Motoring / AC Dynamometer Systems and DYNO mite Drives

Land & Sea’s Variable Frequency AC Drives and Absorption Motor/Generators are state-of-the-art components – suitable for building laboratory-grade dynamometer systems. They are also ideal for emission-research chassis dyno installations, where both loading and motoring capabilities must be provided for.

“Do you have a unique dynamometer application? Call for assistance!”

AC dynamometer systems, like this 800-Hp regen docking station, provide more precise load control, quicker response to

DYNOmite AC Drives and Absorbers offer precision load control, moderate inertia, combined with motoring ability. They even provide full torque loading down to near zero RPM (or to true zero RPM using their encoder option). A variable frequency AC dynamometer provides the most advanced control and load capabilities that you can buy – without the high inertia and maintenance of DC brushed-motor based systems.

Variable-Frequency Field-Oriented Control is used to vary the test RPM and load. It provides RPM or torque regulation without requiring a separate feedback encoder. Power produced by the motor, while it is operating in generator (load) mode, may be dissipated though an air-cooled resistor bank, or returned to the electrical grid – via a regeneration unit. Regeneration can use the test-engine’s power to actually lower your shop’s monthly electrical bill.

AC absorbers are particularly cost effective for precision test control of peaky small engines. This 75-Hp unit is liquid cooled, for 10,000+ RPM, and features a reaction-torque transducer.

120, 208, 240, 380, 480, and 600-volt drives, in either single-phase (lower-voltages only) or three-phase, generate a pseudo sine wave with an output frequency range from 0 to 400 Hertz. Drives are available with an integral LCD programming module and readout, allowing users to configure the drives for custom applications. Multiple 0-10 volt, analog and digital, inputs and outputs are provided for control and drive feedback. These signals are electrically compatible with our DYNOmite-Pro hardware and are utilized by our DYNO-MAX™ software’s control algorithms. Encoder options are also available (although often unnecessary). Even master- to-slave synchronization, between multiple drives (i.e. for unlinked AWD chassis dynamometers) is an available add-on.

Drives include on-board speed and torque regulation so only a 0-10v (scalable to 0-5volt, etc.) analog input is required to adjust test speed (or torque loading). For added convenience, estimated speed and torque data (calculated from the drive’s current and frequency control data) may be displayed on the optional LCD display. This same estimated data is even available as analog 0-10 volt outputs – for data-acquisition applications where the extra precision of actual load cells and frequency counters is not mandatory.

AC (Alternating Current) Absorbers offer the ultimate in electronic load control. Besides lightning-fast response, these motor/generators can deliver nearly full torque braking, all the way down to zero RPM (requires optional encoders). Such stall-torque capability is especially useful for testing electric motors, vehicle launch, etc. Most AC-equipped dynamometers can be designed to “motor” the test engine. In addition to providing convenient engine starting, motoring allows testing friction losses.

DYNOmite 300 Hp AC absorber/motor, electronic control drive, and air-cooled resistance load bank. Other sizes are available, from 1/3 Hp (with internal load) up to 1,250 Hp, with optional full regenerative capabilities that return absorbed engine power to the utility grid – for credit.

Compact DYNOmite 20-Hp AC absorber/motoring control drive. Other sizes are available that run from 1/3 Hp, with integral resistive load, on up to 1,250 Hp regenerative units. Drives are available separately or combined with a matched absorber/motor.

Capacities from ¼ to over 1,250+ Hp are standard. So, there is an AC drive and motor/generator combination to suit almost any testing application. Larger installations can be equipped for regenerative dynamic braking – feeding the engine’s horsepower back into the utility’s grid, for an electric bill credit (call for details).

Many standard NEMA frame and/or input shaft combinations are available. Double-ended keyed-shaft units can be supported – between a pair of pillow block bearings. This configuration allows reading the reaction torque off a load cell, linked to the absorber’s trunnioned frame. Our larger generator/motors have mounting holes in their frames – for fixing them to the dynamometer’s stand or cradle. Units are available in drip proof, open frame, or sealed housings. Integral heaters can be provided for damp environments to reduce corrosion problems.

High-speed spindle bearings and grease seals provide long life, for extended OEM and industrial endurance testing applications. Standard absorbers have speed ranges to 7,800+ RPM. Special water-cooled bearings are available in, smaller, high-speed absorbers, to handle applications to 11,000+ RPM.

Turn-key Yanmar diesel engine, on DYNO-mite engine test stand, coupled to AC (motoring) dynamometer absorber. Shown with resistive load bank and variable-frequency drive.

Smart-Car axle-hub dynamometer testing − with ACtiveSynch™ motoring option. AC motoring allows realistically simulating coasting and long down-hill grades.

Custom hybrid configurations, using a combination of both an AC and eddy-current (or water- brake) absorber, can combine the unique characteristics of each – in a single installation. This makes it possible to have the near-instantaneous control, RPM stability, and motoring capability of an AC absorber, plus the high-power absorption of a water brake that might otherwise be unaffordable (or impossible) to duplicate with any other technology. Control of the mated pair may be done using DYNO-MAX “Pro” software. In some very high horsepower installations, it is possible to reduce, significantly, both the dynamometer’s cost and its inertia via this method – compared to an equivalent capacity alternating-current absorber alone. While the extra complexity of such hybrid systems is typically only justified for unique high-output applications, if yours is one of them, it may be the only way for you to go. Feel free to call and discuss the details of you specific dynamometer-testing requirements.

DYNOmite NEMA C-Face mounting torque transducer provides inertia immune torque data from cantilever mounted AC or DC motor/absorbers. Available in raw 3-mV/volt or 0-5 volt amplified output models.

Ideal for torque reaction cradles where the slightly higher inertia of an AC absorber, as compared to a DYNOmite water brake, is not an issue. We offer custom “reaction cradle” dynamometer-frame designs that easily adapt to changes in drive gear, pulley, or sprocket center distances – for testing a wide range of smaller engines. Wireless rotary-torque transducers, as well as C-face-mount torque traducers (see image above left), are also available to help deal with designing the best dynamometer configuration for the application.

ACtiveSync™ Axle-Hub (or chassis dyno) upgrade option adds axle synchronization and motoring to DYNOmite (or other brand) dynamometers. This optional package may be field installed onto existing DYNOmite Axle-Hub dynamometers, or used to retrofit other manufactures’s unlinked chassis dynamometers to ACtiveSync. Provides precision matching front-to-rear 2WD axles on traction-controlled ABS-equipped vehicles. Includes motors, encoders, drives, and resistive load banks Totally AC (including motoring) axle-hub dynamometers systems are also available in both 2WD and AWD models.

Call for immediate assistance in developing your own unique dynamometer-testing solution - or send an e-mail to: tech@land-and-sea.com – for a prompt response. We have years of wide-ranging experience building one-off testing solutions or retrofitting older hardware with modern load and/or control.

DYNO mite™ Motoring / AC Dynamometer Systems

“Do you have a unique dynamometer application? Call for assistance!”