Outer Rotor SRM Design for Electric Vehicle without Reducer via Speed-Up Evolutionary Algorithm

Reducers utilized in automotive industry provide motor to run in most effective region and transmission output torque to increase. However, they cause mass and cost to increase and also efficiency to decrease due to mechanical losses. The aim of this study is to design a direct drive motor (outer rotor switched reluctance motor (OR-SRM)) without reducer resulting in enhanced efficiency for electric vehicle (EV). To estimate dimension and electrical parameters of OR-SRM, mathematical equations are originally derived from its geometry. Considering the constraints of package size and outer diameter, all the dimension parameters of the motor are optimized via multi-objective genetic algorithm (MOGA) to get the desired efficiency and torque. In order to validate the results in the proposed approach, OR-SRM is modeled by Maxwell 3D using optimized dimension parameters. In-wheel OR-SRM with 18/12 poles (30 kW) is manufactured to employ it in an EV. Theoretical results are compared to experimental results. It can be concluded that the results are satisfactory

Design of electronic differential system for an electric vehicle with In-wheel motor

This paper presents design of Electronic Differential System (EDS) for an Electric Vehicle (EV) with inwheel motor. EDS is generally used in EVs due to some drawbacks of mechanical differential such as being heavy systems and mechanical losses caused by the powertrains. According to the turning angle of the wheel, task of EDS for front wheels is to adjust rpm of the wheels. On the contrary for rear wheels, only rpm control is realized due to not steering. Hence, there are less studies on EDS for front wheels of EV in the literature. In this study, an EDS for front wheels of EV is designed. According to steering angle and speed of EV, the speeds of the front wheels are estimated by equations derived from Ackermann-Jeantand model using Codesys Software Package. The estimated speeds are sent to Induction Motor (IM) Drives via Controller Area Network-Bus (CAN-Bus). EDS is also simulated by Matlab/Simulink. Then, the speeds of the front wheels are experimentally measured by a tachometer. Codesys results are verified by both Simulink and experimental results. It is observed that the designed EDS is convenient for EVs with inwheel motor

Electronic differential system for an electric vehicle with In-wheel motor

This paper presents modeling and simulation of Electronic Differential System (EDS) for the dual-front-wheel independently driven Electric Vehicle (EV). Electronic differential is utilized in EVs due to some drawbacks of traditional mechanical differential such as being heavy and bulky systems which are not convenient for EV, and mechanical losses caused by the powertrains. In this study, an EDS for front wheels of an EV with in-wheel motor is modelled instead of rare wheels which has commonly been studied in the literature. The front wheel speeds are estimated by equations derived from Ackermann-Jeantand model using Codesys Software Package. Then, the simulation of EDS is also realized by Matlab/Simulink. According to the change of the vehicle speed and steering angle of EV, front wheel speeds estimated by Codesys are verified by Simulink results. It is observed that the modelled EDS is appropriate for EVs with in-wheel motors

Examination of radial force with finite element method in switched reluctance motor

The aim of this study is computation of radial forces shown as one of the main and important reasons of noise in Switched Reluctance Motor (SRM). In this paper, radial forces in saturation and unsaturation regions of a standart submersible pump type 8/6-pole SRM have been calculated and their changes have been obtained. ANSYS 10.0 package program which makes a solution with Finite Element Method (FEM) has been used for computation of radial forces. After geometric shapes are given, radial forces have been calculated from unaligned position of rotor towards aligned position with angle of one degree according to different current values

Estimation of confidence regions and severity of undefined faults in driving using synthetic disturbance signals

In this study, we aim to determine fault severity in an electric car that may be caused by yawing due to such disturbances as non-uniform road pavements, in-wheel bearing clearance, suspension system, driver under Influence of alcohol (DUI), and tire deformation. The major research contribution herein is to alert drivers about an unforeseen situation on steering wheel whether it refers to a severe fault or contemporary states. In a sense, the undertaken study serves as a state of the art driving assistant system operating under unsteady conditions. We determine the fault severity of the system via classifying it into specified confidence regions by estimating the deviation from a monotonous straight route for any unstable situation. In this way, the proposed system informs driver to gain an insight about the severity level of arising problematic scenario. In order to realize the classification of confidence regions, we initially obtain the overall dynamic model of the system. Then, disturbance functions with different amplitudes and frequencies are characterized and included in the dynamic system specification. Here, the confidence regions have been constructed as to respective fault severity level of the car through the system response. Trajectory of vehicle in dynamic driving conditions considering these perturbations and noises are interrelated through the Kalman filtering to predict deviations from the desired trajectory and the prediction error. In simulation scenarios, Dynamic Time Warping (DTW) is employed to obtain deviation from ground truth under different noise functions, and results are sketched graphically assigning rate of fault severity into specified confidence regions. Initially, we have modeled the proposed system considering an electric car although the idea can readily be generalized for all cars with four tires. Presently, fault severity with classified confidence regions has been investigated under a simple car model. Keyword

Designing in-wheel switched reluctance motor for electric vehicles

Estimation of dimension parameters for an electrical machine has great importance before manufacturing. For this reason, analytical design should be performed in an optimum form. While motor analysis is accomplished by package programs, initial size parameters are intutivily provided and then various trials are examined to get optimum results. In this study, we are trying to find dimensional and electrical parameters generating mathematical equations in analytic approaches for In-Wheel Switched Reluctance Motor (IW-SRM), which will be employed by Electric Vehicle (EV). Therefore, optimum motor parameters for required speed and torque have been estimated by solving generated equations for in-wheel SRM with 18/12 poles via MATLAB. Using the parameters, analysis of in-wheel SRM has been carried out 3D Finite Element Method (FEM) by Ansoft Maxwell 15.0 Package Software. Consequently, the accuracy of the estimated parameters has been validated by the results of Maxwell 3D FEM

Dynamic risk modeling for safe car parking in climbing over urban curbs

In urban areas, safe and secure vehicle parking presents various problems as vehicles are driven at low speeds toward available parking spots. If there is an obstacle in front or back of the car, drivers have to accelerates their cars from zero to higher speed to pass over the obstruction. Obstacle could be curbs, bumper or any rim over the parking area. In this case, we assume the obstacle to be a curb. Therefore, driver has to get over the obstacle by stepping on the gas of his car. This action can result in hazardous situation to the car, pedestrians or obstacles around the car. In the proposed system, we estimate jumping distance of the car considering major components attributing to scenario. As outcomes, we have obtained the balance between the car performance and steep level of the curb. This would be a guidance not only designing urban areas but also estimating dynamic behavior of the car after detecting the obstacle profile