In this script, we will discuss the most important topic of   Power Electronics, Now we will discuss

  • What is phase controlled converter?
  • Classify of phase control converter.
  • Principle of Phase Controlled Converter 
  • Application of phase-controlled converter

If you have any electrical, or electronics science doubts, then Contact Us.

What is phase controlled converter?

These phase-controlled rectifiers are simple and less expensive and the efficiency of these rectifiers is in general above 95%. Because these rectifiers convert from ac to dc, these controlled rectifiers are also called an ac-dc converter

Classify of phase control converter.

The phase control converters can be classified into two types, depending on the input supply.

1. Single phase converter

  • Semi converter
  • Full converter
  • Dual converter

2. Three-phase converter

  • Semi converter
  • Full converter
  • Dual converter
Principle of Phase Controlled Converter 

The circuit arrangement of the Phase Controlled Converter is shown in the figure with resistive load. A single-phase half-wave Thyristor works as a Phase Controlled Converter.  A single phase half wave Thyristor converter circuit is operated to convert AC to DC power conversion. The i/p AC supply is gained from a transformer to offer the required AC supply voltage to the Thyristor converter established on the o/p DC voltage required. The preliminary and secondary AC supply voltages in the above circuit are denoted with VP and VS.


When supplying the +ve half cycle of i/p  then the upper end of the transformer secondary winding is at a positive potential with respect to the lower end, and the Thyristor is in a forward biased state. The thyristor is triggered at a delay angle of ωt =α, by applying an appropriate gate trigger pulse to the gate terminal of the thyristor. When the thyristor is triggered at a delay angle of ωt =α, the thyristor behaves and assumes a perfect thyristor. The thyristor acts as a closed switch and the i/p supply voltage acts across the load when it operates from ωt =α to π radians For a purely resistive load, the load current io flows when the thyristor T1 is on, is given by the expression.

Application of phase-controlled converter

  • Paper mills,
  •  textile mills using DC motor drives 
  •  DC motor control in steel mills
  • Light dimmer.
  • AC fan speed regulator.
  • AC motor speed control.