Method of realizing wound-rotor motor redundant rotation speed feedback and device

Abstract

The invention discloses a method of realizing wound-rotor motor redundant rotation speed feedback and a device. The method comprises steps: according to the quantity of rotary shaft square wave signals within a unit time and the cycle of the rotary shaft square wave signals, a first real-time rotation speed is calculated; according to the cycle of rotor square wave signals, a second real-time rotation speed is calculated; whether the difference value between the first real-time rotation speed and the second real-time rotation speed is in a set range is judged; if not, whether the difference value duration time exceeds the set time is further judged; and if not, abnormal protection signals are sent. The device comprises an encoder, a differential signal processing circuit, a rotor frequency signal processing circuit, a main control module and a thyristor unit. The real-time rotation speed of the wound-rotor motor whether in a high-speed operation condition or in a low-speed operation condition can be timely and accurately fed back, the speed regulation mechanism of the wound-rotor motor can be safely protected, and a reliable guarantee is provided for safety operation of the wound-rotor motor.

Description

technical field [0001] The invention relates to a method and a device for realizing redundant speed feedback of a winding motor, and belongs to the technical field of motor speed control. Background technique [0002] Winding motors are widely used due to their simple structure, convenient use, reliable operation, high efficiency, easy manufacture and low cost. In order to obtain the speed regulation performance of the wound motor, the stator voltage regulation and speed regulation method with the speed feedback function is usually used. Currently, there are three speed feedback methods: tachogenerator, rotor frequency feedback and encoder feedback. Because: (1) When using a tachogenerator, there will be disadvantages of residual voltage and phase error, and the size and nature of the load will affect the amplitude and phase of the output voltage; (2) When using rotor frequency feedback, when the winding motor When the torque and the speed are in the same direction, the sp...

AI Technical Summary

Problems solved by technology

Because: (1) When using a tachogenerator, there will be disadvantages of residual voltage and phase error, and the size and nature of the load will affect the amplitude and phase of the output voltage; (2) When using rotor frequency feedback, when the winding motor When the torque and the speed are in the same direction, the speed of the wound motor is inversely proportional to the rotor frequency, that is, as the speed of the wound motor increases, the rotor frequency decreases, resulting in a slower feedback response, so that the wound motor cannot be fed back in time. Rotating speed

Therefore, when the torque of the wound motor is in the same direction as the rotational speed, when the wound motor is running at high speed, the rotor frequency feedback cannot detect and feed back the abnormal situation of the wound motor speed in time; (3) When the encoder feedback is used, when When the winding motor is running at low speed, the feedback response of the encoder is slow, resulting in the abnormal situation of the speed of the winding motor cannot be fed back in time; and the feedback signal of the encoder is a weak current signal, which is easily disturbed

Therefore, there are certain defects in the above three speed feedback methods, which are not conducive to obtaining the speed regulation performance of the winding motor and the safe operation of the winding motor

Images