In-Depth IMA System on Honda Jazz Hybrid GP1

Discussion in 'Technical Articles' started by Ichiban, Thursday 29th Jan, 2015.

  1. Ichiban Founder Staff Team

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    The IMA System on the GP1

    The IMA (integrated motor assisted) system is a highly-efficient parallel hybrid drive system with a main power unit (gasoline engine) and an assist unit (electric motor).The engine is an in-line, 4-cylinder, 8-valve power plant with a displacement of 1.339 liters. To reduce fuel use, the engine is equipped with an auto idle stop system and I-DSI, and a valve pause system that resuces engine pumping loss and increases the generation of electric energy during de-acceleration.The IMA motor, directly connected to the engine crankshaft, functions as a generator during deceleration, an engine starter, and a motor to assist the engine that drives the wheels.
    The IMA system contains a 100 V DC battery, an IMA motor, an intelligent power unit (IPU), an IMA motor power cable, a control system, and related parts. The IPU contains a battery module, a motor control module (MCM), a DC-DC converter, and a motor power inverter.The IMA system improves fuel economy by slowing the vehicle with the electric motor, and using that energy to charge the IMA battery.

    IMAGP1HKIMA1.PNG

    IMA Operating Conditions
    1Engine start:
    The IMA system drives the IMA motor and starts the engine during normal starts and when re-starting from an idle stop. The IMA motor is mounted directly to the engine crankshaft.
    2Start running:
    The IMA motor assists the engine.
    3Slow acceleration:
    Runs only with the engine.
    4Low speed cruise:
    At a constant speed of about 40 km/h (25 mph) with light load, all engine cylinders are deactivated, and the vehicle runs only with the IMA motor. When the state-of-charge (SOC) drops, the engine starts and the IMA motor begins to charge the battery module.
    5Acceleration:
    The IMA motor assists the engine.
    6High speed cruise:
    Runs only with the engine. When the SOC drops, the IMA motor begins to charge the battery module.
    7Deceleration:
    All engine cylinders are deactivated, and the IMA motor converts the deceleration energy and charges the battery module.
    8Stop:
    When conditions are satisfied, the PCM stops the engine automatically (auto stop).
    IMAGP1HKIMA2.PNG

    System Diagram

    IMAGP1HKIMA3.PNG

    When the charge (SOC) is at or above a specific value

    When the SOC of the battery module is at or above a specific value, the generation amount is restricted to prevent overcharging. Since regenerative braking force is insufficient at this time, the PCM cancels full cylinder deactivation and increases engine braking power.

    When the charge (SOC) is at or below a specific value

    When the SOC of the battery module drops, idle speed is increased in each shift position to charge the battery module.
    When the battery module SOC value is low, selecting the L range mode gives priority to battery module charging by lowering the IMA motor assist level, increasing the idle speed, and increasing the regeneration amount .
    Charge priority control is canceled when the battery module SOC reaches about 40 %.

    When the engine cannot be started with the IMA motor


    Based on signals from the MCM, when the SOC value drops, when temperature is low, or when there is a problem with the IMA system, the PCM judges that the engine cannot be started by the IMA motor, so it is stated by the starter motor.

    SOC* State of Charge
     
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  2. Ichiban Founder Staff Team

    England CJ Leeds
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    GP1 IMA System Component Location Index
    IMAGP1HKIMA4.PNG IMAGP1HKIMA5.PNG IMAGP1HKIMA6.PNG IMAGP1HKIMA7.PNG IMAGP1HKIMA8.PNG IMAGP1HKIMA9.PNG
     
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