А)Marker beacon systemB) ADF C) TCAS D)Weather radar system E) GPS 4What is navigation used for? A) the specialized knowledge B) Automatic direction finder C) Distance measuring equipment D) Traffic alert and collision avoidance system E) EFIS displays 5Which of these is not a main part of navigation? A)Weather radar system B)Subsystems C)Automatic direction finder D)Distance measuring equipment E)altitude alert system 6 Who invented distance measuring equipment? A)Edward Bowen B) Edward Camble C) Edward Twin D)Edward George E)Edward Brown 7When another engineered version of the system was deployed? A) 1970 B) 1920 C) 1960 D) 1950 E)1940 8. A low-power DME can also be co-located with ….? A)TACAN A) FMS B) TCAS C) an ILS D) ICAO 9. A low-power DME can also be co-located with ….? A)TACAN B) FMS C) TCAS D) an ILS E) ICAO 10. A low-power DME can also be co-located with ….? A) TACAN B) FMS C) TCAS D) an ILS E) ICAO 11. A low-power DME can also be co-located with ….? A)TACAN B) FMS C) TCAS D) an ILS E) ICAO 12. A low-power DME can also be co-located with ….? A)TACAN B)FMS C) TCAS D) an ILS E) ICAO 13. A low-power DME can also be co-located with ….? A)TACAN B) FMS C) TCAS D) an ILS E) ICAO UNIT 3AC/DC HYDRAULIC MOTOR-DRIVEN GENERATORS
AIMS OF THE TOPIC: - to have a basicunderstanding of the ac/dc hydraulic motor-driven generators TASKS 1 Do your best to answer the brainstorming questions. 2 Read the text for general understanding. 3 Make up questions to the text. 4 Find the sentences with the new words in the text. Give the Kazakh or Russian equivalents of the words. 5 Write sentences with the new vocabulary. 6 Do the given exercisesfor better remembering the tеxt.7 Speak on the topic. Given schemes will help you to remember and understand the topic. 8Find more information about the topic. Do some research, create slideshow or a project work and present them.
1What do you know about the ac/dc hydraulic motor-driven generators? 2What does motor-generator controlprovide? 3What does the motor-generator solenoid control valve control?
The ac/dc hydraulic motor-driven generators are emergency power sources. They consist of a hydraulically driven ac/dc generator, a motor-generator control unit, and a control solenoid. The motor-generator provides 115-/200-volt three-phase ac and 28-volt dc power to essential electrical circuits if normal power fails. The kVA rating of this emergency generator is much lower than the primary generator(s), so the emergency generator powers a limited number of circuits. AC/DC generator.—As the rotor turns (hydraulic motor running), the permanent magnet induces power into the PMG. This power energizes the control and regulation circuits and the four essential power transfer relays. Regulated and rectified PMG output power goes to a stationary control field within the motor-generator. The motion of the rotor assembly induces PMG power into the windings of the exciter alternator. This power is rectified and, in turn, induced into the output ac winding and the dc winding. The motor-generator control unit monitors ac output. This unit adjusts the regulation to maintain the ac output at 115 volts per phase ± 1.5% when operating under full hydraulic system pressure. The dc output from the stationary rectifier goes to the dc transfer relay contacts for distribution to the essential dc buses. The hydraulic motor converts 3,000 pounds per square inch of hydraulic pressure to constant-speed rotation, maintaining generator output frequency at 400 Hz. The motor-generator is cooled by hydraulic fluid from the same source that drives the hydraulic motor. Motor-generator control.—The motor-generator control provides voltage regulation for, and fault detection of, motor-generator output. When the motor-generator is operating, PMG power flows to the rectifier, where the three-phase ac is rectified to a dc signal. The dc signal is for control panel and relay control power. The signal then flows to the voltage regulator section of the motor-generator control unit. The voltage regulator supplies field excitation to the motor-generator and monitors the output voltage. Monitoring protective circuits in the motor-generator control prevents out-of-tolerance power from being connected to the essential bus system. Motor-generator solenoid control valve.—The motor-generator solenoid control valve controls the operation of the emergency electrical power system. The valve drives electrically to the closed position when primary electrical power is available. When primary electrical power fails, the valve de-energizes and opens, routing hydraulic pressure to the hydraulic motor, driving the generator. The entire operation is completely automatic upon primary electrical power failure.
EXERCISES FOR BETTER REMEMBERING THE TOPIC
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