What is K-factor?

Jan. 29, 2019, 2:25 p.m.

1 Answer


Jan. 29, 2019, 2:26 p.m.

K-factor is a parameter that characterizes the non-linearity of the load, i.e. the number of harmonic distortions introduced by the consumer to the grid. Unlike SOI, which is also a nonlinear characteristic, when calculating the K-factor, higher harmonics of the current, causing thermal losses in power transformers, are of greater importance.

In fact, the K-factor is the coefficient of increase in losses in the transformer due to non-linearity of the load. There are specialized transformers that allow operation with increased K-load factors. They are more effective and safe and are recommended for use at critical sites.


Well-known independent company Underwriters Laboratories Inc. (UL), a US safety certification provider of technical products, recognized the potential hazards / risks of accidents resulting from the use of standard transformers with non-linear loads. A rating system was proposed showing the ability of a transformer to supply harmonic loads. The K-factor was chosen as the estimated parameter, the estimates are set forth in the UL1561 standard.


Advantages and benefits of K-factor converters
- Convenient processing of weak signals and their interfacing with the system
- Signal protection against interference with the possibility of transmission over long distances
- CSA Compliance
- Strengthening the pulse output of turbine flowmeters


The K-factor is a parameter characterizing the ability of a transformer to withstand harmonic components within the framework of temperature limits and transformer insulation class defined by the standard.