Vp=−NpΔΦΔt V p = − N p Δ Φ Δ t . This is known as the transformer equation, and it simply states that the ratio of the secondary to primary voltages in a transformer equals the ratio of the number of loops in their coils.

An ideal transformer is a transformer without losses. For an ideal transformer, the secondary load can be represented as an equivalent circuit seen from the primary side (fig. 16-7b), as long as: R = k2. Rs ; L = k2.

The transformer turns ratio is the number of turns of the primary winding divided by the number of turns of the secondary coil. The transformer turns ratio provides the expected operation of the transformer and the corresponding voltage required on the secondary winding.

Transformer voltage regulation is the ratio or percentage value by which a transformers output terminal voltage varies either up or down from its no-load value as a result of variations in the connected load current.

Volts per Turn. Another way to consider transformer voltages is by volts/turn; if the 100 volts applied to the 1000 turn primary produces 100/1000 = 0.1 volts per turn, then each single turn on the 100 turn secondary winding will produce 0.1V so the total secondary voltage will be 100 × 0.1V = 10V.

giving the ideal transformer equation: Transformers normally have high efficiency, so this formula is a reasonable approximation. If the voltage is increased, then the current is decreased by the same factor. The impedance in one circuit is transformed by the square of the turns ratio.

The higher the K-factor, the more heat from harmonic currents the transformer is able to handle. A standard transformer that is designed for linear loads is said to have a K-factor of 1, whereas a transformer with a K-factor of 50 is designed for the harshest harmonic current environment possible.

Flux density is simply the total flux divided by the cross sectional area of the part through which it flows - B = Φ / Ae teslas. Thus 1 weber per square metre = 1 tesla. Flux density is related to field strength via the permeability. B = μ × H.

Electric power leaves the distribution substation with voltage ranging typically between 4,000 and 36,000 volts.

## What is the unit of apparent power?

volt-amperes Apparent power is conventionally expressed in volt-amperes (VA) since it is the simple product of rms voltage and rms current.

## What is the real power?

Real power is the power actually consumed due to the resistive load and apparent power is the power the grid must be able to withstand. The unit of real power is watt while apparent power unit is VA (Volt Ampere)

## What is flux unit?

The SI unit of magnetic flux is the Weber (named after German physicist and co-inventor of the telegraph Wilhelm Weber) and the unit has the symbol Wb . Because the magnetic flux is just a way of expressing the magnetic field in a given area, it can be measured with a magnetometer in the same way as the magnetic field.

## What is the unit of flux density?

The tesla (symbol T) is the derived SI unit of magnetic flux density, which represents the strength of a magnetic field. One tesla represents one weber per square meter.

Transformers generally have one of two types of cores: Core Type and Shell Type. These two types are distinguished from each other by the manner in which the primary and secondary coils are place around the steel core.