Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Toyota >> 2007 >> Highlander Base, 2.4 D, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 62 (P310 Hybrid Vehicle Control - Introduction, Diagnostic Trouble Code Chart) >> Hybrid Control System >> System Description

System Description

WARNING: This page is about a different variant/trim than selected.
  1. BASIC OPERATION 
    1. This system generates a motive force in combination with the engine, Generator, Motor, and Rear Motor (with 4WD system) in accordance with the driving conditions. Representative examples of the various combinations are described below.
    2. Front Wheel Operation:
      1. Supply of electrical power from the HV battery to the Motor provides force to drive the front wheels.
        Fig 1: Electrical Power Supplying Operation Diagram - Front Wheel (1 Of 4)
        G05201153Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. While the front wheels are being driven by the engine via the planetary gears, the Generator is driven by the engine via the planetary gears, in order to supply the generated electricity to the Motor.
        Fig 2: Electrical Power Supplying Operation Diagram - Front Wheel (2 Of 4)
        G05201154Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. The generator is rotated by the engine via the planetary gears, in order to charge the HV battery.
        Fig 3: Electrical Power Supplying Operation Diagram - Front Wheel (3 Of 4)
        G05201155Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. When the vehicle is decelerating, kinetic energy from the front wheels is recovered and converted into electrical energy and used to recharge the HV battery by means of the Motor.
        Fig 4: Electrical Power Supplying Operation Diagram - Front Wheel (4 Of 4)
        G05201156Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Rear Wheel (with 4WD System Model)
      1. To ensure the proper driving force of the vehicle during start-off or acceleration, the electrical power of the HV battery is supplied to the Rear Motor in order to drive the rear wheels.
        Fig 5: Electrical Power Supplying Operation Diagram - Rear Wheel (1 Of 3)
        G05201157Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. During the full throttle acceleration of the vehicle, both the electrical power of the HV battery and the electrical power generated by the Generator are supplied to the Rear Motor in order to drive the rear wheels.
        Fig 6: Rear Wheel (With 4WD System Model) Operation Description (1 Of 3)
        G05201158Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. When the vehicle is decelerating, kinetic energy from the rear wheels is recovered and converted into electrical energy and used to recharge the HV battery by means of the Rear Motor.
        Fig 7: Electrical Power Supplying Operation Diagram - Rear Wheel (3 Of 3)
        G05201159Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. SYSTEM DIAGRAM 
    Fig 8: Hybrid Control System Diagram
    G05201160Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. FUNCTION OF MAIN COMPONENTS 
    FUNCTION OF MAIN COMPONENTS

    Item Outline
    Hybrid Transaxle Generator
    • The generator, which is driven by the engine, generates high-voltage electricity in order to operate the Motor or charge the HV battery. Also, it functions as a starter to start the engine.
    • The generator operates so that the gear ratio of the power split planetary gear unit will optimally suit the driving conditions of the vehicle.
    Motor
    • Driven by electrical power from the Generator or the HV battery, and generates motive force for the front wheels.
    • During braking, or when the accelerator pedal is not depressed, it generates electricity to recharge the HV battery (Regenerative brake control).
    Compound Gear Unit Power Split Planetary Gear Distributes the engine's drive force as appropriate to directly drive the vehicle as well as the generator.
    Motor Speed Reduction Planetary Gear Located between the Motor and the power split planetary gear, the motor speed reduction planetary gear reduces the rotational speed of the Motor in accordance with the characteristics of the planetary gear, in order to increase torque.
    Rear Transaxle(1) Rear Motor
    • Driven by electrical power from the Generator or the HV battery, and generates motive force for the rear wheels.
    • During braking, or when the accelerator pedal is not depressed, it generates electricity to recharge the HV battery (Regenerative brake control).
    HV Battery
    • Supplies electrical power to the Generator, Motor, and Rear Motor(1) in accordance with the driving conditions of the vehicle.
    • Is recharged by the Generator, Motor, and Rear Motor(1) in accordance with the SOC and the driving conditions of the vehicle.
    w/ Converter Inverter Assembly A device that converts the high-voltage DC (HV battery) into AC (Generator and Motor) and vice versa (Converts AC into DC).
      Boost Converter Boosts the maximum voltage of the HV battery from DC 288 V to DC 650 V and vice versa (drops DC 650 V to DC 288 V).
    DC/DC Converter Drops the maximum voltage of DC 288 V into DC 12 V in order to supply electricity to body electrical components, as well as to recharge the auxiliary battery (DC 12 V).
    MG ECU
    • Controls the inverter and boost converter in accordance with the signals received from the HV control ECU, thus driving the Generator, Motor, or Rear Motor or causing them to generate electricity.
    • Controls the DC/DC converter in accordance with the signals received from the HV control ECU.
    HV Control ECU Effects comprehensive control of the THS-II system.
    • Information from each sensor as well as from the ECU (battery smart unit, skid control ECU, and EPS ECU) is received, and based on this information, the required torque and output power is calculated. The HV control ECU sends the calculated result to the inverter assembly and skid control ECU.
    • Activates the ETCS-i (Electronic Throttle Control System-intelligent) in accordance with the target engine speed and required engine motive force.
    • Monitors the charging condition of the HV battery.
    • Controls the cooling fan of the HV battery.
    Battery Smart Unit
    • Monitors the conditions of the HV battery and transmits this information to the HV control ECU.
    • Monitors the fault current of the HV battery.
    Skid Control ECU
    • During braking, it calculates the regenerative brake force that is required for control and transmits it to the HV control ECU.
    • Calculates the motive force that is required for control during the operation of TRAC or VSC and transmits it to the HV control ECU.
    • Transmits a front and rear wheel torque distribution request to the HV control ECU for the purpose of 4WD system control.(1)
    Accelerator Pedal Position Sensor Converts the accelerator pedal position into an electrical signal and outputs it to the HV control ECU.
    Park/Neutral Position Switch Converts the shift position into an electrical signal and outputs it to the HV control ECU.
    HV Relay Assembly Connects and disconnects the high-voltage power circuit between the battery and the inverter assembly, through the use of a signal from the HV control ECU.
    Interlock Switch (for Inverter Cover and Service Plug Grip) Verifies that the cover of both the inverter and the service plug grip have been installed.
    Circuit Breaker Sensor Detects the impact that is applied to the vehicle during a collision and transmits a signal to the HV control ECU. Upon receiving this signal, the HV control ECU operates the HV relay assembly to shut down the power supply.
    Service Plug Grip Shuts off the high-voltage circuit of the HV battery when this service plug grip is removed for vehicle inspection or maintenance.
    (1) Only on models with 4WD system
scientia non olet · About Mike's Workshop Manuals