A separately excited DC motor is fed from a variable DC source and it drives a...
A separately excited DC motor is fed from a variable DC source and it drives a variable mechanical load as shown in Figure Q4b. The excitation current If is held constant during the motor operation. (i) How can the motor direction be reversed? (4 marks) (ii) Explain what will happen to the current Ia, the internal voltage Eg, and speed if the mechanical torque increases whilst the DC input voltage VT is held constant. (4 marks) (iii)Explain what will happen to the current Ia, the internal voltage Eg, and speed if the mechanical torque is kept constant and the DC input voltage VT is increased. (4 marks)
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A separately excited DC motor is fed from a variable DC source
and it drives a...
separately excited series, shunt, compound DC motor: *Describe how does decreasing the field current IF affect...
separately excited series, shunt, compound DC motor: *Describe how does decreasing the field current IF affect the speed versus voltage characteristic and constant K1 of a separately-excited dc motor. K1=(n2-n1)/(E2-E1) *Describe how does decreasing the field current IF affect the torque versus current characteristic and constant K2 of a separately-excited dc motor? k2=(T2-T1)/(I1-I2) *Briefly describe how the speed varies as the mechanical load applied to the series motor increases, i.e. as the motor torque increases.
Given a 1/4 hp, separately excited, dc motor with the following parameters: K = 0.61, R, 15Ω, La-...
I can not seem to get the right answers. Thank you!
Given a 1/4 hp, separately excited, dc motor with the following parameters: K = 0.61, R, 15Ω, La-120mb. J = 0.005, and b = 0.0006. The armature voltage is controlled by a 120-V dc PWM source operating at 100 Hz 1. What is the armature current if the no-load speed is 1800 rpm when the armature supply is operated at a 100% duty cycle? 2. What is the no-load...
Problem 2 A separately excited DC motor is characterized by the followng intormation Armature res...
Problem 2 A separately excited DC motor is characterized by the followng intormation Armature resistance Ra-5 2 armature inductance La . very large, Field resistance RS200 Ω, ted voltage Vt 200 V, and an inertia constant J-12 kg m Neglecting friction losses and assuming no-saturation in the machine magnetic core system, answer the folowing questions: Part 1: (6 marks) he motor a as shown in figure 2a. The motor drives a constant power load of vaue 1 40375 hp (ie...
(i) A 220 volts, 825 rpm, 125 A separately excited DC motor has an armature resistance...
(i) A 220 volts, 825 rpm, 125 A separately excited DC motor has an armature resistance of 0.05 2. It is fed from a single phase fully controlled rectifier with an ac source of 225 Volts, 50Hz. Assuming continuous conduction calculate (a) Firing angle for 1/4"hrated motor torque and 750 rpm (b) Motor speed for a=160 degrees and rated torque 5 Marks (ii) Draw and explain with neat circuit diagram of a DC drive circuit, which works with positive output...
A separately excited dc motor is fed by a 3-phase, 6-pulse converter shown in figure Q5. The 3-phase line is a 500 V, 6...
A separately excited dc motor is fed by a 3-phase, 6-pulse converter shown in figure Q5. The 3-phase line is a 500 V, 60 Hz supply. At rated condition, the dc motor armature current is 15 A. The dc motor armature resistance is 0.15 Ω and the rated speed is 1700 rpm. If the delay angle of the converter is 36 °, calculate the following: 3-phase (2 0 line Figure Q5. (2 marks) Rated voltage of the motor a. b....
2. A dc chopper is used for regenerative braking of a separately excited dc motor. The...
2. A dc chopper is used for regenerative braking of a separately excited dc motor. The dc supply voltage is 400V. The motor has ra=0.2 ohms. Km=1.2 V-s/rad. The average armature current during regenerative braking is kept constant at 300A with negligible ripple. For a duty cycle of 60% for a chopper , determine a) Power returned to the supply. b) Minimum and maximum permissible braking speeds and c) Speed during regenerative braking.
A separately excited DC motor has the following data P=32kW (rated power); Va=220V (rated voltage); Ia=171A...
A separately excited DC motor has the following data P=32kW (rated power); Va=220V (rated voltage); Ia=171A (rated curent); n=1000 rpm (rated speed); Ra = 0.096 ohm a.Calculate the armature voltage to reduce the speed to 900 rpm, assuming the load torque is kept constant? b.Calculate the resistance should be added to armature circuit to reduce the speed to 800 rpm, assuming the load torque is kept constant? c.Calculate the reduction of magnetic flux to reach the speed of 1100 rpm,...
Q1. Draw the equivalent circuits of a separately excited and a shunt DC motor. [20] Q2....
Q1. Draw the equivalent circuits of a separately excited and a shunt DC motor. [20] Q2. Derive the speed-torque relation for a DC motor: [40] 0 = VR, Kø (KØ)??ind Q3. A DC motor's speed can be controlled by either changing the field resistance, changing the armature voltage or changing the armature resistance. Of these three, which one is the best method for DC motor speed control and which is the worst? Give reasons. [40]
solve it now please A 220 V, 1000 rpm, separately excited dc motor is fed from...
solve it now
please
A 220 V, 1000 rpm, separately excited dc motor is fed from a three-phase controlled three-phase ac-dc converter through 220 V (line value-rms value), 50 Hz ac-source. It is required to apply 220 V (dc-value) across the motor terminals. What is the firing angle if the motor speed is 1000 rpm and takes 10 A ripple-free current. The armature resistance is 1 ohm. The field circuit with 198 ohms is fed from a fully controlled single-phase...
A separately-excited DC traction motor of a metro train is in series connection, i.e., the armature...
A separately-excited DC traction motor of a metro train is in series connection, i.e., the armature and the field windings are connected in series with a common DC power source. The voltage of the DC power source is I (a) Please show that the angular velocity of the rotor is KT K where o is the is the angular velocity of the rotor, Ra is the resistance of the armature, Rris the resistance of the field windings, T is the...
I can not seem to get the right answers. Thank you!
Given a 1/4 hp, separately excited, dc motor with the following parameters: K = 0.61, R, 15Ω, La-120mb. J = 0.005, and b = 0.0006. The armature voltage is controlled by a 120-V dc PWM source operating at 100 Hz 1. What is the armature current if the no-load speed is 1800 rpm when the armature supply is operated at a 100% duty cycle? 2. What is the no-load...
Problem 2 A separately excited DC motor is characterized by the followng intormation Armature resistance Ra-5 2 armature inductance La . very large, Field resistance RS200 Ω, ted voltage Vt 200 V, and an inertia constant J-12 kg m Neglecting friction losses and assuming no-saturation in the machine magnetic core system, answer the folowing questions: Part 1: (6 marks) he motor a as shown in figure 2a. The motor drives a constant power load of vaue 1 40375 hp (ie...
(i) A 220 volts, 825 rpm, 125 A separately excited DC motor has an armature resistance of 0.05 2. It is fed from a single phase fully controlled rectifier with an ac source of 225 Volts, 50Hz. Assuming continuous conduction calculate (a) Firing angle for 1/4"hrated motor torque and 750 rpm (b) Motor speed for a=160 degrees and rated torque 5 Marks (ii) Draw and explain with neat circuit diagram of a DC drive circuit, which works with positive output...
A separately excited dc motor is fed by a 3-phase, 6-pulse converter shown in figure Q5. The 3-phase line is a 500 V, 60 Hz supply. At rated condition, the dc motor armature current is 15 A. The dc motor armature resistance is 0.15 Ω and the rated speed is 1700 rpm. If the delay angle of the converter is 36 °, calculate the following: 3-phase (2 0 line Figure Q5. (2 marks) Rated voltage of the motor a. b....
Q1. Draw the equivalent circuits of a separately excited and a shunt DC motor. [20] Q2. Derive the speed-torque relation for a DC motor: [40] 0 = VR, Kø (KØ)??ind Q3. A DC motor's speed can be controlled by either changing the field resistance, changing the armature voltage or changing the armature resistance. Of these three, which one is the best method for DC motor speed control and which is the worst? Give reasons. [40]
solve it now
please
A 220 V, 1000 rpm, separately excited dc motor is fed from a three-phase controlled three-phase ac-dc converter through 220 V (line value-rms value), 50 Hz ac-source. It is required to apply 220 V (dc-value) across the motor terminals. What is the firing angle if the motor speed is 1000 rpm and takes 10 A ripple-free current. The armature resistance is 1 ohm. The field circuit with 198 ohms is fed from a fully controlled single-phase...
A separately-excited DC traction motor of a metro train is in series connection, i.e., the armature and the field windings are connected in series with a common DC power source. The voltage of the DC power source is I (a) Please show that the angular velocity of the rotor is KT K where o is the is the angular velocity of the rotor, Ra is the resistance of the armature, Rris the resistance of the field windings, T is the...
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