Analyses our country electric power inverter characteristics and development trends
Power inverter characteristics and development trends: from the first frequency converter production, again after 30 years of research and development and the practice, at the same time as the new electronic technology unceasing enhancement, the function of the frequency converter design is more and more perfect, better stability, the inverter is more and more high cost performance, size smaller and smaller.
In the face of market competition, factory continuously improvements on frequency converter for more better.
Inverter is the use of power semiconductor devices the on-off function of the power frequency power conversion to another frequency power control device, can realize the ac asynchronous motor soft start and frequency control of motor speed, improve the operation accuracy, change the power factor, over current/over voltage/overload protection, and other functions.
Motor is to use the function of frequency converter to control, and reduce the starting current.
In order to produce the variable voltage and frequency, the equipment must first convert power supply of alternating current to direct current (
This process is called rectification.
The direct current (
Transformation of alternating current (ac) (
Device, the scientific term for & other;
General inverter is the dc power inverter for certain fixed frequency and voltage of the inverter power supply.
Frequency inverter for adjustable, adjustable voltage of the inverter we called frequency converter.
Sine wave inverter output waveform is simulation, mainly used in three-phase asynchronous motor drive with, also called frequency conversion governor.
Main used in instrument testing equipment for the waveform of variable frequency inverter, high demand, the waves to arrange, can output the standard sine wave, frequency conversion power.
General inverter frequency power is the price of 15
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Frequency converter as an important power conversion system components, provide controllable high performance variable voltage variable frequency ac power and got rapid development.
Converter performance, depends on the output voltage harmonic of motor, the influence of the second, we must look for grid harmonic pollution and input power factor, the energy loss in the third, we need to look at itself (
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Alternating frequency converter as an example, the paper expounds the development trend of it: the main circuit power switch components from shut off, the modularization, integration, intelligence, constantly improve the switch frequency, further reduce the switching loss.
The network side of the inverter converter device of low-voltage small capacity usually adopt six pulse converter, and to the middle of the large capacity device using multiple over 12 pulse converter.
Load side converter of low pressure small capacity unit often USES two level of bridge type inverter, and to the middle of the large capacity device adopts multilevel inverter.
For four quadrant operation of transmission, in order to implement the converter feedback and save energy, renewable energy to the grid side converter should be reversible converter, at the same time, the power can be two-way flow of dual PWM converter, the network side properly controlled inverter can make the input current is close to sine wave, reduce the pollution of power grid.
At present, the low and medium voltage inverter has this kind of product.