Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 40, Problem 4SQ
When the rotor and stator fields lock into step, why may the reading of the AC ammeter decrease?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The memory map of a 8 kB memory chip begins at the location E000H. The last location of the
memory address.
The question was to obtain the Fourier series for the periodic function f(x)= -2 when -π
Consider the homogeneous RLC circuit (no voltage source) shown in the diagram below. Before
the switch is closed, the capacitor has an initial charge go and the circuit has an initial current go.
R
w
i(t)
q(t)
C
н
After the switches closes, current flows through the circuit and the capacitor begins to discharge.
The equation that describes the total voltage in the loop comes from Kirchoff's voltage law:
di(t)
L
+ Ri(t) + (t) = 0,
dt
(1)
where i(t) and q(t) are the current and capacitor charge as a function of time, L is the inductance,
R is the resistance, and C is the capacitance. Using the fact that the current equals the rate of
change of the capacitor charge, and dividing by L, we can write the following homogeneous (no
input source) differential equation for the charge on the capacitor:
ä(t)+2ag(t)+wg(t) = 0,
(2)
where
R
a
2L
and w₁ = C
LC
The solution to this second order linear differential equation can be written as:
where
81=
q(t) = Ae³¹- Bel
82 =
(3)
(4)
(5)
Chapter 40 Solutions
Electric Motor Control
Ch. 40 - What are the two basic functions of synchronous...Ch. 40 - Prob. 2SQCh. 40 - If all of the control circuits are ACand DC is not...Ch. 40 - When the rotor and stator fields lock into step,...Ch. 40 - Prob. 5SQCh. 40 - Prob. 6SQCh. 40 - In Figure 402, approximately what is the...Ch. 40 - Why are the AC ammeter and DC meter necessary in...Ch. 40 - Prob. 9SQ
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
- 2. 1. A. Simplify the models in the following block diagrams to open loop models (Y/R = G). U(s) o G₁ ROS G₂ 1-GG G4 X₁ Σ az 51- 515 G6 G₂ 5 G₂ M b₁ b₂ Σ o Y(s) X₁ byarrow_forwardNeed handwritten solution do not use chatgpt or AIarrow_forwardB. Design a 2nd order Band Stop Filter (BSF) with overall gain=10, centre frequency-12kHz, and bandwidth=4KHz. (8 Marks)arrow_forward
- Design a fifth (5th) order HPF with 8 KHz cutoff frequency, and overall gain Av=35.57dB. Calculate the roll-off rate and draw its frequency response.arrow_forwardThe reverse recovery charge and the peak reverse current are QH-500 uC and I-250A respectively. Assume that the softness factor is SF=0.5, estimate (a) The reverse recovery time of the diode trr (b) The rate of fall of the diode current di/dtarrow_forwardQ2: A 208V, Y-connected synchronous motor is drawing 40A at unity power factor from a 208V power system. The field current flowing under these conditions is 2.7A. Its synchronous reactance is 0.82 and its armature resistance is 0.2 2. Assume a linear open-circuit characteristic. 1- Find EA and the torque angle. 2- How much field current would be required to make the motor operate at 0.8 PF lagging. 3- How much field current would be required to make the motor operate at 0.8 PF leading. 4- How much field current would be required to make the motor operate at unity PF.arrow_forward
- 6) For each case find the answer: 2 (a) If q (t) = 2+ + 6 + + 3 Coulombs Find i(t) at t = 4 seconds (b) If i(t) = 4 Amperes If Find q (t) for 25 = ≤6 seconds (c) If w(t) = 5t³ Joules Find p(t) at t = 3 seconds (d) If p(t 2t+3+4 Watts Find w(t) for 1st≤5 secondsarrow_forwardAs we will learn in Chapter 8, to maximize the transfer of power from an input circuit to a load ZL, it is necessary to choose ZL such that it is equal to the complex conjugate of the impedance of the input circuit. For the circuit in Fig. P7.50, such a condition translates into requiring ZL = Zth*. Determine ZL such that it satisfies this condition.arrow_forward7.44 In the circuit of Fig. P7.44, what should the value of L be 104 rad/s so that i(t) is in-phase with u,(t)? at i(t) 50 Ω www Ds(f) z- 25 Ω 4μF L b Figure P7.44 Circuit for Problem 7.44.arrow_forward
- 5) An orbiting satellite has both solar panels and a 48-volt battery on board. The instrumentation package has sent the following data regarding supplied Coulombs vs. minutes for the 48 volt battery on the Satellite Coulombs 3.5 3 25 2 15 05 O 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6 minutes (a) what is the battery current at t=0-5 minute: (6) How much power is the battery supplying at 0.5 Minutes? (c) Between 2 and 3 minutes how much poner does the battery supply? (d) Between 3 and 4 minutes what current is produced by the battery?arrow_forward7.36 Find the input impedance Z of the circuit in Fig. P7.36 at 0 400 rad/s. 502 3 mH ww m Z→ 2 mF b 5025 ww ell Figure P7.36 Circuit for Problem 7.36. 9 mHarrow_forwardAn evening meal is being prepared in a home kitchen containing an electric oven and a microwave oven. The cost for electricity in the home's neighborhood is $0.15 per kilowatt hour. The microwave oven is specified as a 1000 watt unit, while the oven requires 240 volts and uses a current of 30 amperes to cook at 350 degrees Fahrenheit. A frozen meal can be cooked in the microwave oven set on full power in 10 minutes. The same frozen meal cooked in the electric oven set for 350 degrees F takes 40 minutes. (a) How much energy does it take to cook the frozen meal in the microwave at full power and how much does it cost? (b) How much energy does it take to cook the frozen meal in the electric oven at 350 degrees Fahrenheit and how much does it cost?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Delmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage Learning
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:9781337900348
Author:Stephen L. Herman
Publisher:Cengage Learning
Electrical Measuring Instruments - Testing Equipment Electrical - Types of Electrical Meters; Author: Learning Engineering;https://www.youtube.com/watch?v=gkeJzRrwe5k;License: Standard YouTube License, CC-BY
01 - Instantaneous Power in AC Circuit Analysis (Electrical Engineering); Author: Math and Science;https://www.youtube.com/watch?v=If25y4Nhvw4;License: Standard YouTube License, CC-BY