Questions tagged [power-engineering]
Power electrical engineering. Includes industrial electrical engineering (i.e. motors, switchboards), transmission and distribution (poles, wires, transformers, grids) and generation.
71
questions with no upvoted or accepted answers
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Induction cooker power receiver
While building some small (single digit wattage) inductive power transmission systems, I wondered if a larger one could be build using an induction cooker as transmitter.
What would be the mandatory ...
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Startup and auxiliary/station transformer power parallel to bus
This question is in regard to switchyard/electrical distribution operations in a utility power plant.
During a startup, the electric distribution system is lined up so that the startup transformers ...
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How to calculate the earth fault current in a transmission system with no ground wire?
Background information, and my thought on the matter are provided in the end of the question.
I need to calculate the fault current in case a fault occur for instance 10 km away from a transformer ...
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Deriving power formulas for transmission lines
I'm trying to derive formulas for active power (\$P_s\$) and reactive power (\$Q_s\$) at the sending end of a transmission line shown below:
Where:
\$E_s\$ and \$E_r\$ are voltage magnitudes
\$X\$ is ...
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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
...
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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 ...
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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 ...
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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 ...
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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
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1
answer
47
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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 ...
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Where is my mistake in this power distribution system homework question?
I have attempted to solve this problem, but the answers don't match. Where am I making a mistake?
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TN-S system neutral point earth resistance
According to many sources on the internet, a secondary neutral earth resistor is added at the distribution stations (transformers) to reduce the earth fault current.
My question is when using a TN-S ...
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Why can the total connected load be equal to system capacity ? what does "maximum demand of the entire system" really mean?
I read some factor in the power transmission ,and there are something i don't really understand
Question 1
demand factor \$ = \frac{maximum \ demand}{total \ connected \ load }=\frac{maximum \ ...
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Currents injected in the grid, connecting a wind turbine
I'm studying the connection to the grid of a wind turbine through a three-phase inverter.
Now I understand that , in normal operating conditions, in the connection to the grid, the reference for id ...
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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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How is AC load distributed across on-site generation and the utility?
I’m trying to understand the physics behind AC load distribution when distributed on-site generation is installed and the load is also connected to the grid.
In the diagram below, I have a building ...
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How is voltage induced in Yd transformer without neutral connection sinusoidal?
Thia is regarding bank of 3 single-phase transformers having star connected primary with isolated neutral and delta connected secondary.
I know that for bank of 3 single phase transformer core flux ...
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2
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AD8318 Maximum Input Voltage
let's consider AD8318, a chip which contains a logarithmic amplifier, often used for power measurements.
I have read its datasheet and there is a thing that I do not understand: no maximum input RF ...
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Power Distribution for multiple 5V consumers
I'm a newby in the field of Electrical Engineering (only basic knowledge from school).
Nevertheless, I need to power up to 10 Raspberry Pis (5V, 2A) with Dupont Connectors and AWG24 cables over GPIO ...
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Use of 3 phase transformers which are ∆-Y connected and Y-∆ connected
Different literatures say different things regarding ∆-Y and Y-∆ 3 phase transformer connection...
Some say that ∆-Y is used for step down and Y-∆ is used for step up while others say just the ...
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Power distribution boards - hierarchical numbering system
I wish to renumber the circuit breakers (and possibly the cables) in an industrial plant.
Numbering should give a unique identifier for each breaker.
Numbering should give a path back to the incoming ...
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Determining VA rating of the small transformers
I have a 1000VA toroid transformer which weighs 8 Kg. Based on this power-to-weight ratio, can I conclude that another transformer which is EI cored and weighs 7 Kg must be 875VA? Or such ratiometrics ...
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What is Virtual Array Antenna?
What is virtual array antenna (VAA)?
I have searched it everywhere but i was unable to find direct answer to this question.
I know this concept was built from phased array antenna. Please explain ...
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What is a Thyristor Switched Series Capacitor (TSSC)?
I'm struggling to understand the physical difference between the Thyristor Switched Series Capacitor (TSSC) and the Thyristor Controlled Series Capacitor (TCSC).
From this book, I understand that a ...
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Simple way to achieve constant output current from a boost converter for battery charging in an EV penetration simulation study using EMTP simulation
I am simulating Level 1 and Level 2 EV chargers to test the impact of such chargers on a grid in a developing country. I am simulating in EMTP-RV (software for simulation and analysis of power systems)...
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Solving an AC Circuit Inverter Estimate
This is an electric power engineering question not electronic so this circuit doesn't actually solve. I added it for illustration purposes. Srate = Sout.
I'm trying to solve this below circuit for Vg ...
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57
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Does a control panel that will start/stop two pumps require its own circuit protection?
Does a control panel used to start/stop two pumps require circuit protection for the main 208V feeder lines if those lines are already protected at the main panel in a separate room?
The main panel ...
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For Delta-Wye transformers, with neither side grounded, can one get electrocuted by standing on earth and touching one of the Delta side wires?
It seems to me that there is no path to ground in this case. So, the voltage on the Delta-side of the transformer cannot drive a current through the ground (ie, through the one touching the wire), ...
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How to replace potentiometer with MCP4725 with separate 5v lines
I'm not an electrical engineer, so maybe my concerns are not valid here:
I want to replace a physical potentiometer on a high voltage power supply, which takes 0-5v as the potentiometer input. I have ...
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Digital control root locus verification
I am stuck answering coursework questions with the following Z-transform open loop transfer function
(𝑧) = (0.04𝑧(𝑧 + 0.675)/(𝑧 − 1)(𝑧 − 0.584)(𝑧 − 0.563))
I need to design a digital lead ...
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1
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Grid Voltage Ride Through using PSSE
I am trying to simulate a low voltage ride through (LVRT) lagging case (Qgenerator = max). The inverter seems to be going to momentary cessation, and although the output power at the inverter ...
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1
answer
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What happens on a DC-DC grid connection after a perturbation in the synchronous grid?
Consider the Continental Europe synchronous grid. This power system has some DC-DC connections with other countries (for example one with Great-Britain). Suppose now there is a sudden big outage ...
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Is there anything to limit LED output dimming 50% while the wall dimmer controls 50% to 0%?
We got a project for a client but our lights are too bright for the space, we still want to sell the the lights because we have extra inventory and need a way to dim the LED output to 25W instead of ...
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Sorting very different voltages and use them to charge batteries
I'm working on a project to produce electricity from a source that can produce sometimes negative, sometimes positive voltages, ranging from mV to kV depending on the situation, with very little ...
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1
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How are locations of power plant and distribution substation decided?
I'm trying to design a basic electrical system of a large island and I'm having trouble deciding for the site locations. The existing grid of the island has a diesel plant located near the town but I ...
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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 ...
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1
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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-...
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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 ...
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2
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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 ...
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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 ...
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0
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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 ...
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223
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Inductance of composite conductor
Why L is calculated using average value and not by the formula
1/L = 1/L1 + 1/L2 + ...
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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 ...
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57
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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 ...
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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 ...
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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 ...
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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 ...
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84
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Transmission line current magnitude
I want to compute the current magnitude in a transmission line. The line has properties b (total line charging susceptance, p.u.), ...
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How to handle duty cycle below deadtime in 2- and 3-level inverters
When programming a pwm for a 2-lvl inverter what would be the suggested strategy for a duty cycle close to 0% or 100%, meaning when I cannot guarantee for dead time. What would cause less distortion ...
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Which case count as leading PF in Salient plot generator?
In the figure above we can see the location of two armature currents. In case 1, \$I_{a1}\$ is leading \$Vt\$ (terminal voltage) but lagging \$E_f\$ (excitation voltage). In case 2, it is obvious that ...
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