Experience on Mae Moh Power Plant operation to damp the power oscillation of 500 kV transmission line

In September 2001, the power of 500 kV transmission lines between the lignite-fired Mae Moh Power Plant and the central area of Thailand were unknown oscillated. To investigate this problem, the Electricity Generating Authority of Thailand (EGAT.) tried to find and solve causes of the oscillation. One of these, it tested the lines with combination of the plant operation by trying to operate the oscillation and managing for safety this operation. The objective of this paper describes the test, which focuses on safety power plant operation. For the test, Load Dispatching Center or National Control Centre (NCC) increased the voltage lines and switching one line out of service while the plant was preparing to operate in safety view. But the power lines have a little oscillation. However, we could monitor some data and effects while the plant was controlling in different way. Finally, the plant brings the power system stabilizer (PSS) to operate for helping this transmission line.