System Description

HYBRID TRANSAXLE


INVERTER ASSEMBLY : System Description


GENERAL
- The inverter converts the high-voltage direct current of the HV battery into three-phase alternating current for driving MG1 and MG2.
- The activation of the power transistors is controlled by the hybrid vehicle control ECU, via the MG ECU. In addition, the inverter transmits information that is needed for current control, such as the output amperage or voltage, to the hybrid vehicle control ECU via the MG ECU.
- Together with MG1 and MG2, the inverter is cooled by the dedicated sub radiator of the coolant system that is separate from that of the engine.
- In the event of a collision involving the vehicle, the sensor detects a collision signal in order to stop the system. For details, refer to During Collision Control on System Diagram.
- A boost converter is used in the inverter assembly, in order to boost the nominal voltage output by the HV battery from DC 244.8 V to maximum voltage of DC 650 V. After the voltage is boosted, the inverter converts the direct current into an alternating current.
- Each of the bridge circuits for MG1 and MG2 contains 6 power transistors. In addition, a signal processor/protective function processor has been integrated into a compact IPM (Intelligent Power Module) for driving the vehicle.
For details on the multiple functions of the inverter, refer to Inverter Assembly Control on System Diagram.






BOOST CONVERTER
- This boost converter boosts the nominal voltage of DC 244.8 V that is output by the HV battery to the maximum voltage of DC 650 V. The converter consists of the boost IPM (Intelligent Power Module) with a built-in
IGBT (Insulated Gate Bipolar Transistor) which performs the switching control, and the reactor which stores energy. By using these components, the converter boosts the voltage. For details, refer to Inverter Assembly
Control on System Diagram.
- When MG1 and MG2 acts as the generator, the inverter converts the alternating current into the maximum voltage of DC 650 V, and then the boost converter reduces the voltage to the nominal voltage of DC 244.8 V, thus the HV battery is charged.

MG (MOTOR GENERATOR) ECU
- The MG ECU is provided in the inverter assembly. In accordance with the signals received from the hybrid vehicle control ECU, the MG ECU controls the inverter and boost converter in order to drive MG1 or MG2 or cause them to generate electricity.
- The MG ECU transmits information that is required for vehicle control, such as the inverter output amperage, inverter temperature, and any failure information, to the THS ECU. It receives information that is required for controlling the motor generator, such as the required motive force and the motor temperature, from the hybrid vehicle control ECU.