AC Dynamometers
The construction utilises a special low inertia AC motor providing exceptional performance in control and torque measurement, designed for steady state, transient and dynamic testing applications. The dynamometers are supplied in either foot mounted in-line torque hub format, which also includes a jackshaft to provide a high overhung load capability to accommodate heavy duty drive shafts, or in a trunnion mounted format using a strain gauge load cell, measuring the torque reacted off the motor casing. In both formats the motor is cooled by forced ventilation using an integral cooling fan.
| Model | Max Speed (RPM) | Torque Nm (lb.ft) | Power kW (BHP) | Power (Motor) kW (BHP) | Curve Ref |
|---|---|---|---|---|---|
| AC140 | 10,000 | 276 (205) | 140 (188) | 129 (173) | |
| AC250 | 10,000 | 460 (340) | 250 (335) | 235 (315) | |
| AC360 | 10,000 | 720 (535) | 360 (483) | 340 (456) | |
| AC400 | 4,000 | 1,900 (1405) | 400 (536) | 400 (536) | |
| AC460 | 9,000 | 973 (720) | 460 (617) | 440 (590) | |
| AC570 | 4,000 | 3200 (2360) | 570 (764) | 570 (764) | |
| AC690 | 3,500 | 4500 (3320) | 690 (925) | 690 (925) | 005762 |
The AC dynamometer is constructed using a low inertia AC motor especially designed for engine test applications mounted on a substantial fabricated baseframe. On foot mounted versions torque is measured using an in-line torque hub. For trunnion mounted machines a precision strain gauge load cell is used. As an option both versions can include an integrated jackshaft that provides additional overhung load capacity for the engine drive shaft.
Heat generated within the dynamometer is dissipated using the integral cooling fan. The AC dynamometer is supplied with a 4-quadrant flux vector AC inverter. This state-of-the-art technology incorporates high speed IGBT (Insulated Gate Bipolar Transistor) and sophisticated control algorithms to provide excellent transient response and steady state control. The drive incorporates a special input stage that operates at near unity power factor, minimises supply current harmonics and in re-generation mode frequency matches to the mains supply. The AC dynamometer and inverter drive unit are designed for use with Froude Hofmann’s range of Texcel control and data acquisition systems.
The Froude Hofmann AC dynamometer is designed to meet the requirement of high performance motoring and absorbing engine development and Quality Assurance testing. Available in trunnion and foot mounted configurations and with a range of additional options including jackshafts and Hi-dynamic performance, these machines have been specifically designed to provide the performance and durability required for today's testing environment.
- Standard range of AC dynamometers consists of machines up to 1,055 kW.
- Standard torque hub measurement accuracy is better than ± 0.2% of the full rated torque of the dynamometer.
- Speed is measured using an encoder providing an accuracy of ± 1 rpm.
- Transient response typically 9000 rpm/sec.
- Operating voltage 380/416V 50Hz or 460V 60Hz
- Compliant with EMC legislation
- Non-standard sizes are available on request
- Integrated jackshaft to increase the overhung load capacity of the dynamometer
- Hi-dynamic performance
- Deadweight calibration equipment
- Control and Data Acquisition systems
- Throttle actuators/In-cell ancillaries
- Engine support stands
- Facilities planning and installation services
- Comprehensive in-house and/or on-site training courses
- Tailored preventative maintenance contracts
- On-line diagnostics and support via modem or VPN
- Technical Helpline Support
