Development of a New Bipolar Square Wave High-Voltage Pulse Power Supply

To meet the special requirements of high-voltage pulsed electric field liquid sterilization for pulse power supply, the traditional Marx circuit is improved. A bipolar square wave pulse power supply for liquid sterilization is designed by combining solid state switch with Marx circuit, which simplifies the control strategy and reduces the number of semiconductor switches. A discharge circuit for residual charge of diverse load is designed, which makes the bipolar pulse waveform have steep rising edge and fast falling edge, and has good circuit clamping function and load adaptability. An experimental prototype of bipolar square wave pulse power supply is developed, which is composed of adjustable dc power supply, three-stage full-bridge Marx circuit, and control protection circuit. The power supply can output high-voltage square wave pulse with voltage amplitude of $\pm$ 6 kV, frequency of 50 $\sim$ 500 Hz, pulse width of 2 $\sim$ 20 $\mu $ s, positive and negative pulse rising edge, and falling edge within 300 ns. The design of the discharge circuit enables the charge on the load to discharge quickly, which significantly steepens the pulse tailing and reduces the abnormal discharge during liquid sterilization, providing theoretical, and technical support for liquid sterilization technology.