Abstract：Traditional UPS bypass power-down detection use voltage RMS detection, voltage instantaneous value detection or a combination of them., so has low detecting speed or weak anti-interference ability. With d-q transform and inverse transform, IIR filter and voltage segment detection, can improve detecting speed (<6ms) and the control system’s robustness, then solve the deficiency of the traditional power-down detection. Calculate the analog filter’s poles according to digital filter’s performance, then calculate the analog filter’s transfer function with these poles, then use bilinear z transform to calculate the digital filter’s transfer function to realize the design of IIR filter. Finally, verify the feasibility of algorithm and theoretical analysis on a 80kVA digital controlled three phase UPS model machine.
2016, Vol. 17 
