Synopsis PART III
Voltage Surges / Transients, Over Voltages And Grounding / Earthing
This part is complementary to Part II and provides
technical support to switchgear assemblies and machines fed by them for surge
and over-voltage protection. It is a very useful part for all those handling
HV and EHVpower systems and their surge and over-voltage protection.
. The part deals with the BIL of a system, protective margins and insulation
coordination. LV surge protection and surge protection devices (SPDs)
. It also deals with electric motors as they are typical for their
surge behaviour and protection.
. It also covers the steepness of TRVs, their significance and methods
of taming them. Reflections of travelling waves and surge transferences are
. This part specifically considers the application and selection of
surge capacitors and surge arresters. Since the internal causes of surge generation
are a consequence of switching operation and type of interrupter, this part
provides details of the various types of interrupters in use, their switching
behaviour, current chopping and quenching of arc plasma. It also makes a detailed
comparison of the various types of interrupters available in the market to
facilitate their selection and adaptation to a more appropriate surge protection
scheme. Gas insulated switchgears (GIS). HV and LV vacuum contactors.
. Temporary over-voltages are different from surges as are their causes.
Therefore temporary over-voltages also form an important parameter in a system
design and its grounding method. This topic is therefore complementary to
surge protection and has been dealt in detail to make a practising engineer
or engineering student more aware of the behaviour of an HV system, particularly
on a ground fault.
. Exposure of a human body to touch and step voltages and methods to
deal with these are also covered. Grounding and ground fault protection schemes
are described in detail with illustrations to help an engineer select the
most appropriate grounding method and ground fault protection scheme for a
machine or a system.
. The use of CBCTs is covered.
. Grounding systems, their choice and protection from transferred surges
. Grounding practices of industrial installations and power generating
Electric Motors | Switchgear Assemblies |
Captive Power Generation | Voltage
surges and Over Voltages
Grounding / Earthing Power Capacitors | Non Isolated Bus Systems
Isolated Phase Bus Systems Rising Mains | Bus Systems