The invention discloses a switch
machine driving
system with open-phase protection, and belongs to the switch
machine technology. A
digital input unit is provided with input signals DO1 and DO2; a
relay is controlled to be sucked up or closed by input signals DO1 and DO2; by controlling the input sequence of the input signals DO1 and DO2, a first output interface or a second output interface of a commutation circuit is enabled to output, and the actuation of a first
electronic switch or a second
electronic switch is controlled, so the commutation operation of the motor of a switch
machine is realized; an input
signal DO1 sequentially passes through the
delay circuit and the reversing circuit, and an input
signal DO2 sequentially passes through the
delay self-locking circuit and the reversing circuit. According to the invention, the
overcurrent condition is detected during locked-rotor and phase loss, the drive of the switch machine is
cut off, an open-phase protector is not needed, and protection of phase loss, locked-rotor and the like can be realized on hardware. The method that the
electronic switch is firstly disconnected and then connected compared with a
relay node is ensured by adopting digital quantity
delay, so that ignition arc of the
relay node can be effectively avoided.