Energy efficient control for hybrid and electric vehicle auxiliary drives

KEB Automation has launched a modular, scalable combined drive & controller system for hybrid and electric vehicles.

The system can be adapted to suit specific customer requirements and associated drive functions, particularly applications in wholly- or partly-electrified trams, buses, trains, agricultural and construction vehicles and Light Commercial Vehicles (LCVs).

In the development of hybrid, fuel cell and electric vehicles, as well as the integration of innovative electric (traction) drive systems, electrification of auxiliary drives is important.

Why?

Because in urban transport, conventional vehicles consume up to 30% of the energy purely for the auxiliary drives and so the potential for energy savings is significant.



Converting to electric auxiliary drives means improved energy efficiencies and greater controllability. Various applications on the vehicle can be controlled individually (eg, power-on-demand) and therefore more efficiently, while optimising processes to meet the precise needs of the vehicle. This can lead to significant reductions in vehicle noise and CO2 emissions.

Compact, flexible and scalable

Regardless of whether energy is produced or provided by diesel generators, fuel cells, battery packs or supercapacitors, the new COMBIVERT T6 APD (Auxiliary Power Drives) from KEB Automation offers a connection or adaptation facility to suit all vehicle energy sources.

This means auxiliary drive components such as air conditioning, air compressors, hydraulic pumps, Power Take Off/Shaft substitutes and ventilators can be decoupled from the combustion engine (main drive) and installed in the most cost effective or mechanically favourable position on the vehicle.

The capabilities of the T6 APD controller are efficient, on-demand adjustment of voltage, current and frequency in up to six drive/motor axes.

The T6 APD controls all types of electric motor, providing automatic motor identification.

The controller provides excellent shaft performance, dynamic speed and torque control, as well as a variety of control algorithms, including open-loop control and SCL (sensorless-closed-loop) for synchronous and asynchronous (A.SCL) motors.

Components of the T6 APD include the inverter modules in three power ratings with output nominal currents of 16.5A, 33A and 60A for up to six electric motors, as well as intelligent control for individual implementation of system characteristics and as a communication gateway for vehicle control (using the automotive standard MCU J1939 CAN APP Communication Gateway).

The motor connector, which is rotatable for easier cable connection, offers high vibration resistance, optimal shielding, cable clamping and includes the temperature sensor for reduced wiring. Software wizards are provided for quick, efficient commissioning.

Suitable for harsh conditions

The T6 APD can control any motor without a feedback device and meets all the requirements for an automotive system with regards to its mechanical and thermal properties, environmental conditions, EMC, safety and service life.

In addition, the Common-Mode-DC-EMC filters fitted as standard, guarantee high operational safety combined with other high voltage components in the vehicle.

Mark Checkley, Sales & Marketing Manager at KEB (UK) Ltd, comments: “The T6 APD is a robust, fully sealed unit manufactured to industrial standards. It is liquid-cooled using the vehicle’s existing coolant supply and is protected to IP67 as standard. However, if the controller needs to operate in extremely harsh operating conditions such as agricultural machinery or an off-highway vehicle, we can provide a version with increased protection to IP6k9k. The T6 APD has also been retrofitted to existing machines and vehicles.”

“The T6 APD is also extremely compact and lightweight, which is important in many on-vehicle applications where space is tight, while weight savings are essential in contributing towards reductions in vehicle emissions and fuel consumption,” he adds.