
Line Reactors For VFDs

Line Reactors protect Variable Frequency Drives (VFDs) from input power line disturbances by smoothing and slowing down incoming voltage distortion. They also reduce harmonics generated by the VFD that travel back into the power line. A line reactor is coil of wire that forms a magnetic field that current flows through. The magnetic field limits the rate of the rise of the current, reducing harmonics.
Line Reactors help to stabilize the current waveform and act as an impedance between the power source and the variable frequency drive. The impedance will protect the input section of the VFD and reduce the harmonic current drawn from the power system by the drive.
The applied impedance of the reactor will work to soften and slow down the incoming line voltage distortion, such as power system surges and voltage spikes, when applied to the input side of a VFD. This will help to prevent drive over-voltage faults and damage to the drive input components when line voltage deviations occur. Line disturbances are common on power systems with power factor correction capacitors coming off and on line, as well as the fluctuation of high current loads. Reactors also mitigate harmonic currents being drawn by the drive and help to block background incoming line voltage harmonics which can affect the operation of the VFD.
Products
FAQs
Does an input ac line reactor protect against all power surges?
No, an input AC line reactor does not protect against all power surges. While line reactors offer some level of protection against certain types of power disturbances, their primary function is to mitigate harmonic currents and voltage spikes caused by the operation of Variable Frequency Drives (VFDs).
Do load reactors protect against harmonic distortion?
Yes, load reactors can help mitigate harmonic distortion in electrical systems. Load reactors are typically connected on the output side of VFDs or other non-linear loads. They are designed to introduce impedance into the circuit, which helps to reduce and smooth out harmonic currents.
Inductive Load Basics
Electrical load is an electrical component or portion of a circuit that consumes electrical power. For example, a power source such as a battery or generator will have a load which consumes that power, such as a light bulb, motor or television.
There are three types of electrical loads: capacitive loads, resistive loads and inductive loads
Capacitive and Resistive Loads
Capacitive loads are similar to inductive loads in that the current and voltage are out of phase with one another, however, capacitive loads see the current reach its maximum before the voltage, while inductive loads see the voltage reach its maximum before the current. Resistive loads typically consist of things like heating elements.
Inductive Loads
Inductive loads use a coil to produce a magnetic field. The most common types of inductive loads are motors, fans, blenders and pumps. Inductive loads resist change in current, which lags behind the voltage. There are two different types of power with inductive loads. There is real power, which is based off of the work that is actually being done by the motor and there is reactive power, which is the power that is drawn from the power source to produce the magnetic field. The total power of an inductive load combines both the real power and reactive power.