Wheel hub safety chain of megawatt wind generating set

The utility model discloses a wheel hub safety chain of a megawatt wind generating set. The wheel hub safety chain comprises a plurality of variable-pitch drivers, a plurality of safety relays corresponding to the variable-pitch drivers, a wheel hub overspeed relay and a switching power supply device, wherein the plurality of variable-pitch drivers are connected with the wheel hub overspeed relay after being sequentially connected in series; the wheel hub overspeed relay is respectively connected with the plurality of safety relays and then is in ground connection; each safety relay is connected with a diode in parallel; the switching power supply device is respectively connected with the plurality of variable-pitch drivers and the wheel hub overspeed relay; a circuit of each variable-pitch driver connected with the switching power supply device is internally connected with a normally open contact of the corresponding safety relay in series, and the safety relay corresponds to the current variable-pitch driver. When the variable-pitch drivers have failure or a wheel hub is overspeed, the safety relays are controlled to lose power by disconnecting the wheel hub safety chain, so that drive servo motors are controlled to be stopped in a way of emergency feathering respectively by the variable-pitch drivers, and the reliability and the safety of the set can be improved.