Electrical Infrastructure

Medium speed rotary emulator


Lir offers a scaled rotational test rig for generator type selection, control strategy design and optimisation, and power quality analysis rated at 22 kW and 1500rpm. The flexible design of the test rig facilitates islanded, direct and indirect connection to the grid of many different types of generator (Permanent Magnet synchronous generator, Wound Rotor induction generator (IG), , Squirrel Cage IG). For significantly lower costs than at-sea testing, results from the test rig can inform device developers’ decision-making through all stages of the development and testing processes. Flexible system control options are available, from simple fixed speed or torque modes to more complex hardware in the loop system modelling modes.

Related publications and projects

FP7 CORES. Further information available at http://www.fp7-cores.eu/

Horizon 2020 OPERA Further information available at http://opera-h2020.eu/

Duquette, J., D. O’Sullivan, S. Ceballos, and R. Alcorn. “Design and construction of an experimental wave energy device emulator test rig.” In Proceedings of European wave and tidal energy conference. 2009. Paper available here

Rea, J., J. Kelly, R. Alcorn, and D. O’Sullivan. “Development and operation of a power take off rig for ocean energy research and testing.” In Proceedings from the 9th European Wave and Tidal Energy Conference, Southampton, UK. 2011. (http://www.lir-notf.com/wp-content/uploads/2015/12/ReaRayKelly.pdf)

Ceballos, Salvador, Judy Rea, Iraide Lopez, Josep Pou, Eider Robles, and Dara L. O’Sullivan. “Efficiency optimization in low inertia wells turbine-oscillating water column devices.” IEEE Transactions on Energy Conversion28, no. 3 (2013): 553-564. (http://ieeexplore.ieee.org/document/6544582/?arnumber=6544582)

Cavagnaro, Robert J. “Impact of Turbulence on the Control of a Hydrokinetic Turbine.” In International Conference on Ocean Energy, Halifax, Canada. 2014. (http://www.icoe2014canada.org/wp-content/uploads/2014/11/2-CavagnaroRob_2-3.pdf)

Armstrong, S., J. Rea, F. X. Faÿ, and E. Robles. “Lessons learned using electrical research test infrastructures to address the electrical challenges faced by ocean energy developers.” International Journal of Marine Energy12 (2015): 46-62. (http://www.sciencedirect.com/science/article/pii/S2214166915000314)

Cavagnaro, Robert J., Jason C. Neely, Franois-Xavier Fa, Joseba Lopez Mendia, and Judith A. Rea. “Evaluation of Electromechanical Systems Dynamically Emulating a Candidate Hydrokinetic Turbine.” IEEE Transactions on Sustainable Energy 7, no. 1 (2016): 390-399. (http://ieeexplore.ieee.org/document/7321812/?arnumber=7321812)

High speed rotary emulator


The high speed rotary emulator consists of a PM (Permanent Magnet) machine with resolver feedback directly coupled to an induction machine with encoder feedback. High speed operation is achievable with ratings of 9,000 rpm and power ratings of 11 kW.

Various advanced electrical control options are available with the Vacon and Parker drive panels both with full regenerative capability and Ethernet connectivity, as well as the HBM torque sensor. A Sorrensen 10 kW dc power supply allows flexibility of power flows.

Linear PTO test rig


Many types of ocean energy devices have a linear power take off system. At Lir a ¼ scale linear electromechanical test rig has been built to emulate the linear motion induced by the waves.  The rig is rated at 20 kW, 1 m/s, 1.8mm/s2 and 15 kN with a stroke length of 1m. Device developers bring their scaled prototypes to Lir-NOTF for characterisation and analysis. Valuable lessons about the controllability, lifetime analysis and stress testing of the prototype can be learned. The system is controlled using an industrial standard PLC and HMI, to ensure safety of equipment and personnel.

Related projects

Mooring Testing:

Power Take Off Testing:

Rotary PTO test rig


The rotary PTO test rig consists of a standard 6 pole, 15 kW machine operated from a universal variable speed ac Emerson UniDrive. The rotary PTO test rig, together with components of the microgrid, provides generator testing options to developers for their initial scaled test device, at various speeds and load profiles.



The Microgrid consists of a dual-bus three phase system. Generation, storage and load elements can be added to the Microgrid to build up a wide variety of test configurations. The Microgrid can operated in parallel with local grid or as an islanded system. Sources of power include a 33 kVA diesel generator a wind/ocean energy emulator and fully controllable Triphase back-to-back 90 kW and 15 kW converters can exchange power between the grid and microgrid and offer a huge flexibility option. Storage is provided by a 5 kWhr lithium ion battery with 10 kW peak power flows. Full controllable and adjustable loads with leading and lagging power factors are available including a 50 kVA Crestchic loadbank. Robust system control is provided by industry standard PLCs, while high speed data acquisition is offered by National Instruments cRIO system. An Opal-RT power hardware in the loop system provides advanced grid specific grid emulation capabilities.

Related publications

Murray, Dónal Brendan. “Energy storage systems for wave energy converters and microgrids.” (2013). (https://cora.ucc.ie/handle/10468/1137)

Messinis, George, Fran Gonzalez-Espin, Virgilio Valdivia, Judy Rea, Darren Mollaghan, and Nikos Hatziargyriou. “Application of rapid prototyping tools for a hierarchical microgrid control implementation.” In 2014 IEEE 5th International Symposium on Power Electronics for Distributed Generation Systems (PEDG), pp. 1-5. IEEE, 2014. (http://ieeexplore.ieee.org/document/6878688/?arnumber=6878688&tag=1)

Hogan, Diarmaid J., Michael G. Egan, John G. Hayes, Gordon Lightbody, and Fran Gonzalez-Espin. “A rapid prototyping tool for load and source emulation in a microgrid test laboratory.” In 2014 IEEE Applied Power Electronics Conference and Exposition-APEC 2014, pp. 2245-2252. IEEE, 2014. (http://ieeexplore.ieee.org/document/6803616/?arnumber=6803616)

Hogan, Diarmaid J., Fran Gonzalez-Espin, John G. Hayes, Raymond Foley, Gordon Lightbody, and Michael G. Egan. “Load and source electronic emulation using resonant current control for testing in a microgrid laboratory.” In 2014 IEEE 5th international symposium on power electronics for distributed generation systems (PEDG), pp. 1-7. IEEE, 2014. (http://ieeexplore.ieee.org/document/6878633/?arnumber=6878633)

Hogan, Diarmaid J., Fran Gonzalez-Espin, John G. Hayes, Gordon Lightbody, and Michael G. Egan. “Adaptive resonant current-control for active power filtering within a microgrid.” In 2014 IEEE Energy Conversion Congress and Exposition (ECCE), pp. 3468-3475. IEEE, 2014. (http://ieeexplore.ieee.org/document/6953872/?arnumber=6953872)

Hogan, D. J., F. Gonzalez-Espin, J. G. Hayes, G. Lightbody, L. Albiol-Tendillo, and R. Foley. “Virtual synchronous-machine control of voltage-source converters in a low-voltage microgrid.” In Power Electronics and Applications (EPE’16 ECCE Europe), 2016 18th European Conference on, pp. 1-10. IEEE, 2016. (http://ieeexplore.ieee.org/abstract/document/7695503/)