Design And Simulation Of Power System For A New Hybrid Electric Vehicle And Research On Electrical Drive System

The hybrid electrical vehicle (HEV) combines the merits of the conventional internal-combustion vehicles and electric vehicles and has been the effective means to alleviate the shortage of energy sources with improvement of the environment, which shows the development trends of modern vehicles and has been placed on the "863 Project" of China. Consequently, research on the key technologies of HEV is very important with practical significance. In this dissertation, based on the present HEV research and development situation and development trends, the hybrid power system with its control strategy, the motor drive system on a new hybrid electrical vehicle HFC6500HEV has been researched and implemented.The work mode of the parallel HEV has been analyzed and the constrained conditions of the power flow in hybrid drive system have been derived. A dynamic analysis on the parallel HEV was carried out, and the drive system was designed with a view to the vehicle arrangement constraints. According to the work conditions and design demands, the parameters of the motor and batteries have been ascertained, the work mode with multi-energy systems is established due to the operation state of the HEV.According to the real datum and system structure of the developed HEV, models of the components and the entire vehicle of HFC6500HEV have been set up on the platform of the ADVISOR software. Based on the analysis of the hybrid control strategy, simulations on the HFC6500HEV using the Parallel Electric Assist control strategy and Fuzzy Logical control strategy in urban driving cycle and Highway driving cycle are carried out and compared with the conventional vehicles. The results have showed the rationality in the structure design of HEFC6500HEV and the fuel consumption and waste gases emission have been effectively improved by hybrid control.In Matlab/Simulink, the brushless DC motor drive system has been modeled and a fuzzy self-turning PI parameters control strategy of BLDC motor has been presented. Based on the error and error derivative of velocity, the percentage and integrate factor were modified online and PWM output signals were produced. As seen form the results of simulation, a satisfied effect has been achieved.The dynamic characteristics of drive and regeneration modes of a switch reluctance motor have been analyzed, a novel method for modeling and simulation of SRM drive system has beenpresented with the independent functional blocks have been set up. By the combination of these blocks, a model of SRM control system can be established easily. The reasonability and validity of this method have been testified by the simulation results which offer new ways for designing and debugging actual motors.In Matlab/Simulink, the dynamic model of permanent magnet DC motor PWM driver system has been established. Considering the effects of the motor temperature on the motor performance, a dynamic temperature rising model was developed with the motor parameters amending according to the temperature change.A dual-mode PWM current control strategy was presented due to the two operation modes of electric driving and regenerative braking. In the electric mode, the PI modulation and limited single polar PWM control are used. In the braking mode, a current hysteresis control mode is presented in this paper in the view of the possible damage on the batteries when the simple PWM method can not effectively control the regenerative peak currents. Simulation results show that this method is superior to the simple PWM control method.With the technologic features of 16 bits DSP and CAN bus communication, the vehicle control unit and the motor control system have been designed. The full-bridge DC-DC converter is used to realize four-quadrant operation of the motor and the intelligent power modules (IPM) are used as main switches. The drive system design was implemented with a view to the strict EMC demands of vehicles.Based on the CAN bus protocol principle and SAEJ1939 regulation, the HFC6500HEV bus application layer protocol has been designed for the HEV control strategy. Referred to SAEJ1939, the ID field of CAN2.0B has been redefined and the specified approaches have been presented.Finally, the HEV prototype has been set up and the system has been debugged. The conversion experiments between the different work modes in steady state and dynamic state have been accomplished. In the actual experiment, the match conditions of the drivetrain has been testified and the structure of the whote system, the control strategy and the control system have been checked. Experiment results show that the system is reliable, the match of the powertrain is rational and the control strategy is effective.