Alternating current pitch control system using electric network to drive emergency feathering

Abstract

The invention relates to an alternating current pitch control system using an electric network to drive emergency feathering. The pitch control system consists of a main control unit and three driving units, wherein the main driving unit is respectively connected with the three driving units by cables, the power supplying of the driving units is improved by a power cable, and the transferring of control signals of the main driving unit and the three driving units is realized by a signal cable. Three asynchronous motors are used as pitch control motors to respectively drive three blades, and the conversion of voltage grades can be realized by the star / delta conversion of the motors. When the alternating current pitch control system normally works, the motor drivers drive the pitch control motors to control pitch angles of the blades. When any motor driver has a fault, the alternating current pitch control system is automatically switched into the electric network to supply power to drive the pitch control motors to realize feathering, and after the feathering position is reached, the power supply of the electric network is automatically cut off. In the feathering process with power supplying by the electric network, if the electric network has a fault, the alternating current feathering system is switched to the motor drivers, the power is supplied by a standby power supply to the motor drivers, and then the feathering operation of a non-fault shaft is realized.

Description

technical field [0001] The invention relates to a pitch changing device of a wind power generating set, in particular to a pitch changing device using an AC motor. Background technique [0002] The pitch system in the wind turbine plays the role of regulating power and aerodynamic braking. In order to ensure the safety of wind turbines, the pitch control system must be able to achieve feathering in any situation. Failure to achieve feathering may lead to catastrophic consequences such as speeding of the wind turbine and collapse of the tower. [0003] At present, electric pitch systems are widely used in wind turbines. Electric pitch systems mainly include DC pitch systems and AC pitch systems. The DC pitch system can be realized by switching the battery to the DC motor armature in case of emergency. Feathering, but the DC pitch system has the disadvantages of high cost, and the DC motor reversing device needs regular maintenance; compared with the DC pitch system, the AC p...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the disadvantage that the existing AC pitch system cannot complete feathering when the motor driver fails, and propose an AC pitch device that uses the power grid to drive emergency feathering. The present invention can realize the AC pitch system in the motor Complete feathering in case of drive failure

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