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How does an impulse voltage generator generate various waveforms

Apr. 26, 2024

  The impulse voltage generator is mainly used for conducting impulse voltage tests on power equipment and other test objects,including full wave lightning impulse voltage,cut-off lightning impulse voltage,and operating impulse voltage,to test insulation performance.A complete set of impulse voltage(current)testing devices for various capacities of the 100-10000kV series.And can provide a variety of waveform series complete sets of impulse voltage(current)generators.
impulse voltage generator
  The impact test device mainly consists of a generator body,a cut-off wave,a voltage divider,a four component control console(which is divided into microcomputer and ordinary types),a digital waveform recording system,and so on.High voltage electrical equipment in the power system needs to undergo impulse voltage testing before being put into operation to verify its insulation performance under overvoltage.

  With the development of power technology,the types of test specimens that require impulse voltage testing are increasing.An impulse voltage generator is a high voltage generating device that generates lightning impulse voltage waves and operational overvoltage waves,and is the basic testing equipment in a high-voltage laboratory.

  Impulse voltage generators usually use Marx circuits,where C is the stage capacitor,which is connected in parallel by a charging resistor R and charged to V through a rectifier circuit T-D-r.At this point,because the protection resistance r is generally about 10 times larger than R,it not only protects the rectifier equipment,but also ensures that the charging of capacitors at all levels is relatively uniform.In the first stage,g0 is the ignition gap,which is initiated by the ignition pulse;In other levels,g is the middle ball gap,and they are adjusted one by one after starting at g0.These ball gaps act as control switches in the circuit.When they all act,all stage capacitors C are connected in series through the wave head resistors Rf of each stage and charged to the load capacitor C0.

  At this point,the total capacitance after series connection is C/n,and the total voltage is nV.N is the number of stages in the generator circuit.Due to its small size,C0 quickly becomes fully charged,and then it will discharge along with the stage capacitor C through the tail resistors Rt of each stage.In this way,a high voltage transient pulse waveform of impulse voltage is formed on the load capacitor C0.During this brief period,due to the charging resistance R being much greater than Rf and Rt,they act as isolation resistors between each level.

  The impulse voltage generator uses multi-stage capacitors for parallel charging and series discharging to generate the required voltage.Its waveform can be adjusted by changing the resistance values of Rf and Rt,the amplitude can be adjusted by the charging voltage V,and the polarity can be changed by reversing the two poles of the silicon stack D.