Views: 0 Author: SDM Publish Time: 2024-10-08 Origin: Site
Inside the permanent magnet synchronous motor, rotary transformer (resolver) (referred to as rotary) is used to monitor the working condition of the motor, and the rotating position is at the back end of the drive motor.
1. Structure of rotary transformer
The rotating transformer is mainly composed of a rotating stator and a rotating rotor. The rotating transformer (referred to as a rotating transformer) is a signal element whose output voltage changes with the rotation Angle of the rotor. When the excitation winding is excited with a certain frequency of AC voltage, the voltage amplitude of the output winding is a positive and cosine function relationship with the rotor Angle, and this rotating transformer is also called sine and cosine rotating transformer. The sensor coil (excitation, sine, cosine three groups of coils) is fixed on the housing, and the signal coil is fixed on the rotor.
2. Function of rotary transformer
A rotary transformer is a rotor position sensor used to detect the position and speed of the rotor of a driving motor. After the output signal of the rotary transformer is decoded by the motor controller, the information of the motor speed, steering and speed can be obtained. It is a rotary transformer that uses the change of air gap reluctance and the change of output signal. It is an Angle sensing element that uses the change of air gap and reluctance according to the principle of electromagnetic induction to make the induced voltage of output winding change with the corresponding sine or cosine of the mechanical Angle.
3. Working principle of rotary transformer
The working principle of a rotary transformer is similar to that of an ordinary transformer, when a signal is input in the primary winding, an output signal is generated in the secondary winding according to the principle of electromagnetic induction. However, unlike the transformer, because the rotor of the rotary transformer rotates with the rotor shaft of the drive motor, there is relative motion between the primary and secondary windings, so the voltage amplitude of the output of the secondary windings will also change.
Because the rotating transformer structure ensures that the flux distribution in the air gap between the stator and the rotor (rotating one week) complies with the sinusoidal law, when the excitation voltage is added to the stator winding, the rotor winding will generate an induced potential through electromagnetic coupling.
4. Rotating transformer features:
Simple and strong structure: the rotary transformer is usually composed of two parts, the stator and the rotor, the structure is relatively simple and durable. This design enables the rotary transformer to work stably in a variety of harsh environments with low environmental requirements.
Reliable operation: Because the rotary transformer adopts a non-contact measurement method, it avoids the failure caused by the wear of the traditional mechanical sensor, thus improving its working reliability.
Large signal output amplitude: the rotary transformer can output a larger signal, which makes it more efficient and accurate in the signal transmission and processing process.
Strong anti-interference ability: the rotary transformer has strong anti-interference ability and can work normally in the environment with large electromagnetic interference, ensuring the accuracy and stability of the measurement.
High precision measurement: The rotary transformer can measure the angular displacement and angular speed of the rotating object with high precision, especially for occasions where the Angle position needs to be accurately controlled.
Widely used: Rotary transformers have a wide range of applications in industrial automation, servo control, aerospace, precision measurement and electric vehicles. For example, in CNC machine tools, the rotary transformer can be used to detect the angular displacement of the lead screw, thereby indirectly measuring the travel distance of the table; In the aircraft autopilot system, the rotary transformer can accurately measure the attitude and heading of the aircraft.
To sum up, the rotary transformer plays an important role in many fields because of its simple structure, reliable operation, large signal output amplitude, strong anti-interference ability and high precision measurement.