A reactor is a significant component used in power and distribution system. Basically, it is a coil which contains a large number of turns and has high ohmic resistance value. The main purpose of installing reactors is to limit the short circuit currents which can cause damage to the equipment of the power system. They are connected in series or parallel configuration with the system depending upon their type.
If you are going to buy reactors, knowing their different types would help you make a quick decision as to which type of reactor is suitable for your application. So, let’s take a look at the available types based on their construction and functioning.
Types of Reactors
Construction-wise
Air Core Reactors
The reactors which don’t have iron, steel or any core are called air core reactors. They can be used up to 33kV and are usually made in a larger size. Arranged in the form of a circle with concrete slabs, they are embedded with stranded copper coil conductors. The slab provides high mechanical strength during short circuit currents.
Post insulators used to support these reactors are made of porcelain material. They are also known as cast concrete type reactors. Conductors are used in insulated form for winding purposes. However, glass or porcelain is used to provide insulation between turns.
Iron Core Reactors
Reactors which have cores consisted of iron are called iron core reactors. In this type of reactor, a coil is placed inside a standard transformer tank and oil is filled for cooling and insulation. Shielding is used to prevent any loss and core is laminated to prevent stray magnetic field. Shields are designed in the form of short-circuited rings and earthed through endplates. The MMF produced in the rings because of short circuit current keeps the flux inside the shield.
Since oil is used for cooling and insulation purposes, they are also known as oil immersed type reactors and can be used for any voltage level.
Function-wise
In this category, there are several types of reactors such as:
Neutral Grounding Reactor – It is used to limit the amount of ground-fault current that a generator contributes to the system. It is generally connected in a series configuration.
Thyristor Controlled Reactor – It is a reactance connected in series with bidirectional thyristor valve. This valve is phase-controlled and allows the adjustment of delivered reactive power to meet varying system requirements.
Smoothing Reactor – It is a reactor connected in series with direct current high voltage line as part of converter station or back-to-back interconnection between different transmission networks. Its main function is to reduce harmonic currents, transient over-currents, and/or current ripples in DC systems.
Test Reactor – Widely used in applications such as current limiting, synthetic testing of circuit breakers, simulation circuits, and inductive energy storage, it is generally installed in high voltage and high power laboratories.
Current Limiting Reactor – Designed to reduce short-circuit currents, it is connected in a series configuration with the power system.
Damping Reactor – Connected in series with one or more capacitor banks, it is designed to limit the capacitor switching inrush current and withstand the rated current as well as fault current during short circuits.
Shunt Reactor – Configured in parallel to the power system, this reactor compensates for capacitive VARs which exist in lightly loaded transmission lines and underground cables.
Filter Reactor – This reactor can be connected either in parallel or series configuration with the capacitor bank to reduce harmonic currents and control ripple current amplitude.
So, once you figure out what functions you want your reactor to perform, you can easily buy reactors online without getting confused with such a wide array of reactors.