Harmonic emission limits and responsibilities at a point of connection

Abstract

A customer expects to receive a voltage supply at his installation that meets the requirements of standards like (national) grid codes, EN50160 standard etc. under normal operating conditions. On the other hand, the devices connected to a customer's installation should meet power quality (PQ) requirements as given in the IEC standards (and other relevant product standards). In contrast, present standards give very limited information about the PQ requirements at a customer's point of connection (POC). Modern household customers use many power electronic-based devices for their daily usage. Those devices inject harmonic currents and all together distort the network's voltage. It is noticed from surveys that harmonic-related inconveniences are increasing in the power system. Some field measurements (on harmonics) in the Dutch low-voltage (LV) network will be discussed in this paper. Also, harmonic simulation is done on a typical LV network that supplies electricity to several households. Both the field measurements and simulation results are compared with the limit values of the standards. Further, harmonic current emission limits at different customers' installations are derived. This information would be helpful for the customers to know their rights and responsibilities in the network. Additionally, a proposal is made about new planning level values of harmonic voltages in the network. Finally, a methodology is developed to assess harmonics-related responsibilities of each of the involved parties in the power system, and it is shown where these can be applied.