GridSense Line IQ LIQ60, User Manual, Page: 8 / 39

File: LIQ User Manual V2.0
Page 6 of 37
2 Introduction to the LineIQ device family
The LineIQ monitoring system allows electricity utilities and other operators of high and medium voltage
overhead conductor distribution and transmission lines to monitor and respond to faults and load changes
on the supply grid. The monitoring system consists of Conductor Mounted Sensors (CMS), data
collators, and remote or on-site PC-based aalysis and control software. The LineIQ system links to existing
SCADA or Distribution Management systems. The CMS communicate with the data collators (LIQ-
Gateways) using short range radio. The LIQ-Gateway and CMS can also communicate with on-site PCs
(e.g. laptop) using short range radio, when an LIQ-LocalLink is connected to the PC. The LIQ-
Gateways in turn communicate with control rooms via a cellular modem or long range radio links, and
can use a variety of different communication standards.
Figure 1 shows a typical implementation of LineIQ monitoring equipment.
The LIQ-60 CMS detect and store network events and also monitor load currents, power f actor , conductor
voltage, and ambient and conductor temperatures.
Events such as faults, momentary interruptions, sustained interruptions and restorations are radioed to
the LIQ-Gateway as unsolicited events, which in turn are sent on to the SCADA and control center.
Ongoing measurements such as load currents, conductor voltage, and ambient and conductor
temperatures are periodically downloaded to the LIQ-Gateway, which collates the information and sends
it to the control center.
The LIQ-60s are installed on energized lines. They are battery and solar powered for long-term continuous
monitoring. They can be configured and have their firmware upgraded wirelessly using the same license-
free short- range radio link (RF link) which is used to download data. Hence, there is no need to remove
the LIQ-60s from the conductors after they have been installed.
LIQ-Gateways function as Remote Terminal Units (RTUs) and are mains powered or battery/solar powered,
depending on location and supply availability. Transmission of load log data from the LIQ-60 to the LIQ-
Gateway occurs during a status check which is periodically initiated by the LIQ-Gateway. This data is then
transmitted by the LIQ-Gateway to the remote monitoring system (e.g. SCADA) or is accessed on demand
using LineMan or SCADA via a variety of supported protocols, for example DNP3, IEC 61850 or Web
services.