Design method of magnetic circuit method for permanent magnet synchronous motor
Through the calculation of the magnetic circuit of the permanent magnet motor, the performance of the initial design is checked by the relevant formula, and it is judged whether the error between the calculated result and the performance requirement of the motor is within the allowable range.
Magnetic circuit design process
1. The following data (performance requirements) are usually given when designing the motor:
1) rated power 2) rated voltage 3) phase number and phase connection method;
4) rated frequency; 5) rated speed or synchronous speed; 6) rated power factor.
2, motor design process
1) Preparation stage: collecting data, that is, relevant national standards, similar motor technical data including test data. Prepare a technical task book based on the analysis of the data.
2) Electromagnetic design: According to the technical task book, electromagnetic calculation is carried out to determine the punch size, core length and electromagnetic performance of the designed motor.
3) Structural design: determine the mechanical structure of the motor, the dimensions of the components, the processing requirements and the specifications of the materials.
• The magnetic circuit design is based on the requirements of the magnetic field, reasonably select the parameters and materials of the magnetic circuit, and design a magnetic circuit that is technically feasible, meets the requirements, has good economy, and can fully exert the material performance.
• For a given magnetic circuit, the magnetic circuit characteristics can be uniquely obtained.
• Given the requirements of the magnetic circuit characteristics, there may be multiple magnetic circuits that meet the requirements, and the purpose of the design is to find a magnetic circuit that meets the requirements.
Preliminary determination of magnetic circuit structure
The rotor magnetic circuit structure is different, and the running performance, control system, manufacturing process and applicable occasions of the motor are also different. Depending on the position of the permanent magnet on the rotor, the rotor magnetic circuit structure of the permanent magnet synchronous motor is usually divided into two types: surface mount and built-in.
1) Surface mount protruding rotor magnetic circuit structure
The utility model has the advantages of simple structure, low manufacturing cost and small moment of inertia, and is mostly used for a rectangular wave permanent magnet synchronous motor and a permanent magnet synchronous motor with a constant power operation range.
2) Surface mount plug-in rotor magnetic circuit structure
This structure can make full use of the reluctance torque generated by the asymmetry of the magnetic circuit of the rotor structure, and improve the power density of the motor. The manufacturing process is also relatively simple. Usually used in some variable speed permanent magnet synchronous motors.
