24-01-2013, 10:56 AM
SINGLE PHASE PARALLEL INVERTER
SINGLE PHASE PARALLEL.docx (Size: 12.5 KB / Downloads: 39)
AIM:
To study and obtain the AC output voltage waveform of single-phase parallel inverter with
R & RL loads.
APPARATUS:
S. No Components Quantity
1 Single Phase Parallel Inverter Kit 01
Bulbs 230V/40W 02
3 CRO 01
4 Patch cords
5 Voltmeter(0-100V) MI 01
Theory:
The circuit diagram of 1-ph Parallel Inverter is shown in fig., SCR1 and SCR2 are main
thyristors. Supply voltage Vdc appears across the left half of the transformer primary winding
OA. Terminal O is positive w.r.t.A. By transformer action terminal B will be at potential of 2Vdc
w.r.t A. Thus capacitor C will get charged twice the supply voltage. The load voltage will be
positive and will have a magnitude VL . At the end of half period SCR2 is firing , capacitor C
will be immediately apply a reverse voltage of 2Vdc across SCR1 and turns off it.
Similarly the Vdc applies to right half of the primary winding and capacitor gets charged
with 2Vdc in reverse direction. Now the load voltage is negative and hence the current. Since the
commutating capacitor is in parallel with SCRs, so it is called parallel inverter.
PROCEDURE:
1. Make the connections as per the circuit diagram.
2. Verify the connections before switching on the supply.
3. Remove the link across the terminals marked “LINK”.
4. Place the load lamps at place.
5. Now switch on the main supply.
6. Observe the wave form at terminal TP-1 and TP2 with respect to ground terminal with
CRO by using 1:10 probe.
7. Now place the connecting link across terminals marked “LINK”.
8. Observe the output by glowing lamp.
9. Observer the waveform at terminals marked TP-3 and TP-4 with respect to the ground
terminal.