Electric reactor, as an important component in the power system, undertakes multiple tasks such as regulating voltage, limiting short-circuit current and filtering harmonics. Its basic function is to hinder the alternating current, thereby playing a role in adjusting and protecting the circuit. This post covers all kinds of information about electric reactors and how to use them. Get started now!
LTEC Electric Reactor
Electric reactor refers to an electronic device that can act as an impedance in a circuit. It is a winding static induction device with inductance. The main functions of this device are to regulate voltage, limit short-circuit current, and filter harmonics. It is basically used in all walks of life.
As the current power system gradually develops and grows, the use of electric reactors is crucial. The reasons include:
Control harmonics
Control harmonics-sourced: pqcomponents
Because modern power systems use a large number of electrical equipment containing nonlinear electrical components such as semiconductors. For example, various rectifier electrical devices, large-capacity inverters, large AC/DC conversion devices and other power and electronic devices commonly used in industry. These electrical equipment generate a large number of harmonics. Reactors are essential to control these harmonics.
Avoid frequent damage to capacitors
Avoid frequent damage to capacitors-sourced: hioki
Point equipment with nonlinear materials, including arc furnaces, transformers, generator sets, etc., is prone to capacitor damage during use. Therefore, the use of electric reactors can improve this problem.
There are a large variety of electric reactors for your choose. It can do you a great works. The types of electric reactors are:
According to the phase type, the electric reactors are: single-phase reactor, three-phase reactor.
Single-phase reactor
Single-phase reactor-sourced: suenn
A single-phase reactor is essentially an air-core coil without magnetic conductive material. It acts as an impedance in the circuit. This type of reactor can help filter out current spikes, reduce the generation and injection of harmonic currents, and protect your inverter and motor, etc.
Three-phase reactor
Three-phase reactor-sourced: dfelectric
Three-phase reactors are specially used to attenuate notches and spikes, and reduce harmonics. In addition, it can protect the power of the capacitor to avoid resonance effects, reduce efficiency and extend the life of the capacitor, etc.
According to the cooling method, the reactor includes dry reactor and oil-immersed reactor.
Dry reactor
Dry reactor-sourced: zhiyue
Dry reactor refers to a reactor that is insulated and dissipated by air or other materials (such as epoxy resin). The difference between it and the oil-immersed type is that the dry-type reactor avoids the risk of oil leakage and is more environmentally friendly, suitable for indoor use or environments with high fire protection requirements.
Oil-immersed reactor
Oil-immersed reactor-sourced: hilkar
Oil-immersed reactor refers to an electrical device that immerses the coil and core in insulating oil to achieve operation. Its coil is usually made of high magnetic permeability materials, such as silicon steel sheets or pure copper. This device can limit the current while improving the stability of the power grid.
According to the structural characteristics, there are air-core reactors and iron-core reactors.
Air-core reactor
Air-core reactor-sourced: trench-group
The air-core reactor mainly adopts an oil-free structure and an iron-core-free design. It mainly consists of three parts: structural parts, support insulators and coils. Unlike the iron-core type, its coil is composed of multiple layers of encapsulation and internal and external parallel connection. The ventilation partition is made of glass fiber to help heat dissipation and ventilation.
Iron core reactor
Unlike air core reactor, iron core reactor inserts iron core into solenoid, and increases the magnetic permeability of iron core to enhance inductance efficiency, thus improving its own performance. In addition to improving the quality of power system, it can also enhance inductance effect.
According to the installation location, there are indoor reactors and outdoor reactors.
Indoor reactors
Indoor reactors are generally installed in the switch cabinet of the cable terminal lead-out line. It is generally installed indoors and will not be affected by external natural conditions such as wind, rain and dust. Therefore, it does not need to take any waterproof, dustproof, anti-corrosion, sun protection and other measures.
Outdoor reactors
Outdoor reactors are generally installed on the tower of the transmission line. It is generally installed outdoors. Unlike indoor reactors in terms of installation environment, service life and operating reliability, its installation and use environment is relatively harsh.
According to the use of classification, there are series reactors, shunt reactors, current limiting reactors, filter reactors, split reactors, static VAR compensation shunt reactors, starting reactors and smoothing reactors.
Series reactors
Series reactors-sourced: hitachienergy
Series reactors are specially used in ultra-high voltage long-distance transmission systems and are connected to the tertiary coil points of transformers. It can be used to compensate for the capacitive charging current of the line.
Current-limiting reactor
Current-limiting reactor-sourced: fdueg
Current-limiting reactor can limit short-circuit current.
Filter reactor
Filter reactor-sourced: giantele
Filter reactor is usually connected in series in the capacitor circuit to prevent excessive harmonics from entering the system.
Split reactor
Split reactor is specially connected in series in the system to limit fault current.
Static VAR compensation shunt reactor
Static VAR compensation shunt reactor-sourced: hitachienergy
It is specially used for thyristor phase-controlled fast VAR compensation device.
Starting reactor
Starting reactor-sourced: fdueg
Starting reactor is specially used for step-down starting of large AC motors.
Smoothing reactor
Smoothing reactor-sourced: hilkar
This reactor is specially used in DC transmission systems and high-power DC electrical transmission devices. This can reduce the pulsating current component in the DC circuit and ensure the stability of the DC current.
According to the voltage level, there are high voltage reactors, low voltage reactors.
High voltage reactors
High reactors-sourced: switchgear
High voltage reactors are mainly used for high voltage levels such as 6kV, 10kV, 20kV, 35kV. It is specially used for series systems of high voltage levels.
Low voltage reactors
Low reactors-sourced: giant-electric
Low voltage reactors are mainly used for series systems of low voltage capacitors in systems such as 380V, 400V, 450V, 480V, 600V, 690V, etc.
Reactors have a wide range of uses, including:
Capacitor protection
Capacitor protection-sourced: diyguru
Reactors can limit the inrush current when the switch is switched on, protecting electrical components. In addition, they can suppress the higher harmonics of the power supply system, thereby protecting capacitors.
Limit short-circuit current
Limit short-circuit current-sourced: iaeimagazine
Reactors can also limit the short-circuit current of power lines. When a line short circuit occurs, it can limit the short-circuit current to a certain limit to prevent the switchgear from removing the fault smoothly and effectively.
Suppress or filter higher harmonics
Suppress or filter higher harmonics-sourced: circuitdigest
One of the basic functions of reactors is to suppress or filter higher harmonics. The higher harmonics mentioned here refer to harmonics such as 3rd, 5th, and 7th. Of course, choosing a suitable and high-quality reactor can achieve this effect.
Compensate for capacitive current
Compensate for capacitive current-sourced: ergunelektrik
The phase angle between capacitance and inductance differs by 180°. Therefore, capacitance can be neutralized and offset by inductance.
Limit Du/Dt or Di/Dt
Limit Du/Dt or Di/Dt-sourced: celduc
Du/Dt refers to the rate of change of voltage, and Di/Dt refers to the rate of change of current. Reactors have the function of limiting Du/Dt or Di/Dt.
Extending transmission distance
Extending transmission distance-sourced: baudcom
Here, it specifically refers to the MLAD-VR-SC inverter-specific output reactor or the MLAD-SR-SC servo-specific output reactor. The reactor has the function of extending the effective transmission distance of the inverter/servo.
Improving power factor
Improving power factor-sourced: electrical4u
The capacitive distributed capacitance of the long-distance transmission line makes the total load capacitive. At this time, after installing the reactor, the power factor of the system can be improved.
Energy saving
Energy saving-sourced: pelen
The reactor can provide the inductive reactive power required by the load locally. The inductive reactive power required by the load does not need to be provided through the cable line. Therefore, installing a reactor has a certain energy-saving effect.
Harmonics refer to a waveform generated when nonlinear electrical equipment, such as inverters, rectifiers, arc furnaces, etc., are running and the current wave is distorted. It has a great impact on the equipment and can easily cause overheating of transformers and motors, trigger capacitor resonance, and thus cause overcurrent or overvoltage, thereby shortening the service life of electrical equipment.
Its hazards can be divided into:
Damage to power supply lines and electrical equipment
Damage to power supply lines and electrical equipment-sourced: ttfpower
Harmonics can damage insulation, and in severe cases cause short circuits and even fires. Since the impedance of capacitors to harmonics is very small, the temperature of capacitors rises, thereby damaging power supply lines and electrical equipment.
Increase motor losses
Increase motor losses-sourced: oswos
Harmonics can generate mechanical vibrations, cause harmonic overvoltages, increase additional losses of motors, and thus damage motor insulation.
Interference with communication lines
Interference with communication lines-sourced: rahsoft
When odd-order low-frequency harmonic currents with large amplitudes pass through power lines, they will generate interference voltages to the communication lines of adjacent power lines. Therefore, it will interfere with the normal operation of communication lines and even affect the destruction of communication lines.
Impact on product quality
When harmonics of a certain frequency pass through the equipment, it will make the equipment unstable, resulting in a decline in product quality. In severe cases, it may even cause the product to be scrapped, causing significant losses.
Impact on dosimeters
The presence of harmonics will cause errors in the dosimeter dial indicator needle, which may even cause the equipment to fail to work.
Each electric reactor has its own model. Each model has a corresponding meaning. Let's take the NKL-6-400-5 model as an example:
What Does The Model Of Electric Reactor Mean-sourced: seec
NKL
The capital letter N refers to the cement column type of the reactor. K represents the reactor. L represents the aluminum wire.
The first number
The first number indicates the rated voltage of the reactor. The 6 in this model means that the rated voltage of the reactor is 6kV.
The second number
The second number indicates the rated current of the reactor. The rated current of this model is 400A.
The third number
The third number represents the percentage (%) of the rated reactance of the reactor.
An arc suppression coil is a device used in a neutral grounding grid. It can compensate for the capacitive current of a grid with a single-phase grounding fault, thereby slowing down the rising speed of the arc gap recovery voltage, ensuring the suppression of the arc and avoiding reignition.
Its types include:
What Is An Arc Suppression Coil-sourced: kompass
There are various types of arc suppression coils. In use, its types include no-load turn-adjusting arc suppression coils, load-adjusting turn-adjusting arc suppression coils, adjustable-capacitance arc suppression coils, bias-magnetic arc suppression coils, and magnetic valve arc suppression coils.
Its functions include:
- Greatly reduces interference to communication equipment and threats to personal safety;
- Allows the system to run with faults for two hours, ensuring power supply reliability;
- Automatic arc suppressing, avoiding the generation of arc overvoltage and fault expansion, and suppressing the occurrence of ferromagnetic resonance.
The working principle of the arc suppression coil is simple and easy to understand:
What Are The Working Principle Of Arc Suppression Coils-sourced: sound-au
- The arc suppression coil is a grounding reactor with adjustable reactance.
- One end is connected to the transformer or ground. The other end of the transformer neutral point is grounded.
- When a single-phase grounding fault occurs in the three-phase line, an inductive current is generated to compensate for the capacitive current generated by the line-to-ground capacitance, so that no continuous arc occurs at the fault site, the fault range is not expanded, and the safety and reliability of the power supply system are improved.
- The reactance or current of the arc suppression coil is adjusted by the no-load or on-load tap changer.
The compensation methods for arc suppression coils include:
- Full compensation: It is easy to form series resonance, causing the neutral point potential to rise, endangering the insulation of the equipment, and is generally not used.
- Undercompensation: When part of the line is cut off or the system frequency is reduced, it may become full compensation, which is generally not used in the power grid.
- Overcompensation: Generally, the arc suppression coil installed at the neutral point of the transformer in the power grid and the arc suppression coil at the neutral point of the generator with direct distribution line adopt this method.
The parameters of arc suppression coils mainly include rated voltage (line rated voltage), rated current (inductance current and adjustment range), and rated capacity (KVA).
Reactors are also named after wires. They include wire-wound reactors and foil-wound reactors. From the perspective of material, they also include aluminum reactors and copper reactors. Therefore, in the following selection process, you can:
Copper reactors
Copper reactors-sourced: directindustry
- Compared to aluminum, they have high density and good current flow, that is, good conductivity;
- Small heat generation, low temperature, and low loss, so they have a longer service life;
- Very suitable for large-scale industrial needs;
Aluminum reactors
Aluminum reactors-sourced: qmlh-power
Suitable for civilian projects;
With the rapid development of the power industry, in order to save energy, improve power supply quality, and increase the level of reactive power compensation. Using series reactors in capacitor banks is an effective and good way. But at the same time, we must also pay attention to the installation conditions and design on site, so as to better suppress harmonics. If you have more questions about reactors or solution requirements, you are welcome to consult us!
