The ancient town of Giubiasco lies at the foot of the Swiss alps, surrounded on three sides by mountains. For decades, waste from the town and its surrounding area has been exported to other cantons for disposal – a costly exercise. But in 2009, the governing canton of Ticino built a waste-to-energy plant which provides heating and electricity to the surrounding area.
The Giubiasco plant converts around 160,000 tons of waste per year into energy. The plant feeds the national power grid and covers the needs of around 23,000 Swiss households. The waste is collected from the Ticino canton or state.
The heat from the waste incineration generates steam that drives an ABB 19.5 MW high voltage generator to produce around 100 gigawatt hours of electricity annually. For 10 years the generator has been running 365 days a year and, like all machines, it is subject to ageing. A generator’s stator winding insulation is particularly susceptible to wear and tear.
That’s why the plant’s maintenance team was interested in ABB’s Life Expectancy Analysis Program – ABB Ability™ LEAP. The analysis predicts the remaining lifetime of the generator’s stator winding insulation and is conducted every three years when the plant shuts down for inspection and maintenance. The first LEAP was performed at the Giubiasco plant in 2017 and showed that that there was no degradation which would impact reliable operation.
ABB Ability™ LEAP can determine, with a high degree of certainty, how much longer the stator winding will hold up. It provides the customer with detailed information on the actual condition of the stator winding insulation and recommendations on actions that should be taken in the short and long term to ensure reliable operation.
“We were quite impressed by the concept. And so we signed a LEAP service contract for the generator,” said Marco Rebozzi, maintenance manager at the Giubiasco incineration plant. “We wanted to avoid a situation in which a breakdown would paralyze our only generator, which contributes significantly to the supply of electrical power for Ticino.”
Based on measurements collected during a single site visit, combined with operating parameters such as running hours, number of starts and temperatures, ABB Ability™ LEAP conducts a lifetime analysis using its own software and algorithms. For the analysis, ABB accesses its own database containing measurements and analysis of thousands of motors and generators throughout the world.
Since the last LEAP analysis in 2017, the generator has operated without faults for over 25,000 hours. “The next inspection cycle is scheduled for the coming year. We will then do another LEAP analysis and plan the future of the centerpiece of our power plant,” Rebozzi said.