Study On High Voltage Pulse Generator Using Computer Control

With the increasing requirements of convient, nutritious and healthy food, many traditional food processing methods are strongly challenged by new techniques.As far as in the field of sterilization, the traditional method is thermal processing. As we all known, the thermal processing brings great damages to the appearance and quality of food, such as nutrition, favor and color, as well as other processing problems. Therefore, low-temperature, high-effective method is needed. Under this background, non-themal sterilization becomes more widely used, including the adoption of aseptics, deliminating microorganisms by centrifuge and radiate processing. High pulsed electric field is a newly-developed non-themal sterilization method, which utilize high pulsed electric field to sterilize bacterium, with the characteristic of short time, high effective and low energy consume.Owing to the promising application of the HPEF, an integrative high voltage pulsed generator is developed, which provides changeable pulsed width and voltage pulsed intensity, and the key problems of generating high pulsed electric fields are settled as a result.Main contents and results of this thesis are as follows: 1 , The history of food processing by high pulsed electric field development is reviewed, as well as thecurrent problems. 2, The high pulse generator system constitutes the main circuit and the control circuit. In the maincircuit, an H-bridge inverter circuit is applied to suffice the design of the high pulse generator.Meanwhile, in the inverter circuit IGBT is adopted as its switch component. Its advantages, such asfast switching and low energy consume, assure the high current and low dithering of high pulsegenerator in the high pulse grade.3 , In the control system of the high pulse generator, microcomputer alongs with LCD screen are usedto design the friendly man-machine interface. Special chips, such as SG3525 and IR2110 are also used to generate PWM and to drive the IGBT.4, With C51 language, the system realized the modularization programme, including main program,keysboard scan program, LCD display program, and communication of serials. With the use of Visual C++ language to the high voltage system, the software of PC actualized the communication between PC and the whole system.