Delta-wye transformer

Delta-wye transformer
Not to be confused with Y-Δ transform.

A delta-wye (Δ-Y) transformer is a transformer that converts three-phase electric power without a neutral wire into 3-phase power with a neutral wire. It can be a single three-phase transformer, or built from three independent single-phase units. The term Delta-Wye transformer is used in North America, and Delta-Star system in Europe.

Delta Wye Transformer

Delta-wye transformers are common in commercial, industrial, and high-density residential locations, to supply three-phase distribution systems.

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 a 3-phase supply at 400 V, with the domestic voltage of 230 available between each phase and an earthed neutral point.

Contents

Output voltages

The line-to-neutral voltage is the voltage between any phase and neutral. The line-to-line voltage is the voltage between any two phases, and is equal to the phase to neutral voltage x \sqrt{3} in balanced steady-state operation.

Phase-to-neutral voltage Phase-to-phase voltage (rounded)
120 208
127 220
220 380
230 400
240 415
250 433
277 480
347 600

Advantages

The closed circuit on the delta side provides some benefits. Voltages on the secondaries have improved balance. Also it cancels third (or ninth et cetera) harmonics since these are not supported on the three-wire system.

Phasing

Delta-wye transformers introduce a 30 degree phase shift. Thus they cannot be paralleled with wye-wye (or delta-delta) transformers; they can be paralleled with other delta-wye (or wye-delta with some attention) transformers.

See also

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Distribution transformer — Single phase distribution transformer in Canada A distribution transformer is a transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the… …   Wikipedia

  • Zigzag transformer — A zigzag transformer is a special purpose transformer. It has primary windings but no secondary winding. One application is to derive an earth reference point for an ungrounded electrical system. Another is to control harmonic currents.As with… …   Wikipedia

  • Pylon transformer — Because of weight restrictions transformers for pylon transformers are only built for voltages under 30kV.Pylon transformers are often used for the power supply of facilities outside settlements, such as farmyards or pumping stations at voltages… …   Wikipedia

  • Y-Δ transform — For application in statistical mechanics see Yang Baxter equation. For the device which transforms three phase electric power without a neutral wire into three phase power with a neutral wire, see delta wye transformer. The Y Δ transform, also… …   Wikipedia

  • Polyphase system — A polyphase system is a means of distributing alternating current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each… …   Wikipedia

  • Mains power systems — This article includes a list of countries and territories, with the plugs, voltages and frequencies they use for providing electrical power to small appliances and some major appliances. For definitions of terms and further information on each… …   Wikipedia

  • Mains electricity by country — This article includes a list of countries and territories, with the plugs, voltages and frequencies they use for providing electrical power to small appliances and some major appliances. For definitions of terms and further information on each… …   Wikipedia

  • Ground and neutral — For uses of the term ground or earth in electricity but not in the context of mains wiring, see ground (electricity). Since the neutral point of an electrical supply system is often connected to earth ground, ground and neutral are closely… …   Wikipedia

  • Ferroresonance — The phenomenon of Ferroresonance is the occurrence of an unstable high voltage, typically on 3 phase electrical systems which only occurs under specific conditions. The nature of the overvoltage can cause the failure of equipment.Ferroresonance… …   Wikipedia

  • Electricity distribution — is the penultimate stage in the delivery (before retail) of electricity to end users. It is generally considered to include medium voltage (less than 50 kV) power lines, electrical substations and pole mounted transformers, low voltage (less than …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”