What is meant by constant losses in DC machine?

What is meant by constant losses in DC machine?

Constant losses Those losses in a d.c. generator that stay constant at all loads are referred to as constant losses. The constant losses in a very d.c. generator are: (a)iron losses. (b)mechanical losses. (c)shunt field losses.

What are the types of losses in DC generator?

Usually, magnetic and mechanical losses are collectively known as Stray Losses. These are also known as rotational losses for obvious reasons. Total loss = armature copper loss + Wc = Ia²Ra + Wc = (I + Ish)²Ra + Wc. Armature Cu loss Ia²Ra is known as variable loss because it varies with the load current.

What are mechanical losses in DC machine?

Mechanical losses can be occurred due to the effects of the machines. These losses are separated into two losses namely bearing friction & windage. These kinds of losses can occur at the moving parts within the dc machine. The air in the DC machine is also called as windage losses.

What are variable losses?

Variable Losses. These losses are also called copper losses. These losses occur due to current flowing in stator and rotor windings. As the load changes, the current flowing in rotor and stator winding also changes and hence these losses also changes. Therefore these losses are called variable losses.

Which transformer losses are variables?

1. Copper losses:- when the transformer is loaded, current flows in primary and secondary winding, there is loss of electrical energy due to the resistance of the primary winding, and secondary winding and they are called variable losses.

How do dc machines reduce losses?

The losses can be reduced by reducing the field current. Ifso, the armature current should be increased to keep the required torque. 1) The adaptive sub-controller repeatedly adjusts the field current until there is a minimum power input.

Which losses in generator are of variable nature?

Copper losses consist of Armature copper loss, Field copper loss and loss due to brush contact resistance. This loss contributes about 30 to 40\% to full load losses. The armature copper loss is variable and depends upon the amount of loading of the machine.

Which one is example of variable loss?

Q.	Which one is an example of variable loss?
A.	Windage loss
B.	Hysteresis loss
C.	Armature copper loss
D.	Friction loss

Which loss is a variable loss?

Copper losses:- when the transformer is loaded, current flows in primary and secondary winding, there is loss of electrical energy due to the resistance of the primary winding, and secondary winding and they are called variable losses.

Which of the following is variable loss?

Explanation: Variable losses include losses in armature resistance and losses in series resistance, which are directly proportional to the square of armature current. It also includes stray load loss (iron plus copper) which is proportional to square of armature current.

Which of the following is an example of variable loss?

Which of the following are variable losses? Armature copper loss is directly proportional to square of armature current. Therefore as the load varies it will also vary. Condition for maximum efficiency is, copper loss = iron loss or variable losses is equal to fixed losses.

What are mechanical losses?

As their name suggests, mechanical losses are caused by movement of the motor. These include the friction in the motor bearings, friction between the brushes and the commutator, and drag on the rotor caused by turbulence of the air around it (sometimes referred to as windage loss).

What are the different types of losses in a DC machine?

1 Electrical or Copper Losses in DC Machine. Electrical/copper can occur within the windings of the DC machine-like field copper or armature. 2 Magnetic Losses or Core Losses or Iron Losses. Alternate names of these losses are iron losses or core losses. 3 Brush Losses. 4 Mechanical Losses. 5 Stray Losses.

What is constant and variable loss in DC power system?

Constant and Variable Losses. For a DC Machine, Total Losses = Constant losses + Variable losses. Constant losses are those losses that always occur irrespective of the load conditions and whose value remains constant for a given machine. Mechanical losses, core losses, and shunt field copper losses are included in constant losses.

What is co-copper loss in DC machine?

Copper loss is those which occur in the windings of the dc machine. Generally, there are field and armature windings in a dc machine, and losses are named armature winding loss and field winding loss. Since the conductor used is copper, hence the losses are known as copper loss.

What are the stray load losses in DC machine?

Stray Losses in dc machine. These losses are the miscellaneous type of losses. The following factors are considered in stray load losses. The distortion of flux because of armature reaction. Short circuit currents in the coil, undergoing commutation.