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With global warming, the depletion of fossil energy, and the growth of the automobile industry, countries are now placing great emphasis on the R&D of new energy vehicles. At present, the progress of electric vehicles is accelerating, but there exist drawbacks, including short driving ranges and long charging times. The selection of electric vehicle configuration and regenerative braking (RB) strategy are currently the best ways to solve the shortcomings of electric vehicles. A good RB configuration and strategy can improve energy recovery efficiency and economy. The configuration of a wheel hub motor plus a wire control brake can improve energy recovery efficiency. However, the current technology of electronic mechanical braking systems is not mature enough, resulting in a high failure rate. Since the vehicle braking fault tolerance potential of this configuration is strong, a fault-tolerant control strategy can be devised to increase security. We established a vehicle dynamics model with single-wheel failure and double-wheel failure, analyzed the vehicle stability under different failure conditions, and selected yaw rate, heading angle, sideways distance, and braking distance as evaluation indicators of vehicle stability. The effects of various failure conditions on the vehicle were examined with joint simulation. According to different failure conditions, we designed fault-tolerant control strategies for mild, moderate, and severe brake failure conditions, with the control targets being yaw rate and center of mass sideslip angle. Under severe failure conditions, we designed a front wheel steering angle sliding film controller to coordinate control with the fault-tolerant control strategy to enhance the vehicle braking stability. A large number of experimental results prove that our proposed solution has good reliability.

The safety problem is the primary factor that should be viewed in the regenerative braking system design of vehicles. To ensure braking safety and battery safety of the electrical vehicles (EVs) a regenerative braking system contain us two fuzzy logic controllers is designed in the paper. In the system, one controller includes slip coefficient, vehicle speed and the driver’s brake requirement to ensure braking security and the other takes battery State of Charge (SOC) and temperature as inputs to assure battery safety. Then, two proportional coefficients $K_r$ and $K_b$ satisfying the safety needs are introduced into the braking system. At last, the simulation model is established in the simulation software-ADVISOR (ADvanced VehIcle SimulatOR). Through simulation, the results verify that more energy can be regenerated from braking under the conditions of ensuring braking and batteries safety.

With fixed running times at sections, cooperative scheduling (CS) approach optimizes the dwell times and the headway time to coordinate the accelerating and braking processes for trains, such that the recovery energy generated from the braking trains can be used by the accelerating trains. In practice, trains always have stochastic departure delays at busy stations. For reducing the divergence from the given timetable, the operation company generally adjusts the running times at the following sections. Focusing on the randomness on delay times and running times, this paper proposes a stochastic cooperative scheduling (SCS) approach. Firstly, we estimate the conversion and transmission losses of recovery energy, and then formulate a stochastic expected value model to maximize the utilization of the recovery energy. Furthermore, we design a binary-coded genetic algorithm to solve the optimal timetable. Finally, we conduct experimental studies based on the operation data from Beijing Yizhuang subway line. The results show that the SCS approach can save energy by 15.13% compared with the current timetable, and 8.81% compared with the CS approach.

To use regenerative braking to act as an auxiliary brake to maintain the constant speed of a brushless DC motor driven electric bus (BDCMEB) on downhill based on the feature of double-loop control structure of the control method for electric vehicle traction motor and the variable structural characteristics of PWM Control System for brushless DC Motor. A double-manifold variable structure control method to control regenerative braking is proposed for the bus cruising downhill. The impact of lead-acid battery's charge acceptance ability over a long charging period on the regenerative braking force of a driving motor is analyzed. Dynamic model of the bus on long downhill is established. A double-manifold variable structure controller is designed for the DCMEB on long downhill. The simulation result shows that the control system maintains enough stability and strong robustness. It may be achieved for the bus to maintain a constant speed downhill only by regenerative braking on a smaller slope. But the dynamic process is very slow. When deceleration or a constant speed is desired on a larger slope, only by electro mechanical parallel braking can the bus track the target speed precisely and quickly.

To use regenerative brake and mechanical brake co-operatively to maintain the constant speed and the braking energy can be regenerated as much as possible when vehicles travel downhill, the mathematical model of the braking system is established, and the adaptive model predictive control method is adopted to control the speed of vehicles. The recursive least square algorithm with the forgetting factor is used to identify the road gradient online. And then the control results of the adaptive model predictive control are compared with the results of PID control, simulation results show that the robustness and the stability of the adaptive model predictive control method are better. The speed can be maintained basic stability with the coordinated use of the regenerative braking and the mechanical braking. Meanwhile, the braking energy can be regenerated as much as possible as the regenerative braking system can be used as much as possible. Moreover, as the charge acceptance ability of the battery is restricted, the brake mode switching model is designed. The braking mode can be switched between the electro-mechanical braking system and mechanical braking system according to the SOC of the batteries.

This paper describes the novel mathematical modeling of the 3-phase induction motor, various operations and study of its dynamic behavior and regenerative braking based on the model. This model uses v/f scheme to apply braking operation with the energy flow to the supply system instead of wasting the energy in braking resistor. It discusses the theory of induction motors, which is explored through both equations and computer simulation model using SIMULINK. The model also helps to study the behavior of the motor during its starting and load variation. The results from the analysis prove the demonstration of regenerative braking and the dynamic behavior and can give an opportunity to learn the different characteristics during these conditions.