Artificial Neural Networks Direct Torque Control of Single Inverter Feed Two Induction Motors

Nowadays the multi-inverter multi-machine conventional system takes a great interest of industrials like railway traction. The implementation of single inverter to dual motor makes all the system cheaper; soft operation, more robust and reliable; This paper is one of control methods proposed in the literature to improve performance of this system, a master slave and average control based in artificial neural networks direct torque control of bi asynchronous motors supplied by single three level inverter NPC is discussed. The result of theoretical analysis is tested with MATLAB SIMULINK environment. And through that, the possibility of DTC single inverter multi-motor system has been verified.

ANALYSIS OF THE STRESS-STRAIN STATE OF AN ASYNCHRONOUS MOTOR WITH A SHORT-CIRCUITED ROTOR UNDER AXIAL LOADS

A comparative description of the most popular and professional 3D modeling packages using the finite element method in solving problems is given. The choice of using the SolidWorks Simulation package at this stage of research is justified. Its main advantages are given. A 3D model of a real functioning asynchronous motor has been designed and modified to perform linear displacement operations. A static analysis of the strength of an asynchronous motor with linear displacement of the actuator using the plug-in module SolidWorks Simulation was performed. A direct analysis of the obtained result of the stress-strain state of the engine is carried out. Conclusions are drawn about its suitability to work with axial loads. The main directions of subsequent research of asynchronous motors with a short-circuited rotor under axial loads are determined.

Comparative research of electrical energy transformation processes in locomotive traction drives with asynchronous motors and series-wound brushed DC motors

An estimate of the Russian railways expenses level for the purchase of fuel and energy resources is given. It is shown the costs for the purchase of electric energy for train traction account for more than half of the total costs. In this regard, the problem of increasing the traction rolling stock energy efficiency seems certainly relevant. The diagram of voltage and current measurements at the primary winding of the AC cargo electric locomotive transformer is given. The experimental data processing algorithm is proposed. A comparative analysis of the results obtained for electric locomotives with series-wound brushed DC motors (throughout what follows will be denoted as BTMs) and asynchronous traction motors (will be denoted as ATMs) showed that the power factor of the asynchronous drive is higher: 0.99, compared to 0.65 for the drive with BTMs; and the coefficient of nonlinear current distortions is only 0.15, compared to 0.53 for the BTMs. The conclusion is made about higher efficiency of electric energy conversion process in asynchronous traction drive in trust mode.

Vector control system of electric traction drive with power losses minimization

Based on the operating conditions analysis of electric traction drives of locomotives, it has been established that the vector control systems for an asynchronous motor fully satisfy all the requirements. On the basis of a T-shaped equivalent circuit, a mathematical model of an induction motor is presented, taking into account losses in the stator steel, the effect of the rotor current and saturation displacement. An algorithm for the formation of the optimal, from the point of view of power losses, task for the rotor flux linkage when using a vector control system with the orientation of the axes of the coordinate system along the rotor magnetic field, is developed. The limiting factors are the limitations on the current and voltage of the motor stator, the diesel generator set power. A shared control system for an electric traction drive with asynchronous motors has been developed, which provides direct control of wheel slip with a subordinate vector control system that minimizes power losses. The results of modeling in a steady-state operation and a start-up mode for an electric traction drive of a two-axle bogie with axial support and 630 kW asynchronous motors with the use of various options for organizing circuit reentrances are presented.

ENERGY SAVING BY REPLACING UNLOADED ENGINES OF NON-STANDARD EQUIPMENT FOR ROLLING STOCK REPAIR

It is established that at various technological processes at repair of a rolling stock of railways electric drives of the universal non-standard equipment can constantly work in essentially underloaded mode that leads to deterioration of their power indicators. The aim of the work is to quantify the reduction of active power losses when replacing constantly underloaded asynchronous motors of unregulated electric drives of universal non-standard technological equipment used in the repair of railway rolling stock with less powerful ones. In this work, the subject of research are the motors of electric drives of this equipment. The analysis of technological processes at repair of a rolling stock, technical characteristics of the specified equipment is carried out and the conclusion is accepted that first of all it is expedient to investigate efficiency of replacement on the equipment of the established engine on less powerful at carrying out at the specialized enterprises of such technological processes warehouse (wheel pairs, traction motors, auxiliary electric machines, frames of rolling stock carts, etc.). The load of the electric motors of transport trolleys of equipment is proposed to be defined as the ratio of the weight of a large unit of electric locomotive, diesel locomotive, electric train and other types of rolling stock to the carrying capacity of universal non-standard equipment of transport trolley. The term "universal" equipment is introduced in the work, which means equipment for performing a certain technological process in the repair of various large units of different types of rolling stock, as well as "specialized enterprise" specializing in the repair of rolling stock, large units which weigh significantly less, than the load-lifting capacity of the transport cart of the equipment. Therefore, the motors of electric drives of universal equipment at these enterprises are constantly operating underloaded. Also actions for quantitative assessment and reduction of active power losses in the electric drive motor are offered.

Sensorless Control of Asynchronous Motor at Low speed

The subject of the submitted paper is to provide a detailed description of simulation control of rotor position sensing of an asynchronous motor by an injection method of high-frequency analogue signal on supply signal frequency of up to 5 Hz, i.e., at zero and low speed. In general, contrary to discrete signal injection, the implementation of the method appears to be simpler for continual signal injection aimed at monitoring of asymmetry of rotary electric machines, however, the process of information gathering related to position of monitored asymmetries during signal reaction processing is more complicated. Genuine verification of the method requires designing a mathematical model of a motor including asymmetries caused by rotor grooving and by magnetic core saturation. The asymmetries occurring in asynchronous motors considerably influence the instant value of a stator induction LS. Asymmetries caused by magnetic circuit saturation were identified and eliminated because of inducing the measured signal distortion. The elimination method LMDEM is the method proposed for repressing the asymmetries. The asymmetries caused by rotor grooving are intended to detect the rotor position. In final part, mathematical functions will be used for converting the signal to rotor position.