MV Inrush Current Limiting Reactor

Power Factor Correction Systems

Inrush Current limiting reactors are designed to mitigate the abrupt high current surges that arises during the switching of capacitors in MV power factor correction systems. They function to limit the current in shortcircuit conditions, thereby protecting the system from damage.

MV Inrush Current Limiting Reactors are single-phase, with their configuration dependent on the connection type, and their installation allows flexibility of use. During switching operations, these reactors are connected in steps to regulate the closing currents of the panel breakers, ensuring safe system operation and protecting the switching components.

What is Current Limiting?

So, what is “current limiting”? Current limiting is the process of controlling sudden current surges or overcurrents in electrical systems. This is often achieved through the use of inrush current limiting reactors or other devices. In power systems, current limiting is essential to prevent specific circuits or equipment from being damaged by excessive current. It increases system safety and extends the service life of the equipment. Additionally, current limiting ensures the stability in electrical systems by protecting them during sudden load changes or short circuits.

In medium-voltage capacitor banks , when a capacitor is switched, the breaker closing currents tend to rise to the short-circuit current level of the installation. In order to mitigate this sudden increase in inrush current, inrush current limiting reactors are connected in series with the steps of MV capacitor banks, bringing the breaker closing current to a safe level. This protective measure protects the switching elements, circuit breakers, and supply units.

Operating Data

Rated Voltage	3kV…36kV
Rated Current	30A….400A or demanded
Rated Frequency	50/60Hz
Tolerance of Inductance	+20%
Insulation (winding-core)	F class 155°C

Standard

TS EN 60076 – 6

Safety and Protection

Installation	Indoor / Outdoor
Impregnation	H Class Vacuum Impregnation for Indoor, Epoxy varnish for Outdoor
Heating	B Class max 125°C
Cooling	Natural Cooling/T40

Design

Design	1 Phase, Air Core, Dry Type
Winding	Aluminium Foil
Terminals	Aluminium / Copper Wire, Indoor: Aluminium or Copper Bar, Outdoor: Aluminium Bar

What is a Inrush Current Limiting Reactor?

A current limiting reactor is used in MV power factor correction systems to mitigate sudden inrush currents. These specialized reactors regulate the current during short circuit conditions, protecting electrical equipment from potential damage. They also manage the currents experienced during circuit breaker closing, improving the overall safety and stability of switching operations within the system.

Designed as either air-core or iron-core configurations, these single-phase reactors offer flexible installation options to accommodate diverse connection requirements. Inrush current limiting reactors serve a vital role in maintaining the safety, longevity, and stability of electrical systems.

Indoor Inrush Current Limiting Reactor

Indoor inrush current limiting reactors are preferred in power factor correction systems and are designed in a compact structure to fit within capacitor banks, these reactors are mostly used in industrial plants.

Outdoor Inrush Current Limiting Reactor

Outdoor inrush current limiting reactors are used in capacitor bank installations. These outdoor reactors are designed to operate in outdoor environmental conditions and are the preferred choice for large electrical distribution networks.

Benefits of Inrush Current Limiting Reactors

Inrush current limiting reactors are critical components that enhance safety and performance in electrical systems. Their key benefits include:

Switching Equipment Life Extension : Inrush current limiting reactors regulate abrupt changes in current, thereby increasing the service life of switching equipment. Sudden changes in load can cause premature breaker failure. However, inrush current limiting reactors mitigate this problem, extending the service life of the switchgear.

Capacitor Service Life Extension: Capacitors used in power factor correction systems play a vital role in regulating reactive power. However, they are susceptible to damage when exposed to excessive currents. Inrush current limiting reactors mitigate this problem by redusing the high currents that reach the capacitors, thereby extending their operational service life and improving overall system efficiency. This, in turn, helps to minimize maintenance expenses.

Back-to-back Capacitor Switching: In power factor correction systems using capacitor banks with steps, current limiting reactors should be used when switching each successive capacitor step. This is necessary to prevent the energized capacitor step from influencing the newly energised capacitor step, which could accur due to fluctuations in the load current.

Characteristics of Inrush Current Limiting Reactors

The characteristics of current limiting reactors can be summarized as follows:

Low-Loss:

These types of reactors operate with minimal energy loss, improving the efficiency of electrical systems and reducing energy costs.

Extended Operational Lifespan:

Manufactured from high quality materials, inrush current limiting reactors offer long lasting performance, improving system reliability.

Copper Terminals:

Copper terminals provide better conductivity and durability, improving electrical performance and ensuring a reliable connection.

Varnished Under Vacuum:

Reactors varnished under vacuum are protected from external factors, offering long-term durability and reliability.

Noiseless Performance:

Typically quiet in operation, inrush current limiting reactors improve environmental comfort and reduce noise levels in electrical systems.

Ergun Elektrik MV Inrush Current Limiting Reactors

Ergun Elektrik’s MV Inrush Current Limiting Reactors are high-quality products designed to increase safety and efficiency in electrical systems. These reactors are designed for use in MV power factor correction systems and offer protection against sudden inrush currents. Whether indoor or outdoor, dry type MV Air Core Inrush Current Limiting Reactors are custom designed and manufactured by our company based on the capacitance of the capacitors they will be associated with.