Abstract
Ozone has strong sterilization capability and does not cause re-pollution to the environment. However, since it has a short half-life, meaning that it deoxidizes into oxygen in a short time span, makes it impossible to be put in mass production and store in containers. Hence, for small scale applications like in domestic use, a miniaturized ozone generator would be very convenient. The dielectric barrier ozone generator is one of the quietest types among all discharge ozone generators. Therefore, the main purpose of this thesis is focused to design and implement a high voltage power supply for miniaturized portable dielectric barrier discharge (also called the silent discharge) ozone generators for the use in indoor environments. Basically, the contributions of this thesis can be summarized as follows. First, propose a high voltage power supply for silent discharge ozone generators used for indoor applications and miniaturization demands. The high voltage power supply consists of two stages. The front stage is a boost-type power factor correction circuit to achieve low current harmonics and high power factor. The second stage is a half-bridge high frequency series-parallel resonant inverter with zero-voltage switching to achieve less voltage stress and higher efficiency. Second, some design criteria are given for designing the high voltage power supply by employing the high frequency equivalent circuit model of the ozone generator together with a burst mode control to achieve more robust output voltage under changing loads. Finally, a high voltage power supply with 80~270Vac 60Hz input, 2kVac 300kHz output, and 500W rated power is actually implemented. The power factor of the front stage PFC is 0.95~0.99, and the highest efficiency may reach 96%. The second stage high voltage inverter can achieve an efficiency of 87% approximately. It turns out that the overall efficiency can reach 83.5%. Also, it is seen that the constructed prototype can indeed achieve the expected performance.