(Đồ án hcmute) calculation and design methodology for powertrain system in hybrid vehicles

MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT AUTOMOTIVE ENGINEERING CALCULATION AND DESIGN METHODOLOGY FOR POWERTRAIN SYSTEM IN HYBRID VEHICLES ADVISOR: TRAN DINH QUY, ME STUDENT: TRAN NGUYEN AN THINH DO HOANG MINH NGUYEN SKL Ho Chi Minh City, December, 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AN EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION THESIS CALCULATION AND DESIGN METHODOLOGY FOR POWERTRAIN SYSTEM IN HYBRID VEHICLES Student: TRAN NGUYEN AN THINH Student ID: 18145064 Student: DO HOANG MINH NGUYEN Student ID: 18145042 Major: AUTOMOTIVE ENGINEERING Advisor: TRẦN ĐÌNH QUÝ, ME Ho Chi Minh City, December 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AN EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION THESIS CALCULATION AND DESIGN METHODOLOGY FOR POWERTRAIN SYSTEM IN HYBRID VEHICLES Student: TRAN NGUYEN AN THINH Student ID: 18145064 Student: DO HOANG MINH NGUYEN Student ID: 18145042 Major: AUTOMOTIVE ENGINEERING Advisor: TRẦN ĐÌNH QUÝ, ME Ho Chi Minh City, December 2022 THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December 15, 2022 GRADUATION PROJECT ASSIGNMENT Student name: Trần Nguyễn An Thịnh Student ID: 18145064 Student name: Đỗ Hoàng Minh Nguyên Student ID: 18145042 Major: Automotive Engineering Class: 18145CLA Advisor: Trần Đình Quý, ME Phone number: 0918069082 Date of assignment: 30/9/2022 Date of submission: 15/12/2022 Project title: Calculation and design methodology for powertrain system in hybrid vehicles Initial materials provided by the advisor: Textbook, previous file Content of the project: Overview of hybrid electric vehicles, theoretical basis of ICE and electric motor in hybrid vehicles, calculation method for hybrid powertrain system, design principle in hybrid powertrain system Final product: Final report file and presentation CHAIR OF THE PROGRAM ADVISOR (Sign with full name) (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December 15, 2022 ADVISOR’S EVALUATION SHEET Student name: Trần Nguyễn An Thịnh Student ID:18145064 Student name: Đỗ Hoàng Minh Nguyên Student ID: 18145042 Major: Automotive Engineering Project title: Calculation and design methodology for powertrain system in hybrid vehicles Advisor: Trần Đình Quý EVALUATION Content of the project: Strengths: Weaknesses: Approval for oral defense? (Approved or denied) Overall evaluation: (Excellent, Good, Fair, Poor) Mark: …………… (in words: .) Ho Chi Minh City, December 15, 2022 ADVISOR (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December 15, 2022 PRE-DEFENSE EVALUATION SHEET Student name: Trần Nguyễn An Thịnh Student ID: 18145064 Student name: Đỗ Hoàng Minh Nguyên Student ID: 18145042 Major: Automotive Engineering Project title: Calculation and design methodology for powertrain system in hybrid vehicles Name of Reviewer: EVALUATION Content and workload of the project Strengths: Weaknesses: Approval for oral defense? (Approved or denied) Overall evaluation: (Excellent, Good, Fair, Poor) Mark: …………… (in words: .) Ho Chi Minh City, December 15, 2022 REVIEWER (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December 15, 2022 EVALUATION SHEET OF DEFENSE COMMITTEE MEMBER Student name: Trần Nguyễn An Thịnh Student ID: 18145064 Student name: Đỗ Hoàng Minh Nguyên Student ID: 18145042 Major: Automotive Engineering Project title: Calculation and design methodology for powertrain system in hybrid vehicles Name of Defense Committee Member: EVALUATION Content and workload of the project Strengths: Weaknesses: Overall evaluation: (Excellent, Good, Fair, Poor) Mark: …………… (in words: .) Ho Chi Minh City, December 15, 2022 COMMITTEE MEMBER (Sign with full name DISCLAIMER We affirm that this thesis is an account of our work there It has not been submitted elsewhere, and all other sources of information, papers, and documents consulted while creating this thesis have been properly acknowledged i ACKNOWLEDGEMENTS We would like to express our heartfelt gratitude to Mr Tran Dinh Quy for his enthusiastic assistance and support in the project "Calculation and design methodology for powertrain system in hybrid vehicles." My team would like to thank the professors who have passionately led and educated us during our time at Ho Chi Minh City University of Technology and Education, studying, practicing, researching, and training Due to limited experience and competence, as well as limited implementation time, faults are unavoidable while working on the issue, thus the team welcomes your comments and recommendations ii TABLE OF CONTENTS DISCLAIMER i ACKNOWLEDGEMENTS ii TABLE OF CONTENTS iii LIST OF FIGURES vi LIST OF TABLE viii ABSTRACT ix Chapter 1: INTRUDUCTION 1.1 Background information 1.2 Goals and objectives of the project 1.3 Research scope 1.4 Research limitation 1.5 Research method 1.6 Organization of chapters Chapter 2: OVERVIEW OF HYBRID ELECTRIC VEHICLES 2.1 Definition of hybrid vehicles 2.1.1 About the hybrid technologies 2.1.2 Hybrid vehicle development trend 2.2 Classification of hybrid drivetrain architectures 2.2.1 Series hybrid vehicle 2.2.2 Parallel hybrid vehicle 2.2.3 Series-Parallel hybrid vehicle 2.3 Pros and cons of each type of hybrid drivetrain 2.3.1 Series hybrid vehicle 2.3.2 Parallel hybrid vehicle 2.3.3 Series-Parallel hybrid vehicle 2.4 Main components in a hybrid vehicle 2.4.1 Internal combustion engine (ICE) 2.4.2 Electric motor 2.4.3 Battery 2.4.4 Powertrain 2.5 Chapter conclusion 10 Chapter 3: BASIC THEORY FOR DESIGNING INTERNAL COMBUSTION ENGINE AND ELECTRIC MOTOR ON HYBRID ELECTRIC VEHICLES 11 iii We have: G = 1400 + 5.65 + 5.25 = 1850 (kg)  Vehicle’s design load distribution: For a travel car with load, we have:  Load distribution on front axle: Z1 = 0,42 G = 0,42.1850 = 777 (kg) = 7620 (N)  Load distribution on rear axle: Z2 = 0,58 G = 0,58.1850 = 1073 (kg) = 10523 (N)  Selected tire: 215/60R18  Wheel design radius: r0 = 215 + 18 25,4 = 443,6 (mm) = 0,4436 (m)  Wheel dynamic radius: rb = λ.r0 Select tires have high pressure, deformation coefficient λ = 0,95  rb = λ.r0 = 0,95.0,4436 = 0,42 (m)  Rolling resistance coefficient: 𝑓𝑟 = 0,01  Aerodynamic drag coefficient: 𝐶𝐷 = 0,3  Vehicle’s frontal area resistance: 𝐴𝑓 =  Transmission efficiency: 𝜂𝑡 = 0,9  Motor efficiency: 𝜂𝑚 = 0,95 Performance specification  Acceleration time (from to 100 km/h): ± 1s  Maximum gradeability: > 25% at low speed and > 6% at 100 km/h  Maximum speed: 160km/h 4.4.2.1 Total power requirement calculation According to equation (4.10), the total power required of the vehicle at a constant speed on a flat road: 𝑃𝑉 = 𝑉 1000.𝜂𝑡 𝜂𝑚 (𝐺 𝑔 𝑓𝑟 + 𝜌𝑎 𝐶𝐷 𝐴𝑓 𝑉 + 𝐺 𝑔 𝑖) We have:  V = Vmax = 160 km/h = 44,44 m/s  𝜂𝑡 = 0,9  𝜂𝑚 = 0,95  𝐺 = 1850 kg  𝑔 = 9,8 m/s2  𝑓𝑟 = f0 (1 + 𝑣𝑚𝑎𝑥 1500 ) = 0,02 (1 + 41,672 1500 ) = 0,04 (due to Vmax > 80 km/h)  𝜌𝑎 = 1,202 kg/m3  𝐶𝐷 = 0,3 Ns2/m4 64  𝐴𝑓 = m2  𝑖 =  𝑃𝑉𝑚𝑎𝑥 = 44,44 1000.0,9.0,95 (1850 9,8 0,04 + 1,202 0,3 44,442 )  𝑃𝑉𝑚𝑎𝑥 = 74,7 (kW) After calculation, we conclude that the total power required of the vehicle at maximum speed of 160km/h (or 44 m/s) on a flat road is 74,7 kW Next, we will continue in calculating and selecting engine and motor type 65 4.4.2.2 Motor power requirement calculation According to the acceleration performance (time used to accelerate the vehicle from zero speed to a given speed, such as 0-100 km/h), the power rating of the traction motor can be calculated Using equation (4.11) with 𝑡𝑎 = 8s, 𝑉𝑓 = 80 km/h, 𝑉𝑏 = 30 km/h, 𝑀 = G = 1850 kg, 𝜂𝑡,𝑚 = 0,95, we have: 𝑃𝑚 = 𝛿𝑀 2.𝑡𝑎 1,04.1850 = (𝑉𝑓2 + 𝑉𝑏2 ) + 2.10 𝑀 𝑔 𝑓𝑟 𝑉𝑓 + (22,222 + 8,32 ) + 𝜌𝑎 𝐶𝐷 𝐴𝑓 𝑉𝑓3 1850 9,8 0,04 22,22 + 1,202 0,3 22,223 = 66448,92 (W) = 66,4 (kW) So, the required motor power is 66,4 kW According http://www.tradewheel.com/ we consider the selected motor: to Numerical order Technical specs Unit Motor code MP202150 Rated power kW 70 Rated number of revolutions RPM 2000 Maximum number of revolutions RPM 8000 Armature voltage V 300 Rated current A 350 Net weight kg 12 Maximum torque Nm 130 website: Value Table Selected motor specifications 4.4.2.3 Power ratio division According to equation (4.12) with Pe+m = 𝑃𝑉𝑚𝑎𝑥 = 74,7 kW; Pm = 66,4 kW, the hybrid fraction (HF) can be calculated: HF =  HF = 𝑃𝑚 𝑃𝑒+𝑚 66,4 74,7 = 0,8 With HF = 0,8 then 𝑃𝑒 = 16,6 (kW) 66 4.4.2.4 Internal combustion engine power requirement calculation The required power of the ICE must be large enough to ensure the vehicle can run outside the city with maximum speed Vmax by design As calculated, the required power of the ICE is 16,6 kW We can consider the following engine model: Numerical order Technical specs Unit Value Engine code MSG425 Engine type SI engine Fuel type Gasoline Volume displacement Litter 2.5 Engine strokes Stroke Number of cylinders Inline Max power/rpm kW/rpm 20/3200 Max torque/rpm Nm/rpm 14/1800 Compression ratio 10 Bore and stroke 9.7:1 mm 89 * 100 Table 10 Ford 20kW gasoline engine specifications [5] 67 4.4.2.5 Generator power requirement calculation Because the generator is driven by the engine and is responsible for generating highvoltage current to supply the electric motor and charge the battery, as well as function as a starter to start the engine, the generator specifications can be chosen as follow: Numerical order Technical specs Unit Value Generator code HPM3000B - High Power BLDC Motor Rated power kW 2~3 Rated number of revolutions RPM 3000 Maximum number of revolutions RPM 5000 Rated current A 85 Armature voltage V 48V Net weight kg 8 Maximum torque Nm 25 Table 11 Selected generator specifications 4.4.2.6 Battery requirement calculation Choose the type of fuel cells used in hybrid vehicles as NiMH batteries (nickel metal hydride batteries) because of its durability and can be reused 500-1000 times if used correctly NiMH batteries are rechargeable batteries similar to nickel cadmium (NiCd) batteries, but using a mixture of hydride absorbents for anodes instead of cadmium which isn’t toxic so that the environment pollution isn’t considerable NiMH batteries have a lot more energy capacity than NiCd batteries, but the higher the capacity, the shorter the life cycle Because the battery capacity is manufactured according to the standard and voltage of the electric motor (usually 48V), we choose Ni-MH batteries in the form of cells with the specifications of each cell as follows:  Voltage per cell: 1,2V Four cells are connected in series in pack with a voltage of 4,8V  Necessary packs = 48 4,8 = 10 (packs) These packs are connected in series  One cell capacity is Ah => Cell packs capacity is E = 10.4.3 = 120 (Ah) 68  The battery capacity is determined as follows: 𝑃 𝑄𝑝 = 𝐼𝑝 𝑡𝑝 = ( ) 𝑡𝑝 𝑈 With: 𝑄𝑝 : battery capacity (Ah) 𝐼𝑝 : discharge current (A) 𝑡𝑝 : discharge time (h) P: motor power (W) We choose preliminarily when the vehicle has run 100 km, the battery will be exhausted corresponding to the maximum capacity of the vehicle in which the car is traveling in the city at a speed of 30 ~ 40 km/h Therefore, we can estimate the number of hours for battery to be depleted is about hours As calculated, the maximum power of motor is: Pm = 70 kW = 70000 W Voltage of electric motor: U = 300V From (4.15) => 𝐼𝑝 = 𝑃 𝑈 = 70000 300 = 233 (𝐴)  𝑄𝑝 = 233 = 466 (Ah)  We also have: 𝑄𝑛 = 𝐼𝑛 𝑡𝑛 With: 𝑄𝑛 : amount of electricity received by the battery during charging (Ah) 𝐼𝑛 : charging current (A) 𝑡𝑛 : charging time (h)  Due to the losses during charging, the charging capacitance is usually larger than discharge capacitance (10% - 15%)  𝑄𝑛 = 1,1 𝑄𝑝 = 1,1 466 = 512,6 (Ah)  According to Vietnamese standards, charging current is usually 0.1 of battery charging capacity: 𝐼𝑛 = 0,1 𝑄𝑛 = 0,1 512,6 = 51,26 (𝐴)  𝑡𝑛 = 10 (ℎ) However, with charging time of 𝑡𝑛 = 10 (h) is only used in the case of recharging the battery by the method of fully charge the battery after the vehicle is no longer working In addition, in order for the vehicle to work continuously, we need to compensate for the energy that has been consumed during the operations of the vehicle, that is, it is necessary to supply more energy by letting the engine to work to pull the generator to charge for the battery 4.4.2.7 Speed-coupling device requirement calculation On the basis of the speed-coupling devices presented in chapter 2, it is reasonable to select planetary gear set as the speed-coupling device for the parallel hybrid powertrain system 69 Figure 4.17 Speed coupling of a planetary gear unit We have the input parameters:  𝑇1 = 𝑇𝑒 = 14 𝑁𝑚; 𝜔1 = 3200 𝑟𝑝𝑚  𝑇3 = 𝑇𝑚 = 130 𝑁𝑚; 𝜔3 = 8000 𝑟𝑝𝑚 We also have the planetary gear set parameters:  𝜔2 = 𝜔1 𝑘1 + 𝜔3 𝑘3  𝑇2 = 𝑇1 𝑘1 = 𝑇3 𝑘3 => 𝑇1 𝑇3 = 𝑘1 𝑘3 = 0,108  𝑘3 − 𝑘1 = => 𝑘3 = 1,12 => 𝑘1 = 0,12  𝑇2 = 14 0,12 = 116,7 (Nm)  𝜔2 = 3200 0,12 + 8000 1,12 = 9344 (𝑟𝑝𝑚) Transmission gear ratio of the speed-coupling device is: 𝑖𝑠𝑑 = 𝜔1 𝜔2 = 3200 9344 = 0,34 4.4.2.8 Gearbox requirement calculation The main gear ratio is designed so that the vehicle can reach its maximum speed at the motor’s maximum rotation: 𝑖0 = With: 𝜋.𝑛𝑚,𝑚𝑎𝑥 𝑟𝑏 30.𝑉𝑚𝑎𝑥 𝑖0 : final drive gear ratio 𝑛𝑚,𝑚𝑎𝑥 = 8000; maximum motor rotation (rpm) 𝑟𝑏 = 0,42; wheel dynamic radius (m) 𝑉𝑚𝑎𝑥 = 44,44; maximum speed of vehicle (m/s)  𝑖0 = 𝜋.8000.0,42 30.44,44 = 7,92 a) Determine the transmission ratio of the powertrain 70 The transmission ratio of the powertrain in the general case is determined according to the formula: 𝑖𝑡 = 𝑖ℎ 𝑖𝑝 𝑖𝑜 in which: 𝑖ℎ : transmission ratio of main gearbox 𝑖𝑝 : transmission ratio of secondary gearbox or distribution box 𝑖𝑜 : final drive gear ratio With a single-wheel drive vehicle, the main power transmission is single, select 𝑖𝑝 = As calculated, the main gear ratio is 𝑖0 = 7,92 b) Determine the gear ratio of the gearbox in 1st gear The gear ratio in the first gear must be selected so that the tangential traction force generated at the drive wheels of the vehicle can overcome the total resistance of the road surface From the equation of traction balance when the vehicle is in steady motion, we have: 𝑃𝑘𝑚𝑎𝑥 ≥ 𝛹𝑚𝑎𝑥 𝐺 + 𝑊 𝑣 [4] When the car is moving in 1st gear, which is in minimum speed, the air resistance can be ignored: 𝑃𝑘𝑚𝑎𝑥 ≥ 𝛹𝑚𝑎𝑥 𝐺 [4]  𝑀𝑚𝑎𝑥.𝑖ℎ1 𝑖𝑜 𝜂𝑡 𝑟𝑏  𝑖ℎ1 ≥      ≥ 𝛹𝑚𝑎𝑥 𝐺 𝛹𝑚𝑎𝑥 𝐺.𝑟𝑏 𝑀𝑚𝑎𝑥.𝑖𝑜 𝜂𝑡 G: vehicle weight at full load, G = M 9,807 = 1850 9,807 = 18142 (N) 𝛹𝑚𝑎𝑥 : total drag coefficient of the road, 𝛹𝑚𝑎𝑥 = 0,01 + tg (20) = 0,37 𝑟𝑏 : wheel dynamic radius, 𝑟𝑏 = 0,42 (m) 𝑖𝑜 : final drive gear ratio, 𝑖0 = 7,92 𝑀𝑚𝑎𝑥 : maximum torque of gearbox at primary shaft (Nm) When starting, only the electric motor works, so the torque transmitted into the gearbox is the output torque of the speed-coupling device (planetary gear set) which is the torque transmitted from the electric motor 𝑀𝑚𝑎𝑥 = 𝑀𝑚,𝑚𝑎𝑥 𝑖𝑠𝑑 = 130 0,34 = 44,2 (𝑁𝑚)  𝜂𝑡 : transmission efficiency, 𝜂𝑡 = 0,9 From equation: 𝑖ℎ1 ≥ 0,37.18142.0,42 44,2.7,92.0,9 = 8,9 In the other hand, the maximum tangential traction force generated at the drive wheels 𝑃𝑘𝑚𝑎𝑥 is limited by the grip condition: 𝑃𝑘𝑚𝑎𝑥 ≤ 𝐺𝑏 𝜑 [4] 71  𝑀𝑚𝑎𝑥.𝑖ℎ1 𝑖𝑜 𝜂𝑡 𝑟𝑏  𝑖ℎ1 ≤      ≤ 𝐺𝑏 𝜑 𝐺𝑏 𝜑.𝑟𝑏 𝑀𝑚𝑎𝑥.𝑖𝑜 𝜂𝑡 𝐺𝑏 : traction weight of the vehicle, 𝐺𝑏 = 10523 (N); rear-wheel drive 𝜑: traction coefficient of the road, select 𝜑 = 0,95 𝑟𝑏 : wheel dynamic radius, 𝑟𝑏 = 0,42 (m) 𝑖𝑜 : final drive gear ratio, 𝑖0 = 7,92 𝑀𝑚𝑎𝑥 : maximum torque of gearbox at primary shaft (Nm) When starting, only the electric motor works, so the torque transmitted into the gearbox is the output torque of the speed-coupling device (planetary gear set) which is the torque transmitted from the electric motor 𝑀𝑚𝑎𝑥 = 𝑀𝑚,𝑚𝑎𝑥 𝑖𝑠𝑑 = 130 0,34 = 44,2 (𝑁𝑚)  𝜂𝑡 : transmission efficiency, 𝜂𝑡 = 0,9  From equation: 𝑖ℎ1 ≤ 10523.0,95.0,42 44,2.7,92.0,9 = 13,3 In conclusion, 𝑖ℎ1 must satisfy the above two conditions: 8,9 ≤ 𝑖ℎ1 ≤ 13,3 We select 𝑖ℎ1 = c) Determine the gear ratio of the intermediate gears Here, we choose the gear ratio for the intermediate gears of the gearbox by exponentially On the basis that the average power usage when working at full load is unchanged during acceleration Exponential transmission ratio: 𝑖ℎ𝑘 = 𝑛−2 𝑛−(𝑘+1) [4] √𝑖ℎ1 where n is the number of gears of the gearbox, k is the ordinal number of the transmission We have the gear ratio of 2nd gear is: 𝑖ℎ2 = √𝑖ℎ1 = √9 = We have the gear ratio of 3rd gear (direct transmission ratio) is: 𝑖ℎ3 = We have the gear ratio of 4th gear (reverse transmission ratio) is: 𝑖ℎ4 = 1,2 𝑖ℎ1 = 1,2 = 10,8 In conclusion, we have the gear ratio system of the gearbox is as follows:     Gear ratio of 1st gear: 𝑖ℎ1 = Gear ratio of 2nd gear: 𝑖ℎ2 = Gear ratio of 3rd gear: 𝑖ℎ3 = Gear ratio of 4th gear: 𝑖ℎ4 = 10,8 72 4.5 Chapter conclusion In this chapter, different hybrid powertrain configurations have been calculated to select suitable components in order to meet the required power and torque output, with a method of combining dynamic sources based on the actual research conditions of the thesis Detailed calculations are also performed on the basis of theoretical foundations presented in the chapter The selected components have been reasonable chosen corresponding to those available on the market However, there may contain errors in calculations and therefore further examinations can be taken into account After all the principles and steps have been executed, we can draw a schematic layout of procedures in calculations: 73 Predetermined parameters: vehicle basic parameters, maximum speed, acceleration, gradeability? Calculate Total power required PV? (Eq 4.9) For parallel and series-parallel hybrid For series hybrid Select engine Calculate Motor power required Pm? (Eq 4.10; Motor power required Pm? (Eq 4.10) Select motor Select motor Calculate HF ratio? (Eq 4.12) Select generator Select engine For parallel and series-parallel hybrid Speed-coupling device transmission ratio? Calculate Calculate Battery capacity? (Eq 4.14) For series hybrid Transmission ratio of gearbox? (Eq 4.16; 4.20; 4.21; 4.22) Figure 4.18 Calculation strategy flowchart 74 Chapter 5: CONCLUSION AND DEVELOPMENT RECOMMENDATIONS 5.1 Conclusion Through the contents presented, analysed and evaluated throughout the entire thesis and through the process of evaluating between theory and experiment, we can come to the following conclusions:  Research and develop hybrid vehicles in the direction of optimal distance and emissions is a right direction and has many prospects in the coming time  There are many methods of combining dynamic sources to create high efficiency and reduce polluting emissions into the environment, in which power-split hybrid configuration is an effective method with many outstanding advantages and has been proven in practice  The thesis can be further studied by applying simulation programs to demonstrate the power harmonizing process between electric motor and internal combustion engine Upon calculations and evaluations about dynamics, economic, technical features and emission characteristics of hybrid vehicles, the following research results can be considered as contributions to practice of the thesis:  The thesis has determined the optimal working region of gasoline engine on hybrid vehicles with low fuel consumption and emissions  The thesis has built a flowchart for the implementation of the thesis as well as flowchart of the strategy of controlling the power source, recharging the battery for hybrid vehicles, controlling the hybrid vehicle according to speed variation and torque variation, improving the efficiency of hybrid vehicle's power sources  The thesis has conducted calculations of energy sources for the electric motor and ICE to make the vehicle work in the most efficient way  Hybrid vehicles installed with the design dynamic system have outstanding advantages in terms of emissions, economy and fuel consumption From the experiment results, it can be seen that the emissions of hybrid vehicles are significantly reduced when the motor supports the main propulsion component which is ICE: NOx reduced from 16,1 to 64%; CO reduced from 30 to 84%; HC reduced from to 66% in different combine working modes of electric motor and ICE The energy consumption of hybrid vehicles is also reduced compared to traditional internal combustion engine vehicles from 3.3 to 38.6%  The propulsion system uses CVT unit in combination with a one-way joint that allows the combination of two power sources and a reasonable power distribution between the motor and the ICE Although the desired outcomes of the thesis have been demonstrated, the results are still not really as expected because of its biggest limitation, all is done theoretically instead of 75 practically In the future, we hope to continue developing and perfecting research to be able to put hybrid technology into mass production in Vietnam 5.2 Development recommendations The research contents presented in the thesis can be further developed and perfected in the following directions:  Applying electronic technology into strategic problem for solving programming optimal control of the hybrid powertrain  Carrying out a test run of the hybrid vehicle on real roads for the purpose of verifying the experimental calculations presented in the thesis as well as reference for following related researches  Improve the efficiency of using regenerative braking to charge the battery  Research to improve the efficiency of the powertrain, reduce mechanical losses  Improve the hybrid generation to the next phase, full electric vehicle, as the booming trend in the near future of the automobile industry 76 REFERENCES [1] http://en.wikipedia.org/wiki/Internal_combustion_engine [2] Modern electric, hybrid electric, and fuel cell vehicles (Ebrahimi, Kambiz M Ehsani, Mehrdad Gao etc.) [3] Hybrid Electric Vehicle System Modelling and Control by Wei Liu [4] Lý thuyết ô tô (Đặng Quý - Đại học Sư Phạm Kĩ Thuật TP.HCM) [5] http://www.centrailmainediesel.com/order/Ford-20-kw-GasolineGenerator.asp?page=F01709 [6] Hybrid Vehicle Market Size, Trends, Share, Report 2022-2030 (precedenceresearch.com) [7] Trần Văn Đăng (2022), “Nghiên cứu tính tốn thiết kế hệ động lực xe hybrid” [8] Lương Quang Huy (2017), “Nghiên cứu tính tốn hệ động lực cho ô tô hybrid” 77 S K L 0