Resonant Grounding

Resonant Grounding or Arc Suppression Coil Grounding: We have seen that capacitive currents are responsible for producing arcing grounds. These capaci­tive currents flow because capacitance exists between each line and earth. If inductance L of appro­priate value is connected in parallel with the capacitance of the system, the fault current IF flowing through L will be […]

Solid Grounding

Solid Grounding or Effective Grounding: When the neutral point of a 3-phase system (e.g. 3-phase generator, 3-phase transformer etc.) is directly connected to earth (i.e. soil) through a wire of negligible resistance and reactance, it is called Solid Grounding or Effective Grounding. Fig. 26.11 shows the solid grounding of the neutral point. Since the neutral […]

Neutral Grounding

Neutral Grounding: The process of connecting neutral point of 3-phase system to earth (i.e. soil) either directly or through some circuit element (e.g. resistance, reactance etc.) is called Neutral Grounding. Neutral grounding provides protection to personal and equipment. It is because during earth fault, the current path is completed through the earthed neutral and the […]

System Grounding

System Grounding: The process of connecting some electrical part of the power system (e.g. neutral point of a star-connected system, one conductor of the secondary of a transformer etc.) to earth (i.e. soil) is called System Grounding. The system grounding has assumed considerable importance in the fast expanding power system. By adopting proper schemes of […]

Grounding or Earthing

Grounding or Earthing: The process of connecting the metallic frame (i.e. non-current carrying part) of electrical equipment or some electrical part of the system (e.g. neutral point in a star-connected system, one conductor of the secondary of a transformer etc.) to earth (i.e. soil) is called Grounding or Earthing. It is strange but true that […]

Busbar Arrangements in Substations

Busbar Arrangements in Substations: Busbar are the important components in a sub-station. There are several Busbar Arrangements in Substations that can be used in a sub-station. The choice of a particular arrangement depends upon various factors such as system voltage, position of sub-station, degree of reliability, cost etc. The following are the important bus-bar arrangements […]

Transformer Substation

Transformer Substation: The majority of the sub-stations in the power system are concerned with the changing of voltage level of electric supply. These are known as Transformer Substation because transformer is the main component employed to change the voltage level. Depending upon the purpose served, Transformer Substation may be classified into : Step-up sub-station Primary […]


Substation: The assembly of apparatus used to change some characteristic (e.g. voltage, ac. to dc., frequency, p.f. etc.) of electric supply is called a Substation. Sub-stations are important part of power system. The continuity of supply depends to a considerable extent upon the successful operation of sub-stations. It is, therefore, essential to exercise utmost care […]

Lightning Arresters

Lightning Arresters: The earthing screen and ground wires can well protect the electrical system against direct lightning strokes but they fail to provide protection against travelling waves which may reach the terminal apparatus. The Lightning Arresters or surge diverters provide protection against such surges. A lightning arresters or a surge diverter is a protective device […]