Based On The Dsp Line Ups Digital Control Technology

Nowadays, with more and more applications of UPS, the requirements for its performance get improved. Except for its main circuit, the control of UPS is very important to achieve perfect performance. The digital control technologies have now become the hotspot on the research of UPS technologies.This dissertation introduces the principle of the on-line UPS, and the SPWM technology for the UPS inverter is also discussed. The effect of blanking time on the output voltage in PWM inverters and the methods to eliminate it is described. The mathematical model of the single-phase full-bridge inverter is mentioned, and then the efficacy of PID control, deadbeat control, repetitive control, fuzzy control together with neural networks control for the UPS inverter is compared. The PID control and repetitive control for the UPS inverter are mainly focused. Finally, a control scheme which requires ordinary hardware, with good robustness and high dynamic response is presented. In this control scheme, the voltage error is processed by PI algorithms first, and then the current of the capacitor which equal to the differential of the voltage is imported to compose a two-loop control. The inverter with the proposed control scheme achieves nice performance.To realize the combination of theory and practice, the control of a 3kVA on-line UPS is well finished with the main processor TMS320F240.