What are the losses in the DC motor and what are the main losses in the operation of the generator

Stator loss, rotor loss, iron loss, stray loss, wind friction loss.

The electric motor converts electrical energy into mechanical energy.

At the same time, it also loses a part of the energy, and the typical AC motor loss can generally be divided into three parts: fixed loss, variable loss and stray loss. Variable losses vary with load and include stator resistance losses (copper losses), rotor resistance losses, and brushes.

resistance loss; Fixed losses are load-independent and include core losses and mechanical losses.

Iron loss is composed of hysteresis loss and eddy current loss, which is proportional to the square of voltage, where hysteresis loss is also inversely proportional to frequency; Other stray losses are mechanical losses and other losses, including frictional losses in bearings and drag losses due to rotation of fans, rotors, etc.

Stator iron loss, stator copper loss, rotor copper loss ** sub iron loss is negligible), mechanical friction loss, additional loss.

Copper loss, iron loss, wind wear, mechanical friction loss.

The main losses of DC generators are:

1) Copper loss of excitation winding;

2) mechanical friction loss;

3) iron loss;

4) Armature copper loss;

5) Brush loss;

6) Additional losses.

Iron loss refers to the hysteresis and eddy current losses in the silicon steel sheet as the armature core rotates in a magnetic field. These two types of losses are related to the magnitude of the magnetic density as well as the alternating frequency. When the excitation current and rotational speed of the motor are constant, the iron loss is almost constant.

It has little to do with changes in load. Armature copper losses are caused by the armature current, and when the load increases, the armature current increases at the same time, and the armature copper losses increase accordingly. The copper loss in the armature is proportional to the square of the armature current.

Diesel generator as a standby power supply, is widely used in various places, many customers in the purchase of diesel generators, in order to save costs, always hope to buy the maximum power of diesel generators, now generator manufacturers simply say that Yuchai generator set in the assembly and use of possible functional wear

1. When the diesel generator is assembled, the fan water tank will be installed, and the shaft connection will be carried out with the generator, at this time, the power of the generator set will lose 10% relative to the diesel engine

2. DC loss, that is, the loss of generator stator current through the stator winding.

3. Iron loss, that is, the magnetic flux generated by the generator in the generator, which includes the magnetic loss generated by the main magnetic flux in the stator core, eddy current loss and additional loss.

4. Excitation loss. That is, the loss of the excitation current in the rotor circuit during the operation of the generator.

5. Additional loss of electrical appliances. The loss of leakage flux at the end of the generator in its vicinity. Losses due to various harmonic fluxes. Iron loss caused by subharmonics and high harmonics on the surface of the rotor, etc.

6. Mechanical loss, that is, the ventilation loss and friction loss of transmission parts in the operation of Yuchai generator set.

The loss of generator can be roughly divided into five categories, namely, stator copper loss, iron loss, excitation loss, electrical additional loss, and mechanical loss. In the operation of the generator, almost all losses are expressed in the form of heat generation.

1) The copper loss of the stator is all the losses caused by the flow of the stator current through the stator windings.

2) Iron loss refers to the loss of generator flux in the iron core, mainly the hysteresis loss and eddy current loss generated by the main magnetic flux in the stator core, and also includes additional losses.

3) The excitation loss is the loss generated by the rotor circuit, mainly the copper loss generated by the excitation current in the excitation circuit.

4) The electrical additional loss is more complicated, mainly including the loss generated by the leakage flux at the end in the ferrous components near it, the loss generated by various harmonic fluxes, and the iron loss generated by tooth harmonics and higher harmonics on the surface of the rotor.

5) Mechanical loss mainly includes ventilation loss, bearing friction loss, etc.

The losses during the operation of the generator mainly include: generator cooling loss (water cooling, hydrogen cooling, air cooling), generator fan blast loss, generator stator coil copper loss, generator core loss, generator rotor excitation loss, rotor friction loss, etc.

The generator is an energy conversion device, there must be losses, the overall efficiency is still very high, the greater the power, the higher the efficiency.

To put it simply, the same loss and iron loss are generated in the magnetic field, for example, the induction cooker we use is heated by the principle of iron loss, the stator and rotor windings of the motor are copper, and the iron core is iron.

Reactive power consumption: the motor or any electrical appliance is divided into active power and reactive power, that is, the power factor of electrical equipment, for example, the power factor of a motor is 0, 8, the power is 1kw, then the active power consumption is 800w, the reactive power consumption is 200w, and part of the reactive power consumption of the motor is lost in copper loss and iron loss.

The economic operation of the motor includes many aspects: for example, the speed is adjusted according to the change of load, and the frequency converter is commonly used. There is also the selection of the motor, the fit with the load, the motor is small, easy to overload and heat, the belt can not move, reduce the life of the motor, the selection is too large, resulting in a waste of resources and a waste of electric energy.

The loss of the motor consists of copper loss of the coil, iron loss of the core, and mechanical loss (bearing and fan). The economic operation of the motor refers to the operating condition that the ratio of the output shaft power to the input electrical power is the maximum value (the highest efficiency). If the highest efficiency of the transformer is when the copper loss is equal to the iron loss, and the motor has the factor of mechanical loss, it is not when the copper loss is equal to the iron loss.

Because the motor coil needs to be excited, of course, there is reactive power loss.

The mechanical power output of an asynchronous motor from the rotating shaft is always less than the electrical power absorbed from the power supply, so it is lossy.

One is the power loss of the current on the resistance of the stator winding, which is called the copper loss. and the hysteresis loss and eddy current loss caused by the alternating magnetic flux in the stator core, collectively referred to as iron loss. The second is the copper loss caused by the current i2 in the rotor winding and the mechanical loss caused by ventilation friction when the rotor rotates.

The third is the additional loss caused by the current induced by the higher harmonics of the stator magnetic flux in the cage rotor.

When the motor is running, there is always a certain amount of power loss inside, which includes: copper (or aluminum) loss on the winding, iron loss on the iron core and various mechanical losses. Therefore, the input power is equal to the sum of the lost power and the output power, that is, the output power is less than the input power.

What is the efficiency of an electric motor.

The magnitude of the internal power loss of the motor is measured by efficiency, and the ratio of output power to input power is called the efficiency of the motor, which is represented by .

Commonly used percentages, i.e.:

High efficiency, indicating low loss and saving electric energy. However, too high efficiency requirements will increase the cost of the motor. Generally, the efficiency of the asynchronous motor is 75 92% under the rated load.

The efficiency of an asynchronous motor also varies with the size of the load. The efficiency is zero when there is no load, and when the load increases, the efficiency increases, and when the load is multiple of the rated load, the efficiency is the highest and the operation is the most economical.

Copper loss: Loss caused by the current passing through the windings (including stator and rotor) due to the resistance of the windings.

Iron loss: Loss caused by eddy currents and hysteresis inside the stator and rotor core, housing, etc.

Mechanical loss: Loss caused by mechanical friction, air resistance, etc.

The losses of DC motors include stator loss, rotor loss, iron loss, stray loss, and wind friction loss.

A DC motor is a rotating machine that converts direct current energy into mechanical energy (DC motor) or mechanical energy into direct current energy (DC generator). It is a motor that can convert direct current energy and mechanical energy to each other. When it is used as a motor, it is a DC motor, which converts electrical energy into mechanical energy; When the generator is running, it is a direct current generator, which converts mechanical energy into electrical energy.

The loss of the motor is mainly copper loss and iron loss, copper loss is generated by the heat generated by the current in the circuit, and iron loss is generated by the flow of magnetic field lines in the magnetic circuit (silicon steel sheet), which is also expressed in the form of heat.

Copper loss, iron loss, mechanical loss, stray loss.

Copper loss is the loss of calorific energy, the square of the current multiplied by the internal resistance.

Iron loss. It's eddy current loss, and I forgot the specific formula.

Mechanical wear and tear. It is the power required for the motor to rotate when there is no load.

Spurious loss. Magnetic flux leakage loss and the like.

The main losses of DC generators are:

1. The copper loss of the excitation winding is the loss caused by friction when the excitation winding copper is used for power generation.

2. Mechanical friction loss, which refers to the friction of machinery, refers to the heat generated by potatoes, resulting in the loss of generators.

3. Iron loss, iron loss refers to the hysteresis and eddy current loss in the silicon steel sheet when the armature core rotates in the magnetic field. These two types of losses are related to the size of the magnetic density and the alternating frequency.

4. Armature copper loss refers to the loss caused by the unstable frequency of armature copper in the motor.

5. Brush loss refers to the functional loss caused by brush friction in the motor.

6. Additional loss refers to the loss of heat generation of the iron core and coil and magnetic flux leakage of the iron core during the operation of the transformer.

Answer]: Talk about rough a, infiltrate c, d

The losses of the parallel excited DC motor include the copper loss, mechanical loss and stray loss of the stator winding and the iron loss of the rotor core.