Operation of a full-wave rectifier with centre tap and active - inductive load with infinite inductance

Figure 1.16

The peak current of a thyristor is ;

The average current of thyristor is

;

The peak-inverse voltage is

;

The average rectified voltage is

It is a control characteristic.

Requirements to equipment could be determined at α = 0, this condition defines a most loading of the transformer and thyristors.

Then

.

Thus

.

Let's define a secondary winding voltage

From this equation is defined a peak-inverse voltage

Hence, a powers of the transformer windings we could define at a=0.

Let's determine an effective value of the current of a secondary winding of transformer and rms-current of a thyristor

I₂ does not depend from a control angle.

Let's determine the an effective value of the current of a primary winding of transformer

I₁ also does not depend from a angle.

The full power of a primary winding of transformer is

,

where P_d – the power of the direct components of the rectified voltage U_d and the rectified current I_d.

The full power of the secondary windings of the transformer is

.

Type power is

.

Let's compare single-phase circuits: with centre tap (FWCT) a nd half-wave (HW) by the thyristors and the transformer loading:

| L_d I_TAV I_TM I₂ I₁ S₁ S₂ S_T U_RM

FWCT| 0 0.5I_d 1.57I_d 0.780I_d 1.11I_d 1.23P_d 1.74P_d 1.48P_d 3.14U_d