Research On Pulse Power Source With Repetition Frequency And Short Pulse Duration Based On IGBTs

Pulsed power technology is an applied research of pulse with high voltage,heavy current and high power.With the development of pulse forming,pulse compressing and overlapping technology,new requirements and technical parameters like rising or falling edge,repetition frequency and power amplitude have to be considered.In order to study the micro biological effect of cells at experiments of Bio-electromagnetics,electrical pulse with high power is used as a stimulant.For producing the needed pulse with repetition frequency and high power,this thesis designs a pulse power source based on IGBTs.The parameters are as follows: 5000 V adjustable output voltage amplitude,adjustable frequency within 100~1000Hz and pulse width within 2us.By analyzing the typical generated ways and properties of high power pulse,this thesis uses the principle of Marx generation module to design the pulse source.Marx generation uses capacitor as the energy converter and generates high-voltage pulse by controlling the turn-on and turn-off of power solid-state switches.The whole system consists of three parts: adjustable high-voltage DC power source,Marx generation circuit and IGBT driving circuit.The high-voltage DC power source uses a control chip TL494 to modulate the BOOST converter.According to the principle of voltage-type Pulsed Width Modulation(PWM),a continuously variable DC output voltage within a range of 400 V to 1kV is produced.Marx generation circuit uses the principle “in parallel charging and in series discharging” of capacitor to generate electric pulse,and each capacitor is isolated by inductance and high-voltage diode.IGBT driving circuit uses a single chip STM32F107 to generate square wave,which width and frequency can be adjustable.By transferring and controlling the circuit,it supplies a driving voltage to drive IGBTs to turn on or turn off.The stability and feasibility of designed system is being tested and verified.Firstly,the experiment tests the waves of key components of designed high-voltage DC power source under load.Secondly,the output of designed Marx generation module with 1k? loading resistance is tested.The power pulse source is tested by analyzing the output versus different input conditions,including DC voltage amplitude,pulse width and repetition frequency.During the testing process,problems like severely damage of component at the moment when powering on,inconvenient adjustability,low IGBT driving power,etc.,are analyzed.The thesis presents some improved methods at the end.