How The Gas Engine Works
The main source of power for Toyota's hybrids remains the gasoline engine. But these aren't your ordinary powertrains. They're built for high efficiency and low emissions. The Prius and Camry hybrids work off a four-cylinder, high expansion ratio Atkinson cycle engine. Atkinson cycle engines squeeze optimum energy from gasoline combustion by increasing the expansion ratio and by extracting every last bit of power from the gas-air mix. For more power, the Highlander Hybrid features a V6 Otto cycle engine, which increases efficiency by compressing the fuel mixture before ignition.
Electric Drive Motor
A result of Toyota home-grown technologies and work done on pure electric vehicles, the Electric Drive Motor is an AC synchronous-type motor using permanent neodymium magnets and a rotor consisting of stacked electromagnetic steel plates. Because the magnets are arranged in an optimal V-shape configuration, the motor produces both high output and drive torque
Power Control Unit
The Power Control Unit is the brains behind the hybrid system, integrating gas engine and electric motor power in a way that is both seamless and achieves the highest levels of performance. The unit contains an inverter to convert direct current from the battery to alternating current to run the electric motor, and a DC/DC converter to produce 12V current. As well, the unit's high-voltage power circuit raises the voltage from the power supply, thus allowing a reduction in current and subsequently a reduction in the size of the inverter. More power. Less space.
High Voltage Battery
High Voltage Battery For Energy Storage
The Toyota hybrid nickel-metal hydride HV battery never needs to be plugged in. That's because the battery is being constantly re-charged by either the gas engine by way of the generator when in cruising mode, or by the electric motor during deceleration and regenerative braking. And the latest battery has been further enhanced through improved electrode material and a new connection structure between battery cells. Tests show that the battery maintains efficiency for up to 300,000 km without deteriorating.
The AC synchronous-type generator is just the thing to charge the battery and supply power to the high-output electric drive motor (or motors, in the case of the Highlander Hybrid) as needed. To provide the optimum power to the motor, the generator is rotated at high speeds, thus increasing the rpm range from the conventional maximum output of 6,500 up to a whopping 10,000 rpm. A higher rpm rate increases power supply in the medium-speed area and improves acceleration in the low/medium-speed range. The result is more power when you need it without burning extra fuel.
Planetary Gear ( Power Split Device)
By splitting power into two routes: mechanical and electrical, the planetary gear, also known as the "hybrid transaxle," can transfer power between the engine, motor/generator, and wheels in just about any combination you could imagine. Directly linked to the engine, the rotational shaft of the planetary carrier inside the gear mechanism is able to transmit the motive power to the outer ring gear and the inner sun gear, using pinion gears. The rotational shaft of the ring gear, on the other hand, is directly linked to the motor. It transmits the drive force to the wheels, while the rotational shaft of the sun gear is directly linked to the generator. Talk about getting in gear.