выполнены упражнения контрольной работы в соответствии с заданиями
a. The traction motors were pulling the train up a very steep grade, when suddenly they stopped working.
b. Another form of dynamic braking has recently been developed in our new laboratory.
c. The traction motors have turned into generators; now they are returning the electrical power back into the grid.
d. Look! The locomotive is not being propelled by the diesel engine!
a. The power (has sent/has been sent) back to the electrical grid.
b. Recently, these locomotives (have equipped/have been equipped) with large batteries.
c. Electric motors (were working/were being worked) in conjunction with the air-brake system.
d. The generator was not new; it (had provided/had been provided) power for some years.
e. Braking energy (is converting/is being converted) into heat force through the use of resistors mounted on top of the locomotive.
a. Dynamic braking may be of two types – rheostatic and regenerative ones.
b. Traction motors can also be used for dynamic braking.
c. You must know that diesel engines do not propel diesel-electric locomotives directly.
d. They had to replace the old generator which could no longer provide enough power.
a) reverse; b) drive; c) propel; d) freeze; e) break; f) convert; g) make; h) equip; i) mount; j) speak.
a. The diesel starts a generator supplying power to large electric motors.
b. During regenerative braking, the electric traction motors are reversed, effectively turning into generators.
c. Being built according to new technology, modern engines are more effective.
d. Having been started by the diesel, the generator began supplying power to the traction motors.
a) (reverse) traction engines; b) braking energy (convert) into heat; c) resistors (mount) on top of the locomotive; d) electrical power (send) back into the electrical grid; e) yard locomotives (equip) with batteries; f) a form of braking (know) as blended braking; g) wheels (drive) by an electric motor; h) mo- tors (mount) between the drive wheels
a. When reversed, the electric traction motors turn into generators.
b. On specially equipped yard locomotives, regenerative braking returns the electrical power into battery storage units.
c. Generators supply power to large electric motors mounted between the loco's drive wheels.
d. If used in regenerative braking, the traction motors send the electrical power back into the electrical grid.
8. Перепишите и письменно переведите текст:
BRAKING SYSTEMSThere are two types of dynamic braking: rheostatic and regenerative braking. Regenerative braking is a method of braking a locomotive where the electric traction motors in the diesel-electric locomotive are reversed, effectively turning into generators. In the diesel electric locomotive, rheostatic braking converts the braking energy into heat force through the use of a large bank of resistors mounted on top of the locomotive; while regenerative braking returns the electrical power back into the electrical grid, as in the case of an electric locomotive, and into large battery storage units on specially-equipped yard locomotives. Another form of dynamic braking is known as blended braking, where the electric motors are used in conjunction with the air-brake system.
Few people know that a diesel electric locomotive is not propelled directly by the huge diesel engine it is equipped with. The main task of the diesel is to start a generator, supplying power to large electric motors mounted between the locomotive's drive wheels. These motors, known as traction motors, not only provide great power to drive the locomotive and pull the train up steep grades, they can also be used for dynamic braking. This can provide up to 70 percent of a locomotive's braking force, however being less effective at slow speeds.
a. Rheostatic braking converts the braking energy into electrical power by means of resistors mounted on top of the locomotive.
b. Diesel electric locomotives are propelled by huge diesel engines.
c. Blended braking, where the electric motors are used in conjunction with the air-brake system, is a form of dynamic braking.
d. Making use of traction motors for dynamic braking can provide up to 70 percent of a locomotive's braking force, being really effective at slow speeds.
e. Traction motors supply enough power to drive the locomotive and pull the train up steep grades.