Locating major harmonic current contributors by layered knowledge discovery in database

Harmonic monitoring becomes increasingly important in harmonic management of building low voltage power distribution system (LVPDS). Excessive harmonic currents result in decreasing energy efficiency. It is also harmful to the sensitive devices and can even lead to the failure of devices. As a result, power quality monitoring system (PQMS) has been widely installed in a facility management to monitor building LVPDS. This paper presents a diagnosis approach for the PQMS to locate major harmonic currents contributors based on a knowledge discovery in database (KDD) procedure. The key data used for the analysis includes the normalized values of instant power consumption and total harmonic distortion of current (THDI). The diagnosis is illustrated with a case study for which a PQMS is installed in an education institute. The results obtained from the PQMS are also useful for demand-side management and demand dispatch in future microgrid system.