Power Electronics Lab Experiments

Microcontroller based Single Phase Bridge Configuration Cyclocon- verter

Nov 27 2023

Aim

Microcontroller based Single Phase Bridge Configuration Cyclocon- verter.

Apparatus Required:

S.No.	Apparatus/Software Used	Specification	Range/Rating	Quantity
1
2
3
4
5

Theory & Formulae Used:

The basic control principle of an ideal cycloconverter is to continuously modulate the fir¬ing angles of individual converter, so that each produces the same sinusoidal ac voltage at its output terminal. Thus the voltages of the two generators in fig. 1 have the same ampli¬tude, frequency and phase and the the voltage at the output terminals of the cycloconverter is equal to the voltage of either of these generators. It is possible for the mean power to flow either "to" or "from" the output terminals and the cycloconverter is inherently capa¬ble of operation with loads of any phase angle within a complete spectrum of 360. Bridge Configuration: Two Single phase fully controlled bridges are connected in opposite direction. Bridge 1supplies load current in the positive half of the output cycle and bridge 2 supplies load current in the negative half of the output cycle. The two bridges should not conduct to¬gether as this will produce a short circuit at the input. Instead of one thyristor in the centre tap transformer configuration, two thyristor come in series with the each voltage source in bridge configuration. For resistive loads the SCR undergo natural commutation and pro¬duce discontinuous current operation as shown in figure. For inductive load , the load current may be continuous or discontinuous depending upon the firing angle and load power factor. The load voltage and current waveforms for continuous and discontinuous load current are shown in figure.