Short circuit detection circuit and short circuit detection method for multi-phase rectifier at frequency domain

A short circuit detection circuit for a multi-phase rectifier, the multi-phase rectifier having a plurality of bridges connected in parallel, each bridge having two rectifying elements connected in series and a phase signal point (PSP) configured between the two rectifying elements, each PSP receiving an alternating current (AC) signal, each AC signal having a same frequency, the multi-phase rectifier rectifying the AC signals to output a full-wave rectified (FWR) signal, and the short circuit detection circuit comprising:

• a spectrum analyzing unit, receiving the FWR signal and analyzing a spectrum of the FWR signal in the frequency domain based on the same frequency of the AC signals to generate a detected signal indicating an amplitude of the same frequency of the AC signals;
• and
• a determination unit, electrically connected to the spectrum analyzing unit and receiving the detected signal and a reference signal to determine whether the detected signal is greater than or equal to the reference signal;
• wherein when the determination unit determines that the detected signal is greater than or equal to the reference signal, the determination unit outputs a result signal indicating that a short circuit condition exists among one of the rectifying elements within the bridges.