Yokogawa completed a major power station refurbishment for AGL Energy
Limited (AGL) involving all four generating units at their Loy Yang A facility.
The Loy Yang is Victoria’s largest power station.
Part of a total upgrade of the power station’s control system and
generating units, the refurbishment contract was awarded to Yokogawa in 2006
with a scope that included creating a common station plant control system, a
coal handling system and a high fidelity operator training simulator as well as
the changing of the operating systems on the generator units by the end of
2014. The Unit 4 generator at AGL’s Loy Yang A power station successfully
passed its full load rejection test in late 2014, signifying the end of Unit
4’s major outage activity.
Commissioned over 30 years ago in 1982, Loy Yang is a 2,210- megawatt
power station that supplies approximately 30% of Victoria’s power requirements.
The upgrade project was necessitated by continuing efficiency initiatives in
the face of rising coal costs, tougher environmental controls and the ageing of
many disparate control and protection systems, which meant that the integrated
control and monitoring systems on the four boilers and generators needed to be
refurbished.
The lengthy contract period allowed Yokogawa to be more efficient and
timely, and ultimately provide more value to Loy Yang’s owners with every unit
outage completed quicker than the previous one. Yokogawa successfully completed
Unit 4’s outage early and importantly, without any Lost Time Incidents.
Yokogawa’s Managing Director John Hewitt explained that Yokogawa’s
ability to bring this project in early was the result of the open and learning
culture at the company where personnel have learned to embrace better ways to
do things and cooperate freely with other suppliers on mega projects to
facilitate cost and time savings.
According to feedback from the plant’s operators, the new control system
will allow more precision in operation of the steam boilers to better cope with
variations in coal quality and moisture content from the adjacent mine.
According to AGL Loy Yang’s Engineering and Maintenance Manager, Ron
Tomasetti, during the initial implementation phase, Loy Yang was already seeing
yield improvements in running the automated control system, which required less
operator input, but gave tighter control of the system. The plant has been able
to achieve 2-3% thermal efficiency improvements, which benefits the power
station, electricity users and the environment.