Utilization of Harmonic Emission Limits by Customer Installations in Low and Medium Voltage Networks

The principle of EMC coordination allocates an allowable harmonic emission to each customer installation. If customers do not utilize their allocated harmonic emission on a larger scale, the existing hosting capacity of the network with regard to harmonic emissions might be under-utilized. This can lead to avoidable costs for either the customers or the network operator, e.g. if unnecessary mitigation equipment is required. This paper characterizes the level of utilization of harmonic emission limits in low and medium voltage networks. For this, a representative set of customer installations in Switzerland is selected, also including renewable generation, storage systems and electric vehicle chargers. Harmonic current and voltage emission limits are calculated according to the applying rules. Data from respective weekly measurement campaign is used to assess the emission levels of customer installations in actual operating modes considering also unbalanced conditions. The utilization of harmonic current and voltage emission limits is presented for the actual operating point of the installations as well as an extrapolated operating point corresponding to the full utilization of the agreed power. Continuous monitored utilization of harmonic emission limits enables the network operators to a more flexible and efficient management of harmonic disturbances and consequently reduction of costs for all stakeholders.