Delayed alarm method for direct current variable pitch motor

Abstract

The invention discloses a delayed alarm method for a direct current variable pitch motor. The method includes: a set step is that electric current loop set in an electric current loop control circuit is changed, and the maximum overload multiple, the maximum overload time and delay time of a time-delay program are set; an accumulative step is that when electric currents start to rise, an accumulated value of an accumulator starts to accumulate in a timing mode, and when the electric currents start to fall, the accumulated value starts to decrease until zero; a protection step is that after given electric currents reach the maximum overload multiple of rated currents and the accumulated value reaches the maximum overload time, the electric current loop control circuit decreases the given electric currents to the rated currents; a delayed alarm step is that within the delay time, the situations that the given electric currents keeps the rated currents constant, and the rotation speed of a direct current series excited motor is smaller than a zero-speed threshold value all along are judged; if yes, the output of an actuator is cut off and failure warning is alarmed; and if not, actions do not happen. According to the delayed alarm method for the direct current variable pitch motor, the production efficiency and the safety performance are improved.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a delay alarm method for a DC pitch motor. Background technique [0002] At present, the DC pitch system occupies a large market in the pitch system used in wind farms. The DC pitch system can directly return the pitch through the backup power supply, thereby increasing the reliability of the system. In the DC pitch system, the DC series excitation Due to the advantages of large starting torque and strong overload capacity, the motor has become the first choice for DC pitch motors. However, in the actual application of wind farms, it is often found that the pitch motor burns out. The reason is that the gearbox is stuck in some cases. , In some cases, the brake is not released, causing the motor to be heavily loaded or even stalled, and the current is too large for a long time to burn the motor. [0003] Due to the soft characteristics of the series-excited motor, when the ex...

AI Technical Summary

Problems solved by technology

Although the series-excited DC motor has a strong overload capacity, if the motor is always locked, the output of the speed loop of the drive will be saturated, that is, the current loop setting is always the maximum. Assuming that the maximum given current is 3 times the rated current of the motor, then in the current loop Under the action, the motor current always maintains 3 times the rated current output of the motor when the rotor is locked. Under the action of such a large current, the motor will burn out after a long time