Power factor correction capacitor banks and harmonic filters.

Power factor correction capacitors and harmonic filters are an essential part of modern electric power systems. Power factor correction capacitors are the simplest and most economical means of increasing the capacity of any power system, minimizing energy losses and correcting load power factor. In addition, power factor penalties can be reduced and power quality can be greatly enhanced.

Several reasons to correct poor power factor.

The lower the power factor the higher the required necessary current draw, which will require a more robust infrastructure and the use of appropriately heavier gauge wires to minimize the dissipation of power. This means that on-premises utility usage will be more costly, and facilities operating with low power factors will be charged at a higher usage utility rate than facilities with high power factors.

The first reason is to reduce or eliminate a power factor penalty charged by the utility.

Another reason is that your existing transformer is, or shortly will be, at full capacity and installing power factor correction capacitors can be a very cost-effective solution to installing a brand new service.

Depending on the amount of power factor correction (kvar that needs to be injected into the electrical system to improve the power factor) and the dynamic nature of the load, a fixed or switched capacitor bank may be the best solution. When capacity becomes a problem, the choice of a solution will be dependent upon the size of the increase needed. Like all power quality solutions, there are many factors that need to be considered when determining which solution will be best to solve your power factor problem.

Various types of power factor correction

Fixed capacitor banks

Automatic power factor correction capacitor banks

Active power factor correction Static var Generator

Harmonic Filtering-A Practical Solution

As the world becomes more dependent on electric and electronic equipment, the likelihood that the negative impact of harmonic distortion increases dramatically. The efficiency and productivity gains from these increasingly sophisticated pieces of equipment have a negative side effect…increased harmonic distortion in the power lines. The difficult thing about harmonic distortion is determining the cause. Once this has been determined, the solution can be easy. Passive and active harmonic filtering equipment will mitigate specific harmonic issues, and correct poor power factor as well.

To reduce or eliminate harmonic resonance and distortion, a true harmonic filter needs to be used at strategic operating circuit points.

What is a harmonic filter?

As previously mentioned, harmonic filters are used to eliminate harmonic distortion caused by excess currents in and out of appliances. It can prevent large quantities of harmonics from causing damage to equipment, downtime of operation, and preventing an increase in operating costs.

What is a harmonic filter made of?

The interior of a harmonic filter is made up of an array of resistors, inductors, and capacitors that are capable of deflecting unwanted harmonic currents, sending them to ground. Some of these filters are designed to deflect harmonics of a specific frequency or frequencies.

Various types of harmonic filters

Passive Harmonic Filters – These filters are typically used in industrial installations with loads representing more than 500kVA. These filters require power-factor correction during installation.

Active Harmonic Filters – Also known as active power filters, these filters are often used in commercial installations with loads less than 500kVA. They help to reduce current distortion that could lead to equipment heating and circuit overloads.

Hybrid Filters – A system that combines passive and active filters for industrial installations with loads more than 500kVA. It has the advantage of the previous two types of filters and covers different power and performance levels.