Research And Design Of High-power Power Supply Using For Ozone Generator

As a strong oxidizer, ozone is widely used in a great deal of respects，such as food disinfection, sewage treatment, medical and health care,environmental governance and industrial synthesis. With the development ofmodern technologies and the further understanding of the ozone, the ozonewill has more extensive application prospects. However, China lags far behindother developed countries in the ozone preparation technology. As the ozonegenerator, power is the most crucial and its performance affects the efficiencyand capacity of the ozone generator directly.At present, the low frequency boost power supply or pulse widthmodulation hard switching power supply is widely used by most of the ozonegenerator equipment manufacturers at home and abroad. For the former, thepower supply is huge and heavy, serious heat loss, and low efficiency. For thelatter, although the high-frequency or intermediate frequency switching powersupply is used, it can reduce the power supply size and weight, and improveefficiency. However, because of the switch working in a hard turn-on andhard-off state, the switching losses are more obvious with the increase offrequency, which have limited the improvement of the frequency of theswitching power supply and affected the power efficiency.Ozone generator of production being500grams per hour is researched inthis paper. A main circuit model of Buck topology SCR full-bridge resonantinverter is constructed based on the the capacitive load characteristics of ozonegenerator, PWM power regulation type of Buck Regulator and the feature ofSCR full bridge resonant inverter shutting down naturally after the resonant current crossing zero. The resonant circuit is constructed by the stored energyinductor of the Buck regulator and the capacitive loads of ozone generator inthis circuit model, which provide the resonant condition for SCR full bridgeresonant. The SCR can be turned off naturally after the resonant currentcrossing zero. It realizes the soft-switching control of SCR zero currentshutdown. Two kinds of control methods, i.e. constant frequency PWM powercontrol and adjustable frequency power control using for this circuit model arepresented. The feasibility of the circuit structure and the reasonable of the twocontrol methods are proved by the software simulations. The simulationresults show that the adjustable frequency modulation power has been limitedby the the inherent frequency of load, it can only work below the frequency ofthe load inherent frequency. However, the power adjustment using constantfrequency pulse width modulation is not restricted. The output powerincreases linearly with the increasing of the duty cycle of pulse width. The twocontrol strategies are considered synthetically in control system design. Finally,the designs that the mechanical structure, the hardwares and software of themain circuit and control circuit for the ozone generator prototype that theproduction is500grams per hour are achieved.