Important Terms - DC to DC Converter

Glossary

1. Chopper:

It is a dc-dc converter which converts fixed dc voltage to variable dc voltage.

2. Duty Cycle:

The output voltage of the chopper can be controlled by varying (On and Off of the semiconductor switch) the duty cycle of the chopper.

3. Time-Ratio control:

It is achieved by varying the T_on / T control.

4. Current Limit control:

In this control strategy chopper is switched On and Off so that the current in the load is maintained between two limits. (Min. current when the chopper is On and Max. current when the chopper is Off)

5. Step-up Chopper:

When the output voltage is greater than the input (E₀>E_dc), it corresponds to step-up operation.

6. Breaking:

It is the process of stopping the machine which is under motion.

7. Commutation:

It is the process of turning-off of a power semiconductor device.

8. Forced commutation:

In this process, current through a power semiconductor device is forced to become zero to turn-off.

9. Voltage commutation:

In this process, a charged capacitor momentarily reverse biases the conducting device and it turns off.

10. Current commutation:

In this process, a current pulse is forced in the reverse direction through the conducting device. Now the net current (forward and reverse current direction devices) becomes zero and the device is turned off.

11. Load commutation:In this process, the load current flowing through the device either becomes zero or is transferred to another device from the conducting device.

13. Harmonic Factor:

It is defined as the ratio of the total harmonic content to the fundamental component.

14. Ac regulators:

It converts fixed ac supply voltage and frequency to variable ac voltage without change in supply frequency.

15. Cyclo-converters:

It converts fixed ac supply voltage and frequency to variable ac load frequency without change in supply voltage.