Open AccessPQ chart: a real‐time situational awareness tool for transmission lines
Author(s) -
Murali Priyanka,
Soman Shreevardhan A.
Publication year - 2020
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2020.0214
Subject(s) - ac power , electric power transmission , phasor , voltage , transmission line , situation awareness , electric power system , control theory (sociology) , phasor measurement unit , computer science , operator (biology) , chart , transmission (telecommunications) , real time computing , engineering , power (physics) , electrical engineering , mathematics , artificial intelligence , physics , statistics , aerospace engineering , repressor , chemistry , biochemistry , control (management) , quantum mechanics , transcription factor , gene
A tool to visualise real‐time phasor measurement unit (PMU) data of a transmission line is proposed, named PQ chart. It is a simple and intuitive visualisation aid for operator situational awareness. The use of PMU data helps in capturing both steady‐state and dynamic behavioural aspects of the transmission line. The tool is based on basic active and reactive power equations of a transmission line. The locus of active and reactive power flow corresponds to a circle in which the radius depends on voltage regulation. If the circle is imagined as a wheel, then the spokes of it correspond to the voltage angular difference across the transmission line. The PMU data is plotted on this canvas and its progression in time is observed. The occurrence of power swings, angular and voltage instabilities lead to a trajectory on the chart. A system operator can be alerted when any such movement occurs. The tool provides a single view from which deciphering active power flow, reactive power flow, voltage regulation, and voltage angle difference across a line becomes easy for the operator. Case studies with PMU data of 400 kV transmission lines in the Indian grid are presented to illustrate the tool's capabilities.