Standards governing distortion parameters in the electric grid such as IEEE 519, G5/4, EN 61000, EN 50160 and D-A-CH-CZ among others most often require voltage harmonic distortion to be below 5-8%. As yet, these standards are all recommended practices, used on a voluntary basis.

Although adherence to standards such as IEEE 519 is not obligatory, utilities and other parties of interest are using these standards to a growing extent as a benchmark to place demands on their customers. This is a way for them to be able to guarantee delivery on their end. Distortion standards are also used as a way to communicate and deliver an active environmental agenda with decreased energy usage and reduced energy costs for many energy intensive processes.

Low Harmonic Solutions to Meeting IEEE Standards

Reducing harmonics to an acceptable level is one way to meet the new requirements. Many modern active harmonic filters can pinpoint the contributing harmonic orders to optimize the compensation power and meet the requirements in the most cost efficient way.

Another popular, and potentially more common solution available, is the Active-Front-End (AFE). This was developed with the main target to feed back energy to the grid when breaking a motor or process. AFE can also be used to reduce harmonic loads, but in a very inefficient way, and in most cases an expensive way.

The modern Active Harmonic Filter is one of the most efficient Low Harmonic Drives in the market today. Filters are commonly available in a 208 – 480V version and a 480 – 690V. The Active Harmonic Filter can be combined with 6 pulse drives and will be placed in parallel with the load, minimizing the need of compensation power to 20 – 30 % of the load. The parallel placement will also ensure the redundancy in the design, which is a major advantage in a critical applications. Modular solutions, which are now more commonly available gives a dynamic and agile solution to work for future improvements to existing machinery.