Optimization of Maintenance and Use of Gensets in the Armed Forces

The Armed Forces use a great number of various types of gensets. The aim is to reduce this large number of diverse genset types, that is, to standardize the equipment used with the aim of simplifying maintenance and modes of use. For this reason, tests are conducted which should provide factual conclusions as to the types of gensets which are both most favourable for use and maintenance and also meet the conditions required by international military operations. One of these requirements is the possibility of using the kerosene fuel F-34 for diesel engines. It is well known that diesel engines running on kerosene fuel develop less power, which can result in the direct reduction of generator rotation speed at rated loads. Therefore, we conducted tests on one type of electric genset by using resistor load. The additional goal was to conduct tests on other types of electric motors by using different types of loads. It was particularly important to conduct the tests during the acceleration of an asynchronous motor since gensets are also used in technical workshops to run compressor units and in these instances asynchronous motors often turn on. So, in order to facilitate conductivity, we also developed mathematical models and computer simulation

Exploring the Possibilities of Adjusting Gensets to NATO Requirements

Stationary and mobile gensets are used in the Armed Forces of the Republic of Croatia. In this research, priority was given to mobile gensets which have a variety of uses. In addition to being used in the Republic of Croatia, the mobile gensets are also used in international military operations in various modes of operation. Therefore, it is necessary to be very familiar with their characteristics and the possibility of adjusting them to NATO requirements. For the purpose of the adjustment, a test was performed on a P-B40.R1 genset. A model that simulates the genset behaviour with different tested fuels was developed. The investigated genset, together with some others, was introduced into the Armed Forces pursuant to the Product Quality Protocol that was in force during the 1990s. The Protocol did not cover all requirements and recommendations for the genset operation in an international military environment. Therefore, research was conducted, which has resulted in the adjustment of the equipment and in the harmonisation of the Product Quality Protocol with the ISO standard and NATO requirements. When adjusting the materiel, special emphasis is given to defining certain genset types that are able to use the modified F-34 kerosene-type fuel instead of diesel fuel. The F-34 fuel is obtained from kerosene used in aviation; this fuel can be easily obtained in international military operations where the tendency is to use the same type of fuel for airplanes, vehicles, and diesel engine equipment. When F-34 is used as the genset fuel, the quality of the generated electrical energy might be reduced. For the purpose of bringing the output characteristics of the generator within prescribed limits, simulations were performed both with and without the tuning of the regulation parameters

Modelling of an Expert System for Diagnosing the Operational Status of a Diesel Genset

The modelling of an expert system for diagnosing the operational status of a diesel genset represents the final stage of the research undertaken so far on military gensets. The research was undertaken in several stages on a large number of gensets, and the results obtained at specific research stages were published at scientific-expert conferences. For the purpose of modelling an expert system, a knowledge base was compiled based on detailed observation of the genset operational status, interviews with experts with many years of experience in maintaining military gensets and also on a breakdown of the occurred faults archived in the overhaul documentation.The paper uses only that one segment of the knowledge base that is necessary for modelling a simplified form of the Bayesian network for fault detection in assembled condition. In addition to input probabilities, the results of diagnostic tests and simulations carried out in the Matlab Simulink program package are also entered in the Bayesian network. Fault detection represents a complex process so the application of an expert system significantly reduces the time needed for fault detection, resulting in optimized maintenance. It is especially significant in military and similar organizations which apply a large number of technical resources. The Bayesian network is processed in the GeNIe program package

Modernisation of mobile gensets

Mobilni elektroagregati namijenjeni su za napajanje potrošača električnom energijom u terenskim uvjetima. Neophodni su pri nastanku većih šteta i kvarova na infrastrukturi do kojih dolazi u slučaju elementarnih nepogoda i ratnih djelovanja. Stoga je značajna njihova pouzdanost i učinkovitost, kako u civilnim tako i vojnim strukturama. Provedbom modernizacije pojednostavljuje se uporaba i održavanje te proširuje mogućnost njihove primjene. To rezultira uštedom financijskih sredstava što predstavlja značajan iznos, naročito u vojnim sustavima gdje se pojavljuje velik broj elektroagregata. Sagledavanjem stanja utvrđeno je da se radi o sredstvima koja nisu opremljena učinkovitim sustavima za zaštitu i upravljanje. Za potrebe modernizacije provedena je detaljna analiza i snimanje karakteristika senzora za prikupljanje informacija, što je uz stvaranje baze znanja i obradu informacija težište ovoga rada. Informacije prikupljene sa senzora obrađuju se u sklopu za zaštitu i upravljanje koji na principu ekspertnog sustava, Bayesovom metodom određuje vjerojatnost pojave određenog stanja elektroagregata. Temeljem obrađenih informacija utječe se na rad zaštitno upravljačkih sklopova.Mobile gensets are designed for supplying consumers of electric power in outdoor environments. They become necessary in case of some major damage or malfunction of the infrastructure that may occur in the event of natural disasters or military operations. For this reason, their reliability and efficiency is of critical importance, both for civilian and for military structures. By modernising them, we could simplify their use and maintenance and extend the scope of their application. That would result in reduced costs which are considerable, especially when it comes to military systems where a large number of mobile gensets is used. After having examined their condition, it was determined that the equipment in question does not contain effective protection and control systems. For the purpose of modernisation, a detailed analysis and screening of the characteristics of data collection sensors was carried out, which, along with the development of a knowledge base and data processing, is the focus of this paper. The data gathered from the sensors are processed in the protection and control system, which, through the application of the expert system principle, and the Bayesian method determines the likelihood of the appearance of a particular condition in mobile gensets. Based on the processed data, the operation of the protection and control circuits can be modified

Optimisation of gensets maintenance in complex systems

Kroz rad je prikazan proces optimizacije održavanja elektroagregata u složenim sustavima. U početnoj fazi istraživanja sagledane su metode održavanja vojne tehnike i proveden vizualni pregled na približno 25% elektroagregata koji se koriste u Oružanim snagama Republike Hrvatske. Pri tome je utvrđeno da postoji velik broj različitih tipova elektroagregata što otežava primjenu i održavanje. Zbog toga se predlaže smanjenje broja različitih tipova. Da bi se proveo pravilan odabir elektroagregata definirana su ispitivanja kojima se određuju svojstveni pokazatelji. Temeljem dobivenih pokazatelja elektroagregati se kategoriziraju, odnosno svrstavaju u određene skupine prema ISO 8528. Osim zahtjeva definiranih u Protokolima o kvaliteti proizvoda i ISO 8528 pojavljuju se i dodatni zahtjevi vezani uz mogućnost primjene sredstava u međunarodnim vojnim operacijama gdje se pojavljuju različiti režimi rada. Jedan od dodatnih zahtjeva je mogućnost primjene kerozinskog goriva F-34 za pogon dizel elektroagregata. Radi se o specifičnom zahtjevu koji u nekim slučajevima može imati negativan utjecaj na izlazne karakteristike elektroagregata. Kako bi se provjerio utjecaj kerozinskog goriva na izlazne karakteristike provedeno je ispitivanje na elektroagregatu P-B40.R1. Osim ispitivanja provedene su i simulacije u programskom paketu Matlab Simuklink iz kojih je vidljivo da se podešavanjem parametara elektroagregata može utjecati na smanjenje nastale razlike izlaznih karakteristika generatora pri uporabi različitih vrsta goriva. Kod složenih tehničkih sredstava, kao što su elektroagregati, velik dio vremena u procesu održavanja odnosi se na utvrđivanje tehničkog stanja, odnosno detekciju kvara. Kako bi se skratilo vrijeme utvrđivanja kvara razvija se Ekspertni sustava za detekciju čija je zadaća na temelju lako uočljivih neispravnosti u sklopljenom stanju definirati mjesto teško detektirajućeg kvara i time dati značajan doprinos u optimizaciji održavanja. Rad ekspertnog sustava zasniva se na Bayesovoj metodi. Rezultati provedenih mjerenja, simulacija i Ekspertnog sustava za detekciju kvara koriste se u postavljanju kriterija za odabir optimalnih tipova elektroagregata prema ekonomskim kriterijima i kriterijima raspoloživosti. Odabir se provodi AHP metodom uz primjenu programskog paketa Expert Choice.The paper presents the process of genset maintenance optimization in complex organizations. In the initial stages of research, military technology maintenance methods were reviewed, and a visual inspection was conducted on approximately 25 % of gensets used in the Military Forces of the Republic of Croatia. It was found that a large number of different types of gensets were in use making application and maintenance more difficult. It is therefore suggested to reduce the number of different types. To select the genset correctly, tests have been defined for the purpose of establishing the specific genset indicators. Based on the established indicators, gensets are classified, that is, grouped according to ISO 8528. In addition to the requirements defined in Product Quality Protocols and ISO 8528, there are additional requirements related to the possibility of using the devices in international military operations where different operating modes appear. One of the additional requirements is the possibility of using F-34 kerosene fuel for powering diesel gensets. This is a specific requirement which can have a negative impact on the genset’s output characteristics. To verify the impact of kerosene fuel on the output characteristics, a test was conducted on the P-B40.R1 genset. In addition to the tests, simulations were carried out in the MatlabSimuklink software package showing that an adjustment of the genset’s parameters can contribute to minimizing the resulting difference in the genset’s output characteristics where different types of fuel are used. In complex technical devices, such as gensets, a large portion of time in the maintenance process relates to the identification of the technical condition, that is, to detecting the defect. To minimize defect identification time, an expert detection system is being developed aiming to use the evident irregularities in assembled condition to define the location of a defect which is difficult to detect and thus contribute to maintenanceoptimization. The expert system workson the basis of the Bayes method. The results of the measurements, simulations and the defect detection expert system are used to define the criteria for selecting the optimum genset types according to economic and availability criteria. The selection is carried out based on the AHP method with the application of the Expert Choice software package

Optimisation of gensets maintenance in complex systems

Kroz rad je prikazan proces optimizacije održavanja elektroagregata u složenim sustavima. U početnoj fazi istraživanja sagledane su metode održavanja vojne tehnike i proveden vizualni pregled na približno 25% elektroagregata koji se koriste u Oružanim snagama Republike Hrvatske. Pri tome je utvrđeno da postoji velik broj različitih tipova elektroagregata što otežava primjenu i održavanje. Zbog toga se predlaže smanjenje broja različitih tipova. Da bi se proveo pravilan odabir elektroagregata definirana su ispitivanja kojima se određuju svojstveni pokazatelji. Temeljem dobivenih pokazatelja elektroagregati se kategoriziraju, odnosno svrstavaju u određene skupine prema ISO 8528. Osim zahtjeva definiranih u Protokolima o kvaliteti proizvoda i ISO 8528 pojavljuju se i dodatni zahtjevi vezani uz mogućnost primjene sredstava u međunarodnim vojnim operacijama gdje se pojavljuju različiti režimi rada. Jedan od dodatnih zahtjeva je mogućnost primjene kerozinskog goriva F-34 za pogon dizel elektroagregata. Radi se o specifičnom zahtjevu koji u nekim slučajevima može imati negativan utjecaj na izlazne karakteristike elektroagregata. Kako bi se provjerio utjecaj kerozinskog goriva na izlazne karakteristike provedeno je ispitivanje na elektroagregatu P-B40.R1. Osim ispitivanja provedene su i simulacije u programskom paketu Matlab Simuklink iz kojih je vidljivo da se podešavanjem parametara elektroagregata može utjecati na smanjenje nastale razlike izlaznih karakteristika generatora pri uporabi različitih vrsta goriva. Kod složenih tehničkih sredstava, kao što su elektroagregati, velik dio vremena u procesu održavanja odnosi se na utvrđivanje tehničkog stanja, odnosno detekciju kvara. Kako bi se skratilo vrijeme utvrđivanja kvara razvija se Ekspertni sustava za detekciju čija je zadaća na temelju lako uočljivih neispravnosti u sklopljenom stanju definirati mjesto teško detektirajućeg kvara i time dati značajan doprinos u optimizaciji održavanja. Rad ekspertnog sustava zasniva se na Bayesovoj metodi. Rezultati provedenih mjerenja, simulacija i Ekspertnog sustava za detekciju kvara koriste se u postavljanju kriterija za odabir optimalnih tipova elektroagregata prema ekonomskim kriterijima i kriterijima raspoloživosti. Odabir se provodi AHP metodom uz primjenu programskog paketa Expert Choice.The paper presents the process of genset maintenance optimization in complex organizations. In the initial stages of research, military technology maintenance methods were reviewed, and a visual inspection was conducted on approximately 25 % of gensets used in the Military Forces of the Republic of Croatia. It was found that a large number of different types of gensets were in use making application and maintenance more difficult. It is therefore suggested to reduce the number of different types. To select the genset correctly, tests have been defined for the purpose of establishing the specific genset indicators. Based on the established indicators, gensets are classified, that is, grouped according to ISO 8528. In addition to the requirements defined in Product Quality Protocols and ISO 8528, there are additional requirements related to the possibility of using the devices in international military operations where different operating modes appear. One of the additional requirements is the possibility of using F-34 kerosene fuel for powering diesel gensets. This is a specific requirement which can have a negative impact on the genset’s output characteristics. To verify the impact of kerosene fuel on the output characteristics, a test was conducted on the P-B40.R1 genset. In addition to the tests, simulations were carried out in the MatlabSimuklink software package showing that an adjustment of the genset’s parameters can contribute to minimizing the resulting difference in the genset’s output characteristics where different types of fuel are used. In complex technical devices, such as gensets, a large portion of time in the maintenance process relates to the identification of the technical condition, that is, to detecting the defect. To minimize defect identification time, an expert detection system is being developed aiming to use the evident irregularities in assembled condition to define the location of a defect which is difficult to detect and thus contribute to maintenanceoptimization. The expert system workson the basis of the Bayes method. The results of the measurements, simulations and the defect detection expert system are used to define the criteria for selecting the optimum genset types according to economic and availability criteria. The selection is carried out based on the AHP method with the application of the Expert Choice software package

Optimisation of gensets maintenance in complex systems

Kroz rad je prikazan proces optimizacije održavanja elektroagregata u složenim sustavima. U početnoj fazi istraživanja sagledane su metode održavanja vojne tehnike i proveden vizualni pregled na približno 25% elektroagregata koji se koriste u Oružanim snagama Republike Hrvatske. Pri tome je utvrđeno da postoji velik broj različitih tipova elektroagregata što otežava primjenu i održavanje. Zbog toga se predlaže smanjenje broja različitih tipova. Da bi se proveo pravilan odabir elektroagregata definirana su ispitivanja kojima se određuju svojstveni pokazatelji. Temeljem dobivenih pokazatelja elektroagregati se kategoriziraju, odnosno svrstavaju u određene skupine prema ISO 8528. Osim zahtjeva definiranih u Protokolima o kvaliteti proizvoda i ISO 8528 pojavljuju se i dodatni zahtjevi vezani uz mogućnost primjene sredstava u međunarodnim vojnim operacijama gdje se pojavljuju različiti režimi rada. Jedan od dodatnih zahtjeva je mogućnost primjene kerozinskog goriva F-34 za pogon dizel elektroagregata. Radi se o specifičnom zahtjevu koji u nekim slučajevima može imati negativan utjecaj na izlazne karakteristike elektroagregata. Kako bi se provjerio utjecaj kerozinskog goriva na izlazne karakteristike provedeno je ispitivanje na elektroagregatu P-B40.R1. Osim ispitivanja provedene su i simulacije u programskom paketu Matlab Simuklink iz kojih je vidljivo da se podešavanjem parametara elektroagregata može utjecati na smanjenje nastale razlike izlaznih karakteristika generatora pri uporabi različitih vrsta goriva. Kod složenih tehničkih sredstava, kao što su elektroagregati, velik dio vremena u procesu održavanja odnosi se na utvrđivanje tehničkog stanja, odnosno detekciju kvara. Kako bi se skratilo vrijeme utvrđivanja kvara razvija se Ekspertni sustava za detekciju čija je zadaća na temelju lako uočljivih neispravnosti u sklopljenom stanju definirati mjesto teško detektirajućeg kvara i time dati značajan doprinos u optimizaciji održavanja. Rad ekspertnog sustava zasniva se na Bayesovoj metodi. Rezultati provedenih mjerenja, simulacija i Ekspertnog sustava za detekciju kvara koriste se u postavljanju kriterija za odabir optimalnih tipova elektroagregata prema ekonomskim kriterijima i kriterijima raspoloživosti. Odabir se provodi AHP metodom uz primjenu programskog paketa Expert Choice.The paper presents the process of genset maintenance optimization in complex organizations. In the initial stages of research, military technology maintenance methods were reviewed, and a visual inspection was conducted on approximately 25 % of gensets used in the Military Forces of the Republic of Croatia. It was found that a large number of different types of gensets were in use making application and maintenance more difficult. It is therefore suggested to reduce the number of different types. To select the genset correctly, tests have been defined for the purpose of establishing the specific genset indicators. Based on the established indicators, gensets are classified, that is, grouped according to ISO 8528. In addition to the requirements defined in Product Quality Protocols and ISO 8528, there are additional requirements related to the possibility of using the devices in international military operations where different operating modes appear. One of the additional requirements is the possibility of using F-34 kerosene fuel for powering diesel gensets. This is a specific requirement which can have a negative impact on the genset’s output characteristics. To verify the impact of kerosene fuel on the output characteristics, a test was conducted on the P-B40.R1 genset. In addition to the tests, simulations were carried out in the MatlabSimuklink software package showing that an adjustment of the genset’s parameters can contribute to minimizing the resulting difference in the genset’s output characteristics where different types of fuel are used. In complex technical devices, such as gensets, a large portion of time in the maintenance process relates to the identification of the technical condition, that is, to detecting the defect. To minimize defect identification time, an expert detection system is being developed aiming to use the evident irregularities in assembled condition to define the location of a defect which is difficult to detect and thus contribute to maintenanceoptimization. The expert system workson the basis of the Bayes method. The results of the measurements, simulations and the defect detection expert system are used to define the criteria for selecting the optimum genset types according to economic and availability criteria. The selection is carried out based on the AHP method with the application of the Expert Choice software package