SRM with 8/6 magnetic system topology for electric drive of mine battery electric locomotives: design and modelling

The paper deals with the development and simulation results of the switched reluctance motor for electric drive of mine battery electric locomotives instead of the DRT-14 DC motor. The switched reluctance motor parameters are obtained based on numerical calculation of the magnetic field by QuickField program and are embedded in MATLAB/Simulink model of a switched reluctance motor created for 8/6 magnetic system configuration. SRM-14-615 has the mechanical characteristics as DC motor DRT-14 and meets the required operating modes as part of the AM8D mine battery electric locomotive. Also two types of models using methods and techniques of the artificial intelligence theory are presented: a model with a fuzzy control system in the Fuzzy Logic Toolbox package and a model with a neural network control system in the Neural Network Toolbox package.

Investigation of Torque Performance and Flux Reversal Reduction of a Three-Phase 12/8 Switched Reluctance Motor Based on Winding Arrangement

The goal of this paper is to present a comparative analysis of two types of winding arrangements for a three-phase 12/8 switched reluctance motor (SRM), where short- and fully-pitched winding arrangements under unipolar operation are considered. From the analytical results, the short-pitched winding has the best torque per copper weight ratio. The core loss based on counting the number of flux reversals in the stator yoke for each winding arrangement is also proposed and mentioned. To reduce the magnetic flux reversals in the stator core, changing the direction of the magnetic flux path by modifying the winding polarities of the short-pitched winding could reduce 10–13% of core loss compared to the conventional winding. A 1 kW, 12/8 SRM prototype for the ventilation fan application is constructed and tested in order to verify the design consideration of winding configuration. At the rated condition, a maximum efficiency around 82.5% could be achieved.

SIMULATION OF TROLLEBUS STEERING SYSTEM WITH ELECTRIC POWER STEERING BASED ON ROLLING ROTOR SWITCHED RELUCTANCE MOTOR

The analysis of power steering which used on modern rolling stock is carried out. Their main shortcomings are identified. Given the requirements for the steering of trolleybuses, a solution to increase its efficiency is proposed. Based on the developed mathematical model and functional diagrams of the trolleybus steering system with a electric power steering based on rolling rotor switched reluctance motor, a simulation model of trolleybus steering was created using the Matlab Simulink package. The peculiarity of the simulation model is taking into account the mass and size characteristics of the rolling stock, the parameters of the suspension of the steered axle, the impact of the road surface and the speed of the trolleybus, changes in the parameters of the electric motor magnetic system during operation. The rolling rotor switched reluctance motor which is offered for use as the electric power steering of the LAZ E183D1 trolleybus is calculated. The calculation of the magnetic system of the engine by the finite element method with the subsequent approximation of the obtained results is carried out. With the help of the developed simulation model the simulation of the trolleybus steering system with electric power steering based on rolling rotor switched reluctance motor was performed. Time diagrams of transients in the trolleybus steering system are obtained and their processing and analysis are carried out.

Position Estimation of a Two-Phase Switched Reluctance Motor at Standstill

In this paper, a sensorless position detection method of a two-phase switched reluctance motor (SRM) at standstill is proposed based on the voltage pulse injection method. Due to the torque dead zone and the lack of starting capability in the two-phase SRM, a rotor with a stepped structure is adopted to ensure continuous torque generation. The inductance characteristics of the asymmetric SRM are analyzed, and the region of the rotor position is categorized into linear regions and nonlinear regions with several key rotor positions and threshold values of self-inductance. A simple analytical model of the phase self-inductance profile of the asymmetric rotor SRM is proposed, which only requires a few linear equations, to replace the conventional look-up table. A pulse injection-based position estimation method is proposed based on the aforementioned analytical model. Short voltage pulses are injected into both phases at the same time to determine the position where the rotor is actually located at standstill. The proposed position detection method is simple and requires no extra circuitry. The simulation results are given and show the proposed estimation method can acquire a precise rotor position accurately at a standstill condition.

A Full-Period Mathematical Model for a Hybrid-Rotor Bearingless Switched Reluctance Motor

A bearingless switched reluctance motor (BSRM) has the combined characteristics of a switched reluctance motor (SRM) and a magnetic bearing. The hybrid-rotor BSRM (HBSRM) discussed in the paper has a twelve-pole stator and an eight-pole hybrid rotor, which is composed of a cylindrical rotor and a salient-pole rotor. Although the asymmetry of the hybrid rotor makes the structure and magnetic field of the HBSRM more complex, it can always produce a significant amount of magnetic pulling force to levitate a rotor shaft at all the rotor angular positions of each phase, which is not available in a traditional BSRM. The classical mathematical model for a conventional BSRM is valid only when its rotor rotates from the start of the overlap position to the aligned position, and the radial force and torque derived from this model are discontinuous at the aligned positon, which is harmful to the motor’s stable operation. In this paper, a full-period mathematical model on the assumption that the gap permeance is cut apart by straight lines or improved elliptical lines for a 12/8-pole HBSRM is provided. On the basis of this mathematical model, the continuity of the radial force and torque at all the rotor angular positions can be guaranteed, and the fine characteristics of this mathematical model have been verified by simulations.

Torque Ripple Reduction of Switched Reluctance Motor with Non-Uniform Air-Gap and a Rotor Hole

A switched reluctance motor has a very simple structure which becomes its key signature and leads to various advantages. However, because of its double saliency and switching principle, the motor is also known to have a relatively high torque ripple, and this hinders its use as a high-performance drive. In this paper, a method to reduce torque ripple while maintaining average torque is introduced. Two elements are used to achieve this, namely, a non-uniform air-gap on the rotor-pole face and one hole in each non-uniform region, which maintains the saturation level of the air-gap. This approach preserves the mechanical simplicity of the motor and is easy to implement. Simulations and experiments were performed to verify the effectiveness of the proposed design.