Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 50, Problem 1SQ
To determine
Explain the necessity of
Expert Solution & Answer
Explanation of Solution
A motor cannot be completely stopped by applying the dynamic braking alone. In dynamic braking process, the DC motor acts as a generator by reconnecting the running motor, as a result the field gets excited and a low resistance path is created across the armature. Some of the mechanical energy of motor is converted to electrical energy resulting in the reduction of motor speed, current, generator action and the braking lessens. However, the motor does not attain complete stand-alone state due to dynamic braking, the mechanical brake is needed to stop and hold the drive at the final stage of braking.
Conclusion:
Thus, the necessity of the mechanical brake after dynamic braking occurs is explained.
Want to see more full solutions like this?
Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Explain regenerative braking in detail as applied to electric motive
Explain regenerative braking in detail , as applied to electric locomotives
What is regenerative braking in electric cars and how does it work?
Chapter 50 Solutions
Electric Motor Control
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- (B)- Indicate whether the following statements are true or false and correct the false statements 1- Wave wound armature has two parallel paths. 2- The current ratio is equal to 1/ turn ratio at no-load while the voltage ratio is equal to 1/ turn ratio at full load 5.4. 3-When a series de motor is operated without a load, the armature draws excessive current Ph 4- The hysteresis loss can be minimized by using core of thin laminations ل لهول 259 Ne 02arrow_forwardOne type of failure that's more common with 200 HP motors than with 10 HP motors is A. rotor bar failure.B. contactor failure.C. bearing failure. D. stator failures.arrow_forwardPlease be fastarrow_forward
- 1) Does the motor constant depend on the angular speed? 2) Does motor efficiency, ratio of Vemf to Va, depend on the angular speed of the motor? 3) Does the motor constant depend on the load? 4) When the magnetic load on the motor increases, does the current increase, remain constant, or decrease?arrow_forwardI need the answer as soon as possiblearrow_forwardAnswer the question quecly please Machinearrow_forward
- 1- Why D.C motor can be consider a useful for operating equipment such as winches, cranes, and missile launchers? 2- Define the motor. 3- How we can find the direction of mechanical force in motor? 4- What is the magnitude of the mechanical force of the motor? 5- Is there a constructional differences between D.C motor and D.C generator? 6- What is the function of a commutator in the motor ? 7- What will happened if the armature current is turned on when a = 900? 8- Why the counter emf effectively cancels part of the armature voltage? 9- Why counter emf cannot be equal to or greater than the applied battery voltage? 10- What is the benefit of counter emf and what will happened If there were no such thing as counter emf? 11- Shunt motors should never be started on heavy loads, Why? 12- Why in shunt motor with armature current increase speed drops ? 13- Why series motor used with heavy masses? 14- Why series motor should never started without load on it? 15- Why The speed of cumulative…arrow_forwardplease answer both questions and dont copy pastearrow_forwardD1- Which DC motor's magnetic field gets stronger with an increase in mechanical load? a) series b) shunt c) compound d) "a" and "c", not "b" D2- The greater the mechanical load on a DC motor the faster it will turn. a) true b) false D3- Which of the following causes a DC shunt motor to automatically adjusts its input to take care of changes in mechanical load. a) the speed decreases with increases in load b) the cemf decreases with increases in load c) the supply current increases due to the decrease in cemf d) all of the abovearrow_forward
- g) Explain the pull up torque. h) Explain the breakdown torque. i) Explain the rated(nominal) torque.arrow_forward5) The deflecting torque of an ammeter varies as the square of the current flowing through it. If a current of 10 A produces a deflection of 90°, what deflection would occur for a current of 5 A when the instrument is (a) spring controlled and (b) gravity controlled? [Ans. (a) 22.5°, (b) 14.5°]arrow_forwardQuestion 1 [Soalan 1] (a) The model for a position control system using a DC motor is shown in Figure 1.1. Calculate the value of K₁ and K₂ so that the response peak time is 0.2 second and the overshoot for a unit step input is less than 4%. [Satu model untuk satu sistem kawalan kedudukan yang menggunakan motor DC ditunjukkan didalam Rajah 1.1. Kirakan nilai K, dan K₂ supaya sambutan masa puncak ialah 0.2 saat dan terlajak untuk input unit langkah adalah kurang daripada 4%.] R(s) K₁ s(s+1) 1+ K₂s Figure 1.1 [Rajah 1.1] Y(s)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Electricity for Refrigeration, Heating, and Air C...Mechanical EngineeringISBN:9781337399128Author:Russell E. SmithPublisher:Cengage Learning
EBK ELECTRICAL WIRING RESIDENTIALElectrical EngineeringISBN:9781337516549Author:SimmonsPublisher:CENGAGE LEARNING - CONSIGNMENT
Electricity for Refrigeration, Heating, and Air C...
Mechanical Engineering
ISBN:9781337399128
Author:Russell E. Smith
Publisher:Cengage Learning
EBK ELECTRICAL WIRING RESIDENTIAL
Electrical Engineering
ISBN:9781337516549
Author:Simmons
Publisher:CENGAGE LEARNING - CONSIGNMENT