A DC motor, when supplied from a 90 V power supply is observed to rotate under...
A DC motor, when supplied from a 90 V power supply is observed to rotate under no-load conditions at 1,200 rpm. A stall test shows that the winding resistance is 2 Ω. Assume a linear model for the DC machine as presented in lectures.
What is the back-emf constant for this machine? Give your answer in V.s.rad-1 to 3 decimal places.
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A DC motor, when supplied from a 90 V power supply is observed
to rotate under...
A DC motor, when supplied from a 211 V power supply is observed to rotate under...
A DC motor, when supplied from a 211 V power supply is observed to rotate under no-load conditions at 1,700 rpm. A stall test shows that the winding resistance is 1.65 ? The motor is connected to a load whose torque-speed characteristic is given by ? = ?×0.178. Find the speed (in rpm) at which the motor will drive this load. rpm (Give your answer in rpm to 3 s.f.)
Q1b) DC Machines [ 6 marks ] You are given a 24 V DC motor. When...
Q1b) DC Machines [ 6 marks ] You are given a 24 V DC motor. When you connect it to a 24 V supply, under no-load conditions it spins at 2,000 rpm. With the same 24 V supply, when the motor is stalled, the input current is 50 A. i) Calculate the back-emf constant and hence the stall torque of the motor. Find also the armature resistance. [3 marks ] ii) The DC motor has a rated input current of...
A 6 hp, 180 V shunt dc motor draws a full-load current of 30 A from the power supply. The motor h...
A 6 hp, 180 V shunt dc motor draws a full-load current of 30 A from the power supply. The motor has a field (shunt) resistance of 150 Ω. The armature resistance of the motor is 0.1 Ω. When the motor speed is 1800 rpm (this is not the full-load speed), the relationship between the induced voltage
A dc series excited motor is connected to 230V power supply. The resistance of the armature...
A dc series excited motor is connected to 230V power supply. The resistance of the armature winding is 0.25 ohms and the series winding resistance is 0.15 ohms. At 1100 rpm the motor consumes 50A. Calculate the speed of the motor when connected to a 200V power supply. Assume that the motor shaft torque is unchanged.
For a PMDC motor powered by a 12 V DC source, the no-load speed and stall...
For a PMDC motor powered by a 12 V DC source, the no-load speed and stall torque are 3800 RPM and 30 mNm, respectively. If the motor is running at 2500 RPM, find a) Shaft torque (Tshaft), b) Rotor current (Im), c) Back emf (Eb), d) Electrical power consumed, e) Shaft power, and f) Power loss in rotor coil.
5.7. A DC machine has a back-emf constant of 0.24 V/(rad/s) and a resistance of 0.5...
5.7. A DC machine has a back-emf constant of 0.24 V/(rad/s) and a resistance of 0.5 ohms. It is operating from a 12V DC power supply. At its rated speed of 400 rpm, calculate its (a) rated back-emf voltage (that is, the back-emf at rated speed) (b)rated current (that is, the current at rated speed) (c) rated torque (d) rated output power POUT= To (e) rated output power POUT = EI (f) rated input power (g) rated efficiency-PouTlPi (h) rated...
A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance...
A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance Rf of 40 Ω, and an armature resistance Ra of 250 mm2. The field winding has 1500 turns. An adjustable resistance Rad is connected in series to the field winding. Rad is set at 20 Ω, but it can vary from 0 to 80 Ω. The magnetization curve is shown in Figure.1 and it is taken at a speed of 1200 rpm. (Armature reaction...
3. A 25-kW, 230-V shunt motor has an armature resistance of 0.064 Ω and a field-circuit...
3. A 25-kW, 230-V shunt motor has an armature resistance of 0.064 Ω and a field-circuit resistance of 95 Ω. The motor delivers rated output power at rated voltage when its armature current is 122 A. When the motor is operating at rated voltage, the speed is observed to be 1150 r/min when the machine is loaded such that the armature current is 69.5 A a. Calculate the rated-load speed of this motor In order to protect both the motor...
Question 3: DC motors can be simplistically modeled as shown in Figure 5 MoTor back emf Vi: +1 Re...
Question 3: DC motors can be simplistically modeled as shown in Figure 5 MoTor back emf Vi: +1 Resistor Ra Ia Figure 5: Simplified model of DC Motor (a) Write the three characteristic equations that determine the behavior of the DC motor. Denote torque constant and speed constant as Ka, K, respectively. (b) Motor parameters are the quantities that define the behavior of the motor. List the motor parameters from the described model. What are their units? (c) For given...
Q5.8：The specifications of machine 5.8. For the machine in the previous question, calculate (a) its no-load speed (b)its rated efficiency-olcoxL-n/nN (c) the following when the speed is ze...
Q5.8：The specifications of machine
5.8. For the machine in the previous question, calculate (a) its no-load speed (b)its rated efficiency-olcoxL-n/nN (c) the following when the speed is zero (stall condition) (i)induced voltage (ii) nput current (ii) output torque (iv) ut power (v)output power (vi) efficiency (d) he speed (in rpm) when the torque is 0.2 Nm 5 A DC machine has a no-load speed of 10,000 rpm and a rated speed of 8,000 rpm when operating with its rated supply...
A DC motor, when supplied from a 211 V power supply is observed to rotate under no-load conditions at 1,700 rpm. A stall test shows that the winding resistance is 1.65 ? The motor is connected to a load whose torque-speed characteristic is given by ? = ?×0.178. Find the speed (in rpm) at which the motor will drive this load. rpm (Give your answer in rpm to 3 s.f.)
Q1b) DC Machines [ 6 marks ] You are given a 24 V DC motor. When you connect it to a 24 V supply, under no-load conditions it spins at 2,000 rpm. With the same 24 V supply, when the motor is stalled, the input current is 50 A. i) Calculate the back-emf constant and hence the stall torque of the motor. Find also the armature resistance. [3 marks ] ii) The DC motor has a rated input current of...
5.7. A DC machine has a back-emf constant of 0.24 V/(rad/s) and a resistance of 0.5 ohms. It is operating from a 12V DC power supply. At its rated speed of 400 rpm, calculate its (a) rated back-emf voltage (that is, the back-emf at rated speed) (b)rated current (that is, the current at rated speed) (c) rated torque (d) rated output power POUT= To (e) rated output power POUT = EI (f) rated input power (g) rated efficiency-PouTlPi (h) rated...
A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance Rf of 40 Ω, and an armature resistance Ra of 250 mm2. The field winding has 1500 turns. An adjustable resistance Rad is connected in series to the field winding. Rad is set at 20 Ω, but it can vary from 0 to 80 Ω. The magnetization curve is shown in Figure.1 and it is taken at a speed of 1200 rpm. (Armature reaction...
3. A 25-kW, 230-V shunt motor has an armature resistance of 0.064 Ω and a field-circuit resistance of 95 Ω. The motor delivers rated output power at rated voltage when its armature current is 122 A. When the motor is operating at rated voltage, the speed is observed to be 1150 r/min when the machine is loaded such that the armature current is 69.5 A a. Calculate the rated-load speed of this motor In order to protect both the motor...
Question 3: DC motors can be simplistically modeled as shown in Figure 5 MoTor back emf Vi: +1 Resistor Ra Ia Figure 5: Simplified model of DC Motor (a) Write the three characteristic equations that determine the behavior of the DC motor. Denote torque constant and speed constant as Ka, K, respectively. (b) Motor parameters are the quantities that define the behavior of the motor. List the motor parameters from the described model. What are their units? (c) For given...
Q5.8：The specifications of machine
5.8. For the machine in the previous question, calculate (a) its no-load speed (b)its rated efficiency-olcoxL-n/nN (c) the following when the speed is zero (stall condition) (i)induced voltage (ii) nput current (ii) output torque (iv) ut power (v)output power (vi) efficiency (d) he speed (in rpm) when the torque is 0.2 Nm 5 A DC machine has a no-load speed of 10,000 rpm and a rated speed of 8,000 rpm when operating with its rated supply...
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