Transmission lines sag while the current flowing through electrical conductors exceeds the transmission capacity and causes overheat on wires. Severe transmission line sag may seriously affect the safety of power grids. When a transmission line sags excessively, it is likely to result in further ground faults and prompt and massive blackouts.
On August 14, 2003, a widespread power outage occurred in the U.S.. The sagging lines caused by overload of power transmission, touched the trees underneath, and resulting in a serious ground fault. The power outage impacted an area of 24 thousand square kilometers and over 50 million people with 61.8 gigawatts power loss up to 4 days.
In the traditional grid, a very conservative transmission capacity is set to avoid the occurrence of sag. Therefore, the capacity can only be increased by building more transmission lines or by replacing lines with better performance.
A direct monitoring equipment for conductors -
Prevent line from excessive sagging and improve the capacity of power transmission in the meanwhile
TSSG tracks the sag level and provides the real-time data of power grid status including conductor temperature, line current, ambient temperature and humidity. TSSG is suitable for transmission line up to 635 kV by passing the high voltage test and is also capable of withstanding ± 1500kV lightning surge.
Transmission Span Sag Guardian (TSSG)
is an innovative smart sag sensor designed by Gridwell
Wireless sensing device with high communication security
Track the sag level directly to keep a safe distance with the objects below and prevent transmission lines from being exposed to danger
Measure conductor temperature directly to enhance the capacity of power transmission.
Present real-time data with user interface to control the status of transmission lines immediately; therefore ensureing the safety of power grids.
The Accuracy of Sag Measurement by Gridwell TSSG is within 10 cm, and the range for current measurement is up to 2000 A. In addition, it possesses a wide range of operating temperature, and the wireless transmission distance can reach up to 500m.