Control strategy of regenerative braking for hybrid electric vehicle based on engine braking

Focusing on a continuously variable transmission(CVT) hybrid electric vehicle with integrate starter generator(ISG), modeling and simulating of engine braking was conducted. An optical control strategy of regenerative braking was put forward. When there is no regenerative braking, engine brake force can be used effectively by changing the CVT ratio to reduce the braking force requirements for wheel brakes based on the calculated results of engine braking. When there is regenerative braking, the braking priority sequence is generator braking, engine braking, and finally frictional braking. A forward simulation model for regenerative braking system of hybrid electric vehicle was built. The simulation and analysis under typical driving cycles was conducted. The result shows the control strategy and the models are reasonable and feasible.     

Study and Simulation on Control Strategy for CVT Ratio in HEV when Regenerative Braking

In order to satisfy the safety of vehicle braking and the fuel economy,a control strategy for regenerative braking force distribution is proposed by considering of battery SOC and braking severity.In addition,a CVT speed ratio control strategy is proposed to operate the motor in the high efficiency area to improve motor generating efficiency.A simulation model of mild hybrid electric vehicle is set up.Simulation result on ECE+EUDC typical driving cycles show that the effectively regenerating energy of braking of hybrid vehicle with CVT is lager than that of hybrid vehicle with MT by 2.5%.     

Simulation analysis on braking system of hybrid vehicle with ISG

A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.     

Model predictive control strategy of a medium hybrid electric vehicle

The intense coupled and nonlinear behaviors were observed on the tall long span tower line systems which were under the icing and wind loads in heavy icing areas. A set of stiffness equations of insulator, conductor and boundary conditions was deduced. Taking the ±800 kV UHV DC transmission line from Xiangjiaba to Shanghai as an example, the simplified numerical model of transmission tower, conductor, insulator and constraint was developed. The long span transmission tower line system models under seven loads conditions were analyzed by static nonlinear methods. It was found that the P Δ effect of tower components was small when the covered ice was uniformly distributed. The unbalanced wire loads on the tower would lead to twist effect when the covered ice was uneven distributed. The axial forces, moments at restraint nodes and the longest cantilever member were greatly affected by the P Δ effect, under which the unfavorable effect on the structure should be considered.     

Coordinated pressure control of a regenerative braking system based on a hybrid electric vehicle with an integrated startor and generator

With a focus on a Changan hybrid electric vehicle (HEV) with an integrated startor and generator (ISG), strategies for braking force distribution and coordinated pressure control are put forward, and a dynamic braking control model is constructed for off     

Fuzzy Control Strategy and Simulation for ISG-Type Hybrid Electric Vehicles

Fuzzy control strategy is used to study the fuel economy of ISG-Type hybrid electric vehicle with CVT.Based on the instantaneous state of vehicle,the fuzzy logic controller is built aiming to get minimum fuel consumption.In order to avoid the subjective factor,the control rules are established with the optimized results from the sequence quadratic programming(SQP) method.Through the second development of ADVISOR,the simulation for ISG hybrid electric vehicle at different cycles has been accomplished.The results show that the fuzzy logic control strategy is efficient in improving the fuel economy of hybrid electric vehicle.     

Heat dissipation optimization of DC-DC and IPU for hybrid electric vehicle

Due to the bad heat dissipation of the existing heat dissipation structure of DC-DC and IPU for hybrid electric vehicle(HEV), the temperature of DC-DC and IPU will rise during the running process, which in turn decreases the stability and reliability of the hybrid electric system. Aiming at this problem, a three-dimensional, transient heat dissipation model is built for DC-DC and IPU heat dissipation structure based on the mass, momentum and energy conservation equations. By using computational fluid dynamics (CFD) software, flow field and temperature field of DC-DC and IPU heat dissipation structure are numerically simulated. Based on the simulation, and combined with heat transfer theory, an improvement scheme of heat dissipation structure is proposed. The simulation results and experiment results of thermal performance and temperature rise show that the improvement scheme can improve the thermal performance, and decrease the temperature rise of DC-DC and IPU effectively, thus satisfy the application requirements in HEV.     

Parameter Simulation on the Control Strategy for a Parallel Hybrid Electric Vehicle by CRUISE

The purpose of a parallel hybrid electric vehicle(PHEV) is for the best energy distribution between internal-combustion engine(ICE) and electric motor though the appropriate control strategy.It can not only keep the advantage of the ultra-low emission of electric vehicles(EV),but also take advantages of the hyperbaric energy of ICE.Simulation model for PHEV is built based on CRUISE,an auxiliary control strategy is designed,and then parameter simulation study on the control strategy is performed.The simulation results show that according to the different control requirements,the vehicle performance can be improved by adjusting!the corresponding control parameters.     

Dynamics Simulation of ISG-HEV Engine During Starting

The behavior of engine automatic starting and stop under idle speed is an important working model for HEV(hybrid electric vehicle), which can avoid engine running under idle speed. So it can reduce engine fuel consumption, exhaust gas emission and wear efficiently. The ISG(integral starter/generator) motor control strategy is given by dynamic research of the HEV engine starting, based on the model and simulation of resistant characters during engine starting, then an ISG motor-engine integral control model is built up and simulated. The result shows that the ISG motor can drive engine quickly and the simulation meets well with the need of starting time.     

Simulation of The Torque Control System of Motor for Hybrid Vehicle

A strategy for induction motor control based on the grade of errors is developed to improve the performance of hybrid vehicle drive system. The stator flux error, electric magnetic torque error and flux position angle are used as control variables, and rules for the switching states are chosen according to the errors and the principle of the Direct Torquc Control. This strategy improves efficiently the electric magnetic torque response of the system. The result of simulation shows that this strategy is an ideal control strategy of hybrid vehicle, which can make the motor generate the electric magnetic torque efficiently, steadily and quickly.     

搭载机电控制无级变速器混合动力汽车模式切换仿真分析

通过分析机电控制无级变速器(electrical-mechanical continuously variable transmission,EM-CVT)的结构特点,提出了搭载EM-CVT混合动力汽车的传动方案,建立了动力源数值模型、EM-CVT模型,分析了混合动力系统工作模式,并针对模式切换时的冲击问题,以减小冲击度为目标,通过分析典型工况下动力源输出转矩特性和各部件的动态特性,提出了基于发动机、ISG电机、自动离合器以及EM-CVT相互协调控制策略。利用MATLAB/SIMULINK仿真平台建立混合动力传动系统动力学模型,并对典型的模式切换过程进行了仿真分析。结果表明,所提出的控制策略能够有效控制混合动力传动系统在模式切换时产生的冲击,提高了混合动力汽车的驾驶舒适性。     

纯电动车车用复合储能装置控制策略及参数优化

为解决目前纯电动车动力电池比功率不足的缺陷,对纯电动车的储能装置进行了研究。根据复合储能装置的特点和目的,制定了复合储能装置的工作模式,提出了基于速度与电流约束的模糊控制策略。为了进一步提高整车性能并降低蓄电池的输出电流,对复合储能装置的关键参数进行了线性优化,仿真结果表明:加装复合储能装置的纯电动车的加速时间缩短了12%,制动能量回收效率提高了39%,百公里耗电量减少了8.55%,并显著降低了蓄电池的输出电流,有效延长了蓄电池使用寿命和整车的续驶里程。     

Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV

Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy.     

Hardware in the loop test for plug-in hybrid electric vehicle

Mathematical modes of engine,cooperation of motor and batteries,automatic clutch and vehicle are built with analysis of configuration of plug-in hybrid electric vehicle (PHEV). Specifications of data input and output and signal characters are defined. Hardware in the loop (HIL) system based on MATLAB/xPC for PHEV is built up. The motor/engine drive shift control logic test of PHEV is carried with inputting real acceleration pedal data. Testing results show that automatic clutch acts abnormally. Bugs in control logic are found out. Road test results with revised control logic are very good.     

Automobile anti lock braking system control based on a least squares support vector machine

Using the referenced slip rate and angle acceleration of the wheel as input vectors and the braking pressure as an output vector, an automobile anti lock braking system (ABS) controller based on a least squares support vector machine (LS SVM) was designed. Training the LS SVM controller using the supporting vector, the parameter of the controller was calculated. An anti lock braking system was designed that includes an input layer, a control layer, and an output layer. Using wheel speed as an input, the braking pressure of each wheel was calculated. The pulse width modulation (PWM) method was used to control the braking pressure, and thereby to bring ABS control. An automotive ABS test and control system was constructed. Road tests under different conditions were completed according to international standards. Test results show that an anti lock braking control method based on LS SVM has good braking stability and adaptability. It is an effective new ABS control method.     

Multi-objective control strategy for parallel HEV using fuzzy logic

A fuzzy multi-objective control strategy is proposed for parallel hybrid electric vehicles (PHEV). By the concept of motor equivalent fuel consumption, the overall vehicle fuel economy and the corresponding emissions can be treated as the optimization objectives. Then a minimum average weighted deviation method is designed to find the Pareto optimal solution with considering the variations of objective preference in different district. The simulation on ADVISOR reveals that, compared with the rule based control strategy (RBCS), with the premise that there is no loss to power performance, the proposed fuzzy multi-objective control strategy (FMCS) not only improves fuel economy and emission level but also maintains battery SOC within its operation range more effectively.     

Test Bench of Air Braking System for Vehicles

The stability of the brake system is a key factor for the vehicle safety.It is important for the air braking system's stability to shorten the time lag between the front brake and the rear brake,the reasonable disposal of the air pipeline and the optimization of the braking system design.A test bench is developed to test the performance of the air braking system,which is mainly made of pressure sensors,signal amplifiers,data acquisition system,computer,pressing air resource and so on.Based on this test bench,the reaction time of the system while braking and abandoning brake can be measured.Using this test bench,the performances of the air braking system of a certain commercial vehicle is detected.Compared with the actual road test,it can save the cost and the time for experiment largely.     

The cooling structure of Ni MH batteries in hybrid electric vehicles

Focusing on Ni MH batteries used in hybrid electric vehicles (HEV), a simulation analysis of the flow and temperature fields of the cooling structure in existing batteries is carried out using computational fluid dynamics software. The results show that the temperature uniformity is poor. The uniformity of the flow and the temperature fields is improved by adjusting the baffle and battery positions, changing the tilt angle and the distance between the batteries, inserting wind plates and a coating insulation layer. The coating insulation layer achieves the best effect. Further simulation shows that the coating insulation layer method has the best effects. The results provide the design basis for thermal management program of Ni MH batteries in HEV.     

Modeling and Simulation of a Mini-bus With Dynamics of Multi-body Systems

A few of new structures, which represent technical characteristics of mini- bus design today, have been applied into development of a new type mini- bus. Modeling of the mini- bus with dynamics of multi- body systems was researched into by using the ADAMS software, and then validity of the vehicle model was verified. Furthermore the operational stability of the mini- bus was investigated and evaluated by simulation analyses such as step steer analyses, snake cornering analyses, braking analyses in line, as well as complicated course analyses and so on.     

Apply the Hybrid Method of FDTD/MoM to Calculate the Radiation from the Aperture

This paper presents a hybrid method of the Finite-Difference Time-Domain(FDTD) and the method of moment(MoM) to compute the radiation from the aperture.The FDTD is a commonly used electromagnetic simulation way.It can solve the question with complex dielectric,but it is difficult(even cannot) for FDTD to calculate the far field because of large compute time and computer memory.So the authors can make use of the FDTD to get a large number of near electric field intensity,and then use the MoM,which based on electric field integral equation to compute the far field.Using this procedure,the authors solve the radiation of the box with apertures on one or more sides and reduced the compute time and the computer memory.