FUSO 4M4 – HYBRID ELECTRIC VEHICLE SYSTEM – STRUCTURE AND OPERATION – Electronic Control System

2.1 System block diagram

2.2 Motor electronic control unit
• See Gr22E since main control related to the hybrid electric vehicle system is executed by INOMAT-II electronic control unit.

(1) Motor generator torque (drive force) control function

• When the INOMAT-II electronic control unit commands the motor electronic control unit to generate torque (drive force), the motor electronic control unit outputs a signal to the inverter to activate the motor generator.
• When the motor generator or inverter is overheated or in other abnormal conditions, the motor electronic control unit operates the motor generator restricting its torque (drive force and regenerated force).

(2) High voltage cooling system control function

• The motor electronic control unit operates the blower motor and water pump according to the motor generator and inverter temperatures.

(3) Contactor control function

• Contactors, housed in the junction box of the high voltage battery box, serve as relays to open and close the high voltage circuit between the high voltage battery and inverter.
• To activate the hybrid electric vehicle system, the motor electronic control unit commands the main contactor (+) and (–) to close. This can cause electric power to be sent to the inverter to activate the motor generator.
• To charge the high voltage battery, the motor electronic control unit commands the pre-charge contactor to close.

(4) Diagnostic function
• The motor electronic control unit constantly monitors the operating condition of respective sensors for failure during the starter switch ON. If any sensor is faulty, fault information is indicated on the meter cluster to inform the driver. At the same time, the fault location is stored as a diagnosis code and control-during-fault is started.
• During control-during-fault, the motor electronic control unit restricts the system function to ensure safety of the vehicle and driver. The stored diagnosis code can be retrieved on Multi-Use Tester or through the warning lamp illumination.
• Control-during-fault can be categorized as in the following table.

• Diagnosis code differs between Multi-Use Tester and warning lamp indication.

2.3 Battery electronic control unit
(1) High voltage battery monitoring function

• The battery electronic control unit performs such functions as measurement of the total voltage of the high voltage battery and estimation of high voltage battery state of charge, and monitors the high voltage battery to ensure the secure power supply.
• The cell controller equalizes the voltages of all the cells.
• The battery electronic control unit controls the battery cooling fan in accordance with cell temperature data received from the cell controllers to cool the high voltage battery.

(2) Diagnostic function
• The battery electronic control unit has the same diagnostic functions as the motor electronic control unit does; however, some diagnosis codes (minor faults) can be accessed on Multi-Use Tester only.

 

Leave a Reply

Your email address will not be published. Required fields are marked *