HYBRID BATTERY SYSTEM


  1. SYSTEM CONTROL


    1. State Of Charge (SOC)


      1. HV Mode


        1. The hybrid vehicle control ECU estimates the SOC of the HV battery from the accumulated amperage that is constantly and repeatedly being charged and discharged. In order to maintain the SOC at the appropriate level all the time, the hybrid vehicle control ECU controls the hybrid system optimally.

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      2. EV Mode


        1. If the EV/HV mode switch (pattern select switch assembly) is pressed when driving in EV mode, the hybrid vehicle control ECU changes from EV mode to HV mode and maintains the SOC at the time the switch was operated.

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      3. HV Battery Charge Mode


        1. If the EV/HV mode switch is pressed and held when driving in HV mode or EV mode, the hybrid vehicle control ECU increases the SOC of the HV battery using power generated by the engine.

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    2. Detection of Insulation Resistance Decrease


      1. The leak detection circuit is built into the battery ECU assembly. The leak detection circuit constantly monitors that the insulation resistance between high-voltage circuits and body ground is maintained.

      2. The hybrid vehicle control ECU determines decreases in the insulation resistance based on the information from the battery ECU assembly.

      3. The leak detection circuit has an AC source and causes a small amount of AC to flow to the high-voltage circuit (positive and negative).

      4. The more insulation resistance decreases, the more voltage steps down at the detection resistor and the lower the waves of AC. The insulation resistance value is detected based on the amplitude of AC waves.

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    3. Cut-off of High-Voltage Circuits during Collision


      1. If the vehicle is involved in a collision as described below, the hybrid vehicle control ECU will shut down the power supply by turning the system main relays off for safety.

      2. The hybrid vehicle control ECU receives the airbag deployment signal from the airbag ECU assembly during a frontal collision, side collision or rear collision.

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