Forensic Engineering Investigation of Electrical and Electronic Causes of an Industrial Equipment Failure

This case involved industrial equipment whose repeated, seemingly random failures resulted in the buyer of that equipment suing the seller. The failures had been isolated to a group of several transistors within electro-mechanical modules within the equipment, but the root cause of those transistors failing had not been determined. The equipment seller had more than 1,000 units in the field with no similar failures. And the electro-mechanical module manufacturer had more than 20,000 units in the field with no similar failures. Electrical contractors hired by the buyer had measured power quality, and reported no faults found in the three-phase power at the equipment terminals. This paper presents circuit analyses of the failing electro-mechanical module, basics of electrostatic discharge damage and protection, and the root cause of these failures — an electrical code-violating extraneous neutral-to-ground bond in a secondary power cabinet.

Improving the reliability of the amplification and switching unit of on-board radio telemetry equipment

В настоящей статье представлены научные результаты решения задачи повышения надёжности и технологичности бортовой радиотелеметрической аппаратуры. Рассмотрены 3 варианта решения поставленной задачи и выбран наиболее перспективный - замена ЭРИ на источники вторичного питания. Данный метод показал наиболее высокие характеристики по сравнению с аналогичными методами. Приведённые расчёты наглядно показывают эффективность предложенного метода. This article presents the scientific results of improving the reliability and manufacturability of on-board radio telemetry equipment. We considered 3 variants of the solution of the task and choose the most promising - the replacement of radio elements with secondary power sources. This method demonstrates the highest characteristics compared to similar methods. The above calculation clearly demonstrates the effectiveness of the proposed method.

RESEARCH OF CONDITIONAL DIAGNOSTIC ALGORITHMS MANY SOURCE OBJECTS

Without regard to the swift increase of reliability of element base of modern special communication means actual is a question of providing of their a fitness is to repair, of value of indexes of that regulated by leading documents. Considerable time of permanent repair of special communication means occupies the search of defective elements, that is why important enough improvement of the diagnostic providing. It is arrived at by the use of effective algorithms of searching activity of masters that abbreviate the necessary amount of verifications of the damaged apparatus. It is set that to 30 percent of refuses of special communication means conditioned by disrepairs their sources of secondary power supply, that behave to the class of many source objects. In the article with drawing on modern accomplishments of technical diagnostics and metrology, that was not taken into account before, research possible variants of construction of conditional diagnostic algorithms. Also research their indexes of quality dependin g on the structural features of object of diagnosticating and the brought results over of comparison. The terms of repressing choice of algorithms of search of defects are set on the criterion of a minimum of mean time of renewal, the order of decision of this task is formalized. The got results it is expedient to draw on during development of the diagnostic providing of perspective special communication means, and also and at the improvement of existing. Thus, taken off part of limitations that is used in the known methodologies, that allows to promote efficiency scientifically reasonable practically implemented recommendations in relation to time of proceeding in special communication means at the refuse of their sources of secondary power supply

Diagnostics of secondary power supplies means of communication

The article discusses an approach to technical diagnostics of secondary power supplies for communication facilities. Diagnostics is carried out during the current repair. This takes into account the features of the object being diagnosed, which affect the process of searching for defects. The purpose of the article is to analyze possible options for the development of diagnostic support for secondary power supplies. This takes into account the metrological reliability of measuring equipment. The probability of correct diagnosis is also calculated when searching for defects during routine repairs. Practically implemented recommendations for ensuring the required values of the indicators of the maintainability of communication facilities are substantiated. The possibility and expediency of using effective methods for diagnostics of secondary power supplies of communication facilities, which consider the sources as objects with many inputs, are shown. This allows the design to take into account the requirements for the maintainability of the product. During routine repairs, the time needed to search for defects is minimized. This is done through a rational choice of diagnostic procedures. When choosing, design features and conditions for restoring performance are taken into account. The proposed block diagram of the algorithm for choosing a diagnostic option minimizes the average recovery time of an object. A specific example of using the results obtained in the development of a conditional diagnostic algorithm for the power supply unit of the exciter and the radio receiver of an average power radio station is given. It is advisable to use the results obtained in the development of diagnostic support for promising communication facilities or in the improvement of existing communication facilities without additional costs.

A flexible power management strategy for PV-battery based interconnected DC microgrid

In this paper, a coordinated power-sharing strategy for interconnected DC-microgrid (DC-MG) is proposed. The DC-MG consists of two subgrids with an interlinking bidirectional DC/DC converter (IBDDC). Each subgrid has a secondary-1 controller based on a state of charge (SoC) balancing based droop control strategy of the battery unit (BU). The proposed droop strategy regulates the DC bus voltage according to the SoC of BU. With the SoC balancing based droop method, BU with higher SoC supplies more power to the microgrid (MG) as compared to low SoC BU. The SoC information of batteries in all subgrids is communicated through low bandwidth communication (LBC). In case of failure of LBC, a secondary-2 controller is implemented for the battery controller to regulate the DC bus voltage considering the SoC of BU. Secondary-2 does not depend on the communication line. Considering the levels of DC bus voltages, a secondary power regulating controller is introduced for IBDDC. Further, a coordinated power control strategy is proposed for distributed generation to avoid overcharging of batteries. The whole system operates in a distributed way without a central controller. The proposed strategy has been verified in MATLAB/Simulink.

PROGRAMMING METHOD OF THE MDR32F9Q2I MICROCONTROLLER IN CONTROL AND MONITORING TASKS

Разработана методика, обеспечивающая полный спектр организации работ по программированию микроконтроллера MDR32F9Q2I, которая позволяет получить, в частности, системы управления и мониторинга источников вторичного электроснабжения. Программирование микроконтроллера, построенного на базе высокопроизводительного процессорного RISC ядра ARM, производилось в интегрированной среде разработки Eclipse IDE в операционной системе Windows 10 Pro. Интегрированная среда разработки Eclipse выбрана как наиболее удобная и доступная среда, поддерживает всевозможные типы языков программирования и непрерывную компиляцию. В настоящее время 16- и 32-битные микроконтроллеры быстро набирают популярность в сфере промышленных задач. Их применение обусловлено постоянно возрастающей сложностью задач, жесткими требованиями к производительности интегрируемых контроллеров управления, необходимостью иметь в электронных устройствах развитые органы пользовательского управления. Представленный стенд для моделирования, использующий интерфейсный мост между шинами I2C и 1-Wire - DS2482-100, преобразует протоколы между управляющим I2C микроконтроллером (мастером) и ведомыми 1-Wire устройствами, а также контролирует скорости нарастания и уменьшения напряжения в линии. Основой для написания класса DS2482 являются заголовочные файлы Arduino.h и OneWire.h, которые находятся в свободном доступе In this article, we developed a technique that provides a full range of organization of works on programming the MDR32F9Q2I microcontroller, which allows you to obtain control and monitoring systems for secondary power supply sources. The microcontroller based on the high-performance ARM RISC processor core was programmed in the Eclipse IDE on the Windows 10 Pro operating system. We chose the Eclipse integrated development environment as the most convenient and accessible environment, it supports all kinds of programming languages and continuous compilation. Currently, 16- and 32-bit microcontrollers are rapidly gaining popularity in the field of industrial tasks. Their use is due to the ever-increasing complexity of tasks, stringent requirements for the performance of integrated controllers, the need to have advanced user controls in electronic devices. We present a simulation stand that uses an interface bridge between the I2C and 1-Wire buses - DS2482-100, converts protocols between the I2C microcontroller (master) and 1-Wire slaves, and also controls the voltage rise and fall rates in the line. The basis for writing the DS2482 class is the Arduino.h and OneWire.h header files, which are freely available