Explain Delta winding Phase-to-Line voltage conversion and vice versa?

Delta Winding Configuration

In a delta (Δ) configuration, every phase winding is connected in a loop, with line conductors connecting at the junctions between windings. This means that the line voltage is measured over the entire winding, whereas the phase voltage is measured for each individual winding.

In a delta-connected winding, the windings are arranged in a triangle pattern, with one end of each winding connected to one end of the other two.

Key Parameters

  • Line Voltage (V_L) is the voltage measured across any 2 line conductors.
  • Phase Voltage (V_Ph) is the voltage determined across a single delta winding.

Converting Phase Voltage to Line Voltage

To convert phase voltage (Vph) to line voltage (Vline) in a delta connection, use the formula

Vline = √3 × Vph

This is because the line voltage is the phasor sum of the voltages across two series-connected phases.

Converting Line Voltage to Phase Voltage

To convert line voltage (Vline) to phase voltage (Vph) in a delta connection, use:

Vph = Vline / √3

In a delta connection, the line voltage is divided by √3 and applied to each phase winding.

Practical Example

Assume the delta-connected system has a phase voltage (Vph) of 230V.

To determine the line voltage (Vline), we use:

Vline = √3 x Vph

Vline = √3 x 230V

Vline = 398.4V

To calculate the phase voltage, use the formula Vph = Vline / √3. For example, if the line voltage is 400V, the phase voltage would be 230.9V.

To convert phase & line voltages in a delta connection, multiply the phase voltage by √3, or divide the line voltage by √3.