Typical Applications
Shunt reactors are mainly used for reactive power compensation of long or lightly loaded transmission lines as well as underground cables used in:
Advantages
A Current Limiting Reactor (CLR) is one of the most effective short circuit current limiting devices. It reduces stresses on busses, insulators, circuit breakers and other high voltage devices. Use of CLR is the most practical and economical approach at current limiting.
Current Limiting Reactors should be placed where the prospective short circuit current in a distribution or transmission system is calculated to exceed the interrupting rating of the associated switchgear. The inductive reactance is chosen to be low enough for an acceptable voltage drop during normal operation, but high enough to restrict a short circuit to the rating of the switchgear.
They are also used as load sharing reactors for balancing the current in parallel circuits. Current limiting reactors are manufactured up to 420 kV. These reactors are designed in a way to withstand the rated current continuously and fault currents for a certain period of time.
Inrush Current Limiting Reactors (Damping Reactors)
Inrush current limiting reactors are series connected with capacitors in order to limit the inrush currents that occur during their switching (switch-on) operations.
Advantages
Technical Specifications
*Consult factory for higher values.
Neutral Earthing (Grounding) Reactors are single phase reactors generally connected between ground and neutral of transformers or generators in order to control single line-to-ground faults at a desired level. They achieve this by resisting current flow through inductive elements.
Neutral Grounding Reactors are used in order to limit line-to-ground fault current to a value which will not damage the equipment in the power system, yet allow sufficient flow of fault current to operate protective relays to clear the fault. If the circuit is balanced, current flow through the reactor will be zero, thus, there will be no losses.
Neutral Grounding Reactors reduce short circuit stresses on substation transformers which is one of the most widespread type of fault in an electrical system.
A loaded generator can develop a third-harmonic voltage. Providing impedance in the grounding path with a Neutral Earthing Reactor, can limit the third-harmonic current component.
Area of Usage
Advantages
Technical Specifications
*Consult factory for higher values.
Shunt Reactors act as absorbers of reactive power to increase energy efficiency in the power system.
Shunt Reactors are inductors that are used in order to compensate capacitive reactive power generated by long and lightly loaded transmission lines as well as underground cables. This allows for the flow of more active power through the system and avoiding over voltages. The shunt reactors provide inductive compensation.
Shunt reactors are connected to the tertiary winding of the main transformer or they are directly connected to the line. In high power and high voltage systems, shunt reactors should be used with RC snubber filters because in such systems switching transient voltages are extremely high and the switching equipments are prone to failure.
Advantages
Technical Specifications
*Consult factory for higher values.
Use of nonlinear loads such as power electronics based equipment and electric furnaces have been on the rise for the last decades. Such loads decrease the power quality of the network that they are connected to. One of the most important parameters for defining the power quality is harmonic distortion.
Harmonic distortion in a network causes:
Passive harmonic filters are the most commonly used devices for reducing the harmonic distortion in a network. These filters are built up from passive RLC components, i.e. resistors, inductors and capacitors.
The inductors (reactors) in these filters serve to provide a resonance path together with the capacitors existing in the harmonic filter. By appropriately tuning the resonance frequency of a harmonic filter, the unwanted harmonic currents injected by the nonlinear loads can be prevented from going into the electrical grid. This is a very important measure that is taken for reducing the harmonic distortion in a network. Harmonic filter reactors may be used in single-tuned, second order, and C-type filters according to the type of load and purpose. Moreover, they may be used in series with Flexible AC Transmission Systems (FACTS) devices such as Static VAr Compensator (SVC), Static Synchronous Compensator (STATCOM) and High Voltage Direct Transmission (HVDC) in order to reduce the amount of harmonics that would be injected by these systems into the electrical grid.
At medium voltage level, usually air core dry type reactors are used as harmonic filter reactors. Having no magnetic core, air core reactors are free from saturation. They may be installed outdoor and indoor as long as magnetic flux path is considered during installation in order to stay away from ferromagnetic material during use.
In some industrial applications such as arc furnaces and ladle melt furnaces, it is vital to filter out some harmonics while not amplifying the existing interharmonics. Otherwise, excessive heating or overvoltages can occur which may damage or at least degrade the lifetime of equipment. Moreover, industrial customers are forced to obey harmonic current and harmonic voltage limits defined with respect to voltage level and with respect to the ratio of short circuit power to load power, in standards such as IEEE 519.92. Therefore, careful design of the tuning frequency and rating of the reactors is important and must consider a wide frequency band including both the harmonics and interharmonics.
All Hilkar air core harmonic filter reactors are custom designed for various and diverse applications. The designs take into consideration the voltage, current, inductance, type of application (or filter type), harmonics, interharmonics, size, transient events such as switchings and loss characteristics in order to provide the most efficient design at the most economical prices. All the routine tests are performed in accordance with EN 60289 or other standards depending on customer request. Type test reports are available on request. All the test reports are submitted to customer. Basic testing program includes some or all of the following tests:
Features
Technical Specifications
*Consult factory for higher values.
Motor starting reactors are used to reduce voltage during starting of large 3 phase motors while limiting inrush currents.
Large motors generally draw 6-8 times more current than their nominal current. Typically, they are started with 70% voltage while the remaining 30% is dispersed via the motor starting reactor. After 15 - 20 seconds, the reactor is switched off by contactors in the system.
Advantages
Technical Specifications
*Consult factory for higher values.
Arc Furnace Reactors are serially connected reactors that are installed in the supply systems of arc furnace transformers to stabilize arc and limit the unstable arc furnace current and voltage drop which optimize their melting process. These buffer reactors are connected in series to the primary side of the furnace transformer. Typically these reactors are tapped coils and manufactured as per customer's tap requirements.
Advantages
Technical Specifications
*Consult factory for higher values.
Smoothing Reactors are serially connected reactors inserted in DC systems. They reduce harmonic currents and transient over currents and/or current ripples in DC systems.
These reactors are necessary in order to smooth the direct current wave shape, reduce losses and improve system performance. Smoothing Reactors are used in HVDC links and industrial applications including traction systems, variable speed drives, UPS systems, etc.
Smoothing Reactors also reduce the occurance of alternation failure in inverters caused by the dips in AC voltage at the converter bus. When the direct voltage of another series connected bridge collapses, communication failures in inverters are prevented due to the reactor’s ability to reduce the rate of rise of direct current in the bridge.
Smoothing Reactors even out ripples in the direct current in order to prevent the current becoming discontinuous for light loads. They decrease harmonic voltages and currents in DC lines and limit the crest current in the rectifier due to a short circuit on the DC line.
Additionally, smoothing reactors limit the current in the valves during the converter bypass pair operation due to the discharge of shunt capacitances of the DC line.
Advantages
Technical Specifications
*Consult factory for higher values.
Line and load reactors are generally serial-connected to the input and/or output terminals of three phase equipment such as motor speed controllers, inverters and UPS systems. These types of equipment make use of semiconductor switches such as IGBTs, thyristors, and diodes and therefore create harmonic distortion and high switching over-voltages (dv/dt). Use of such equipment has been becoming more widespread as the technology advances. However, the negative effects should not be overlooked.
By using line and load reactors, the adverse effects that comes with using such equipment can be decreased in the following ways:
These reactors are designed in order to provide 4% voltage drop. Different voltage drop values are provided on demand.
All line and load reactors are custom designed for various and diverse. The designs take into consideration the voltage, current, inductance, type of application, harmonics, interharmonics, size, transient events such as switchings, and loss characteristics in order to provide the most efficient design at the most economical price.
All routine tests are performed in accordance with IEC 60076-6 or other standards, depending on customer request. Type test reports are available on request and all reports are submitted to customer. Basic testing programs includes some or all of the following tests:
Features
Technical Specification
*Consult factory for higher values.
Test Laboratory Reactors are designed for high voltage and high power test laboratories.
They are designed to withstand the most extreme electrical service conditions during test periods. Design techniques are implemented in accordance with the most demanding service conditions. These reactors are used for various purposes in test laboratories such as current limiting and synthetic testing of circuit breakers, capacitor testing, artificial line simulation etc.
Advantages
Technical Specifications
*Consult factory for higher values.
Line Traps are used in transmission and distribution networks. They are the key components in Power Line Carrier (PLC) systems used for remote control signals, voice communication, remote metering and control between substations in the electrical T&D networks.
Wave traps are used for preventing high frequency signals from flowing towards undesired directions.
Features
Selection Details
Iron Core Oil-immersed Shunt Reactors act as an absorber of reactive power in order to increase the energy efficiency of a power system.
Shunt Reactors are used to compensate the capacitive reactive power that is generated by long and lightly loaded transmission lines, as well as underground cables. This allows the flow of more active power through the system while avoiding over-voltages. Shunt Reactors can be connected directly to the power line or tertiary windings of a three-winding power or distribution transformer.
The main windings and magnetic circuit are immersed in oil, which acts as a cooling medium. It can both absorb heat from the reactor windings as well as conduct the heat away through the oil.
The core of an oil-immersed reactor is made of ferromagnetic materials, with one or more built-in air gaps. These air-gapped iron cores are designed to withstand not only mechanical stress during normal operation but also fault conditions in the network.
In high power and high voltage systems, shunt reactors should be used with RC snubber filters due to the fact that in such systems, switching transient voltages are extremely high and the switching devices may get damaged without proper damping measures.
Typical Applications
Technical Specification
*Consult factory for higher values.
A Current Limiting Reactor (CLR) is one of the most effective short circuit current limiting devices. It reduces stresses on busses, insulators, circuit breakers and other high voltage devices. Use of a CLR is the most practical and economical approach to current limiting.
Current Limiting Reactors should be placed in a distribution or transmission system where a potential short circuit current has been calculated to exceed the interrupting rate of the associated switchgear. The inductive reactance is set low enough for an acceptable voltage drop during normal operation, but high enough to restrict a short circuit to the rating of the switchgear.
CLRs are also used as load sharing reactors to balance the current in parallel circuits. They are designed to continuously withstand the rated current and fault currents for a limited period of time.
Technical Specification
*Consult factory for other values.