3MW test rig puts tidal power systems through their paces
A 3MW medium-voltage drive and a 3.26MW 12-pole motor are providing the motive power for the world’s first facility dedicated to testing drivetrains for marine-based renewable energy systems.
The UK-based test facility, located at the National Renewable Energy Centre (Narec) in Northumberland, aims to remove the risks associated with field-testing of tidal power generation technologies by allowing customers to perform extreme event and accelerated lifetime testing of their technologies in a controlled, onshore environment.
The test facility, called Project Nautilus, can load a complete drivetrain both mechanically and electrically with the any possible load, including side-loads on shafts. The system can be used to test complete drivetrains of marine renewable devices, as well as their electrical generation, control and support systems.
The facility has been funded jointly by a £10.3m investment by the UK government and £6.4m of funding from the European Regional Development Fund.
The test facility’s prime mover is a 3,256kW water-cooled ABB motor, weighing almost 60 tonnes. The 12-pole machine is designed to develop high torque with a high speed accuracy. It uses hydrostatic bearings, and incorporates a lubrication and jacking system in its pedestal.
The 3MW modular medium-voltage AC drive system, also supplied by ABB, includes a 24-pulse input rectifier to ensure that harmonics remain low. It feeds a common DC bus, to which two 11MVA-rated inverter sections are connected.
The two inverter sections, in turn, feed the motor’s double winding. A braking chopper is also connected to the DC bus. This allows fast braking of the facility and the system under test in the event of a process or emergency stop. It also allows energy to be dissipated if there is a mains power failure. The drive’s high power density, compact design and communication facilities have helped to reduce installation and operating costs.
The MV drive is fitted with ABB’s DriveMonitor monitoring and diagnostic system, which provides secure access to the drive from anywhere in the world. ABB also supplied medium- and low-voltage switchgear, an oil-filled input transformer, three oil-filled distribution transformers, and two portable equipment buildings to house the VSD and the switchgear.
Narec’s operations director, Tony Quinn, says he has been pleased with the performance of the system to date. “Projects of this nature are rare; they are one-off in terms of scale and technicalities,” he points out. “As operations director, my job is to get involved when things go wrong. I did not have to get involved with ABB at all.”
To date, Narec has invested more £150m of UK Government, private sector and European Union funding to create a portfolio of testing and research facilities, which it operates on an open-access, commercial basis.