CPLD Implementation In Switch Power Drive System Of High Power CO₂ Laser

High power supply technique is the key character of CO2 lasers, and the drive circuit is one of the most important factors for a switch power supply device in lasers. In order to enhance the performance of power supply, and steady the variation of laser power, a research work on drive and control system of switch power supply in high power CO2 laser has been done. The new method overcomes the disadvantages of traditional drive modes, such as complex in signal processing and easy to be interfered.A new kind of drive system, based on the co-operation of DSP and CPLD (Complex Programmable Logic Device), has been presented in the thesis. CPLD is the core chip in the drive and control system. It monitors and distributes the PWM drive signals which generate from DSP to intelligent power modules (IPM). The IPM has the self-protecting functions. The optic-couple isolation drive method has been adopted in the system.Different from traditional IGBT drive methods, the system mainly focuses on the CPLD that offers driving and protecting functions to the intelligent power module. Verilog HDL is used to realize logic functions of CPLD and can be programmed in system to fit different requirements in the experiments. Fiber, the medium that could ensure stability and accuracy of the signals in transmission, is used to transport both PWM drive signals and fault signals. In addition, the series connected drive mode, used between several drive boards, has made the modification and expansion of drive system easier and more convenient.The experiments on high power CO2 laser device show that this approach has satisfactory effects both on driving and protecting of IPM with quick response, and benefits in providing stable power to the laser.