Basic Terminology Of Power Quality Part 3

Basic Terminology Of Power Quality Part 3

1. Bonding

Bonding is the link of two or more conductive objects which are interconnected to one another by means of a conductor. 

Bonding is done primarily for two reasons:

1. To provide minimal of negligible voltage difference between the bonded parts.
2. To ensure that, faults incurred can be safely moved to ground or other grids.

2. Grounding

Grounding, also referred to as "earthing", is a type of bonding where one or more conductive objects are connected to the ground by means of a conductor. In Fig. , equipment 1 and equipment 2 are connected by means of a thin wire and they are then connected to the ground.

                          (Figure)

3. Capacitance

The property of the circuit characterised by a two parallel plates which are separated by a dielectric medium and expressed in farad (F).

In other words, it is the means by which the energy can couple from one electric circuit to the other.

4. Coupling

The process by which electrical energy from one circuit is transferred to other circuit that are not connected electrically is called as coupling.

5. Crest Factor

It is the ratio of the peak value to the RMS value of the voltage/current.

 

Crest Factor Waveform

6. Distortion

Waveform with Distortion

It is the variation of a periodic waveform from its ideal waveform.

Distortion created in the waveform may cause waveform deformation as well as phase shift.

                    

7. Distortion Factor

It is the relation between the RMS value of the harmonic content of a periodic waveform to the RMS value of the periodic wave and usually expressed as a percent.

8. Form Factor

It is the ratio of RMS value to the peak value of the periodic waveform.

It represents the deviation of the system waveform.

9. Flicker

It the visible change due to rapid fluctuations in the voltage of the power supply.

Flicker is due to a modulating low frequency disturbing voltage.

The frequency range visible to the human eye is about 1-30 Hz.

10. Frequency

Number of complete cycle in the periodic waveform and measured in hertz (Hz).

11. Ground Electrode

It is the body of the conductor that has contact with the earth for providing grounding to the network.

12. Ground Grid

The conductors that are arranged in such a way to make specific pattern and are buried

below 2.5A from the ground.

13. Ground Loop

They are usually formed when two or more connection is provided between two

conductors. To prevent ground loop the following things need to be done.

All the ground point should go through one common ground point

To isolate the source from ground

14. Ground Ring

The loop surrounding the structure or which is in straight contact with ground is called the ground ring.

The depth of the ground ring should be more than 2.5ft below the surface of the earth.

15. Grounding

A conductor, by which the electrical circuit or the equipment is connected to the earth or to some conducting body. Grounding is primarily done for two reasons:

Grounding the metal conductor protects any person coming in direct contact, if fault occurs.

It also allows the faulty current, to the earth or ground plane.