Simulation of a Plasma Jet Power Supply with Feedback

A sinusoidal high-voltage high-frequency (20 kHz) power supply is simulated in the Matlab environment. In the power supply model developed, the principle of constructing the control system feedback signal from the load represented by the plasma jet equivalent circuit is proposed. The power supply main functional units are presented, including a rectifier with a filter, a step-down converter, an inverter, and a step-up transformer. To obtain better simulation quality, the characteristics of the chokes and the step-up transformer were refined on the mockups of these components. The feedback signal pickup points (the charge transferred to the nozzle wall) and the control signal application points (the controller and the step-down converter) are selected. The possibility of influencing the load through the obtained control channel is shown; the response time to the model disturbance was found to be 17 ms. The control system functional diagram demonstrates the possibility of regulating the plasma jet operation mode by using the charge transferred to the nozzle wall as the feedback signal. The control is performed by adjusting the voltage applied to the inverter-transformer-gas discharge system. The proposed model can be applied in constructing devices that use a plasma jet as an actuator, and also in designing high-voltage power supplies.