General System Description

Because testing systems for the first time in the ocean is avoided due to the higher risks and greater unknowns, it is best practice to first “dry” test offshore equipment as much as possible in a laboratory environment. The electronic systems of the SNMREC’s small-scale research turbine are no exception. Therefore, the Center has invested in a laboratory-scale dynamometer, or a device to measure power. Two motors are attached to one another so that one “drives” the other, simulating how the ocean currents might “drive” a rotor attached to a turbine’s shaft. This allows engineers and researchers to set up the offshore power and measurement systems indoors under controlled conditions to explore how to manage the generator when it is put into service offshore.

The dynamometer has been named the Ocean Current Power Generation Simulator, or OCPGS. This capability will not only allow SNMREC engineers to configure and prepare technology projects for testing offshore, but will also be used to optimize intelligent measurement and prognostics systems being developed by researchers. The OCPGS will also be made available to commercial developers who similarly wish to pre-configure and test their proposed design generators in the future.

A smaller dynamometer has also been installed at the facility which allows researchers to investigate phenomena that scales electrically (like power generation control, variable generation characteristics, and heterogeneous device power generation).

Detailed System Description

The ocean current turbine motor-generator is a 30 HP (22.4 kW) Sumitomo Cyclo 6000 AC Induction Motor (Frame 180 MG, Type TK-F) with rated nameplate values of 230 VAC, 3-Phase, 4-Pole, 60 Hz., 1740 RPM and 74.7 Amps. As a NEMA Design Class A (standard AC induction motor design), the motor features normal starting torque, normal starting current and low slip (the difference between stator and rotor rotational speeds required for motoring and regeneration). Note that nameplate values are cited with respect to 230 VAC operation.  Utility mains at the SNMREC are supplied at 208 VAC, so actual ratings are adjusted accordingly to 208 VAC, 54.3 Hz, 27 HP (20kW), and 1606 RPM.  Off-shore turbine operation will be supported by a ship-board isolation transformer at 208 VAC as well. The epicycloidal gear (speed-reducer) is also from the Sumitomo Cyclo 6000 family of products (Model CHVM30-6185 YB-25) with rated nameplate values of 30 HP, 25:1 gear ratio, and shaft speed of 70 RPM. The coupled motor and gear are referred to as a Sumitomo Cyclo 6000 Gearmotor. The variable frequency drive is a 30 HP US Drives Phoenix Vector EX AC Drive (Model # E2-0030), and the torque meter is a 7,000 kW S. Himmelstein & Co. MCRT 48007P Non-Contact Horsepower/kW-h meter.

Table 1.  Dynamometer Shaft Speeds and Power Ratings

Please send additional information and schedule requests via email to snmrec@fau.edu.