A power supply
system and power
overvoltage safety protection control method, the power supply
system comprises an AC / DC
switching power supply, a spare battery and at least one DC / DC
transformer, and further comprises an
overvoltage detection unit which is used for detecting the output
voltage of each DC / DC
transformer in real time, comparing the output
voltage of the DC / DC
transformer with a reference
voltage and outputting a fault
signal. When detecting a dangerous voltage at a later stage output, the
system firstly clamps and absorbs a transient dangerous voltage, uses the
overvoltage detection unit to detect an overvoltage fault
signal synchronously, cuts off the power supply to each transformer from the AC / DC
switching power supply and the spare battery, and directly turns off a control
chip after converting the fault
signal into a proper voltage, thereby realizing the
tertiary protection of the system, avoiding the
safety risk possibly resulted from the input and output
short circuit of the transformer, and improving the reliability of the system.