Want to know all about the use and benefits of line reactors? Read on…

  • 25 Sep, 2019

Clean and consistently flowing electric currents are excellent for the well-being of your industrial equipment. When a line reactor is added to the equipment, it safeguards the equipment from input power disruptions that can potentially damage the drive.

What are the line reactors? 

These are electromagnetic devices consisting of a steel core that is wrapped using copper coils. These coils form a magnetic field through which the current flows and this limits the rate at which the current rises. This reduces the harmonics and safeguards additional electrical devices. Generally, there are two types of line reactors that are used with variable frequency drives (VFDs): AC and DC.

The reactor that is installed between the power system and the VFD is known as an AC line reactor. When a DC reactor is inserted in the DC link of a drive, it is referred to as the DC link reactor.

While it is true that both AC and DC reactors act as restrictors of harmonic current, it is AC reactor that safeguards more numbers of equipment as it is installed the power source and VFD. Thus, it limits the exposure to fluctuations and power system urges. It can rightly be said that reactors prevent trips due to overvoltage, improve total power factor, expand the dependability and lifespan of the VFD, and reduce abnormal tripping.

When should you install a line reactor?

  • The input line power is known to experience spikes, power surges, transients, and more.
  • The supply line power is unusually rigid; usually more than 10 times the kVA rating of the VFD that is connected.
  • Where there is an issue of harmonic distortion.
  • When you want a buffer between your motor and VFD so as to alter the waveform and decrease the voltage pressure on the motor.

How are line reactors beneficial for your variable frequency drive (VFD)? 

Although VFDs prove highly advantageous as far as energy savings and manufacturing efficiency are concerned, they are also the main cause of electrical power system pollution. In this respect, reactors are the most common means to reduce this pollution and are highly popular as the best drive solutions.

VFDs accumulate current so that they can recharge their capacitors every time the AC voltage reaches a certain high. The consequence of this is bursts of current in place of the normal sine wave that must be there. These short bursts of current causes the voltage to drop and distort the voltage waveform.

The enormity of this distortion is known as Total Harmonic Current Distortion (THCD) or Total Harmonic Voltage Distortion (THVD). The bigger is the VFD, the more it will impact the power system.

The AC line reactor has the potential to easily eliminate around 65 percent of this THCD, which accounts for a huge improvement. Currents at the high peak may also lead to the intermittent blowing of fuses and fuse degradation. AC line reactors safeguard the VFD from power system surges and also prevent trips due to overvoltage.