Network Harmonics are created by devices connected by the customer to the electricity network. These harmonics are typically referred to as grid pollution due to the effect they have on the power quality within the network. This change in power quality can impact on the performance of sensitive devices such as computers, transformers and motors causing them to malfunction or fail.
The harmonics are created by non-linear loads. The most common piece of equipment responsible for the creation of harmonics is Variable Speed Drives (VSD’s). The harmonic currents created by these devices cause voltage distortion at various points in the network dependant on the system impedance.
These harmonics are produced by customer devices and therefore must be controlled at the site where they are produced. This is essential because controlling the individual sources will mitigate the flow of harmonics into the network. This will also mitigate the effects of the harmonics on the wider network.
Any customer with a cumulative VSD load exceeding 20kW must adhere to this standard.
Refer to our Rural Network Harmonics Standard for further details.