in optocoupler/TRIAC circuit

I'm building a ac motor starter with a optocoupler (FOD4218) and a TRIAC (BTA16), one for each phase in a three phase 400V system. I have a question regarding the circuits that can be found all over ...
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2answers
662 views

Choosing Diodes for 3-Phase Rectifier

I'm building a rectifier to rectify a 3-phase signal for part of a school project, so I'm not working at these power levels without help and supervision. This seems to be an appropriate circuit as ...
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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 ...
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3answers
108 views

Power on a three-phase system

Given a balanced three-phase voltage source and unbalanced loads connected in wye whose individual apparent power dissipation and power factor are given, find the the line currents. What is your ...
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1answer
147 views

AC Machine Stator Winding

In designing a 3 Phase, 4 Pole, 24 Slot AC machine assuming a RYB phase sequence i am confused on the starting point of the blue phase. The calculations, table and diagram look like the following. ...
3
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2answers
404 views

Three-phase Y and Delta Configurations Polarities

Please take a moment to look at the three-phase Y and Delta configurations pictures below (The pictures are screenshots taken from the “All About Circuits” online book). The first picture (Y ...
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1answer
54 views

3-Phase Generator Frame Ground

I have a couple of basic questions on three phase generator connections. I am trying to connect a three phase machine (datasheet) as a generator to a three phase load on a breadboard, as shown: ...
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2answers
287 views

Calculating Active power in 3 Phase

When calculating the active power in the 3 phase Star, and Delta formations, there are two different currents used depending on the layout. I have shown my working below, with what I have been taught. ...