Evolution:
The oldest electrical machinery depend on permanent magnets to provide magnetic field, but the best magnetic materials available at the time was only able to offer very low areas limits the potential applications for demonstration laboratory machines. Finally found that very strong magnetic fields can be generated using electromagnets powered by the application or the tension generated in the line. This allowed the construction of more powerful machines that allow the development of practical applications. Advances in magnetic materials have now created a much more powerful magnet and permanent they can be used for specific machines, simplifying the machine construction, eliminating one set of windings. In parallel, many functions, such as encoders, tachometers, thermal cutouts, brakes and the fans are integrated into the machine similar Controllers
Motor Data Some general observations:
Couple In general, the torque produced by an engine is proportional to power consumption and also depending on the flow into the ditch.
T = B K1I
Speed In DC speed of the motor is proportional to the applied voltage. Speed, however, is inversely proportional to flow into the breach.
N = K2 V
B
Alternating current velocity is proportional to the frequency of the applied voltage and inversely proportional to the number of magnetic poles.
N = K3 F
P
Torque - speed characteristic DC motors produce maximum torque at zero speed or when a deadlock (when consuming more today) and the torque decreases linearly with increasing speed, reaching zero when the reverse voltage generated by rotation of the coils in one magnetic field (back EMF) is equal to the applied voltage.
With AC starting torque at zero speed can be about 70% to 90% of maximum, peaking as the speed increased dramatically and zero as the motor speed of modern approaches. See note on modern engines.
(The couple - the speed characteristics of electric motors is in contrast to internal combustion engines whose torque is very small at low speed, timing generally 800 revolutions per minute, but increases with speed to a peak of 80% of the maximum speed slightly groove reaches its maximum speed.)
Getting Started Some models motor, are they not run the basic setup, but incorporate adjustments to normal project allowing self starting so the user can ignore the problem.
Energy Management Engine power is directly proportional to its speed. The power P in watts is given by:
P =? T
Where? Is the speed in radians per second and T is the torque in Newton-meters
Or
P = 2p NT = NT
60 9.55
Where N is the speed in revolutions per minute (RPM)
Maximum power:
Motor Data Some general observations:
Couple In general, the torque produced by an engine is proportional to power consumption and also depending on the flow into the ditch.
T = B K1I
Speed In DC speed of the motor is proportional to the applied voltage. Speed, however, is inversely proportional to flow into the breach.
N = K2 V
B
Alternating current velocity is proportional to the frequency of the applied voltage and inversely proportional to the number of magnetic poles.
N = K3 F
P
Torque - speed characteristic DC motors produce maximum torque at zero speed or when a deadlock (when consuming more today) and the torque decreases linearly with increasing speed, reaching zero when the reverse voltage generated by rotation of the coils in one magnetic field (back EMF) is equal to the applied voltage.
With AC starting torque at zero speed can be about 70% to 90% of maximum, peaking as the speed increased dramatically and zero as the motor speed of modern approaches. See note on modern engines.
(The couple - the speed characteristics of electric motors is in contrast to internal combustion engines whose torque is very small at low speed, timing generally 800 revolutions per minute, but increases with speed to a peak of 80% of the maximum speed slightly groove reaches its maximum speed.)
Getting Started Some models motor, are they not run the basic setup, but incorporate adjustments to normal project allowing self starting so the user can ignore the problem.
Energy Management Engine power is directly proportional to its speed. The power P in watts is given by:
P =? T
Where? Is the speed in radians per second and T is the torque in Newton-meters
Or
P = 2p NT = NT
60 9.55
Where N is the speed in revolutions per minute (RPM)
Maximum power:
The maximum power that can withstand engine determined by the maximum allowable temperature. Power rating can be increased by using materials that can withstand higher temperatures, particularly for the insulation of the liquidation, or providing forced cooling lowers the temperature of engine for a given current consumption.
Power Corner Power Corner is an alternative method to determine engine performance, which some people find it useful to compare machines.
It is simply the product can offer maximum torque and maximum speed can be achieved. Since the maximum torque rarely, if ever, made simultaneously at maximum speed, engine power actually delivered is always less than the angle of power.
In DC motor threshold is determined by the ability of parts of the collector and brushes of high voltage (speed limit) and high currents (torque limit).
Also note that at high voltages and currents forced cooling may be required.
Cooling The strength of an electrical machine is limited by the maximum allowable temperature of the windings. Power handling may increase the use of insulation can withstand higher temperatures or providing forced cooling to remove heat from the windings. Forced cooling is not normally required for fractional horsepower motors increased, but integral horsepower engines often include a high-cooling fan to push air into the machine. Forced air cooling can be effective in machines up to 50 megawatts, but larger engines with a power of several megawatts, as used in the electricity industry should use cooling liquid refrigerant flowing in the hollow conductors. The fluid may be water, but for larger engines using hydrogen because of low weight and high thermal capacity.
Gearing For a given torque, engine power is proportional to velocity. Engines at low speed will give you much power very low. Applications requiring high torque at low revs, it will be very high currents and disproportionately large engines. These applications are better served by mechanisms higher engine speed orientation to reduce speed and torque increases.
Size Vehicle size is determined by the pair has to offer. For similar engines with similar cooling systems engine torque is proportional to the volume of the rotor and therefore the engine total volume.
Profitability As mentioned above, for a given torque, engine power is proportional to the speed and electrical waste and drift tend to be broadly stable, relatively slow growth. Thus, increasing energy efficiency of the engine speed.
Efficiency is also dependent on engine size and tend resistance losses are much higher in smaller devices than larger machines can be designed in a more efficient magnetic circuit.
Cogging Cogging is jerky, non-uniform angular velocity of the machine rotor is particularly evident at low speed with a small number of poles. Is it because the rotor tends to accelerate as it approaches the stator poles and slow down when he leaves the poles. It is also obvious when DC pulsed used if the wave frequency of supply is very low. The problem can be reduced by using rotor windings through and increase the number of motor poles.
Losses:
Power Corner Power Corner is an alternative method to determine engine performance, which some people find it useful to compare machines.
It is simply the product can offer maximum torque and maximum speed can be achieved. Since the maximum torque rarely, if ever, made simultaneously at maximum speed, engine power actually delivered is always less than the angle of power.
In DC motor threshold is determined by the ability of parts of the collector and brushes of high voltage (speed limit) and high currents (torque limit).
Also note that at high voltages and currents forced cooling may be required.
Cooling The strength of an electrical machine is limited by the maximum allowable temperature of the windings. Power handling may increase the use of insulation can withstand higher temperatures or providing forced cooling to remove heat from the windings. Forced cooling is not normally required for fractional horsepower motors increased, but integral horsepower engines often include a high-cooling fan to push air into the machine. Forced air cooling can be effective in machines up to 50 megawatts, but larger engines with a power of several megawatts, as used in the electricity industry should use cooling liquid refrigerant flowing in the hollow conductors. The fluid may be water, but for larger engines using hydrogen because of low weight and high thermal capacity.
Gearing For a given torque, engine power is proportional to velocity. Engines at low speed will give you much power very low. Applications requiring high torque at low revs, it will be very high currents and disproportionately large engines. These applications are better served by mechanisms higher engine speed orientation to reduce speed and torque increases.
Size Vehicle size is determined by the pair has to offer. For similar engines with similar cooling systems engine torque is proportional to the volume of the rotor and therefore the engine total volume.
Profitability As mentioned above, for a given torque, engine power is proportional to the speed and electrical waste and drift tend to be broadly stable, relatively slow growth. Thus, increasing energy efficiency of the engine speed.
Efficiency is also dependent on engine size and tend resistance losses are much higher in smaller devices than larger machines can be designed in a more efficient magnetic circuit.
Cogging Cogging is jerky, non-uniform angular velocity of the machine rotor is particularly evident at low speed with a small number of poles. Is it because the rotor tends to accelerate as it approaches the stator poles and slow down when he leaves the poles. It is also obvious when DC pulsed used if the wave frequency of supply is very low. The problem can be reduced by using rotor windings through and increase the number of motor poles.
Losses:
Losses reduce the efficiency of the machine and usually result in unwanted heat.
Copper losses Are the I2R heat losses resulting from current in the windings. Loss of copper is variable, depending on the current and thus the load on the machine. Iron and other losses tend to be relatively stable. Stator winding resistance Rotor winding resistance
Iron losses These losses occur in the magnetic circuit.
Saturation This waste of energy associated with the use of materials at the fluence above the saturation point.
Hysteresis loss:
Copper losses Are the I2R heat losses resulting from current in the windings. Loss of copper is variable, depending on the current and thus the load on the machine. Iron and other losses tend to be relatively stable. Stator winding resistance Rotor winding resistance
Iron losses These losses occur in the magnetic circuit.
Saturation This waste of energy associated with the use of materials at the fluence above the saturation point.
Hysteresis loss:
Is the energy required to magnetize and demagnetize the iron magnetic circuit of each machine cycle. Since the loss per cycle is constant, it increases with frequency. More behind. Tailor Steel low hysteresis to reduce these losses.
Losses by eddy currents These losses are due to induced currents flowing in the side of the circuit device magnets, winding. Is minimized by using circuits laminated magnetic iron instead of solid iron. Plates insulating oxide inhibits flow by eddy currents between the strips.
Leakage flux In practice, the magnetic circuits is not always possible to concentrate all the magnetic flux where it is necessary for the optimum combination and the maximum energy exchange between the rotor and stator. Therefore, some of the available energy is lost.
Windage / friction Are mechanical damage resulting from drag the cursor's movement.
Power factor:
Losses by eddy currents These losses are due to induced currents flowing in the side of the circuit device magnets, winding. Is minimized by using circuits laminated magnetic iron instead of solid iron. Plates insulating oxide inhibits flow by eddy currents between the strips.
Leakage flux In practice, the magnetic circuits is not always possible to concentrate all the magnetic flux where it is necessary for the optimum combination and the maximum energy exchange between the rotor and stator. Therefore, some of the available energy is lost.
Windage / friction Are mechanical damage resulting from drag the cursor's movement.
Power factor:
Induction motor appears that the transmission line of electricity as a large coil and therefore the line current lags behind the applied voltage. The actual engine power then VAcosF V is the applied voltage, A is the current flow and F is the phase angle by which the current behind the voltage.
Cosf known as power factor. When F = 0 is the current phase of tension, cosf = 1 and there is no loss of power. When F = 1, the delay on the present tension of 90 °, cosf = 0 and there is no power actually delivered to the load. The factor (1 - cosf) represents the additional power that the machine must use from the source to deliver their rated power.
Generators As explained above, the response system in an applied force, all rotating machines are also acts as two motors and generators. The same electromagnetic forces involved in both cases, the same equations that represent the behavior of machines in both applications.
Note:
Cosf known as power factor. When F = 0 is the current phase of tension, cosf = 1 and there is no loss of power. When F = 1, the delay on the present tension of 90 °, cosf = 0 and there is no power actually delivered to the load. The factor (1 - cosf) represents the additional power that the machine must use from the source to deliver their rated power.
Generators As explained above, the response system in an applied force, all rotating machines are also acts as two motors and generators. The same electromagnetic forces involved in both cases, the same equations that represent the behavior of machines in both applications.
Note:
The voltage produced in each dc generator is inherently alternating and direct current is only after being corrected by the collector. Although rotating machines produce alternating current, not necessarily purely sinusoidal. The waveform depends on the size of the poles and the distance between them, the distribution of the windings and the flow into the void. The generator output waveform at the terminals is likely to adversely affect all but the most complex machines.
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