The invention discloses a three-phase power supply default phase and power failure detection
system and a braking method. The detection
system comprises a three-phase power supply RST, a rectification circuit, a
relay circuit, an IPM circuit, two optocoupler
processing circuits, a
DSP processor, a braking circuit, a
Nixie tube and a
servo motor and is applicable to a
motor control system of a
servo driver. The braking method comprises the following steps: judging abnormal conditions such as default phase and power failure of the three-phase power supply, then closing a PWM
signal by the
DSP processor,
cutting off a
busbar power supply by virtue of the
relay circuit, starting and accessing the braking circuit, connecting a braking power
resistor among three-phase windings of the
servo motor in series for realizing short connection of the three-phase windings, and generating current in a short connection loop by virtue of residual
magnetism potential of a
stator winding, so that the motor is rapidly braked. The detection system and the braking method, which are disclosed by the invention, have the advantages that security protection effect on
electrical equipment and personnel is realized, implementation is easy, cost is low, and the problems that a motor in existing
electrical equipment adopts a band-type
brake module, price is high, size is large and control and wiring are complex can be solved, so that the detection system and the braking method have a good application prospect.