Abstract — Surge arresters are crucial devices that
protect electrical systems from voltage spikes caused by lightning and
transients. This paper categorizes them into three types: Distribution
Arresters (up to 35 kV), Intermediate Class Arresters (up to 72 kV), and
Station Class Arresters (over 72 kV). Each arrester type is designed for
specific applications to ensure effective protection. Understanding these
classifications and the role of substations is essential for proper surge
arrester selection.
Keywords— Surge arresters,
electrical protection, distribution circuits, substation classificatio
I. GENERAL
Surge arresters are essential protective
devices used in electrical systems to safeguard equipment from voltage spikes
caused by lightning strikes, switching events, or other transients. Their
primary function is to divert excess voltage to the ground, thereby preventing
damage to electrical components. Understanding the various classifications of
surge arresters is crucial for selecting the appropriate type for specific
applications. The final decision is normally driven by the substation type from
which the circuit is deriving and the ground fault availability.
II. DISTRIBUTION
ARRESTERS
Distribution arresters are utilized in distribution circuits operating
at voltages of 35 kV and below. These circuits originate from distribution
substations, primarily aimed at delivering electricity to end users. Typically,
distribution arresters have grounding fault current ratings of 5 kA and 10 kA,
ensuring effective protection against transients in residential, commercial,
and light industrial applications. Their design is specifically optimized for
the lower voltage levels commonly found in these settings.
III. INTERMEDIATE
CLASS ARRESTERS
Intermediate class arresters
are designed for applications involving up to 72 kV Duty Cycle. These devices
function within distribution substations and can handle grounding fault
currents of up to 10 kA. They play a crucial role in scenarios where the
distribution system may experience higher voltage conditions, enabling a smooth
transition to protective measures as voltage levels rise.
IV. STATION
CLASS ARRESTERS
Station class arresters are used in
generation, transmission, and sub-transmission systems for voltages exceeding
72 kV and can handle grounding fault currents above 10 kA. They are essential
for protecting large-scale electrical infrastructures, ensuring the stability
and reliability of power systems operating at significantly higher voltages.
While primarily associated with higher voltage applications, station class
arresters are also available for voltages starting at 3 kV, showcasing their versatility
across a range of settings.
A power substation manages transmission
and sub-transmission voltages, whereas a distribution substation handles
distribution voltages. When a substation facilitates the transition between sub-transmission
and distribution voltages, such as from 220 kV to 35 kV, it is classified as a
distribution substation. Additionally, a generation substation is always
categorized as a power substation. A similar classification differentiates a
distribution transformer bushing from a power transformer bushing.
Download Resource