Inc.’s Drive Technologies Division (Norcross, GA) was chosen to provide the motors and AC flux vector drives packages with regenerative braking for increased energy efficiency. RedViking worked closely with Siemens to devise an AC system, utilizing the regenerative technology found in Sinamics drives with 480V and 690V standards and investigated performance specifics of regen drives used with 3000 hp (2238-kW) motors.
proximately $400 less per hour to operate than current com- parable systems. With improvements over the conventional non-regen testing process, the RedViking main transmission test system could generate approximately $500,000 in annual power savings.
RedViking test stand for evaluating performance on transmissions from multiple helicopter OEMs.
The use of Siemens regenerative braking technology al- lows a system to recover power, minus the parasitic losses. Conventional dynamic load testing requires loading to occur via an eddy current or fluid brake system, which requires ad- ditional energy, maintenance, and up front capital investment. In more innovative industrial environments, according to Siemens, Sinamics regenerative drive technology can enable energy savings of 40% or more.
With a common DC bus architecture, this allows for only one AC to DC conversion in the motoring direction and the regenerative braking power goes straight to another inverter, which is motoring via the common DC bus link. This method eliminates two conversion points where energy would be lost, increasing overall efficiency. In addition, the common bus solution paired with the active front end (AFE) has the ability for power factor correction, which will further increase the overall savings of a common bus system. All AFE drives allow for unity power factor and low total harmonic distortion (THD) that meets IEEE 519 harmonic standards. This means these drive systems can improve the present power factor displace- ment in a customer’s facility.
RedViking estimates that a test on the main transmission flexible test system, while running at full capacity, will cost ap-
For this project, Siemens supplied its high-performance asynchronous Simotics 1PL6 and 1RN4 motors, the largest being 3000 hp (2237-kW), to power the various mechanisms on the RedViking test stands. When in operation, these motors simulate the power generated by the helicopter’s jet engines, in addition to simulating the loading of the main rotor and tail output blades. This allows RedViking to test the helicopter transmission components to the full speed and torque requirements as specified by the military with very precise closed-loop control. On the Tail and Intermediate Gearbox Flexible Test Module, it was determined that the use of two more Siemens Simotics motors was less expensive and more efficient than the previous test stand’s gearbox design. This solution involves multiple motor connections to an output variable frequency drive (VFD) with auxiliary connections, thereby eliminating the need for additional VFDs.
SINAMICS “Drive Alley” houses the main drives for the RedViking test stand.
“We knew we were building these test stands to validate the performance of military helicopters that see wartime action,” said Joshua Gibbs, RedViking manufacturing coordinator. “We take it very personally at RedViking to ensure these systems protect man and machine alike, as well as provide the ultimate in test validation.” RedViking currently performs both DO and DX contracts for the military and its subcontractors. ME For more information from Siemens Industry Inc., go to www.usa.siemens.com/motioncontrol, or phone 800-879-8079.