23 hp, dc shunt motor is running at 1000 rpm when the armature voltage is 600...

23 hp, dc shunt motor is running at 1000 rpm when the armature voltage is 600 V. The armature resistance of the motor is 0.8 ohm, and the field resistance is 900 ohm. The efficiency of the motor at full load is 92 %.

a) Calculate the value of the resistance of the dynamic braking at full load. The armature current should be limited to 150% of the rated value.

b) If the motor operated in regenerative braking at a speed of 1100 rpm, calculate the line current.

c) Design a circuit for countercurrent braking (by reversing supply voltage) so that the line current will not exceed 120% of the rated value.

Expert Solution

Manojponduru answered 1 year ago

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 240v, 4pole shunt motor running at 1000 r.p.m gives 15 hp with an armature current...

a 240v, 4pole shunt motor running at 1000 r.p.m gives 15 hp with an armature current of 50 A and field current of 1 A. the armature winding is wave connected and has 540 conductors. the armature resistance is 0.1 ohm and drop at each brush is 1v. find (i) useful torque, (ii) the total torque (iii) useful flux per pole, (iv) iron and friction losses

A DC shunt motor drives a centrifugal pump at a speed of 1000 rpm when the...

A DC shunt motor drives a centrifugal pump at a speed of 1000 rpm when the terminal voltage and line currents are 200 V and 50 A, respectively. Given the armature resistance, Ra = 0.1 ohm and field resistance, Rf =100 ohm. Design a circuit which the speed of the motor can be controlled by using the added resistance method to the armature circuit and the maximum starting current is 120 A. Next, if the added resistance in the designed...

The following details are known about a 150 hp motor, 240 V, 500 rpm, dc shunt...

The following details are known about a 150 hp motor, 240 V, 500 rpm, dc shunt motor. Nominal full load current: 500 A Insulation class: H Weight: 3400 kg Find 1.The total losses and efficiency at full load. 2.Calculate the approximate shunt filed exciting current if the shunt field causes 20% of the total losses. 3.Calculate the value of the armature resistance knowing that 50% of the total losses at full load are due to armature resistance. 4.With your calculated...

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...

Problem: A PM DC motor has the following parameters: Rated Power 10 hp; Rated armature voltage...

Problem: A PM DC motor has the following parameters: Rated Power 10 hp; Rated armature voltage 230 V-DC; Rated RPM: 1800; Armature Resistance: 0.2 Ohm Armature Inductance: 0.005 H Inertia (motor plus mechanical load): 0.1 kgm^2; Viscous friction coefficient: 0.015 Nms 1. Compute the voltage constant of the motor. Also compute the rated current and rated torque of the motor (obtained at the rated RPM). If the motor is supplied by 230 V across the armature, and the only torque...

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,...

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) In DC motor, quadrant of operation can be defined by the armature voltage and current...

(a) In DC motor, quadrant of operation can be defined by the armature voltage and current of the motor. By using an appropriate diagram, briefly explain the definition of all four quadrant of operation based on armature voltage and current. (b) A chopper is used to control speed of 45.36 kW, 1750 rpm, 240 V, 189 A permanent magnet DC motor with 0.01 Ω armature resistance. This chopper-fed DC motor is able to operate in both motoring and braking mode...

Q1A 4-poles, wave wound, 600 conductors DC long shunt generator has the armature, series and shunt...

Q1A 4-poles, wave wound, 600 conductors DC long shunt generator has the armature, series and shunt resistances are 0.15 ohm, 0.18 ohm and 200 ohm respectively. It runs at 1500 rpm. Calculate the following if it is required supply to the load resistance of 20ohm with flux per pole as 8.33 mWb. Take the Iron and Frictional losses as 550 W.(i)Induced Emf(ii)Terminal Voltage(iii)Output Power(iv)Input Power(v)Efficiency Q2Write short notes on following characteristics of dc generator(i) Open Circuit Characteristics (OCC)(ii) Load Characteristics...

Question