Energy saving of motor is mainly realized through six programs such as choosing energy-saving motor, properly selecting motor capacity to achieve energy saving, using magnetic slot wedge instead of original slot wedge, using Y/△ automatic conversion device, power factor reactive power compensation of motor and liquid speed regulation of winding motor.
Energy consumption is mainly manifested in the following aspects.
1、Low motor load ratio.
Due to improper motor selection, excessive affluence or changes in production process, the actual working load of the motor is much smaller than the rated load, about 30%~40% of the installed capacity of the motor is running at 30%~50% of the rated load, and the operating efficiency is too low.
2、The power supply voltage is asymmetric or too low.
Due to the unbalanced single-phase load of the three-phase four-wire low-voltage power supply system, the three-phase voltage of the motor is asymmetrical, and the motor generates negative sequence torque, increasing the three-phase voltage asymmetry of the motor, and the motor generates negative sequence torque, increasing the loss in the operation of the motor.
In addition, the grid voltage is low for a long time, making the normal work of the motor current is large, and thus the loss increases, the greater the three-phase voltage asymmetry, the lower the voltage, the greater the loss.
3, the old, old (eliminated) type of motor is still in use.
These motors use E-grade insulation, larger size, poor starting performance, low efficiency. Although experienced years of transformation, but there are still many places in use.
4, maintenance management is not good.
Some units of motors and equipment are not maintained in accordance with the requirements of maintenance, allowing them to run for a long time, making the loss increasing.
Therefore, for these energy-consuming performance, it is worth studying what kind of energy-saving solutions to choose.
01
The selection of energy-saving electric and high-efficiency motors, compared with ordinary motors, optimizes the overall design, selects high-quality copper windings and silicon steel sheets, reduces various losses, and the losses drop by 20% to 30%, and the efficiency increases by 2% to 7%; the payback period is generally 1 to 2 years, some months.
In comparison, the efficiency of high-efficiency motor is 0.413% higher than that of J02 series motor. Therefore, it is imperative to replace the old motors with high-efficiency motors.
02
Proper selection of motor capacity to achieve energy saving The country has made the following regulations on 3 operating areas of three-phase asynchronous motor:
the load rate between 70%~100% is the economic operating area; the load rate between 40%~70% is the general operating area; the load rate below 40% is the non-economic operating area. Improper selection of motor capacity will undoubtedly cause waste of electric energy.
Therefore, using suitable motor, improving power factor and load factor can reduce power loss and save electric energy.
03
Using magnetic slot wedge instead of the original slot wedge magnetic slot wedge mainly reduces the no-load iron loss in the asynchronous motor. The no-load additional iron loss is generated in the stator and rotor cores by the harmonic flux caused by the tooth slot effect in the motor.
The high frequency additional iron loss induced in the core by the stator and rotor is called pulsation loss. In addition, the stator and rotor teeth are sometimes right and sometimes wrong, and the flux of the tooth surface cluster changes, which can generate eddy currents in the tooth surface line layer, resulting in surface losses.
Pulsation loss and surface loss are collectively called high frequency additional loss, they account for 70% to 90% of the motor stray loss, and the other 10% to 30% is called load additional loss, which is generated by the leakage flux.
Although the use of magnetic slot wedge will reduce the starting torque by 10%~20%, the iron loss of the motor with magnetic slot wedge can be reduced by 60k compared with the motor with ordinary slot wedge, and it is very suitable for the modification of motor with no-load or light-load starting.
04
Y/△ automatic conversion device is used to solve the waste of electric energy when the equipment is lightly loaded, and Y/△ automatic conversion device can be used to achieve the purpose of power saving without replacing the motor. Because in the three-phase AC grid, the voltage obtained by different connections of the load is different, and thus the energy drawn from the grid is also different.
05
Power factor of motor reactive power compensation to improve the power factor and reduce power loss is the main purpose of reactive power compensation. Power factor is equal to the ratio of active power to apparent power. Usually, a low power factor will cause excessive current, and for a given load, when the supply voltage is certain, the lower the power factor, the higher the current. Therefore the power factor is as high as possible to save power.
06
Liquid resistance speed control technology for wire-wound motor is developed on the basis of the traditional product liquid resistance starter.
It still adjusts the size of resistance by changing the pitch of pole plate to achieve the purpose of stepless speed regulation.
This makes it has good starting performance at the same time, it is energized for a long time, bringing the problem of heating up, due to the use of a unique structure and a reasonable heat exchange system, its working temperature is limited to a reasonable temperature below.
Liquid resistance speed control technology for winding motor, with its reliable work, easy installation, energy saving, easy maintenance and low investment advantages, has been rapidly promoted, for some speed control accuracy requirements are not high, speed range requirements are not wide, and infrequent speed control of the winding motor, such as fans, pumps and other equipment of large and medium-sized winding asynchronous motor using liquid speed control effect is remarkable.
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Professional electric motor manufacturers in China
Dongchun motor offers a wide range of electric motors that are designed and built to meet international standards and comply with the specific requirements of their clients.
The company has an extensive product portfolio that includes single-phase and three-phase AC motors, brake motors, gear motors, and special motors for customized applications.
