Single Phase to Single Phase Cycloconverter Design Using Simulink

Single Phase to Single Phase Cycloconverter Design Using Simulink: A cycloconveter is a converter that constructs a lower frequency alternating voltage wave from high frequency alternating voltage wave form and this is done through some switching arrangements of SCRs (silicon control rectifiers) or thyristors. Cycloconverterts are mainly used in VVVF (variable voltage variable frequency) ac drives, which are used for running the ac motors of cement and steel industry. Beside this, these type of cycloconverter are also used in aircraft and naval ships industry where motors are drive at variable speed but at constant speed. Different types of cycloconverter drives such as single phase to single phase, three -phase to three -phase and three -phase to single phase ac dives are available in market. Here we will make a design of single phase to single cycloconverter with the help of MATLAB using Simulink library as well as we also tell how we will make a new model in MATLAB. First, we will open the Simulink library browser and for Simulink library browser we will just open the MATLAB and then click on Simulink library then a new page would be opened shown in figure 1

   Figure 1 MATLAB Simulink Library Browser

The Simulink library browser have different options on their Manu bar but for new model we will just click on a new model option then a new page would be opened shown in figure 2

 Figure 2 MATLAB Simulink New Model

At this Simulink new model, we can make any circuit as we want but for making a new circuit we will have to choose the components. Because we are going to make single phase to single cycloconverter therefore we are required a power electronics component. For searching power electronics components just write the word power electronics on search Manu bar a new page would be opened with different power electronics components blocks shown is figure 3

 Figure 3 Power Electronics Components Blocks

Similarly, for searching the components block such as oscilloscope and display etc. just write the word sink on search Manu bar of Simulink library browser then a new page would be opened shown in figure 4

Figure 4 Oscilloscope and Display Blocks

Similarly, we can easily search all the other blocks such as voltmeter, ammeter, pulse generator, resistor and ac supply voltages etc. After searching all the blocks then drag all these block on a new model page or we can also add all these blocks on a new model page. Now we would be made a new model of single phase to single phase cycloconverter with the help of all these blocks. For this, first we will drag all blocks on this new model page then joint them according to single phase to single phase cycloconverter figure shown in figure 5

    Figure 5 Single Phase to Single Cycloconverter

In this single phase to single phase cycloconverter, 200V ac voltages at 50Hz frequency are set in ac voltage source block and one pulse generator has used with every leg of this cycloconverter. Each pulse generator gives the trigger pulse to every leg in such a way that on one thyristor switched on simultaneously. 20% duty cycle and 60Hz frequency have been used in every pulse generator. The switching pulses of these four-pulse generators are shown in figure 6.

Figure 6 Switching Pulses of Four Pulse Generators

We can see easily that, not any two or three thyristors are switched on simultaneously they are switched on after one another this is the main technique which have been used in this single phase to single phase cycloconverter. The input and output voltages ac of this single phase to single cycloconverter are shown in figure 7

Figure 7 The Input and Output AC Voltages

This is all about simulation of single phase to single phase cycloconverter using MATLAB simulink.  I will also share a working video of this project soon.