| Title |
Phase Identification Method for In-Line Measurement Devices in a Distribution System Using Section Load Variability |
| Authors |
이혜규(Hye-Gyu Lee) ; 강제헌(Je-Heon Kang) ; 황평익(Pyeong-Ik Hwang) |
| DOI |
https://doi.org/10.5370/KIEE.2026.75.8.1731 |
| Keywords |
Phase identification; Section load; In-line measurement device; Feeder remote terminal unit (FRTU); Advanced distribution management system (ADMS) |
| Abstract |
The advanced distribution management system (ADMS) models a distribution line as sections bounded by in-line measurement devices (ILMDs), installed on equipment such as circuit breakers and automatic switches, and estimates section loads from ILMD measurements. Accurate phase connection information of ILMDs is therefore essential. However, recorded phase labels may disagree with actual connections owing to construction errors, equipment replacement, and post-fault rewiring. Conventional methods based on voltages or synchrophasors are not directly applicable, since feeder remote terminal units (FRTUs) provide reliable measurements only for current magnitudes and power factor angles, while their voltage measurements are inaccurate. This paper proposes a phase identification method for ILMDs using only existing FRTU measurement histories. It is shown that a phase mismatch adds a disturbance term to the calculated section load, which probabilistically increases its variability. Based on this property, a suitability index is defined as the reciprocal of the sum of three normalized variability measures, i.e., the standard deviations of the section load magnitude and power factor angle, and the standard distance in the complex power plane. The phase combination maximizing the index is then selected. For an entire system, the network is divided into zones bounded by ILMDs and phases are estimated sequentially from the circuit breaker. Case studies on a test system based on an actual distribution line demonstrate that the proposed method accurately identifies the phase connections of ILMDs under measurement noise. |