To observe the working operation of 1-φ to 1-φ Cycloconverter with R and RL loads and to plot the voltage waveforms across the load.
☞Trainer kit- Cycloconverter -1 No
☞Patch Chords – Sufficient Nos
☞Load – Internal Resistive Load
☞CRO – 1 No
☞10:1 CRO Probe – 1 No
Figure: Single Phase to Single Phase Cycloconverter
☞Time (X) Axis : 5ms/div
☞Voltage (Y) Axis : 20V/div
☞Probe : 1:10 CRO Probe is suitable one.
☞Ensure the 230V Power Supply is in proper with Tester.
☞Ensure the CRO is working properly with probe checking and proper ground line axis.
☞Switch on the main supply to the firing circuit.
☞Observe the test points and trigger outputs by changing frequency division and by varying firing angle, using CRO.
☞Switch OFF the supply to the firing circuit.
☞Make the power circuit connections as per the circuit diagram.
☞Connect the firing pulses from the firing circuit to the respective SCRs in the power circuit.
☞Switch ON the supply to firing circuit and the main supply.
☞Set the frequency division.
☞Vary the firing angle potentiometer and observe the waveforms across the load and note down the readings.
☞Repeat the experiment for different firing angles.
☞Switch OFF the supply to the firing circuit and main supply.
Note: If the connections are wrong the kit will get damage.
|S.NO||Total Time (ms)||F select Position in (Hz)||Firing angle (α in Degree)||Vo (Volts)|
Data from input waveform:
Total Time for one cycle = 20ms For one cycle = 360 ° Calculate for 1ms = 360/20 For 1ms = 18 degree
Calculate off time of scr from output waveform = eg.4ms Then αvalue is = 4*18= 72degree
Calculate Output Frequency:
Total Time for one cycle (T) = 20ms So, F= (1/T) T in Sec = 1/ (20*10-3) = 50Hz
Figure : input voltage and load voltage