Numercial Calculation And Experimental Study On The Performance And Parameters Of Permanent Magnet Machine

In the permanent magnet machine (PMM) design stage, the key technical problems in current stages are how to get the accurate performance indicators, and how to fast and accurately simulate the operating characteristics of PMM. This thesis establishes a time-stepping Finite Element Method (FEM), and propose some procedures for obtaining the key performance indicators from the operation curve obtained by time-stepping FEM under reasonable calculation conditions. The variations of steady parameters under a wide range cross-saturated condition are studied, and nonlinear PMM simulation models for operation behavior analysis as well as a quick access method for the performance indicators are proposed. The main works are as below.1. In the study on common problems of PMMs' dynamic process, a time-stepping FEM model with field-circuit-motion coupled is established for meeting the demand of PMM design. The effect of contrived calculation conditions on the calculation of motor performance indicator is studied, and the method for calculating the key performance indicator is proposed. Compared with the actual test results, the good computational accuracy of the calculation model is verified.2. Aiming at the difficult access of "the minimal torque" as one of the key indicators during the start process of Line-Start Permanent Magnet Synchronous Motor (LSPMSM), this thesis studies the problem which is revealed that under some conditions the intense ripple torque may submerge the actual existed minimal torque. An optimized loaded simulation experimental method based on time-stepping FEM as well as a novel data processing method is proposed, which provide the effective way to strike the minimal torque fast and accurately.3. Through the FEM research of the loaded performance of PMM, the existence of cross-saturation effect is confirmed. Aiming at the shortage of direct load method on testing the reactance parameters, the steady model considering both the quadrature-and direct-axis components of permanent magnet excitation potential is proposed, and the quadrature-direct axis armature reaction inductances of the LSPMSM under the rated voltage are obtained. Furthermore, the frozen permeability method is introduced to study the steady parameters varying with load conditions, such as the quadrature-direct axis armature reaction inductances, the mutual inductance, and the quadrature-direct axis flux linkage excited by the permanent magnet solely.4. This thesis also proposes a nonlinear dynamic model for fast and accurately simulation of the PMM dynamic characteristics, while a new method for the direct access of permanent magnet motor and generator steady performance is proposed. The former method is used to study the start process of LSPMSM, which can fast obtain the accurate results. In addition, the latter method is used to calculate the performance indicators for one direct-driven permanent magnet generator. Many key indicators, such as overload capability and power factor at steady operation, are obtained which point out the design of the generator is conservative and provides the direction for optimizing the design.