Performance Analysis And Design Optimization Of Switched Reluctance Motor

Switched reluctance motor has double salient poles structure and operates with a switched power supply, these inherent identities bring a non-liner saturation characteristic of switched reluctance motor's electromagnetic field. Performance analysis and design of switched reluctance motor are very different from conventional motor. The vibration that resulting acoustic noise in switched reluctance motor becomes fetters which restrict the development of switched reluctance motor drive. Theoretic analysis, simulation and experimental research are carried out with themes of performance analysis and design optimization of switched reluctance motor, and this dissertation is mainly composed as follows:Switched reluctance motor's electromagnetism design is the basis of motor design, also is the starting point of its optimal design. The electromagnetism design method is introduced; structural parameters of the motor selection are discussed step-by-step in detail. A prototype motor's frame is built according to the design methodology, and finite element simulation analysis of the prototype motor is presented with single-phase excited and double-phase excited working modes. The magnetic field distribution, static performances, dynamic performances are simulated and investigated, also, motor with two different winding constructers are simulated and compared.Minimize switched reluctance motor's vibration and noise is the priority of design optimization. A basic description of noise sources, noise cancellation and mitigation is introduced. And the qualitative design measures to reduce the noise are implemented in initial design stage. The principle of virtual work and principle of virtual displacement are employed to analysis the magnetic forces, by using a generalized variable , energy storage is presented as a function of flux and generalized variable, the analytical expression of radial force and tangential force is obtained by choosing different variable. The stator's angular natural frequency is calculated based on the conversation of energy. From the expressions, key configuration parameter which influences the vibration and noise is extracted. Then the parametric simulation analysis is carried out to investigate the motor's performances including the limiting case. Basic and effective design optimization principle is summarized. The results form the basis of switched reluctance motor drive system design optimization. In this dissertation, the optimal design of switched reluctance motor is divided into two aspects:Switched reluctance motor's fuzzy optimal design method is proposed, the fuzzy optimal model including fuzzy constrained restriction and fuzzy object function are established with considering the uncertain information. The model with fuzzy constrained restriction transforms into general optimization model by build subjective function which has fuzzy bound transition, and solving the optimal level sets. The model with fuzzy object function transforms into general optimization model by build single fuzzy object function, build integrated fuzzy function. Both the transformed models are solved by genetic algorithms. The methods are applied to optimize the motor, and the results showed that switched reluctance motor fuzzy optimal design is rational.An optimal rotor's structure which mitigates motor's vibration and noise is presented by fine tuning rotor structure to improve the distribution of radial force. Set circular holes on the rotor without filling materials to reduce the magnetic flux at the aligned position, the circle center locates at the cross point of rotor pole center line and axis concentric circle. Based on the permeability theory, reduce the magnetic flux at the aligned position; further more reduce the radial force amplitude from the motor's noise origin. The optimal rotor structure's reluctance equation is deduced, and finite element simulation is carried out especially with two parameters which decided the optimal structure. The optimal motor's performance is analyzed under different controlling modes including single phase excited mode, double phase excited mode. And it is verified with a prototype motor, the output torque is ensured while the radial force is reduced effectively. And optimal structure has the advantage over the conventional switched reluctance motor and Y- asynchronous motor with same grade in noise.