Sinusoidal AC Voltage Regulator Using PWM Technique

This paper proposes an AC voltage regulator for resistive loads using the
PWM technique. The load voltage can be controlled using one switching
element( MOSFET) and three limb magnetic circuit.
The suggested regulator gives smooth variation of the load voltage and
nearly sinusoidal current at the supply terminals with minimum harmonics. The
power factor at the supply terminals is nearly unity over the control range of
the load voltage. Equivalent circuit of the regulator is proposed. The computed
results are compared with those obtained experimentally using a test model,
where good agreement is achieved.
I-List of symbols:
RI, R 2, R.3, R4 coil resistance's from 1 to 4 respectively,
L1, L 2, L3, L4 coil leakage inductance's from 1 to 4 respectively ,
R ,, R b, R equivalent iron losses resistance's of limb a, b, c
respectively,
L ,, L I,, L magnetizing inductance's of limb a, b, c respectively,
...
la,lb,lc magnetizing current's of limb a, b, c respectively,
Ea,Eb,Ec induced E.M.F's of limb a, b, c respectively,
... .
IS, 11, ISM,, 15 supply, load, switch and capacitor current respectively,
RI load resistance.