Flying Fiber Laser Marking Machine Automatic Mark Production Line For Can PVC Bags Plastic Bottle Marking Machine
Enclosed Type
Jinan stone engraving machine, engraving machine, carving factory - home Jinan CNC equipment co. , LTD
by：Transon
2020-08-26
Engraving machine in the frequency converter is one of the most important part of, so the importance of the frequency converter, today we will learn about the, application of frequency converter to solving interference?
What anti-interference measures, the interference of frequency converter used in main show is: higher harmonic, noise and vibration, load matching, fever, and other issues.
These interference is inevitable, because of the frequency converter input part for the rectifier circuit, the output part of inverter circuit, they are all composed of nonlinear components in one of the switch, and in the process of open circuit, to produce higher harmonic, making it the input power and output voltage waveform and current waveform distortion.
The following analysis on harmonic problems and corresponding measures are put forward.
smaller inverter capacity, the influence of high harmonics is school but larger capacity or quantity is large, it must be dealt with by the higher harmonic current caused by higher harmonic interference, otherwise will affect the equipment and the detecting element, serious when can make the equipment misoperation. According to Britain's ACE report, various objects on the sensitive degree of higher harmonic is as follows: no influence motor under 10% ~ 20%; Instrument | | instrument voltage distortion of 10%, the current distortion, 10% error below 1%; Electronic switch more than 10% will produce false action; Computer is more than 5% will go wrong. In view of the above situation, in the industrial field, measures must be taken to reduce the interference, the interference suppression in the permitted range.
1. Cut off the interference of transmission
( 1) The spread of interference is often spread by common grounding line. Separate the grounding and the line of control of the power line is the basic method, cut off the way to the GND terminal of the power plant to the ground, will control the earthing terminal receives the device metal case.
( 2) Signal lines near the interference sources of the lead, interference will be induced into the signal lines, make the signal interference, wiring effective separation to eliminate the interference. In practical engineering need to put the high voltage cable, power cable, control cable are often separated from instrument cable, computer cable wiring, take different bridge. The main loop of the inverter control line are the best circuit wiring in vertical way.
2. Inhibition of higher harmonic
( 1) In inverter side before installing line reactor, inhibits tilting power supply voltage, and reduce the current of inverter produces distortion, avoid serious disturbance to the main power supply.
it is cheap, but restricting the efficiency of the harmonic is limited, and reactance is too large will produce unacceptable voltage drop loss.
( 2) In front of the frequency converter with LC passive filter, filter out the high harmonics, harmonic filter out five and seven, usually but all depends on the power and load, the method of flexibility.
( 3) Special filter used to detect frequency and phase, and generate a harmonic current at the same amplitude and opposite phase current, flux to the frequency converter, which can effectively absorb the harmonic current.
( 4) When equipment near the environment affected by electromagnetic interference, should be installed radio frequency interference filter, can reduce the number of main power conducted emission, and to take measures to block the motor cable.
( 5) When the motor cable length is more than 50 m or 80 m ( Opposite). , in order to prevent motor startup transient overvoltage, leakage current to ground and noise reducing motor, motor protection, installation reactor between inverter and motor.
( 6) Increase in the inverter power supply impedance. Internal resistance of power supply devices can usually cushion inverter dc filter capacitor of the reactive power, the greater the internal resistance, the smaller the harmonic content, the internal resistance is the short circuit impedance transformer. So choose the inverter power supply, had better choose large short-circuit impedance transformer.
( 7) Using polyphase transformer operation. General converter for six pulse rectifier, the resulting harmonic is bigger. If using polyphase transformer operation, the phase Angle difference each 30 & deg; , such as Y - Δ 、Δ - Δ Combined the effect of pulse transformer of 12, can reduce low harmonic current, very good restrain harmonics.
smaller inverter capacity, the influence of high harmonics is school but larger capacity or quantity is large, it must be dealt with by the higher harmonic current caused by higher harmonic interference, otherwise will affect the equipment and the detecting element, serious when can make the equipment misoperation. According to Britain's ACE report, various objects on the sensitive degree of higher harmonic is as follows: no influence motor under 10% ~ 20%; Instrument | | instrument voltage distortion of 10%, the current distortion, 10% error below 1%; Electronic switch more than 10% will produce false action; Computer is more than 5% will go wrong. In view of the above situation, in the industrial field, measures must be taken to reduce the interference, the interference suppression in the permitted range.
1. Cut off the interference of transmission
( 1) The spread of interference is often spread by common grounding line. Separate the grounding and the line of control of the power line is the basic method, cut off the way to the GND terminal of the power plant to the ground, will control the earthing terminal receives the device metal case.
( 2) Signal lines near the interference sources of the lead, interference will be induced into the signal lines, make the signal interference, wiring effective separation to eliminate the interference. In practical engineering need to put the high voltage cable, power cable, control cable are often separated from instrument cable, computer cable wiring, take different bridge. The main loop of the inverter control line are the best circuit wiring in vertical way.
2. Inhibition of higher harmonic
( 1) In inverter side before installing line reactor, inhibits tilting power supply voltage, and reduce the current of inverter produces distortion, avoid serious disturbance to the main power supply.
it is cheap, but restricting the efficiency of the harmonic is limited, and reactance is too large will produce unacceptable voltage drop loss.
( 2) In front of the frequency converter with LC passive filter, filter out the high harmonics, harmonic filter out five and seven, usually but all depends on the power and load, the method of flexibility.
( 3) Special filter used to detect frequency and phase, and generate a harmonic current at the same amplitude and opposite phase current, flux to the frequency converter, which can effectively absorb the harmonic current.
( 4) When equipment near the environment affected by electromagnetic interference, should be installed radio frequency interference filter, can reduce the number of main power conducted emission, and to take measures to block the motor cable.
( 5) When the motor cable length is more than 50 m or 80 m ( Opposite). , in order to prevent motor startup transient overvoltage, leakage current to ground and noise reducing motor, motor protection, installation reactor between inverter and motor.
( 6) Increase in the inverter power supply impedance. Internal resistance of power supply devices can usually cushion inverter dc filter capacitor of the reactive power, the greater the internal resistance, the smaller the harmonic content, the internal resistance is the short circuit impedance transformer. So choose the inverter power supply, had better choose large short-circuit impedance transformer.
( 7) Using polyphase transformer operation. General converter for six pulse rectifier, the resulting harmonic is bigger. If using polyphase transformer operation, the phase Angle difference each 30 & deg; , such as Y - Δ 、Δ - Δ Combined the effect of pulse transformer of 12, can reduce low harmonic current, very good restrain harmonics.
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