Abstract

Developing a methodology and algorithms for statistical process control and diagnostics of electric engines in a distributed control system

Content

Topicality

Presently, a difficult power equipment, which requires permanent control for prevention of emergency situations, is widely used in industry. The cost of its maintenance and downtime much higher than the cost of systems that can prevent an accident or significantly reduce the damage. Application of modern computing systems can solve problems of different nature, such as monitoring parameters of controlled objects, optimizing operating modes, determining the optimal condition, predict the development of the equipment.

The most common mechanisms of power are electric engines. In real conditions of production, they are highly susceptible to wear due, because of heavy terms of usage. To control the engine parameters, for monitoring and protection, can be used standalone devices AZD, AZD-K, KORD.U developed by AMI LTD [1].

The device of defence of electric engines AZD provides defence of engine at next emergency situations:

• not finished starting
• technological overload;
• jamming (overturn);
• breakage phase power.

The device of defence and control of electric engines KORD.U depending on the performed function has several options of implementation:

• KORD.U1 - to protect the engine at start-up and overturn;
• KORD.U2 - to protect the engine of technological overload;
• KORD.U3 - combines the functions of KORD.U1 and KORD.U2;
• KORD.U4 - KORD.U3 and serves as an additional maximum-current protection.

The device of defence of electric engines, based on the microcontrollers of AZD-K provides performance enhanced features compared to AZD. Possibility to realize new functions and more flexible algorithms of control and defence of engines appeared due to the use of microcontroller. The functions of engine protection, which performed by the device in case various situations are listed below:

• not finnished starters;
• technological overload;
• jamming (overturn);
• non-fullphase operations (AZD-K 2)
• breakage phase power (AZD-K 2) (operation of the device in the vanishing current in one or two phases);
• loss of productivity ("dry fly pump");
• overheating;
• reduction of insulation resistance to earth (at work with the sensor leakage to earth type DUZ1).
• device with an external device display allows to visualize some engine parameters.

However, such devices do not allow for automated and operational control of the electric engine of the operator's workplace. Furthermore, there is an opportunity to receive and store information about operating conditions and status of engines for a long period does not allow the trend of deterioration and to predict remaining life. With an increasing number of engines increases considerably the complexity of control.

The purpose and tasks of work

The purpose of this work is to solve problems and identify trends wear prediction residual life of the engine, permanent control, storage conditions and operating conditions for a long time. Ways of increasing efficiency of operation of electric engines is possible with the proposed automated system (ACS), whose structure is presented in Figure 1.

Tasks which need to be decided during master's work are:

• Control of the engine status
• Diagnostic techniques and algorithms based on statistical data
• Techniques and algorithms for predicting results based on statistical data
• Creating practical implementation of the server PCS

The scientific novelty and planned practical value

Scientific novelty:

• The general going near realization of the model system is offered
• Has been developed technique and algorithms for diagnosis
• Has been developed technique and algorithms for statistical control
• Comparative evaluation of existing algorithms protection and diagnostics of electric engines has been performed

Practical value: Using the methods of diagnosing the technical state of engines allows to perform the timely detection of defects arising during the operation, the costs associated with hardware failure of electric engines could be minimized, as well as the transition from routine preventive maintenance to the service system for state. The results of this investigation can be used in the developing of electric machine protection system and automated control systems for manufacturing application working product.

The results of the master's work

In this work consider two methods for protection electric engine: power (voltage control, current control, temperature control engine) and statistical (gathering and storage information about characteristics of energetic performance, forecasting changes in power characteristics, diagnostic of status)

These two methods give reliable protection from engine accidents, and may indicate a violation of it`s conditions of usage. The energy method will be realized promptly, and statistical work begins only after the accumulation of sufficient input data.

Conclusion

As a result of work at the moment, has been created a theoretical model of gathering information system and engine control in industrial conditions. The question of protocols of a transport level of communication of data is subject a further revision and deepening in the designed variant of network. There are currently close to completion the theoretical model of the intellectual protection system for three-phase electric engine. Most of the set tasks to achieve the goal theoretically permitted, but require laboratory and experimental verification.

List of Literature

• Аппараты защиты и контроля электродвигателей http://azd.ami.ua
• Ласкутов А. Релейная защита электродвигателей
• Божкова С.Обнаружение неисправностей в электрических сетях.
• Томас Кюгельштадт. Защита узлов шин от переходных процессов. http://i.cmpnet.com/industrialcontroldesignline/2009/..Nodes.pdf
• Техническая коллекция Schneider Electric. Руководство по организации сети Modbus. – 2007 www.schneider-electric.ru.
• Яшкардин В. RS-485 рекомендованный стандарт электрических характеристик генераторов и приемников для использования в балансных многоточечных системах. – 2009 www.softelectro.ru.
• Гребченко Н.В., Сидоренко А.А., Бельчев И.В., Метод определения параметров изоляции присоединений электродвигателей, имеющих статическую и динамическую несимметрию // Наукові праці Донецького нац. тех. університету Серія: Електротехніка і енергетика, випуск 9(128): Донецьк: ДВНЗ «ДонНТУ». - 2009. - c. 58-65.
• Ульянов С.А. Электромагнитные переходные процессы в электрических системах. – М.: Энергия, 1970. – 520 с.
• Сергиенко А.Б. Цифровая обработка сигналов. – СПб., Питер, 2002. - 608 с. ил.
• Метод ударных импульсов SPM для диагностики условий работы и состояния подшипников качения

Remark

Master`s final work is not completed at the moment of writing esse. Date of final completion of work: December 1, 2011. Full text of the work and materials on the topic of work can be obtained from the author or his scientific adviser after that date.