Preface
■ Traditional automobile engines must have idle speed to meet drive requirements;■ There must be a clutch or torque converter to meet the starting requirements;
■ The engine needs sufficient backup power to meet the acceleration requirements;
■ Conventional powertrains cannot recover braking energy.
Definition of electric transmission >EVT( Electrically Variable Transmission)
Electric drive transmission is a mechanical energy-electrical energy-mechanical energy conversion device with two mechanical interfaces; Input and output interface, an electrical interface connected to the battery, typical hybrid vehicle drivetrain structure, output shaft output torque and power are desirable from the engine can also be taken from the battery.
Type of an electric transmission
Basic concepts of planetary gears
Planetary train angular velocity simulation lever method
Planetary gear train torque simulation lever method
Relationship between planetary gear train and lever method
Parallel Hybrid.Serial Hybrid.Power Split (Dual) Hybrid
Serial Hybrid
ICE- Internal Combustion Engine EGM- Generator EDU- Drive Motor GCU- Generator Controller
BCU- Battery Controller Battery- Power Battery SDU - Safety Protection Unit
CEU- Motor Controller ----- DC, High Voltage ----- AC, High Voltage ----- Control Signal, Low Voltage
Features
● No need to use gearbox, simple structure, simple control algorithm
-High efficiency with small internal combustion engines (always working on the best fuel curve)
No gear shift shock
Two electric drive systems are required
● High power of electric motor
● High battery power, high weight and high cost
● Large battery charge/discharge depth and short life span
BAE SYSTEMS
Partnership with Orion Bus
325 Orion VII 12m low-floor buses in operation in New York, 500 new orders
Fuel savings of 31% (diesel) - 50% (gas)
110 kW motor, Hawkwer advanced lead-acid batteries
$500K/bus;$100K>CNG;$150K>Diesel
ISE Corporation
170 /288 kW bi-directional motor; 300 kg
Bidirectional inverter; 72 kg
■ Cummins ISB engine
▪ Cobasys 576-240 NiMH battery, 300 kg
Three vehicles in test operation in New Jersey, 20% more fuel efficient than conventional vehicles in best condition
◆ 150/240kW, or 65/120kW induction AC motor; 160/290kg
◆ 50kW engine/motor unit
◆ 120/240kW,250-425V Input inverter
◆ Cummins ISB engine
Used with various batteries
Parallel Hybrid
1.Front parallel structure
Features
● Only one set of electric drive system is required
● Low motor power, low battery power, light weight and low cost
● Reduces the power of internal combustion engine
● Multiple operation modes such as pure electric, pure engine and hybrid can be realized, and reliability High reliability
● Complex structure and control algorithm
2. Rear-mounted parallel structure
Features
● Can be modified and retrofitted to existing vehicles
● Only one set of electric motor and control device is needed
● High motor torque, high battery power, high weight and high cost
Eaton Corporation
26 /44 kW permanent magnet motors;
Various electronically controlled engines
Lithium-manganese battery
Automatic mechanical gearbox
Dry automatic clutch
Mitsubishi Fuso
◆ 35 kW permanent magnet motor; 92 kW engine
◆ Lithium-manganese battery
◆ Automatic mechanical transmission, dry automatic clutch
Enova Corporation
◆ 60-90 kW induction type AC motor;
Various different batteries have been used
Power Split (Dual) Hybrid
◎ Stepless variable speed, no gear shift shock
●Two sets of electric drive system are needed
●High motor power
●High battery power, high weight and high cost
●High development cost due to special hybrid drive unit required
●Complex structure and control algorithm
Allison
Two 100/160 kW induction motors;
▪ 280-330 hp engine
600V 200kW NiMH battery 430kg
Stepless variable speed function
▪ 60′, 50' and 40′ passenger cars in partnership with New Flyer
325 units in Seattle, 1732 units in Washington and Philadelphia
Planetary gear power splitting is the best solution for deep hybrids
Deep hybrids dominate the world's new energy vehicles, accounting for 90% of global sales
of global sales
100% of deep hybrid solutions use planetary gear power shunts
Global market for deep hybrids continues to grow
Planetary gear power splitting technology is a gap in China's automotive industry
Global market sales of hybrid cars (million units)
Power Transmission Theory
Single- and dual-flow transmission theory
Electromechanical coupling system
Torque coupling
Rotational speed coupling
Power coupling
● Output torque and speed are the linear sum of engine and motor torque and speed, respectively, so that engine torque and speed are controllable.
Rotational speed coupling method
K is the ratio of planetary gear teeth, n is the speed, T is the torque
Characteristics: The load torque determines the torque of the power source
Single Planetary Row Speed Coupling System
Compact planetary row hybrid driveline (CHPTD)
Compact planetary row hybrid driveline (CHPTD)
Torque coupling method
K is the ratio of planetary gear teeth, n is the speed, T is the torque
Characteristics: The speed of the load determines the speed of the power source
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Honda Parallel Hybrid System (IMA)
work mode
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Single row planetary gear coupling
Double-row planetary gear coupling
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Dual rotor motor coupling
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Single-mode hybrid
Hybrid infinitely variable speed control system optimization working principle
1. For any output torque and speed, within a certain range, you can configure any The speed and torque of the engine;
2. At a specific working point, considering the charging and discharging efficiency of the battery and the efficiency of the motor, the best point of fuel consumption can be found and the engine can be optimized. To find the best point of fuel consumption and achieve engine optimization;
3. In the hybrid working condition, when the battery is in balance, there is always a motor, a motor drive, there will be efficiency losses, affecting the efficiency of the system; but consider Optimization of the engine working condition, can get better economy than the traditional car;
4. control completely torque control mode, for a specific speed output torque demand, according to the system optimization strategy, the distribution of the calculation of the engine torque, and the torque of the two motors.
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Dual-mode hybrid
