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controller). What differences remain between these two categories? Is there a performance gap between PLCs and PACs that users should keep in mind when choosing the best solution for a particular application?
A brief bit of history can put the discussion in context. PLCs were created in the late 1960s to replace relay-based systems. Conceptually they were similar and used ladder logic that mimicked the appearance of wiring diagrams engineers used to represent physical relays and timers, and the connections among them. Early PLCs required dedicated proprietary terminals for programming, had very limited memory, and lacked remote I/O.
By the 1980s, PC-based software was introduced for programming PLCs, which had become faster and had added more features as years passed. Since then, many new technologies have been applied to PLCs, greatly expanding their capabilities on an almost continuous basis.
PACs are relatively new to the automation market, using the term coined by the market research firm ARC in 2001. Since then, there has been no specific agreement as to what differentiates a PAC from a PLC. Some users feel the term PAC is simply marketing jargon to describe highly advanced PLCs, while others believe there is a definite distinction between a PLC and a PAC. In any case, defining exactly what constitutes a PAC isn't as important as having users understand the types of applications for which each is best suited.
References
1. [Electronic resource]: Integrated Publishing. URL: http://www.tpub.com/ (дата обращения: 01.06.2016).
2. [Electronic resource]: Advanced Micro Controls inc. URL: https://www.amci.com/ (дата обращения: 01.06.2016).
Analysis of consumption of electric power the reclamative pumping stations
in the Republic of Uzbekistan Hidirov A.1, Mamasharifov M.2 (Republic of Uzbekistan) Анализ потребления электроэнергии мелиоративными насосными станциями
Республики Узбекистан Хидиров А. А.1, Мамашарифов М. А.2 (Республика Узбекистан)
'Хидиров Абдумалик Абдувохидович / Hidirov Abdumalik — преподаватель; 2Мамашарифов Мансур Алижонович /MamasharifovMansur — студент, кафедра гидравлики и гидроэнергетики, Ташкентский государственный технический университет им. Абу Райхана Беруни, г. Ташкент, Республика Узбекистан
Abstract: in this article questions of energy consumption by pump stations of the Republic of Uzbekistan are considered and it is given general information about the operated pump stations and electric motors. Аннотация: в данной статье рассмотрены вопросы энергопотребления насосными станциями Республики Узбекистан, и даются общие сведения об эксплуатировании насосных станций и электрических двигателей.
Keywords: pump stations, electric motors, melioration, electric power, power, machine irrigation, area, pressure head pipeline, consumption, energy losses.
Ключевые слова: насосные станции, электрические двигатели, мелиорация, электроэнергия, мощность, машинное орошение, площадь, напорный трубопровод, потребление, потери энергии.
If to examine machine irrigation on the whole, then on results our researches it is possible to do next conclusion, weighted average set power of pumps, on 1 ha of machine irrigation in Republic there are 2,1 thousands kW. And in the areas of the Fergana.
Regions Watering squared of earth Using pumping stations Common voltage of pumping station, kVt 1gr square for watering using voltage of pumping, kVt
Andijan 76,9 143 306,7 3,99
Bukhara 583 30 575,2 0,99
Jizzakh 122,.52 29 191,14 1,56
Kashkadarya 565,1 62 670,3 1,8
Navoiy 89,1 32 95,3 1,07
Namangan 164,85 218 562,3 3,41
Samarkand 61,32 88 141,63 2,31
Surkhandarya 262,2 118 642,5 2,45
Sirdarya 119,02 45 69,3 0,85
Tashkent 44,37 133 110,7 2,50
Fergana 126,5 147 268 2,12
Khorezm 68,2 285 70,34 1,03
Karakalpakstan 132,1 273 97,73 0,74
Common on country 2415 1602 3804,2 1,58
Analysis of the modes, undertaken studies, showed exploitations of the pumping stations and cascades of the pumping stations, that the basic consumers of electric power are the large reclamative pumping stations, but to their number it is necessary to take the pumping stations with long pressure pipelines. Appearance and all greater distribution of such pumping stations are related to that mastering of new arrays is attended not only with getting up of water on command marks but also moving of her, on considerable distances from a water source [1].
In a table 2 dependences of change of middle length of one thread of pressure pipeline are presented for the different periods of development of machine irrigation in Republic of Uzbekistan. by pressure pipelines. Appearance and all greater distribution of such pumping stations are related to that mastering of new arrays is attended not only with getting up of water on command marks but also moving of her, on considerable distances from a water source.
Table 2. Dependences of change of middle length of one thread ofpressure pipeline
Years 1965 1975 1985 1995 2005 2015
Pressure tubing large of pumping station, m 1100 1800 2400 2600 2780 2950
As be obvious from a table, in the last few years the size of middle length of one thread of pressure pipeline grew almost in 2,53 time, making 2780 meters. And this process will proceed, with development of machine irrigation in Republic. Most lengths of pressure pipelines are marked in the areas of the Fergana valley. For example, from 48 the most large pumping stations of the Namangan area - 20 stations have pressure pipelines long 2,3 kilometres, on 6 stations length arrives at are 7 kilometres, and on 4 pumping stations - exceeds a 10 km the Analogical indexes are observed in Bukhara, Kashkadarya and row of other areas. The increase of length of pressure pipelines resulted in growth of losses of energy in them on overcoming forces of hydraulic friction. Analysis of actual exploitation of the pumping stations, showed that correlation of losses of electric power is in pressure pipelines, pumps and electric motors, accordingly make:
- pressure pipelines are 956 millions kW/h;
- pumps are 779 millions kW/h;
- electric motors are 308 millions kW/h.
In a table 3. the results of calculations of losses of electric power are presented in the regional managements of the pumping stations [2].
Departure of pumping station Energy consumption of pumping station kVt.h Common losing of energy mln. kVt.h
Notes
A3 A3 m A3 P A3 , pi A3 em
Karakalpakstan 49,9 16,13 1,01 3,53 7,47 3,95 0,20
Andijan 452,3 206,53 12,26 17,60 72,22 101,23 3,23
Bukhara 186,6 76,18 5,03 11,15 29,46 29,86 0,69
Jizzakh 9,3 3,80 0,24 0,63 1,46 1,42 0,05
Kashkadarya 80,6 40,53 2,49 2,17 10,10 25,22 0,55
Navoiy 134,6 56,50 3,19 6,75 14,13 31,39 1,04
Namangan 975,6 420,72 25,87 31,50 147,2 210,47 5,68
Samarkand 142,3 62,28 3,93 7,20 16,26 34,14 0,74
Sirdarya 98,9 30,30 1,91 7,74 14,30 5,99 0,36
Surkhandarya 883,6 302,34 17,69 40,83 135,9 102,59 4,98
Tashkent 89,2 31,08 1,85 4,57 11,51 12,67 0,48
Fergana 353,1 166,53 10,24 12,43 58,33 83,27 2,25
Khorezm 48,9 17,22 0,97 3,88 6,87 5,29 0,32
Amu-Bukhara Magistral river energy departure 1592,5 673,00 38,13 36,89 242,7 309,68 9,64
KarshiMagistral energy departure 2390,2 848,69 49,67 167,9 338,0 279,12 13,99
Mirzacho'l energy departure 257,6 108,09 6,23 11,72 32,09 56,17 1,88
Republic of Uzbekistan 7745,2 3023,9 180,7 366,5 1137,95 1292,7 46,07
ZA3- common energy
A3 — mechanic motor consumption energy m
A3— pumping consumption energy
A3 — pipeline consumption energy pi
A3 — exe mechanic consumtion energy em
Increase of length of pressure pipelines of the pumping stations, conduces not only to the increase of losses of electric power, at water lifton command marks but also puts additional difficulties into the operation of these objects. It is first of all constrained, with possible transients on the pumping stations. Normal technological transients are plugged in itself - starting, stop, switching etc., these processes during correct exploitation do not entail emergency situations. But force, transitional processes caused, for example in the process of work can disconnecting of electric power entail large troubles, by creation of emergency situations. For example, water-hammer in a pressure pipeline.
References
1. Muxammadiev M. M., Urishev B. U. «Hydropower equipment». Textbooks. Tashkent. «Science and Technology», 2013. 150 p.
2. Mamajonov M. «Pumps and pumping stations». Textbook. Tashkent: «Science and Technology», 2013. 167 p.
