Wye/Delta or Y/∆ Connection
The main use of this connection is at the substation end of the transmission line where the voltage is to be stepped down. The primary winding is Y-connected with grounded neutral as shown in Fig. 33.6. The ratio between the secondary and primary line voltage is 1/ 3 times the transformation ratio of each trans- former. There is a 30° shift between the primary and secondary line voltages which means that a Y – D transformer bank cannot be paralleled with either a Y – Y or a D – D bank. Also, third harmonic currents flows in the D to provide a sinusoidal flux.
Delta/Wye or ∆/Y Connection
This connection is generally employed where it is necessary to step up the voltage as for example, at the beginning of high tension transmission system. The connection is shown in Fig. 33.7. The neutral of the secondary is grounded for providing 3-phase 4-wire service. In recent years, this connection has gained considerable popularity because it can be used to serve both the 3-phase power equipment and single-phase lighting circuits.
This connection is not open to the objection of a floating neutral and voltage distortion because the existence of a D-connection allows a path for the third-harmonic currents. It would be observed that the primary and secondary line voltages and line currents are out of phase with each other by 30°. Because of this 30° shift, it is impossible to parallel such a bank with a D – D or Y – Y bank of transformers even though the voltage ratios are correctly adjusted. The ratio of secondary to primary voltage is 3 times the transformation ratio of each transformer.
Example 33.1. A 3-phase, 50-Hz transformer has a delta-connected primary and star-connected secondary, the line voltages being 22,000 V and 400 V respectively. The secondary has a star- connected balanced load at 0.8 power factor lagging. The line current on the primary side is 5 A. Determine the current in each coil of the primary and in each secondary line. What is the output of the transformer in kW ?
Solution. It should be noted that in three-phase transformers, the phase transformation ratio is equal to the turn ratio but the terminal or line voltages depend upon the method of connection employed. The D/Y connection is shown in Fig. 33.8.
Example 33.6. A 100-kVA, 3-phase, 50-Hz 3,300/400 V transformer is D-connected on the h.v. side and Y-connected on the l.v. side. The resistance of the h.v. winding is 3.5 W per phase and that of the l.v. winding 0.02 W per phase. Calculate the iron losses of the transformer at normal voltage and frequency if its full-load efficiency be 95.8% at 0.8 p.f. (lag).
(A.C. Machines-I, Jadavpur Univ. 1989)
Example 33.8. A 3-phase transformer has its primary connected in D and its secondary in Y. It has an equivalent resistance of 1% and an equivalent reactance of 6%. The primary applied voltage is 6,600 V. What must be the ratio of transformation in order that it will deliver 4,800 V at full-load current and 0.8 power factor (lag) ?
(Elect. Technology-II, Magadh Univ. 1991)
Tutorial Problem No. 33.1
1. A 3-phase, star-connected alternator generates 6,360 V per phase and supplies 500 kW at a p.f. 0.9 lagging to a load through a step-down transformer of turns 40 : 1. The transformer is delta connected on the primary side and star-connected on the secondary side. Calculate the value of the line volts at the load. Calculate also the currents in (a) alternator windings (b) transformer primary windings (c) transformen secondary windings.
[476 V (a) 29.1 A (b) 16.8 A (c) 672 A]
2. A 11,000/6,600 V, 3-f, transformer has a star-connected primary and a delta-connected secondary. It supplies a 6.6 kV motor having a star-connected stator, developing 969.8 kW at a power factor of 0.9 lagging and an efficiency of 92 per cent. Calculate (i) motor line and phase currents (ii) transformer secondary current and (iii) transformer primary current.
[(a) Motor ; IL = Iph = 126.3 A (b) phase current 73 A (c) 75.8 A]
Incoming search terms:
- 86 OR CHINA Transformer\ @126 com mail
- current transfomer ratios calculation on star delta transformer
- delta wye transformer phase shift power factor correction
- VS DELT YY TRANSFORMERS
- convert 100 kva to kw 3 phase#imgrc=WLgminkxjJGKkM:
- delta wye transformer calculations
- 15mva 33/11kv winding connection
- 3 single phase loads each of Kw and having a powerfactor of lagging are connected in delta to the star connected secondary of transformer the secondary phase voltage of transformer is 6 6kv calculate the voltage across eachload and the current in each loa
- 3 star connected aditical coils are suppyed by 200V 3Phase suppy each coil are take 1000W the power facter is O Point 8 lagging what are the line current If total power of coils are in delta connection Ans
- a transformer bank of 7 967KV/230V each are connected in wye-delta connection supply a three phase load of 100kVa
- equivalent tranformer wye delta of 3
- factors determining traformer ratio in three phase transformer
- factors that determine the transformation ratio of a three—phase transformer?
- observation the phase shift in delta wye transformer in 3 phase transmission line
- solution to A thrre phase 415V load takes a line current of 800A from a 3300/415V delta-star transformer
- the turns ratio of a 11000/415 V Delta/Star connected 3phase transformer is ------------
- what are the factors that determine the transformation ratio of a three phase transformer
- what are the factors that determine the transformation ratio of a three—phase transformer?
- what is the winding connection that will b suitable for a 15MVA/11KV 50Hz three phase transformer
- 100kva 11000/440v single phase transformer calculate the full load current
- 11000 V transformer connecation
- 11000/415 delta-star transformer feeds power to a30 kw 415v 3 phase induction motor having an efficency of 90%
- 11000/415 transformer
- 11000/433 v transformer line voltage determine
- 11kv to 415v transformer
- 11kV transformer has line or phase voltage
- 11kv/440v delta to delta transformer
- 3 - 10 kva 1330/230v 50Hz transformers are connected in star delta to supply a 230V line to line heating load of 2 kW per phase and 3 phase induction motor load of 21kVA The power factor of induction motor load is 0 8 Determine the line current supplying
- 3 pahse star Delta transformer and solution
- 3 phase 415v delta connected full load current is
- 3 phase delta star transformer efficiency
- 3 phase y-delta
- 3phase delta star transformers problems
- 3phase high tenssion transformer y connection
- 400v ac connection to a 11kv transformer
- 50kw 440v 3 phase across motor efficiency 90% 0 8 lagging power factor supplied by 6600/440v delta star currents calculate
- a 3 phase 33000/6600 v
- a 3 phase delta star transformer is supplied at 6000 v on the delta connected side the terminal voltage on the secondary side when supplying full load at 0 8 lagging power factor is 415 v the equivalent resistance and reactance drops for the transformer a
- a 3 phase star connected alternator generates 6360 v per phase and supplies 500kw
- a 3 phase transformer has its primary connected in delta and secondary connected in star secondary to primary turns ratio per phase is 5 what would be the secondary voltage for a primary voltage of 400v
- a 3-phase ac motor has efficiency of 90% power factor 0 8 delta-star transformer calculate phase currents
- A 400 V 3-phase star connected alternator supplie
- a 50 hp 440v three phase induction motor with an efficiency of 9 and power factor 85 an full load is supplied from 6600/440v delta to star connected transformer ignoring exciting current calculate current in low and high voltage winding of transformer whe
- a 50kw 440v phase ac motor has an efficiency of 90% and operates at 0 8 lagging power when on full load it is supplied by a 6600/440v delta star
- A three - phase 415V load takes a line current of 800A from a 3300/415V delta-star transformer The 3300V system is supplied from an 11000/3300V star- star transformer a ) Draw the network diagram and assuming no losses find both line and phase values of v
- a three phase transfomer has star and delta connected and load is connected to secondary side resistive load and find the impedance on primary side
- A three-phase 415 V load takes a line current of 800 A from a 3300/415V delta – star transformer The 3300V system is supplied from an 11000/3300V star – star transformer Draw the circuit diagram and assuming no losses find both line and phase values of vo
- a100Kva 11000/410V three phase transformer has its primary connected in delta and secondary in star If the number of turns of primary winding per phase is 1022 Calculate the number of turns per phase of the secondary winding calculate also the fullload cu
- At sub-station end of transmission line the transformer connection are A Star star B Delta delta C Star delta D Delta star
- calcularing line current on dy 11000/400
- calculate ratios on the hv side and lv side of transformer
- calculate voltage ratio of a three phase delta star connected transformer that delivers a line voltage of 346 41 V when connected to a 6kV supply
- consider 11KV/400v step down distribution transform delivers 200KVA balanced load and 120KW active power calculat reactlv power and power facter?
- delt delta star transformer
- delta wye primary and secondary voltage calculations
- delta wye transformer in 3 phase transmission line
- delta wye transformer vendor for machinery
- describe the winding connection suitable for a 15mvA 33/11kv 3-phase transformer
- do we use phase or line values to calculate transformation ratio in 3 phase
- electrical 3phase transformer connection arts name
- has gained considerable popularity to serve 3–phase equipment and single phase lighting load is
- how are current transformers connected in delta and Wye to measure line currents?
- how do identify neutral in delta connected 500kva alternator?
- How to connect a100kva transformer to HT line
- how to find secondary current in 3 phase star delta transformer
- how to solve for phase voltage of grounded wye transformer given line to line voltage
- loss of phase on a delta connected transformer
- lv side of transformer
- name and describe the windings connection of 15mva
- name the winding connection of 15MVA 33/11KV three transformer
- observation the phase shift in delta wye transformer in a three phase transmission line
- observations on three phase transformers voltage ratios
- phase shift delta to wye transformer
- power transformer coneection at alternator side
- reactance value of 15 MVA 11/33 kV step up transformer
- solved problems on three phase star delta step down transformer
- star connected lighting load and Delta connected lighting load
- star delta transformer ttr
- star-delta transformer turns ratio of 1:8
- step up 415V/11KVtransformer connection terminal
- substation transformers delta delta or star Wye
- the resistance and reactance of 100kva 11000/400v delta-star distribution transformer 0 02 and 07pu respectively
- the resistance and reactance of a 100 kva 11000/400v delta star distribution transformer are 0
- the resistance and reactance of a 100KVA 11000/400V delta star distribution transformer are 0 02 and 0 07 pu respectively the phase impedance of the transformer refered to primary is
- the resistance and reactants of a 100 kva 11000/400v delta to star distribution transformer are 0 02 and 0 07 pu respectively the phase impedance of the transformer referred to the primary is
- The transformer connection which has gained considerable popularity to serve 3–phase equipment and single phase lighting load is#spf=1
- the turns ratio of 11000/415 delta/star connected 3phase transformer is
- the winding connection for 15MVA 3phase transformer
- the winding connection for a 15mvA 33/11kv 3-phase transformer
- three phase transformer 261 turns secondary 2488 primary 6600v 50Hz 3phase supply calculate no load secondary line terminal voltage star delta
- Three phase transformer which lag behind in delta star winding
- Transformer connection for 15MVA
- Variable-frequency transformer mail
- what are the factors that determines the transformation ratio of three phase transformer
- what is a high and low wye
- What is d winding connection for 15MVA 33/11Kv three phase transformer
- what is problem delta to star connected deliver full load?
- what is the name of 15MVA 33/11kv 3 phase transformer
- why delta connection is required in high tension side
- why delta connection is required in high tension side and wye connection is required in low tension side
- why delta connection is required in high tension side and Y connection requrid low tension side in transmission line
- Why should a step up primary transmission station be delta connected
- winding connect of 15 MVA 33/11kv 3 phase transformer
- winding connection for 15MVA 33/11kva star - star delta- delta or star - delta connection
- Winding connection of 15MVA 33/11KV 50Hz Three phase transformer
- winding connection of a 15mva 33/11kva three phase transformer
- wye wye conncetion windings observation