what is star-open delta connetction in three phase transformers?
374405
Star-delta systems, as they are known in Great Britain and Europe, (transformers, motor starters, line reactors, electrode boilers etc) are essentially the same as what America refers to as delta wye systems, the only difference being in geographic terminology. \nThe phrase refers to two connection methods of a device in a three-phase electrical system: an example would be a distribution transformer with a delta primary, running on three 11KV phases with no neutral or earth required, and a star (or wye) secondary providing three 240v phases and an earthed neutral point.
458600
You say 3 phase, so the simple amps times volts doesn't work.\n\nThe complete formula is KW= 1.73 * amps * volts * power factor /1000\n\nThe 1.73 is the square root of 3.  The amps is your line current (same as phase current if it is wye, not the phase current of a delta) and the volts is the phase to phase voltage (not phase to neutral of a wye).  Power factor is 1 for simple resistive loads, and is less than 1 for inductive loads such as motors and fluorescent light ballasts.\n\nIf you take the power factor out of the formula, you get apparent power measured in KVA.
277131
Three phase transformers are used change values of three phase voltage and current. three phase power is the most common way in which power is produced, transmitted, and used. Three phase has properties that make it very desirable in distribution. Firstly all three wires carry the same current. Secondly power transfer into a linear balanced load is constant. Generators output at a voltage that ranges from hundreds of volts to 30,000 volts. At the power station, transformers "step-up" this voltage to one more suitable for transmission.
998615
In order to use the generator more effectively a phase is spli into three namely R,Y,B. each 120 phase shift from other.\nThe power generated is transmitted by 3phase-3 wire system considering economy.\nIn distribution side there are low consumers for whom Single phase power feeding is inhalf. For them a seperate cnductor called neutral is provided ad a return path.\nNeutral also helps to balance the load during unbalaced loading/fault.\nNeutral is a point that is taken from the meeting point of three phases and is usually grounded to ensure balanced loading.\n\nIn dc +ve side is something where excess protonsr present and flow towards otherside and -ve side contains full of electrons which flow towards +ve side.\n\nu can visit www.play-hookey.com
387680
Ok...you guys got this all wrong.  Voltage doesn't travel.\nThis is simple:\n\nSeries:\nAll series stuff see the same current\n\nParallel:\nAll parallel stuff see the same voltage
752334
I have no idea what you mean by an "Eight Bus System"...... Please define it. \nHowever, an on load tap changer on the transformer being fed from the generators will help the reactive loading on the generators. It will keep the voltage stable on the generator bus thereby tending to keep the generator's output at or close to unity PF. Instead of the AVR holding the bus voltage at the required voltage and the generators providing the the VARs.
831085
"Three-phase electrical generation is very common. Three separate coils in the generator stator are physically offset by an angle of 120° to each other. Three current waveforms are produced that are equal in magnitude and 120° out of phase to each other."\n\nFrom Wikipedia, the free, online encyclopedia at:\nhttp://en.wikipedia.org/wiki/Alternating_current\n\nMore on three-phase on Wikipedia at:\nhttp://en.wikipedia.org/wiki/Three_phase\n\nFurther links are available on both pages...\n\nHope this helps!
851608
WYE connections reference the line values of current and voltage to a "hard-wired" neutral. This means  \n (line voltage) = 1.732 * (phase voltage)\n (line current) = (phase current)\nThis is a much easier system to use when manufacturing an electric machine ... there will be a "neutral" - complete with leads - that can be used when troubleshooting.\n\nDELTA connections reference the line values of current and voltage to a "theoretical" neutral. This means \n (phase voltage) = (line voltage)\n (phase current) = (line current) / 1.732\nBecause of the "theoretical" nature of the neutral connection, the winding can experience far harsher effects from harmonics than the standard WYE version. Thus it isn't used as often in large machines ... although it's fairly common in smaller (<100 HP) designs.\n\nAny 3-phase machine can be used in either format; in fact, most multi-speed windings employ one of each.\n\nThe simplest advantage may come when looking at transformers, though. With a WYE-DELTA transformer, there is no possibility of ground faults between the input and output sides (unless, of course, a major accident happens!). IT also has an immediate 1.732 ratio in terms of voltage/current ... even if the turn count is the same on both sides.
1040867
Using 3 phase current, it is possible to get 3 times the energy down the same wire - so it is much more efficient.  Each phase is 120 degrees out from the others, so the signal looks kind of like braided hair, when one phase is at the peak, the other two are crossing at 70%, one going up the other going down.  Once we get the energy to where we want to use it, then we can tap off the different phases for single phase use. \n\nI forget about the delta and wye stuff, it's been a while. \n\nCheers!
1022654
Good previous answer on the engineering side, also depending on the type of load served, local distribution requires balancing of  "peak loads" and balancing the power factor to correct for highly inductive(motors,etc) or capacitive (computers,etc) loads.  Wattless or "reactive" power has to be accounted, for proper operation of three phase systems and is usually measured in power plants with a VAR meter, which measures Volt Ampere Reactive loading not shown on Kilowatt meters.\n\nThe main components of the system are:\nGenerators, Switchgear, Instrumentation and protective relays, Transformers, Capacitors, Reactors, and the towers, insulators, and miles of wires to carry electricity where we want it.\n\nAlso in power plants, batteries..a series bank of about 1500ah per 12 v cell to provide contol power backup to switch the motor operated, large circuit breakers of 600 amps and up.  The batteries in some plants are also used to flash and strengthen residual magnetism in the exciter for feeding current through the slip rings to the alternator's rotor on generating equipment.
169135
Simply put, the generator voltage (volts), frequency (Hz) and power (watts) and phase (single/three) are called ratings. These are selected to suit the load that will be connected. and the environment in which it will be used
742046
For three phase AC powered loads, three separate power lines provide power to the load. The voltage waveforms on these three lines differ only in their timing, or phase relationship. A fourth wire may provide a neutral connection to the load. In the case of balanced loads, where the current in each of the three phases is equal, the current in the neutral wire will be zero. The neutral wire may therefore be eliminated, as it is not necessary for the purpose of carrying current. The vector sum of the currents drawn from the three phase lines will be zero with a balanced load. A non-zero sum of the current indicates an unbalanced load and that a current is returning to the generator, or current source, via an unintended path. This is the ground fault current.\n\nThe ground fault current for a three-phase system, without neutral, may be measured by performing a vector summation of the phase currents. This summation may be performed by a current sensing transformer with the phase currents passing through the common aperture in parallel. The magnetic field induced in the transformer core is then the vector sum of the three individual phase currents and the voltage induced in the secondary winding placed on the transformer provides a signal representing the vector sum of the currents, the ground fault current.\n\nThe electrical characteristics of ground faults in solidly grounded WYE systems allow for simple detection of ground currents by monitoring the phase and neutral currents for a simple unbalance in those currents. The principle is that the current going to the load on the normal phase and neutral conductors should return via those same conductors. Any missing current is deemed a fault to ground on the load side of the detector and, when that unbalance exceeds a set threshold, a ground fault is determined. The basic ways of measuring this unbalance for solidly grounded four-wire systems use one ground sensor surrounding the phase and neutral conductors, four individual current transformers connected in a WYE configuration, or four voltage sources connected in a delta configuration.
93725
Three phase or two phase?
412964
use the delta when you are starting a large motor since it can be hooked to energize only part of the windings of the motor at a time this allows for less amperage to be used to get the thing turning
78853
It is IEEE standard 754. See the link below to see exactly the details of how to apply this standard.
1076888
By reduces the target distance is one way to reduce power losses in transmission lines.\nuse capacitors and also a amplifiers as junction between sources and destination.\n\nstep transformer is more usefull.
803633
It is a step down transformer.\nNs/Np = 6/220\nwhere Ns is the number of turns in the secondary and Np is the number of turns in the primary.