PECM Issue 14 2015 | Page 36

LEFT Advances have been made in the design and construction of the high voltage stator coils used within the generator, which can provide improved efficiency and reliability this technology and is offering free thermographic surveys to both new and existing customers. pump and turbine. One cost effective alternative approach is to use a reverse-running centrifugal pump, which can improve the efficiency of the pumping cycle and thus reduce operating costs. Maintaining these pumps and the associated generators requires expertise and experience as well as access to the latest in pump design innovations, which Sulzer, as one of the world’s leading pump manufacturers, can provide. Preventative maintenance A power station needs to optimise output in order to meet demand as efficiently as possible, but, inevitably there comes a time when maintenance repairs, either electrical or mechanical, will be required. Therefore, a programme of periodic, preventative maintenance can be combined with condition monitoring techniques to improve the reliability and longevity of the equipment. Employing a range of condition monitoring equipment, combined with suitable analysis techniques, can provide an accurate assessment of the status of turbines and generators, allowing operators to ensure continued production. One of the most useful tools is vibration analysis, which can indicate potential problems with bearings and large rotating parts; combined with thermal imaging, it can produce an accurate indication of the overall status of the plant. Additional testing of the electrical windings, especially partial discharge (PD) analysis, can also provide very useful information on the overall RIGHT The resin rich coil uses a thermosetting epoxy resin infused mica tape for the slot 36 PECM Issue 14 condition of the generator. PD can cause insulation degradation, which if not remedied, can lead to reduced output of the generator and premature failure of the insulation system causing stator failures. The appropriate use of condition monitoring provides an excellent m aintenance tool and can ensure efficient generator output. Thermographic surveys The use of infra-red cameras for predictive and preventative maintenance is becoming more common, especially when assessing high value equipment or where an unexpected failure could cause considerable disruption. These cameras can be used to analyse the running temperatures of bearings, motors, electrical connections and other equipment and, as such, can indicate potential areas for concern without having to stop any of the machinery. By applying infra-red technology, engineers are only required to carry out maintenance procedures when they are required, rather than on a fixed basis, which improves efficiency and reduces maintenance costs. Sulzer believes that more clients can benefit from Complete Hydropower solutions Sulzer is a leading provider of engineering solutions for the power generation sector, from on-going condition monitoring to complete turnkey projects. The company has developed a large network of service centres capable of maintaining all rotating equipment such as turbines, generators, motors and pumps as well as employing experienced engineers, equipped to complete projects on site if necessary. The high voltage coil manufacturing facility based at the Birmingham Service Centre, employs an in-house copper rolling mill to enable roundthe-clock coil production to meet even the tightest deadline. Using the latest CAD systems, precise quality control and extensive testing, modern coil production can significantly improve the performance and efficiency of any generator which is due for refurbishment. Employing the latest materials technology and manufacturing processes enables the hydropower sector to maximise the efficiency and reliability of the existing infrastructure as well as develop new opportunities. Sulzer has the expertise, tools and equipment to provide engineering support to its clients for any scale of project, from engineering supervision to completion of the largest repairs to turbines, generators and pumps. Author: Graeme Robertson, Head of Operations UK for Sulzer