Prius Transmission generator (MG1)

The small electric motor / generator (MG1) is an AC synchronous brushless AC motor . The maximum engine / generator speed is 10,000 rpm.Power: 25 Kw (34 hp) at 10,000 rpm. 

    The Prius / generator (MG1) in the Prius has two functions :

The first function is to generate electrical energy for the battery, s and the electric motor, MG1 then acts as a generator.The second function is to start the combustion engine, MG1 then works as a motor.

The Electric Motor MG2

The main electric motor / generator in the Prius is an AC 500V AC synchronous brushless AC power.
This engine has been fully engineered by Toyota after long experience with electrically powered vehicles and has the high KW per Kg output

The electric motor has two functions, the first function is the Prius drive and the second function is the generation of electrical energy within the Prius regenerative brake system. When the accelerator pedal is released and / or the brake pedal is depressed, the electric motor inhibits the Prius by operating as a generator. The resulting electrical energy is fed to the high voltage batteries so that they are charged

MG2 data: Power: 50 Kw (68 hp) at 1200 – 1540 rpm. Max. Torque: 400 Nm at 0 to 1200 rpm.            

What happens when we drive the Prius? 

Starting the ICE:



Starting the prius ICE:


Starting the ICE is provided by MG1, it runs by using
electric power from the high voltage battery.
If the Prius stops, the outer ring will also be kept quiet, because it is linked via MG2 to the front wheels.
The rotation of the Sun coupled with MG1 ensures that the Planetary wheel also rotates.
The planetary wheel rotates at a speed of 1 / 3.6 times the velocity of the Sun.
Where a conventional car starts the engine directly by supplying fuel and igniting it, Wait the Prius until the engine has a speed of 1000 rpm. MG1 rotates with a speed of 1000 x 3.6 = 3600 rpm. This speed is reached in less than 1 second. Starting the ICE at this speed ensures that the oil pump can bring oil pressure to normal operating pressure. As a consequence, less wear on the engine will arise during starting when starting a conventional combustion engine. At the start of the ICE, not all ignition cylinders are initially installed, which takes place stepwise, so that it starts smoothly and without vibration. Once the ICE is started, the speed is controlled by the computer to a desired value to heat the engine. Electricity is no longer used by MG1, because MG1 now works as a generator, electricity is returned to the batteries. There is a difference in starting the Prius when the ICE is cold and when The ICE is hot.

Driving with the Prius after a cold start of the ICE

Because the ICE is started in this situation, the power of the MG1 is transmitted to MG2 during gas (MG1 is connected to the planetary wheel via the Sun). At the time when more power is required, the ICE speed is increased by the computer. During this process, the ICE will turn the Sun tougher and the MG1 will turn the Sun slower, resulting in a power that sets the Prius on its way. The coupling of the ICE is split by the planetary wheel coupling in 72% to the outer ring and 28% to the Sun. Before we throttle the accelerator, the ICE drives stationary and does not provide a torque, but when we accelerate the accelerator, the ICE will deliver 28% of its torque to generator MG1 and the other 72% to the front wheels. The electrical energy generated by MG1 is reduced by MG2 and converted into a torque and transmitted to the front wheels. The electrical energy generated by MG1 is reduced by MG2 and converted into a torque and transmitted to the front wheels. (Figure 6) The electrical energy generated by MG1 is reduced by MG2 and converted into a torque and transmitted to the front wheels.


Driving with the Prius with a warm ICE:

Driving with a warm ICE takes place entirely on the electric motor.
During gas delivery, electrical power from the high-voltage batteries in MG2 is converted into a torque supplied to the front wheels. The speed of MG2 determines the driving speed of the Prius.

As long as the speed is low, the power consumption is not too high and the voltage level of the batteries is not too low, the Prius will be driven by the electric motor and the ICE will remain out of service.
The Prius is then called EV mode, also called stealth mode


Accelerate and hill on driving with the Prius:

If the power’s demand is high, the ICE and MG2 work together to meet this demand. When the accelerator pedal is pushed further, the ICE will provide more torque, which increases the mechanical torque to the planetary wheel and increases the amount of power generated by generator MG1. The excited electric power of MG1 ensures that MG2 delivers a larger torque to the front wheels. Depending on the status of the high-voltage batteries, an amount of electrical energy from the batteries can be used to make MG2 even more attached to the front wheels. However, when the speed of the Prius increases even more, the share of MG2 decreases in total power demanded. This is because the limit of 50 Kw is reached. The ICE takes account of the remaining assets. When the desired speed is reached and the accelerator pedal is lowered far, the demand for mechanical and electrical power will decrease and a portion of the power generated by MG1 will be released. This excess of power is then used to recharge the high voltage batteries. The available power in the battery ‘ S will only be used in this situation when accelerating quickly or when riding a steep hill. However, if there is no additional power in the batteries at this time, the ICE will have to deliver all the power and will temporarily decrease the performance of the Prius.
Driving at an average speed:

The moment we drive the Prius at a constant average speed on a flat road is the only thing to overcome the driving resistance. Row resistance consists of components, rolling tires, aerodynamics (air resistance), total car weight and friction loss of the various rotating components.
In this situation, the ICE is brought to a lower speed by the computer system. This has the advantage that the noise level of the drive is as low as possible and the comfort is at a high level.

During this higher speed and low speed of the ICE there is a typical situation. The direction of rotation of MG1 is now the other way round (see Figure 9), and in this mode, MG2 operates as generator and supplies electrical power to MG1, which in turn works as a motor. The Prius is powered by the ICE and MG1 in this fashion.
This is also called the “heretical fashion”

Prius Transmission While coasting

When you take off the foot pedal, the Prius slowly decreases due to rolling resistance and aerodynamics (air resistance). In a conventional car the engine remains connected to the driven wheels. The engine then runs without fuel supply, but still has compression and thus greatly inhibits the car. At the Prius this does not have to be the case because the ICE is stopped and thus stands still.
The Prius does, however, slow down like a conventional car, which is caused by the fact that MG2 will work as a generator in this situation.
The resulting electrical energy is fed to the high voltage batteries. The batteries will be charged. In Figure 10 , you see that the planetary wheel stops in this situation. The ICE has stopped and the generator takes care of the effect of braking on the engine. The advantage is that energy is being generated instead of energy being destroyed as in a conventional car.


Prius Transmission in reverse Gear

The Prius has no gearbox like a conventional car and therefore no reverse gear. The Prius drives backwards by using electric motor MG2. In normal situations, the ICE will stop when switching to reverse. (Figure 11)

The electric motor is rewound and drives the front wheels so that the Prius drives backwards. If the ICE does not stop, for example, because the charge level of the batteries is too low, the reverse speed is limited to protect MG1 from overflow. The speed of MG1 is higher when the ICE is in operation and the Prius is powered by MG2. (See also Figure 9)

The required power during reverse operation with the ICE in operation is provided by MG1 in this situation.