Contents
What are the constant losses in a DC machine?
The losses that occur in a DC Machine is divided into five basic categories. The various losses are Electrical or Copper losses (I2R losses), Core losses or Iron losses, Brush losses, Mechanical losses, Stray load losses.
What is copper loss in DC motor?
Copper loss is the power lost as heat in the windings; it is caused by the flow of current through the coils of the DC armature or DC field. This loss varies directly with the square of the current in the armature or field and the resistance of the armature or field coils.
Are copper losses constant?
Iron loss is a constant loss. Copper losses vary as the square of load current . Copper loss is a variable loss.
What are the various types of losses in DC machines?
Various types of losses, including rotational losses, reduce motor efficiency.
- Mechanical losses. As their name suggests, mechanical losses are caused by movement of the motor.
- Magnetic losses (aka core losses or iron losses)
- Copper losses (aka electrical losses or winding losses)
- Brush losses.
- Stray load losses.
Which DC motor is preferred for constant speed?
Explanation: Rotary compressor generally demand constant speed operation throughout the load. Sometimes, DC machines are not able to produce constant speed throughout the process hence, synchronous machine is used. 4.
How do you fix copper loss?
Copper loss calculation formula: Copper loss Pc in Watts is equal to the resistance R(Ω) in ohms times of the square of the current I(A) in Amps.
What causes copper losses?
Copper losses are due to the resistance of the wire in the primary and secondary windings and the current flowing through them. These losses can be reduced by using wire with large cross-sectional area in the manufacturing of the coils.
What is back emf in DC motor?
Back emf is the generator output of a motor, and so it is proportional to the motor’s angular velocity ω. It is zero when the motor is first turned on, meaning that the coil receives the full driving voltage and the motor draws maximum current when it is on but not turning.
What is eddy current loss?
Eddy current loss is conductive I2R loss produced by circulating currents induced in response to AC flux linkage, flowing against the internal resistance of the core.
What kind of loss occurs in an armature copper motor?
Generally, this loss is included into armature copper loss. As the armature core is made of iron and it rotates in a magnetic field, a small current gets induced in the core itself too. Due to this current, eddy current loss and hysteresis loss occur in the armature iron core. Iron losses are also called as Core losses or magnetic losses.
What causes the loss of power in a DC motor?
Though this induced emf is small, it causes a large current to flow in the body due to the low resistance of the core. This current is known as eddy current. The power loss due to this current is known as eddy current loss. Mechanical losses consist of the losses due to friction in bearings and commutator.
What causes a DC machine to lose copper?
These losses in dc machines occur due to currents in the various windings of the machine. Note: There is also brush contact loss due to brush contact resistance (i.e., the resistance between the surface of brush and surface of commutator). This loss is generally included in armature copper loss.
What are the various losses in a DC shunt motor?
Following are the various losses that take place in DC shunt motor: Copper Losses or Electrical Losses in DC motor or Winding Loss. Armature Copper Loss in DC motor. Field Winding Copper Loss in DC motor. Brush Contact Resistance Loss. Core Losses or Iron Losses or Magnetic Losses in DC motor.