A 230 V, 500 rpm, 100 A separately- excited dc motor has an armature resistance of...

A 230 V, 500 rpm, 100 A separately- excited dc motor has an armature resistance of 0.1 ohms. The motor is driving, under rated conditions, a load whose torque is constant and independent of speed. The speeds below the rated speed are obtained with armature voltage control (with full field) and the speeds above the rated speed are obtained by field control (with rated armature voltage).

What motor terminal voltage is needed to run it at 400 rpm?
By what amount should flux be reduced to get a motor speed of 800 rpm?

Neglect the motor’s rotational losses.

3.The separately- excited motor of the previous problem is now coupled to an overhauling load with a torque of 800 N-m. Determine the speed at which the motor can hold the loadby regenerative braking. Source voltage is 230 V. Neglect the motor’s rotational losses.

Expert Solution

Manojponduru answered 1 year ago

A 230 V, 250 rpm, 100 A separately excited dc motor has an armature resistance of...

A 230 V, 250 rpm, 100 A separately excited dc motor has an armature resistance of 0.5 Ω. The motor is connected to 230 V dc supply and rated dc voltage is applied the field winding. It is driving a load whose torque-speed characteristic is given by TL = 500 − 10ω where ω is the speed in rad/sec and TL is the load torque in N-m. Find (a) the steady state speed at which the motor will drive the...

a) A 50kW separately excited DC motor has armature resistance of 2.5W, armature inductance of 30mH...

a) A 50kW separately excited DC motor has armature resistance of 2.5W, armature inductance of 30mH and back e.m.f of 100V when the motor is fed from a buck converter with 250VDC input, 50Hz switching frequency and 50% duty cycle. Assuming continuous conduction and lossless converter, find out the maximum, minimum and ripple currents in armature. b) Determine the values of inductor and filter capacitor for a buck converter with following specifications: Input= 48V, output = 24V, Load curernt =...

A 100 hp, 220 V, 1200 rpm DC shunt motor with an armature resistance of 0.05...

A 100 hp, 220 V, 1200 rpm DC shunt motor with an armature resistance of 0.05 ? and a field resistance of 50 ?. The motor has compensating windings, so armature reactance can be ignored. Mechanical and core losses may be ignored also. The motor is driving a drilling machine, TL ? (1/n). The motor is driving a load with a line current of 120 A and an initial speed of 1200 rpm. Assume Linear Magnetization curve i. What is...

A 120+m -V , 2400+n-rpm shunt DC motor has a armature resistance 0.4+0.1*m ohm and a...

A 120+m -V , 2400+n-rpm shunt DC motor has a armature resistance 0.4+0.1*m ohm and a shunt field resistance of 160+m Ohm . The motor operates at its rated speed with full load which takes 15+m Amp. A small of current of 2+.1*m A at no load due to rotational loses. Assume that rotational loss is proportional to the speed. Find Field current at no load Armature current at no load Rotational loss at no load Armature current at Full...

Assuming n=m=1 A 120+m -V , 2400+n-rpm shunt DC motor has a armature resistance 0.4+0.1*m ohm...

Assuming n=m=1 A 120+m -V , 2400+n-rpm shunt DC motor has a armature resistance 0.4+0.1*m ohm and a shunt field resistance of 160+m Ohm . The motor operates at its rated speed with full load which takes 15+m Amp. A small of current of 2+.1*m A at no load due to rotational loses. Assume that rotational loss is proportional to the speed. Find a. Field current at no load b. Armature current at no load c. Rotational loss at no...

‏The speed of a 11 KW, 150 V, 1300 rev/min separately excited DC motor is controlled...

‏The speed of a 11 KW, 150 V, 1300 rev/min separately excited DC motor is controlled by a ‏single-phase fully-controlled thyristor converter. The rated motor current is 25 A, and the ‏armature resistance is Ra = 0.5 Ohm. The ac supply is 160 V. The motor voltage constant KE = ‏0.182 V/rev/min. Assume that sufficient inductance is present in the armature circuit to make ‏the armature current continuous and ripple free. ‏For a firing angle of alpha = 20 degree...

A 400 V dc shunt motor has a rated armature current of 76 A at a...

A 400 V dc shunt motor has a rated armature current of 76 A at a speed of 1000 rpm. The armature resistance of the motor is 0.4ohm, the field resistance is 100 ohm, and the rotational losses are 0.9 kW. The load of the motor is bidirectional. Calculate the following: (a) No-load speed of the motor. (b) Motor speed, where the armature current is 60 A during regenerative braking. (c) Developed torque during regenerative braking. (d) Back electromotive force,...

Distinguish between a Shunt, a Series, a Separately Excited, and a Compound DC Motor.

Problem 5) A long shunt 600 V, 1200-rpm DC motor has a series field winding resistance...

Problem 5) A long shunt 600 V, 1200-rpm DC motor has a series field winding resistance of 0.05 Ω, a shunt field winding resistance of 200 Ω, and an armature resistance of 0.1 Ω. The machine is connected to 600 V DC source. The rotational loss is 3.2 kW. If the machine draws a 100 A from the supply, calculate a. Back EMF b. Determine the machine’s converted power (or developed power) and its efficiency. c. Determine the speed regulation...

A 5-kW, 250-V shunt motor has an armature resistance of 0.1 ? and a field-circuit resistance...

A 5-kW, 250-V shunt motor has an armature resistance of 0.1 ? and a field-circuit resistance of 80 ?. When the motor is operating at rated voltage, the speed is observed to be 1200 r/min when the machine is loaded such that the armature current is 30 A. In order to protect both the motor and the dc supply under starting conditions, an external resistance will be connected in series with the armature winding (with the field winding remaining directly...

Question