Why Are Reactors Used in Substations?

A part of the generation, transmission, and distribution process of electricity, substations are used to convert high to low voltage or low to high voltage when applicable. However, to limit current and prevent an overload of electricity to sensitive components, reactors are used as dampeners for a range of substations. Constructed in the shape of a coil or capacitor bank, reactors provide substations with additional support to mitigate a short circuit from an influx of current. To better understand the importance reactors play in helping to regulate power system safety, we will discuss their commonly applied types and how they function.

Reactors, commonly referred to as line reactors or chokes, are a class of variable frequency drive (VFD) components installed in tandem with electrical systems varying in frequency. Often found in the form of shunt, current limiting/neutral earthing, damping, tuning, arc suppression, and smoothing reactors, any reactor combined with an electrical power system may be classified based on its modes of application. Further diversifying reactor uses, depending on whether a reactor will be applied for lightly loaded or heavy loaded currents,  implementation can greatly impact what reactor will be best for an application.

Current Limiting Reactor

Identifiable by their large coils, current limiting reactors employ the use of inductive coils and are commonly manufactured in variation as iron-core or air-core reactors. When affixed to applicable substation equipment, these coils provide an electrical system with immense inductive reactance capabilities in comparison to their produced resistance. Implemented to minimize the flow of current within short circuits, reduce voltage disturbances induced by short circuits, as well as recognize and discontinue the flow of a faulty current, current limiting reactors are considered one of the most efficient options to reduce surges in current.

Shunt Reactor

Shunt reactors are one of the more common reactor types used for high voltage power transmission systems. Applied to stabilize voltage prone to fluctuating load values, shunt reactors are frequently constructed as a single-phase device within a substation to allow power lines to directly connect with a reactor unit. Otherwise, 3-winding tertiary transformers or three-phase systems can be used as an alternative. Requiring systems with prolonged endurance that are proficient at operating around 400 KV, the voltage rating in a power frequency utilizing a shunt reactor is 5% higher than that of an average voltage rating in a standard power frequency.

Damping Reactor

Regarding installation for improved flexibility in dampening capabilities, damping reactors can also be classified into the following subcategories: conventional dry type, cast resin dry type, single-phase, three-phase, oil-immersed, variable reactance, fixed reactance, with magnetic shield, without magnetic shield, and closed or unclosed variations. Despite the options available, all aforementioned damping reactors must be chosen in accordance with current load limitations to avoid damage to the reactor and any accompanying parts along a current load.

When deciding which type of reactor is best suited for your intended application, it is imperative that research is done to ensure a chosen reactor is in accordance with its intended load. At NSN Components, we understand the importance of reliable part procurement. As a dependable distributor of various electrical equipment, we invite you to browse our inventory for numerous power systems, line reactors, reactor switching devices, and all applicable apparatuses. Due to our quality control and export compliance, we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation. If you would like to request a quote for your comparisons, you can submit an RFQ form as provided on our website. Upon receipt, a dedicated account manager will quickly review and respond with a personalized solution to your needs in just 15 minutes or less, 24/7x365. 

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1. alex marsh
2. Posted on September 1, 2021
3. it hardware

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