Electric drive truck: BEV

http://www.greencarcongress.com/2010/12/trex-20101201.html#more

BremachUSA introduces T-REX 4x4 class-3 electric drive truck: BEV or series hybrid

1 December 2010

The Bremach T-REX offers a 45° slope climbing ability. Click to enlarge.

BremachUSA has introduced a Class-3 medium-duty electric drive truck—the Bremach T-REX 4x4—with either a full battery-electric (100 kWh pack) or series hybrid (40 kWh pack) drivetrain; Bremach also offers gasoline- and CNG/LPG-fueled models of the T-REX.
The 10,000+ lb GVWR electric-drive T-REX offers a 3.87 ton payload—enabled by an adaptive modular space frame chassis architecture—and is powered by a 200 kW peak (150 kW continuous), 360 N·m peak torque brushless DC permanent magnet motor. The Li-ion pack is built with large-format prismatic cells.
Standard features across all the T-REX powertrains includes eight (8) forward torque /gear settings; Brembo disc brakes and Bosch ABS on all four wheels; permanent four-wheel-drive; heavy-duty transmission and suspension; auto electric locking rear differential; and non-petroleum-based oil / lubricants.

T-REX electric drive and storage system. Click to enlarge.

Prior to tax incentives, the 100 kWh BEV T-REX (100% electric) has a $120,000 MSRP, and the 40 kWH plug-in Series Hybrid a $140,000 MSRP.
Battery-electric. The battery-electric T-REX is designed to travel some 200 miles on a single charge; practically, this will translate into a range between 75 and 100 miles, depending upon use, the company says.
The Bremach T-Rex Hybrid VLV (Very Low Voltage) high performance traction system operates at 114 VDC much lower voltages—much lower than typical high-performance electric propulsion systems (250 to 400 VDC or higher). This VLV operation improves safety without sacrificing performance, according to the company. Low voltage propulsion also has the added benefit of reduced cost, both in the traction system itself and also in the energy storage system.
Lower cost is realized through cheaper switching electronics in the controller, charger, and lower series count battery pack requiring fewer balancing circuits and improved battery load distribution, which in turn reduces battery stress.
Special MOSFET matching and assembly techniques enable the controller to handle the high current required to drive the motor to a very high level of performance. The controller has proven reliability in hundreds of fielded applications over many years in the forklift and airport tug industry.
The Bremach T-Rex Hybrid-VLV motor is compact (9.5” in diameter).
The Battery Management System (BMS) for the T-REX supports all aspects of battery management and charging for military, industrial, and automotive applications. The BMS continually monitors the state of every module, the current flowing out of or into the pack (via internal or external current shunt), its own internal temperature and that of every module in the pack (through remote thermistor sensors). The BMS measures pack current within 0.1% accuracy.
A proprietary leveling process equalizes the load stress on the cells, not just open circuit voltage, impedance, or capacity. This process learns the behavior of the system over time, allows for compensation based on driving habits and environmental conditions which may vary widely.
Stress leveling operates continuously, not just at the end of the charge process, enabling charger disconnect at any time while maintaining a balanced battery pack and adjusting in dynamically to impacts from regenerative braking processes.
A telematic feature supports remote statistics, including real-time pack voltage, current, ambient temperature, state-of-charge (SOC), state-of-health (SOC), amps expended, and operating time through its integrated external interfaces. The unit has isolated digital I/O.
The integrated current shunt simplifies installation and provides realtime current status, coulomb counting, and over-current protection (OCP). Two configurable levels of OCP are also provided: timed and instantaneous. Timed OCP allows the pack to discharge up to a specific rate for a defined period of time before shutoff. Instantaneous shuts the pack off immediately before damage can occur.
Bremach T-Rex Hybrid BMS performs state-of-charge (SOC) calculations based on voltage levels, discharge rates, coulomb counting, and pack SOH, compensated for temperature and Kalman filtered.
The system also logs parametric data to its integrated nonvolatile memory with capacity for up to 10 years of recording. The recorded data can be retrieved at any time over the Ethernet maintenance interface and analyzed to evaluate system performance. The statistics recorded show environmental conditions, load demands, charging profiles, operating time, charge cycles, and so forth. Such data can be used for product improvement and warranty evaluation purposes.
Series-hybrid. The series-hybrid version of the T-REX uses a VLV motor as a generator (100 kW continuous, 150 kW peak power), combined with a 2.0-liter gasoline engine. This powertrain allows for some 30 and 60 miles of all electric travel prior to the system recharging the batteries while being driven.