Hybrid Synergy Drive



The Electric Motor

The compact, lightweight high-efficiency AC permanent magnet synchronous motor does not use brushes like a direct current motor, so it offers superior durability. And since the permanent magnet needs no electricity to create a magnetic field, it is much more energy efficient. The motor functions as a generator during regenerative braking, converting the vehicle’s kinetic energy into electricity to charge the battery.

The Battery

The sealed nickel-metal hydride battery, designed especially for electric vehicles, offers high power density, light weight, and long life. Its performance has been further boosted for the Toyota Hybrid System, with output per unit capacity more than triple that of most electric vehicles. This allows the battery to provide a huge surge of electricity to the motor precisely when it’s needed for all-out acceleration.

Generator

The high-efficiency AC permanent magnet synchronous generator produces electricity to charge the batteries and power the motor. By controlling the generator speed, the power split device functions like a continuously variable transmission. The generator also functions as a starter for the engine.

Power Split Device

The power split device uses planetary gears that allocate engine output between the drive wheels and the generator. By controlling the generator speed, the power split device also functions like a continuously variable transmission. Engine output is directed inward to the planetary carrier of the power split device and outward through the sun gears to the generator and through the ring gear to the motor and the wheels.

Regenerative Braking System

When decelerating or braking, the motor acts as a generator, recovering kinetic energy from the wheels, converting it into electricity and storing it in the battery. It’s an ideal energy-saving system for stop-and-go city driving. When the driver applies the brakes, both the hydraulic brakes and the regenerative brakes are used, with the priority going to the regenerative braking system to maximise energy recovery.

Inverter

The inverter changes the battery’s direct current into alternating current to drive the motor and turns the generator’s alternating current output into direct current to charge the battery. It also varies the frequency of the current, depending on motor rpm to maximise efficiency. The inverter unit is water cooled for improved reliability.