Power Electronics

Applications of Cycloconverter Cycloconverter can be used for controlling the speed of AC motors like induction motors or synchronous motors, where a variable frequency state supply is required to be used. They are sometimes used to “start” the induction motors. After starting it the control is transferred to a voltage or current source inverter. In … Read more

Advantages and Disadvantages of static switches Advantages of Static Switches : As there is no mechanical parts and motion involved in the operation of static switches, there is no wear and tear. Therefore static switches are maintenance free switches. Arcing does not take place in the static switches. Therefore they are suitable for switching in high voltage … Read more

Advantages and Disadvantages of Cycloconverter Advantages of Cycloconverter : It is an ac to ac converter therefore no “dc link” is required to be used as in case of the inverters. The power flow is bidirectional, from source to load or load to source. With the variable firing angle control adopted as shown in Figure … Read more

Static Switch Definition of Static Switches : The SCRs and Triac are latching type devices. They can be either fully on or fully off. So they are equivalent to closed switches when conducting and open switches when off. Therefore SCR and triac are known as the static switches. The word “Static” is used because there are no … Read more

Three Phase to Single Phase Bridge Cycloconverter The circuit diagram of a three phase to single phase bridge cycloconverter is as shown in Figure A. Here two ac to dc converter 3-phase bridges (P-converter and N-converter) are connected to a common resistive load. Figure B shows the waveforms for fo = 1 / 3 fin. The thyristors from … Read more

Three Phase to Single Phase Cycloconverter Circuit Diagram of Three Phase to Single Phase Cycloconverter : Figure A shows the circuit diagram of a three phase to single phase cycloconverter. Figure A This circuit is used for converting a three phase supply at one frequency to a single phase supply at a lower frequency. Operation of Three … Read more

3 Phase to 3 Phase Cycloconverter As shown in Figure, we can connect three units of 3 phase to single phase cycloconverter to constitute a 3 phase to 3-phase cycloconverter. P correspond to the positive group SCRS and N represents the negative group SCRs. The IGR is used between each pair of P and N group … Read more

Three Phase Half Wave Cycloconverters The working principle of a three phase cycloconverter is same as that of a single phase cycloconverter. The type of a three phase cycloconverter is decided by the number of pulses used and the ripple contents in the output decreases with increase in the number of pulses used. We will … Read more

Centre Tapped Transformer Cycloconverter or Mid point Cycloconverter Figure A The circuit diagram for mid-point cycloconverter is as shown in Figure A. In order to understand the circuit operation let us analyse the circuit for a purely resistive load. There are four SCRs S1, S2, S3 and S4. The SCRs 1, 2 and 3, 4 are connected in antiparallel … Read more

Introduction of Industrial Applications of Power Devices The SCRs and Triacs are used in many of the industrial circuits. In this chapter we are going to discuss some of the industrial circuits using SCRs and Triacs.