Split ratio optimisation of high‐speed permanent magnet synchronous motor with multi‐physics constraints

Abstract

Split ratio is one of the most crucial parameters in a permanent magnet synchronous machine (PMSM), which has great impact on both machine torque or power, and efficiency. Extensive studies have been carried out on the split ratio optimisation. Compared with the regular‐speed machines, the high‐speed PMSM has more types of power loss playing dominant roles, and has deeper coupling of multi‐physics fields. Therefore, special concerns need be made. More comprehensive and accurate power loss estimation should be implemented; both of the critical mechanical stress constraint of the rotor and the critical thermal constraint, which in turn are associated with the machine electromagnetic performance, should be analysed and must be satisfied during optimal design. All these concerns will be presented in this study. Based on these, a procedure of the split ratio optimisation is proposed. It solely uses analytical equations which are derived in this study, hence it is simple and fast. A 250 kW, 25 krpm high‐speed PMSM is taken as a study case, and its optimisation results using the proposed procedure are validated with finite‐element analysis. Moreover, influence of the split ratio on various machine performances is discussed.

Multidisciplinary Design Automation of Electric Motors—Systematic Literature Review and Methodological Framework

“…The type of validation depends on the analyses conducted, i.e., if the MDDA included high-fidelity simulations of one specific domain, validation can only be performed by even higher fidelity simulations or experimental results. In [8], an FEA-based validation is conducted for each analysis module. Reference [35] compares the results of their optimization workflow with an analysis in the software Ansys Motor-CAD for validation.…”

“…The contact pressure, the thermal expansion as well as the centrifugal forces are considered. Similar approaches to design rotor magnets and rotor sleeves are adopted in [8,39,55,73,75]. Some authors use analytical calculations for more detailed rotor and stator geometries as well, e.g., ribs in SynRM rotors by employing beam theory simplifications [36].…”

“…Overall, surface permanent magnet motors (SPM) predominate. The SPM motor type is often used for high-speed motors [8,55,73,75,100]. A general topology of SPM motors used in this review is shown in Figure 17b.…”

“…This often results in lengthy iteration cycles, increased project risks and prevents the inclusion of aspects from different domains in decision making. Various authors claim this to be a key factor for future electric motor development to meet rising efficiency standards [6][7][8][9]. For this reason, new design methods are suggested in the literature, which will be summarized under the term multidisciplinary design automation (MDDA) in this work.…”

Vector Control of Permanent Magnet Synchronous Motor Based on MRAS Method

“…The sampling type samples the three-phase voltage and obtains the input voltage through coordinate transformation. There is a certain phase delay and there is a large demand for sampling resources, which increases the workload of the control system [29,30]. Therefore, the voltage reconstruction technology is used to obtain the input voltage of the model, which can not only reduce the error between the input voltage and the actual situation, but also avoid increasing the burden of the control system and improve the accuracy of motor rotor estimation.…”