Development of An All Solid State Bipolar Rectangular Pulse Adder

Since bipolar high-voltage pulses is more effective in the treatment of air purification, water treatment, and other applications than unipolar pulses, a newly developed bipolar high-voltage rectangular pulse adder is proposed with a new control strategy. The structure of the all solid state pulse adder based on the half-bridge structure has been improved by changing the driving signal of the MOSFETS in the main circuit to obtain high-voltage rectangular narrow pulses. Magnetic ring transformers with a common primary winding and rectifiers were employed to charge capacitors under a high frequency. Improved phase shift control strategy is proposed, which makes it possible to generate unipolar or bipolar pulses with or without chopping off over resistive and capacitive loads. The bias voltage in the pulse removed and the size of magnetic cores is reduced. A nine-stage laboratory prototype is assembled. Experimental results show that unipolar and bipolar rectangular pulses with an amplitude of 4 kV, frequency of 12 kHz, pulsewidth of 600 ns-4 μs, and rise time of 80 ns are obtained over different loads.