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Electrical drives and power electronics (0)

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Punktid
Electrical drives and power electronics TESTS
  • The synchronous machines are associated with the names of Ferraris
  • Name the scientists who first studied electrical phenomena Coulomb
  • The DC machines are associated with the names of Jacobi Henry
  • The leading companies in the world market of electrical drive engineering are Mitsubishi

  • The electromagnetic torque is born in air gap
  • What kind of drives the majority of drive systems present low accuracy
  • The induction machines are associated with the names of Dolivo-Dobrovolsky Tesla
  • One of the first eletrical motors has been built by Jacobi
  • Electromagnetic efficiency is measured in tesla
  • Time constants are measured by ms s hours
  • Who is the author of the first electrical motor Henry
  • Which rectifier cannot be built without a transformer 3-phase midpoint
  • Call the benefits of 3-phase rectifiers upon the 1-phase ones output voltage
  • Which rectifier has more diodes 3-phase bridge
  • In the case of high- pass filter before the load , what can you tell about the current higher
  • What is the difference between the construction and operation of a rectifier and an inverter input wave output wave
  • What are the advantages of a single -phase bridge inverter high efficiency high reliability
  • What kind of control provides the highest output power of the inverter block
  • What load inductance provides the interruptible output current zero
  • What should be the value of an inverter output frequency to reduce audible noise very high
  • What is the maximum modulation index of a linear PWM system one
  • What semiconductor devices are most widely used in inverters diode transistor
  • What is the most important component of a full -bridge inverter transistor
  • What is delay time of VSI ˂1 ms
  • What should be the value of an inverter output frequency to reduce inverter losses very low
  • What are some applications of CSI heaters welding
  • Which ac/ac converters change the voltage only voltage regulators
  • What is obtained as a result of frequency converting new frequency
  • How does the connected thyristors assemble a three-phase voltage regulator reverse- parallel
  • For a single-phase cycloconverter, what kind of dependence exists between the output frequency and the input frequency output ˂input
  • How many thyristors are required for the cycloconverter with the three-phase output 18
  • What does the term “a direct ac converter” mean without rectifying without energy storage
  • What is the most obvious use of the cycloconverter low-frequency
  • Why does a matrix converter need full controlled devices to change current
  • Why a device is called as “dc link converter” internal dc circuit
  • What does the dc link converter consist of rectifier inverter capacitor
  • What are the applications fields of cycloconverters rolling mills
  • What does a continuous current means non-pulsing
  • Call the difference of half-bridge and full-bridge dc/dc converters input/output voltage ratio
  • Why the transformer-isolated converters are used voltage set-up
  • Why the back diodes are required current reversing
  • In the steady state mode, the drive has pulsations ripples
  • In the very accurate drive, the over- speed is 1..10%
  • The mechanical time constant will be high if Td is low
  • The friction torque is passive
  • In the high-efficient electrical drives the overload capacity is high
  • The counter -torque of the hoist is active
  • The speed –torque relation of a pump is quadratic
  • The source of the magnetic flux of the motor is permanent magnet
  • The energy balance is described by Energy conservation law
  • Which equations are correct P=sW
  • The angular frequency is 2πn/60 2πf
  • The motor torque is equal to P/ω TL + Jdω/dt
  • The cheapest and the most reliable is induction motor
  • The torque production is the result of interaction of current – flux
  • Efficiency of the electrical drive is the power ratio of load to supply
  • The best electrical drive has efficiency very high
  • The torque is proportional to the current in dc motor
  • The inductor supplies the motor with flux
  • The armature supplies the motor with current
  • The mutual motion of the stator and rotor windings result in counter-EMF
  • If the angular frequency of the stator field is 300, how much the synchronous speed of the 2-pole motor will be 300
  • The characteristics of the rigid drive is rigid
  • The rigidity of the high-efficient electrical drives is high
  • The standard supply grid has the oscillation period of 20 ms
  • Select the components that belong to the servo drive position sensor
  • The multi -quadrant operation is typical for car
  • If the required speed would rise, the mechanical time constant do not change
  • At the very low speed the torque is less than rated
  • In the case of low quick action the overtorque is 0
  • The overshot of the stable system no overshoot
  • The usual time response processes are step
  • In the accurate drives, the accuracy range is small
  • Select the motors with the slip rings wound -rotor synchronous
  • Select the natural reference frames L1, L2, L3
  • Select the stationary reference frames α,β
  • If the stator field frequency is 100, what will be the synchronous frequency of the 2-pole motor? 100
  • Select the correct frequency equilibrium ω1 = ω2 + ω12 ω12 = ω1 - ω2
  • If the stator field frequency is 100, what will be the slip frequency of the loaded induction motor?
Electrical drives and power electronics #1 Electrical drives and power electronics #2 Electrical drives and power electronics #3 Electrical drives and power electronics #4 Electrical drives and power electronics #5
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Autor Auren Õppematerjali autor
8 testi ainest electrical drives and power electronics

Sarnased õppematerjalid

Test VIII - cumulative test
8
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Test VIII - cumulative test

The DC machines are associated with the names of Jacobi and Henry. The electromagnetic torque is born in air gap. The torque is proportional to the current in dc motor. Which equations are correct? P = sW; oomega = tuletis fii'st The angular frequency is 2*pi()*n / 60 ja 2*pi()f The motor torque is equal to TL + J * oomega tuletis aja järgi The inductor supplies the motor with flux. The leading companies in the world market of electrical drive engineering are: Mitsubishi. The energy balance is described by energy conservation law. The armature supplies the motor with current. The cheapest and the most reliable is induction motor. The torque production is the result of interaction of current - flux. The mechanical torque as compared to the electromechanical torque is ?? The source of the magnetic flux of the motor is DC or permanent magnet. The most suitable for the speed control is synchronous servo motor.

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3
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Quiz3 vastatud

- 25. If J = 3, = 2, and t = 10, what will be T? -3*2/10=0,6 I*w/t 26. If J = 12 and T = 10, what will be acceleration? -10/12=0,8m/s2 T/J 27. If J = 4 T = 2, and = 5, how long the start-up will continue? -4*5/2=10s I*w/T 28. If J = 1 and T = 5, what speed will be reached at t = 2? -5*2/1=10rad/s t*T/J 29. If J = 12, what torque is required to provide acceleration of 5? -12*5=60Nm 30. If J = 5 and T = 5, what time is needed to reach the speed of 5? -5*5/5=5s I*w/T 2. Quiz on Electrical Drive Characteristics 1. Name the typical kinds of the time response processes. 2. What units are used to measure the drive quick action? 3. What units are used to measure the time constants? 4. What is the usual accuracy range of the accurate drives? 5. Does the mechanical time constant depend on the start-up speed? 6. How can the electromagnetic time constant be calculated? 7. Which time constant is usually the longest and which one is the shortest ? thermal, mechanical, or electromagnetic? 8

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Book Analog Interfacing to Embedded Microprocessors

I hope it proves useful. ix Introduction Modern electronic systems are increasingly digital: digital microprocessors, digital logic, digital interfaces. Digital logic is easier to design and understand, and it is much more flexible than the equivalent analog circuitry would be. As an example, imagine trying to implement any kind of sophisticated micro- processor with analog parts. Digital electronics lets the PC on your desk execute different programs at different times, perform complex calculations, and communicate via the World Wide Web. While the electronic world is nearly all digital, the real world is not. The temperature in your office is not just hot or cold, but varies over a wide range. You can use a thermometer to determine what the temperature is, but how do you convert the temperature to a digital value for use in a microprocessor- controlled thermostat

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Tallinn University of Technology Department of Electrical Engineering Report on laboratory work 1 on General Course of Electrical Drive SENSORLESS DRIVE POWER FLEX (ALLEN BRADLEY) Jüri Lina 666BMW Group M16 Variant 2 Tallinn 2014 1. Functional Diagram 2. Tables of observations Task Operation/Record Observation 1 Reverse the motor speed. How long Time to reverse was 16 does the motor reverse

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circuit. 6) One of its main applications is in rectifiers, circuits that convert the Alternating voltage or alternating current into direct voltage or direct current. It is also applied in detectors, which find the signals in the noisy operation conditions. The third application is in switching circuits because an ideal rectifier acts like a perfect conductor when forward biased and lik a perfect insulator when reverse biased. 7) A power diode is more complicated in structure and operational characteristics than the small signal diode. The forward bias characteristic of the power diode is approximately linear, which means that the voltage drop is proportional to the omic resistance and to the current. The rated currents of power diodes are thousands of amperes and the area of the pn junction may be tens of square centimeters. In the case of power diode, the additional n- layer exists between these two layers, which is

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Microcontroller homework 07
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Some hybrid steppers have more than one stackof magnets for more torque. 2. There are two types of stator winding methods forstepper motors: bipolar and unipolar. Bipolar windings use field coils with no common connections. The coils must be driven independently to reverse the direction of motor flow and rotate the motor. Unipolar motors use coils with centertaps. The centertap is usually connected to the positive supply, and the individual coils are grounded (through transistors) to drive the motor. Each time the field is changed in a bipolar motor or a different coil isturned on in a unipolar motor, the motor shaft steps to the next rotation position. Typical step sizes for a stepper are 7.5° or 15°. A 7.5° stepper will have360/7.5 or 48 steps per revolution. The step size depends on the number of rotor and stator teeth. 3. Considering the following circuit diagrams The Table:

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Elektriajamite 4. labor

Tallinn University of Technology Department of Electrical Engineering Report on laboratory work 4 on General Course of Electrical Drive INDUCTION MOTOR DRIVE (LUCAS-NÜLLE) Jüri Lina 666BMW Group M16 Variant 2 Tallinn 2014 1. Functional Diagram Nameplate data: Loading Machine SO3636- VDE 0530 IP:5 Is.KL: 6V 4 F U: 390V I: 4,4 A 4Nm/1.7k cos: W

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value of the worst spurious signal. 6. Channels - related to the inputs of the ADC can either be multiplexed or individually selected. 7. Linearity - relates to how a ADC follows a linear function. All ADCs are to a certain extend nonlinearity. 8. Operating temperature - measurement, which in optimal state for ADC-s, lets them function correctly. 9. Power dissipation - refers to the amount power dissipated when the ADC is operating. Question 2 An 8 bit ADC has a reference voltage of 5V. What is the digital output code word for an input of 1.2V? What is the voltage range corresponding to 1 LSB? 1,2𝑉 0,0195𝑉 = 61 ; 61 = 001111012 Digital output code for an input of 1.2V is 001111012. Voltage range corresponding to 1 LSB is U= 0,0195V. Question 3 A 15 bit ADC has a reference voltage of 10V. What is the digital output code word for an input of 6.83V

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