Theme: unusual railways

I THEME: POWER SUPPLY SYSTEM

(1) Nowadays technical progress, including the progress in railway engineering, is unthinkable without the proper power supply system.

(2) Till recent years, all electric energy has been gene­rated by thermal and hydro-power stations. But the hydro-power stations are always tied to rivers As for the thermal power plants the supplies of fuel needed for their operation are not inexhaustible. So power engineers are now in search of new sources of energy.
(3) The great efforts of scientists and engineers have resulted in discovering atomic energy which caused a revo­lution in energetics.
(4) One of the most significant achievements in the devel­opment of atomic power engineering was made in the Soviet Union in 1954 with the construction of the world's, first atomic power plant (A-power plant). On being put into operation it opened up an epoch of peaceful uses of nuclear energy. [Now the atomic power stations have passed an experimental stage and successfully compete with the con­ventional power stations especially in the countries which experience the energy crisis.
(5) The main and most remarkable feature of nuclear fuel is that it contains great thermal energy. Indeed, one ton of nuclear fuel is equal to more than 2.5 million tons of coal. Nuclear fuel reduces the cost of electric energy and saves valuable raw materials for other uses.
(6) It goes without saying¹ that nuclear energetics is faced with a bright future and very soon we may expect its being turned into the main source of power supply.
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(7) However, there are a number of problems the sci­entists must solve in order to make the A-power plants still more attractive, one of these problems being the disposal of radioactive by-product should be placed in special containers and safely buried deep under the ground or on the ocean bottom.
(8) While discussing of the A-power plants one should also mention the danger of accumulating radioactivity by the working personnel.
(9) In order to provide greater reliability of opera­tion and safety for people modern A-power plants are automatically controlled. Boilers, reactors, turbines and other equipments are operated from the plant's control room where there are batteries of dials and records giv­ing the operators a second-by-second picture of every­thing what is happening. Electronic robots, manipulators and mechanical hands which are able to measure, could and touch are now indispensable for handling radioactive elements² at A-power plants. Automatic sound warning is given as soon the slightest fault occurs, and light shows exactly where the fault is located. A special system enables the operator to direct all the processes any possible trouble.
(10) After having been generated, the electric energy is sent to the electricity grid system³ of the country. It is the grid system that distributes the power to the consumers, including the electrified railways.
(11) Both conventional and nuclear power stations gen­erate a high voltage alternating current, (a. c.). The fact' is that the alternating current can be more economically transmitted over long distances than the , direct current, (d. c.) and higher the voltage the less energy is lost.
(12) Although the alternating current, can be used to drive trains, in many countries it is converted to the di­rect current because d. с motors are simpler in construc­tion than a. c. machines.
(13) As is known, the conversion of а. с to d. с_. takes place in railway substations. The first essential of a sub­station is a transformer in which the electric current taken from the transmission line is lowered in voltage. Another important instrument the substation is fitted with is a rectifier which converts a. c. to d. c, this one-way (i. e. direct) current being then fed to the overhead wire.
(14) Electronics has found a wide application in railway substations, silicon rectifiers being one of the most commonly used electronic instruments. Due to electronics most substations are now operated by remote control.
(1) Hozirgi vaqtda texnik taraqqiyotni, shu jumladan temir yo'l qurilishidagi taraqqiyotni to'g'ri elektr ta'minoti tizimisiz tasavvur qilib bo'lmaydi.
(2) So'nggi yillargacha barcha elektr energiyasi issiqlik va gidroelektr stansiyalari tomonidan ishlab chiqarilgan. Ammo GESlar doimo daryolarga bog'langan IESlarga kelsak, ularning ishlashi uchun zarur bo'lgan yoqilg'i zahiralari bitmas-tuganmas. Shunday qilib, energetiklar endi energiyaning yangi manbalarini qidirmoqdalar.
(3) Olimlar va muhandislarning katta sa'y-harakatlari natijasida energetikada inqilobga sabab bo'lgan atom energiyasi kashf qilindi.
(4) Atom energetikasi rivojlanishidagi eng muhim yutuqlardan biri 1954 yilda Sovet Ittifoqida dunyodagi birinchi atom elektr stantsiyasining (A-elektr stansiyasi) qurilishi bilan erishildi. U ishga tushirilishi bilan atom energiyasidan tinch maqsadlarda foydalanish davrini ochdi. [Hozirda atom elektr stansiyalari eksperimental bosqichdan oʻtib, anʼanaviy elektr stansiyalari bilan, ayniqsa, energetika inqirozini boshidan kechirayotgan mamlakatlarda muvaffaqiyatli raqobatlashmoqda.
(5) Yadro yoqilg'ining asosiy va eng ajoyib xususiyati shundaki, u katta issiqlik energiyasini o'z ichiga oladi. Darhaqiqat, bir tonna yadro yoqilg'isi 2,5 million tonnadan ortiq ko'mirga teng. Yadro yoqilg'isi elektr energiyasining tannarxini pasaytiradi va boshqa maqsadlarda foydalanish uchun qimmatbaho xom ashyoni tejaydi.
(6) O'z-o'zidan ayonki1, yadro energetikasi porloq kelajak oldida turibdi va tez orada biz uni energiya ta'minotining asosiy manbaiga aylantirishni kutishimiz mumkin.
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(7) Biroq, A-elektr stansiyalarini yanada jozibador qilish uchun olimlar hal qilishlari kerak bo'lgan bir qator muammolar mavjud, bu muammolardan biri radioaktiv qo'shimcha mahsulotlarni maxsus idishlarga joylashtirish va xavfsiz tarzda joylashtirishdir. yer ostida yoki okean tubida chuqur ko'milgan.
(8) A-elektr stansiyalari haqida gapirganda, ishchi xodimlar tomonidan radioaktivlikni to'plash xavfini ham eslatib o'tish kerak.
(9) Ishlashning ishonchliligini va odamlar uchun xavfsizligini ta'minlash uchun zamonaviy A-elektr stantsiyalari avtomatik ravishda boshqariladi. Qozonxonalar, reaktorlar, turbinalar va boshqa jihozlar zavodning boshqaruv xonasidan boshqariladi, bu yerda operatorlarga sodir bo'layotgan hamma narsaning soniyasiga soniyali tasvirini beruvchi terish va yozuvlar batareyalari mavjud. Elektron robotlar, manipulyatorlar va o'lchash, teginish va teginish qobiliyatiga ega bo'lgan mexanik qo'llar endi A-elektr stantsiyalarida radioaktiv elementlar2 bilan ishlash uchun ajralmas hisoblanadi. Kichkina nosozlik paydo bo'lishi bilanoq avtomatik ovozli ogohlantirish beriladi va yorug'lik nosozlik qaerdaligini aniq ko'rsatadi. Maxsus tizim operatorga barcha jarayonlarni har qanday yuzaga kelishi mumkin bo'lgan muammolarni boshqarishga imkon beradi.
(10) Elektr energiyasi ishlab chiqarilgandan so'ng mamlakatning elektr tarmog'iga3 yuboriladi. Bu elektr energiyasini iste'molchilarga, shu jumladan elektrlashtirilgan temir yo'llarga taqsimlovchi tarmoq tizimi.
(11) An'anaviy va atom elektr stantsiyalari yuqori kuchlanishli o'zgaruvchan tok hosil qiladi, (a.c.). Haqiqat shundaki, o'zgaruvchan tok uzoq masofalarga , to'g'ridan-to'g'ri oqim (d. c.) dan ko'ra ko'proq iqtisodiy tarzda uzatilishi mumkin va kuchlanish qanchalik kam bo'lsa, energiya yo'qoladi.
(12) Garchi o'zgaruvchan tok poezdlarni haydash uchun ishlatilishi mumkin bo'lsa-da, ko'p mamlakatlarda u to'g'ridan-to'g'ri oqimga aylanadi, chunki d. s motorlar konstruksiyasi a ga qaraganda oddiyroq. c. mashinalar.
(13) Ma'lumki, a ning konvertatsiyasi. s dan d. s. temir yo'l podstansiyalarida sodir bo'ladi. Substansiyaning birinchi zarurati - bu elektr uzatish liniyasidan olingan elektr tokining kuchlanishini pasaytiradigan transformator. Podstansiya o'rnatilgan yana bir muhim asbob - rektifikator bo'lib, u a. c. d ga. c, bu bir tomonlama (ya'ni, to'g'ridan-to'g'ri) oqim keyinchalik yuqori simga beriladi.
(14) Elektronika temir yo'l podstansiyalarida keng qo'llanilishini topdi, silikon rektifikatorlar eng ko'p ishlatiladigan elektron asboblardan biri hisoblanadi. Elektron qurilmalar tufayli aksariyat podstansiyalar endi masofadan boshqarish pulti bilan boshqariladi.