ТОЙОТА ФОРУМ БЪЛГАРИЯ

Hursa написа: ↑05 Юни 2020 09:10 И 40% максимално термично КПД (което евентуално може да бъде достигната в някой режими) все пак не означава автоматично висока ефективност по отношение на потреблението на гориво.

1.5-litre Hybrid Dynamic Force Engine

The all-new 1.5-litre Hybrid Dynamic Force engine is from the same TNGA engine family as the 2.0-litre four-cylinder unit featured in the Toyota Corolla and C-HR. It has a long stroke, 14.0:1 compression ratio and high-speed combustion with better temperature and pressure control. This contributes to the its exceptionally high thermal efficiency – 40% – ensuring that more of the energy potential of every drop of fuel is captured.

In common with all Toyota’s hybrid engines, it uses the Atkinson cycle, which keeps the intake valves open for longer, delaying the compression stroke. This improves efficiency and fuel economy, but reduces power output. Nonetheless, the new engine has a maximum output of 93 DIN hp/68 kW with a peak 120 Nm of delivered at lower revs (3,600 rpm).

The three-cylinder configuration also bring benefits in terms of noise levels. When running at 4,000 rpm, its performance is like a four-cylinder unit operating at 3,000 rpm, thus delivering more power and torque, but generating less noise.

Motor/generators

The hybrid system in the new Yaris has two motor/generators – MG1 and MG2. MG2 is linked to the front wheels and can be used as the power source to drive the vehicle. The motor rpm at which power can be directed to the wheels determines the maximum speed at which the car can be driven in EV (electric vehicle) mode, making MG2 critical to the car’s drivability on electric power.

MG1 is deployed to start the engine and to generate power to charge the battery.

Lithium-ion Hybrid Battery

The new Yaris adopts a lithium-ion hybrid battery, with voltage rising from 144 to 177.6 V. The number of cells has been reduced, from 120 to 48. The current flow is significantly improved: by 100% into the battery and 50% out.

With a significantly higher power density, the battery is both smaller and lighter, by 12 kg. Its compact dimensions allow it to be located beneath the rear passenger seat, together with the auxiliary battery, avoiding intrusion in the load space.

Lithium-ion battery technology is better able to supply current flow, which is key to the new Yaris having powerful EV performance in urban driving.

Hybrid Transaxle

The all-new hybrid transaxle is more compact and lightweight, with the two motor generators placed on multiple shafts instead of being placed one behind the other, reducing the unit’s width by around 37 mm. Motor/Generator 2 benefits from new segment-type coils on the stator, which makes the unit more compact. It can deliver 59 kW of power and 141 Nm of torque to the front wheels at a maximum 17,000 rpm. The key benefit is a major improvement in performance, so that the engine can be turned off and the vehicle run in all-electric EV mode at speeds up to 130 km/h.

The transaxle also has a new oil pump, driven by the ring gear, which provides lubrication for both the gears and motor/generator 2.


Power Control Unit

The Power Control Unit has the capacity to handle 100 A of current, boosting the 177 V from the battery to 580 V and using transistor control in the inverter to change the current from direct to alternating. The transistors’ efficiency is affected by heat control inside the unit; by arranging them vertically, they can be cooled on both sides, allowing for more accurate heat control and thereby a higher frequency of current switching – up to 10,000 times a second. This makes a significant contribution to the system’s efficiency and transfer of power to the motor.

The converter in the power control unit converts the 177 V from the hybrid battery to 12V to power the car’s auxiliary components.

Hursa написа: ↑11 Авг 2020 20:25 continuously variable transmission (W-CVT)