Questions tagged [power-engineering]

Power electrical engineering. Includes industrial electrical engineering (i.e. motors, switchboards), transmission and distribution (poles, wires, transformers, grids) and generation.

Filter by
Sorted by
Tagged with
-1
votes
1answer
31 views

How power system handle unbalanced load?

how a delta connected primary winding of three phase distribution transformer tackle unbalanced load of three phase 4 wire unbalanced load(unbalanced load is quite common due to supply of single ...
0
votes
3answers
112 views

Short circuit current calculation

** I DON'T WANT THE SOLUTION ** The question is: A three phase 50MVA, 4,160V generator with a reactance of 7.9% is connected to a three phase 4,160V/480V step down transformer rated for 1.5MVA with an ...
1
vote
4answers
319 views

Electrical phase in a power grid and power transmission

I'm very new to the study of power grids and I'm having some trouble understanding some very basic concepts. I have been looking at the problem of synchronisation on power grids and I'm not quite sure ...
3
votes
1answer
72 views

Fault Ride Through requirements for wind turbines

First a short introduction: (the question is below the first image). The capability of fault ride-through of wind turbines is the most important requirement related to national grid codes. Based on ...
0
votes
0answers
57 views

Transformer load

I have 50 kVA delta-wye transformer with 3 single phases secondary (line-neutral) delivered to 3 houses, So if one of the 3 houses drown more power would that affect another 2 houses, or each phase ...
3
votes
1answer
85 views

Sequence Impedance/Zero Sequence Impedance of lines

I am trying to calculate the Sequence Impedance/Zero Sequence Impedance of couple of lines, but Im not sure if the calculation are right, and besides there are some tricky things on the data provided. ...
0
votes
0answers
28 views

What does pole rating and bipole rating mean for HVDC transmission cables?

I was just reading on HVDC underground cables. And according to the picture below, as they were listing out the parameters of the cables used, they mentioned pole ratings and bipole ratings. How are ...
0
votes
1answer
93 views

Arlec grid connect bulb and power points DC convert smart WiFi hack

These devices works off 240V AC. I was looking to convert them to run off DC and keep the grid connect app function. https://www.bunnings.com.au/arlec-9w-950lm-4000k-grid-connect-bc-smart-...
2
votes
1answer
66 views

How does the grid handle small deviations of power consumption when most of load is regulated?

This is a continuation of this question. Suppose we have a grid which distributes say one gigawatt total power and all this power is perfectly fully consumed by electrical devices. However all ...
0
votes
0answers
9 views

Installing 4 ploe Rccb

Could I install 4 pole RCCB for unbalance 3phase load (like residential building) ? How does 4 pole RCCB work? Thank you.
0
votes
1answer
57 views

2 simultaneous voltages from a transformer

I need a step down transformer that can give me 2 voltages simultaneously. Primary will be 380vac and secondaries will need to be 24 vac and 12 vac. Instead of using 2 transformers, I would like to ...
0
votes
3answers
68 views

How to tap the full power of a 3-phase circuit

I know I can power my high voltage single phase AC or DC circuit by tapping either one of the L-1 to L-3 legs and return a neutral to the neutral line however I'll only get as much power from one 60Hz ...
0
votes
3answers
64 views

How do appliances prefer to use my solar power from a grid-tie inverter over the power from the grid?

I have a grid-connected solar inverter. In the swtich board the incoming wire from the street, the incoming wire from the inverter and the outgoing wire to the loads in my house are all connected ...
3
votes
1answer
65 views

How does a grid-tie solar power inverter know when the mains power has failed?

Solar power inverters that send excess solar power back to the grid are (usually) required to shut down if the grid power fails. (This is to protect people working on the power lines.) The inverter ...
0
votes
0answers
44 views

How close can a circuit board be to an overhead power line without being effected by EMI?

I am researching a technology that will need to put some circuitry near a power line used on the electric grid and I was trying to determine how close can I get to the power lines with my circuit ...
0
votes
2answers
67 views

Can switching between two unsynchronized sources cause problems for an average office building?

We have a 100kW 3Φ 208V generator and ATS operating in North America. The system as installed does not allow for a test where the load can be placed on generated power when utility is available. We ...
0
votes
2answers
107 views

Confusion in modelling of total loop inductance of a rectangular loop

I was reading an article about partial and total loop inductances from this site and in a section where for calculation of total inductance of a rectangular loop is given as: In each portion of the ...
0
votes
0answers
26 views

Tertiary control loop in Automatic generation control of Power system

Here I need help with AGC related research paper. I have certain confusions about tertiary control... Why do we use tertiary control loop in automatic generation control of Power system? Because ...
0
votes
0answers
14 views

NEPLAN Load Flow Analysis with 1-day measurement

currently I am working on a project to identify energy loses in an electrical network. I am using NEPLAN 10, and already build a small system and implemented measurements. As soon as start the ...
-1
votes
3answers
88 views

How does electricity from a 3 phase 4 wire 480Y/277v EV meter differ from a standard 120v wall outlet?

I am wondering what the difference is the electricity that comes out of the switchboard/utility meter that is designed to be a separate meter to measure a customer's use of power that only goes to an ...
4
votes
4answers
144 views

what role does transmission line termination take in long distance power lines?

Does transmission line theory and transmission line termination take any significance when dealing with long high-voltage power lines? Do power companies terminate their power lines to avoid ...
0
votes
3answers
194 views

Is there a circuit element which dissipates energy but does not act as a resistor? [closed]

I know this sounds a bit weird, but is there a circuit elements which dissipates energy if a current flows through it but is not a resistor? In other words, is there an energy sink which does not ...
0
votes
0answers
51 views

Can electronic devices be installed on the pillar of UHV towers such as 345kV?

Can electronic devices be installed on the pillar of UHV towers such as 345 kV? Because I have an idea to install a remote automatic control electronic device on the tower to control the rotation and ...
0
votes
0answers
60 views

Inductance of composite conductor

Why L is calculated using average value and not by the formula 1/L = 1/L1 + 1/L2 + ...
3
votes
2answers
80 views

Delta-Wye transformer differential protection during external line to line faults [closed]

During these kind of line to line faults current flows in the faulted phases of the secondary and all phases of the primary as it is shown in the image. So now the currents in phase A are not equal to ...
1
vote
0answers
76 views

Calculating the line-to-neutral voltage of a generator

A three-phase generator is connected to a strong grid with line-to-line voltage 14 kV and frequency 50 Hz. The generator is rated at 15 kV and 180 kVA. The resistance in the windings is 2 Ohm/phase ...
0
votes
0answers
31 views

Selecting the correct wire for very short power transmission

Looking for the thinnest wire for very short distance power transmission. Supply is 5V, 10A. Ambient temperature is 35C. There are 5 consuming elements, each consuming 10W. The elements are linked ...
0
votes
3answers
52 views

What happens when a multi-fuel generator reaches capacity on LPG or NG?

I have a multi-fuel generator rated for 7.5KW on gasoline, 5.5KW on natural gas. It has a 30A circuit breaker that will trip if demand exceeds capacity on gasoline I would like to understand in some ...
1
vote
0answers
28 views

How much information would a network protector need to determine if a backfeed is due to feeder failure or power export?

Many downtown or otherwise densely built-up areas, as well as some major metropoles (much of NYC, most notably), use secondary network electrical service to maximize service reliability and keep ...
-1
votes
2answers
65 views

frequency for a 90° phase shift [closed]

It seems an easy question but I just can find out how I'm supposed to do it: what frequency is needed so that Vin and Vout have a 90° phase shift. (picture below just as a matter of an example circuit)...
17
votes
4answers
5k views

How can energy "physically" be fed back into the grid?

I have found some similar questions (below), but I am still having issues understanding what is "physically" happening when energy is "fed back into the grid" and the equipment ...
0
votes
0answers
56 views

Offgrid backup AC power option

I’ve been building an off grid home for a few years - recently moved in full time. Living in VT, with limited solar, we depend on a Honda EM6500SX 240v generator to occasionally recharge 20 batteries ...
0
votes
0answers
58 views

Convert AC grid to DC and back to AC grid same phase

I would like to execute long time running transistor switch tests with high currents. I would like to source AC power from grid, convert it to DC, pass through my transistor switch, after that I want ...
1
vote
1answer
58 views

How are ground wires and OPGW connected to ground and neutral point of transformer, and to the com.system?

Note: This question is about power systems in the kV, MVA range. Many distribution and transmission systems are impedance grounded, which means that (some of) the transformer neutrals are connected to ...
0
votes
1answer
55 views

Two electrical sources for one load

How can two electrical sources 220 volts feed one electrical load about 20 amperes where the first power source spends all its capacity and when required the remainder is taken from the second source?...
0
votes
2answers
2k views

How generator becomes under excited/ over excited?

I keep reading in power system notes that a generator when under excited/ over excited either absorb/ release reactive power. Question is, what determines these under excitation and over excitation? ...
0
votes
0answers
16 views

Can we control the data sending by Phasor Measurement Unit (PMU)?

Since PMU send the data after sampling the data to the PDC. Can we design any scheme so that PMU send the data to PDC only when I want? That means to reduced the communication bandwidth can we design ...
0
votes
1answer
103 views

Why are current transformers used in power stations?

I read that surge arresters in power stations suppress the high incoming voltage and the output passes on to the current transformer. If surge arrester already reduced the voltage then why is the ...
12
votes
3answers
2k views

Australia–ASEAN Power Link - why not build the solar farm near Singapore?

World's Largest Solar Farm to Be Built in Australia The 10GW, 120 square km solar farm in Australia is connected to Singapore via a 4,500-kilometre high-voltage direct current (HVDC) network. The ...
1
vote
1answer
147 views

What cause sudden spike in the output voltage of transformer?

What issues can cause the output voltage of a transformer to suddenly increase from 230 volts to 400 volts (in the case of any transformer and in the case of the delta to Y configuration of the ...
5
votes
2answers
265 views

Transmitting VCC and GND signals for use with RS-485

The specific question I want to ask is whether I can transmit VCC(5VDC) and GND power signals for powering the destination circuit (in an RS-485 arrangement) or not. The power lines will be grouped ...
0
votes
0answers
53 views

Reactive power of a discharged capacitor

I was wondering if a DISCHARGED capacitor connected to a grid gives to this one a positive reactive power. Is it yes? If not, it's true to say that only charged capacitors gives positive power to the ...
1
vote
0answers
33 views

Equipment for analyzing large DC distribution system

I'd like obtain the transfer function of a large DC power distribution system. My question is whether there's equipment (like vector network analyzers) designed to assist with modeling these type of ...
1
vote
0answers
78 views

Nodal voltage magnitude properties of electricity distribution networks

I am wondering how to know about an electric bus according to its measured voltage magnitudes (possibly and its corresponding real power injection profile). Following assumptions can be made: One ...
3
votes
2answers
255 views

Need help to understand inductor based non-isolated offline buck converter [closed]

Here ADGJ IC is used in offline buck topology. Can anyone share the schematic of it. Picture taken from sonoff mini and shelly1 board is attached below
1
vote
0answers
38 views

Where do I find electrical power transmission grid data?

I am looking for websites which provide datasheets of 3 phase electrical power transmission networks with information about their ...
1
vote
1answer
44 views

About signal conversion

Question is weird but it's about something that I really want to try. AC power here in India has 50Hz frequency. What I really want to try is to make a series path with two continuous conversions. In ...
1
vote
0answers
88 views

Laplace vs Fourier Transforms in Transmission Lines

Consider an electric transmission line with transient equations $$\frac{\partial v}{\partial x} =-Ri -L\frac{\partial i}{\partial t}, \qquad \frac{\partial i}{\partial x} =-Gv -C\frac{\partial v}{\...
3
votes
2answers
75 views

Phase voltage in impedance grounded vs solidly grounded system during ground fault

Why does a phase-ground fault in an impedance grounded 3-phase system lead to variation of voltage in healthy phases but this variation doesn’t happen in solidly grounded systems? I was thinking about ...
-1
votes
1answer
49 views

Transformer cooling difference between water cooling and air cooling [closed]

I just know air cooling method is cheaper than water cooling method. Please tell me what is the difference between air cooling and water cooling? And if you could please use some pictures to explain ...

1
2 3 4 5
9