Pure Electric Braking Research Articles

Research on Regenerative Braking Control Strategy and Simulink Simulation for 4WD Electric Vehicle

With the reduction of energy and environmental degradation, pure electric vehicles are a breakthrough point to solve the global energy and environmental crisis. However, due to the current battery technology limitations, the mileage cannot meet the use requirements. Regenerative braking is based on the existing structure and components of the electric vehicle. The braking torque is generated simultaneously by controlling the motor to generate electricity, and the braking energy is recovered at the same time. The realization of regenerative braking can compensate for the shortage of continuously driving mileage of pure electric vehicles, and maximize the energy saving advantages and social benefits. The electro hydraulic braking system is the intermediate product of traditional brake system and brake by wire system, electro-hydraulic brake system of pure electric vehicle braking energy recovery can not only improve the effect of energy recovery based on, but also can realize the braking performance. Based on Simulink, a pure electric vehicle model of electro-hydraulic braking system is established. Based on this model, the regenerative braking control strategy of electro-hydraulic braking system of 4WD Electric vehicle is developed.

Research of Sensor Fault Detection and Diagnosis for EMB System Based on CSA-SVM Model

Electro Mechanical Brake (EMB) is a high efficiency pure electric vehicle braking system which is based on the technology of Electronic, machinery, communication network. Because of the expensive cost and immature key technology in safety and reliability, the products cannot be mass-produced on the market at present. Electronic control of the EMB system needs a variety of sensors information feedback, therefore, how to correctly detect and diagnose the faults of the sensors is one of the important problems for the development of pure electric vehicles. Based on three-loop control architecture model of EMB system, the sensor fault detection model is established on the basis of Support Vector Regression (SVR), and the sensor fault diagnosis model is established on the basis of Support Vector Classification (SVC). In order to further improve the Support Vector Machine (SVM) for fault classification accuracy and fault detection reliability, the parameters of SVM can be optimized by using Clonal Selection Algorithm (CSA) and the modified CSA-SVM model is established. Simulated result of experiment indicates that the proposed CSA - SVM fault detection rate is increased than the traditional SVM by 62.5% and the fault classification accuracy is increased by 10% which laids a solid foundation of fault-tolerant control technology for the EMB system.

Research of Sensor Fault-Tolerant Control Based on CSA-SVR Algorithm for EMB Actuator System

The electro mechanical brake (EMB) system is a efficient pure electric vehicle braking system in where technologies in the fields of electronics, mechanics, and vehicle communication network were considered at the same time. Because that offered information to the electronic control of the EMB system is taken from several detectors, during developments of the pure electric vehicle, unsolved difficulties in EMB system are the accurate fault detection as well as the timely process of a fault tolerant control. In this paper, the fault detection and the fault tolerant control on the mathematical models of a current, a speed, and a pressure detector loaded on the EMB actuator system will be studied. Based on the three-loop control architecture model of the EMB actuator, these models of detectors are constructed by the method of the dynamics analysis of the actuating agency respectively. On the purpose of improving the accuracy of fault detection, the clonal selection - support vector regression algorithm (CSA-SVR) is proposed, which is a combination of CSA and SVR calculation methods. Through CSA-SVR algorithm, optimized parameters of support vector machine (SVM) and improved accuracy of fault detection are obtained. The adaptive fault tolerant control architectural model mentioned which is designed using CSA-SVR algorithm in this paper shows effective function in fault detection, isolation from fault, and fault estimation.

Wide speed range for traction motor in braking force of electric braking control system

A vehicle stopping method using an electric brake until a traction motor is stopped is studied. At the moment of vehicle stop, electric brake is changed to control mode where torque is reduced at a low speed. Gradient is controlled by estimating the load torque of motor, thereby traction motor is not rotated after stop. In addition, coasting operation and brake test are performed from normal-opposite operation and start using a small-scale model comprising the inertial load equipment and the power converter. Further, traction motor is made to be equipped with a suspension torque. Pure electric braking that makes traction motor stop by an air brake at the time of stop is also implemented. Constant torque range and constant power range are expanded during braking so that braking force is secured with the electric brakes even in high speed region. Therefore, vehicle reduction effect can be expected by reducing parts related with an air brake which is not used frequently by using a pure electric brake in the M car in wide speed region. Further, maintenance of brake system can be reduced. Besides, ride comfort of passenger in the electric rail car, energy efficiency improvement, and noise reduction effect can be additionally expected. Further, an improved brake method that uses only an electric brake till motor stop is proposed by comparing those in the blending brake that uses an air brake while reducing brake torque at vehicle stop.

Analysis of Influence Factors on Braking Energy Recovery of Pure Electric Vehicle

Based on the analysis the theoretical of regenerative braking and energy flow of the pure electric vehicle, the main influence factors of braking energy recovery were obtained. Ignoring the energy loss and the efficiency of system components as well as the response delay of the hydraulic braking system, two different regenerative braking control strategies were established without regard to the braking force distribution restrictions of the relevant brake laws. The simulation model was built on MATLAB/Simulink platform to analysis the effect of control strategies, vehicle mass and driving cycle for pure electric vehicle braking energy recovery. It was guidance for the development of pure electric vehicle braking energy recovery control strategy.

Run-Curve Design for Energy Saving Operation in a Modern DC-Electrification -Efficiency Calculation Assuming Perfect Regenerative Braking-

Mechanical brakes are often used by electric trains. These brakes have a few problems like response speed, coefficient of friction, maintenance cost and so on. As a result, methods for actively using regenerative brakes are required. In this paper, we propose the useful pure electric braking, which would involve ordinary brakes by only regenerative brakes without any mechanical brakes at high speed. Benefits of our proposal include a DC-electrification system with regenerative substations that can return powers to the commercial power system and a train that can use the full regenerative braking force. We furthermore evaluate the effects on running time and energies saved by regenerative substations in the proposed method.

Technological Trend of AC Traction Drive System for Railway Vehicles. 4. Pure Electric Braking and Train Automatic Stop Position Control.

Technological Trend of AC Traction Drive System for Railway Vehicles. 4. Pure Electric Braking and Train Automatic Stop Position Control.

Precise Speed and Torque Control for AC Traction Pure Electric Braking System in Low Speed Range

This paper describes a possibility to increase the operation range of railway's pure electric braking system at low speed range. Since low-resolution speed encoders are normally installed, precise speed information is unavailable at low speed. An estimation scheme called instantaneous speed observer is introduced to estimate the speed for precise torque and speed controls. The stability of the system is analyzed by multirate sampling theory and digital control theory. Several simulation results and experiments positively show the improvement of speed estimation and the possibility to extend the operation of the pure electric brake.