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Abstract

Contents

Introduction

Development and implementation of new algorithms identify, control and surveillance various electromechanical systems are inextricably linked to the stage of full-scale tests, working off of individual components and the whole system, verification and correction of the basic ideas and models that formed the basis of theoretical research. In the synthesis of control systems for complex electromechanical systems multimass with elastic and non-linear elements necessary mathematical models adequately real system. The reliability of the results obtained during the synthesis of control systems for complex electromechanical multimass Objects can be scanned only when dealing with a real object. One approach to solving this problem is the use of stands that mimic the structure of a control object. At the same time, the original debugging controls and comparing their performance work in conditions close to real, is performed at such a stand, containing all the necessary elements. Research stands for debugging software management systems transducers allowing for the kinematic relations between the drive motor and the driven machine are produced by many electrical companies. However, the cost of such stands is many times the initial cost of production of converters and motors.

1. Objectives and tasks of the study

The aim of this work is to develop mathematical models and methods of synthesis of two-mass regulator Stand electromechanical system, and a study of dynamic characteristics of the synthesized control system stand two-mass electromechanical system.

2.Key questions that need to be resolved in this work:

3.The structure of the stand for Research

The test is designed for complete electric vector control synchronous motor with permanent magnets (PMSM). Schematic representation of the laboratory complex is shown in Fig. 1.

Fig. 1 - Laboratory for the study of complex vector control system PSDM

It consists of two electric cars: SDP Dutymax DS type R95DCS300AAA and DC motor (DPT) independent excitation 112L-4MGV, mounted on the same shaft and rigidly connected to each other. DPT is used as a loading machine for the synchronous motor. SDP is used to control the frequency inverter Unidrive SP1404, and to control the DPT - thyristor converter MENTOR II. An integral part of the transducers are embedded controllers, which are designed to implement basic control algorithms provided by the developers. The frequency converter is equipped with well coprocessor module SM-Application, and thyristor converter - module MD29. Both of these additional modules designed to implement user applications. SM-Application module is based on high-performance specialized processor, equipped with a Flash-memory capacity of 384kb, 80Kb RAM capacity. Module MD29, implemented on a 32-bit RISC-processor INTEL 960; It has 96 Kbytes of flash memory and 8 Kbytes of RAM. In the case of a synchronous machine installed position transmitter resolver. Contact position sensor with a frequency converter via the optional module SM-Resolver. With Hi-Speed CT-Net enables communication between the drive and the computer is also included in the stand and intended for programming of additional modules in the medium SyPT-Pro and maintenance of the virtual oscilloscope ST-Scope in real time [1].

4. Real-time operating systems

Control of electromechanical systems is significantly different from the usual data on the computer. This processing follows the events in the object of control. Digital control system must be fast enough to respond to external events and are constantly processing the input data stream, often without being able to change the speed of their arrival. The same time the system should provide and perform the other, the auxiliary functions – information exchange, processing, preservation and archiving of data, its display, an appropriate response to certain signals, etc. For real-time a mode of computing devices, using special programming techniques because of features inherent in this mode. These features include the fact that real-time system contains not one but several programs, each of which is responsible for solving a particular task, and the relationship between these programs can be very difficult. In addition, the order of the commands of the real time program can not be determined in advance, since it depends on external events and can be changed by interrupts. Therefore, the time required to compute each cycle of operation may vary considerably [3].

The basic requirements for real-time are as follows:

To provide real-time operating systems can be implemented the following requirements [4, 5]:

The most common in the programmable logic controllers and computers for solving problems of automation are operating systems Windows CE, QNX and ОS-9.

5. The principle of implementation of real-time program control

Consider the implementation of the principle of program control in real-time coprocessor module SM-Application, which is used to control the frequency converter (Control Techniques). User application consists of separate sections (tasks) that are executed in strict sequence. These sections are (in order of priority): Initial, Event, Pos, Clock and Background . When power is applied first to the statements recorded in the section Initial, which are given values of constants and initial values of the signal control system, and is defined by its configuration. After that, begin to run real-time tasks of section Pos (there may be several such Pos0 and Pos1) and Clock. Instructions are placed in these sections, cyclically repeated at fixed intervals of time (discrete periods). The period for the discrete task Clock (T∂1) can take integer values from 1 to 200 ms, and for tasks Pos0 and Pos1 (T∂2) – strictly fixed values: 250 ms, 500 ms, 1 ms, 2 ms, 4 ms and 8 ms.

Regulations sections Event have the highest priority, so their task contain very small number of instructions. They interrupt the operation of section Pos and Clock, and only at the end of their performance management program continues the interrupted instruction sections Pos and Clock. Thus, in the sections Event advisable to put the algorithms of certain events, such as emergency situations.

Background – is a background task. It runs only in the pauses between the instructions of the other sections. This task is organized in the form of an infinite loop. If it is completed, it will no longer run.

In figure 2 introduced the concept of mutual termination of tasks [6].

Time diagram of the implementation specific instructions

Figure 2 – Time diagram of the implementation specific instructions

(animation: 7 frames, 7 cycles, 20 kilobytes)

Conclusions

In writing this essay master's work is not yet complete. Final completion: December 2015. The full text of work and materials on the topic can be obtained from the author or his manager after that date. It will be held a series of experiments, research and refinement of the available results.

list sources

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