Research On DSP Based Digtal Control Of On-Line UPS

Digital control is being paid more and more attention in power electronics for its advantages such as control flexibility, performance stability and more powerful functions, compared with conventional analog control . The development of microelectronics provides more and more solutions for power electronics. And the entire digital control of UPS with modern control strategy becomes possible and urgent.An experimental control system based on TMS320F240 for single-phase on-line UPS is proposed in this dissertation. With single polar SPWM(Sine Pulse Width Modulation) , the whole solution of hardware and software is presented based on the resource of the DSP controller chip. The hardware of the control system mainly consists of the DSP controller, the sampling and pre-processing units of analog signals such as output voltage, output current, input voltage, etc, and the insulation and driving units of PWM signals. The software includes procedures to control and monitor the UPS such as software PLL(Phase-locked Loops), the value modulation of the output voltage, the producing of PWM signals and kinds of protectionsThe control system and operation principal are analyzed and verified by detailed simulation and experiment results. This dissertation not only put forward a digital control solution of UPS, but also is referential for designing DSP based control system.