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In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits.A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core.
Most single phase alternating-current electrical outlets in the world supply power at 210–240 V or at 100–120 V. A transformer or autotransformer can be used; (auto)transformers are inherently reversible, so the same transformer can be used to step the voltage up, or step it down by the same ratio. Lighter and smaller devices can be made ...
A solid-state transformer usually contains a transformer, inside the AC-to-AC converter or DC-to-DC converter, which provides electrical isolation and carries the full power. This transformer is smaller due to smaller DC-DC inverting stages between transformer coils, which consequently mean smaller transformer coils required to step up or step ...
The invention of a practical, efficient transformer made AC power distribution feasible; a system using distribution transformers was demonstrated as early as 1882. [2] If mounted on a utility pole, they are called pole-mount transformers. Suppose the distribution lines are located at ground level or underground.
The insulation of the transformer windings must be specially designed to withstand a large DC potential to earth. Converter transformers can be built as large as 300 Mega volt amperes as a single unit. It is impractical to transport larger transformers, so when larger ratings are required, several individual transformers are connected together.
Ferro-resonant transformers run hotter than standard power transformers, because regulating action depends on core saturation, which reduces efficiency. The output waveform is heavily distorted unless careful measures are taken to prevent this. Saturating transformers provide a simple rugged method to stabilize an AC power supply.
Operating at high frequency and supplying low power, power converters have much smaller transformers compared with those of fundamental-frequency, high-power applications. The current in the primary winding of a transformer help to sets up the mutual flux in accordance with Ampere's law and balances the demagnetizing effect of the load current ...
The phenomenon can be avoided by connecting a minimal resistive load on the transformer secondaries or by interrupting the applied voltage by a 3-phase interrupting device such as a ganged (3-pole) circuit breaker. [8] In many cases, it also suffices to unground the transformer in a Δ configuration, which increases the line shunt impedance.