General Testing: Bi-directional power take off systems for ocean wave energy and marine current turbine systems. Start of system usage: March 1 2025 Budget: $510k (was previously $600k) Electrical service: 480 V 3 phase, 200 A, fully regen Power: 30 kW Two main operational cases: wave energy and marine current. For wave energy mode, torque, speed, and position are oscillating, with periodic reverse power flow from the device under test to the dyno. For marine current mode, torque and speed are unidirectional, with only brief reverse power flow under braking or transient conditions. Speed: in oscillating mode, 15 RPM; in unidirectional mode, 150 RPM. Torque: in oscillating mode, 20 kNm; in unidirectional mode, 2 kNm. Physical Space: Ideally the testbed itself, with the driving motor/generator and space for the PTO under test would be some sort of t-slot bed with a total area of at most 5 foot by 15 foot. Drives and supporting equipment could be free-standing next to that. The DUT under test should have 5 x 7.5 foot. Testbed: T-slot or similar so that the DUT can be rigged and mounted flexibly. Any adjustable or swappable testbed components must be serviceable via a 3 ton overhead crane. Center line requirement: because of large torque, the devices under test could have large diameters. Spec is 1.27 m a soft target, absolute minimum of 0.6 m. Control Control mode 1: constant speed Control mode 2: constant torque Control mode 3: sinusoidal torque of a programmable amplitude and period, with a peak amplitude up to the rated torque, and a fastest period of 1 second. Control mode 4: sinusoidal speed of a programmable amplitude and period, with a peak amplitude up to the rated speed, and a fastest period of 1 second. Control mode 5: sinusoidal position of a programmable amplitude and period, with a fastest period of 1 second, and an amplitude not to exceed the speed rating. Control mode 6: position control based on time and position vectors supplied as a csv file Control mode 7: speed control based on time and position vectors supplied as a csv file Control mode 8: torque control based on time and position vectors supplied as a csv file Control mode 9: torque control with reference provided externally via Ethercat Control mode 10: position control with reference provided externally via Ethercat Slew rate capability: at the shaft, maximum rate of change of speed of 15*2*pi RPM/s in oscillatory mode, and 150*2*pi RPM/s in unidirectional mode. Maximum rate of change of torque at the shaft of 20,000*2*pi Nm/s in oscillatory mode, and 2,000*2*pi Nm/s in unidirectional mode.
