Research On Multi-performance Optimization Method Of Three-phase Open Winding PMSM Drive System

In recent years,the frequency conversion speed control systems based on AC motors have been widely used in various industries due to their excellent speed control performance and low cost.Among them,the topology of Open Winding Permanent Magnet Synchronous Motor(OW-PMSM)driven by a common DC bus type dual inverter has attracted more and more researchers’ attention due to its potential advantages.However,the multiple performance issues such as zero sequence current,high common mode voltage,and dual inverter temperature rise balance in this drive system have limited the practical application of this topology solution in production The use of transportation and other fields.Therefore,this article will build on the existing research of the OWPMSM drive system and optimize the existing multi performance issues and deficiencies of the common DC bus OW-PMSM drive system.Firstly,based on the topology structure of the common DC bus type OW-PMSM drive system,mathematical modeling is conducted for OW-PMSM and dual inverters respectively.Then,considering the feasibility and freedom constraints of synchronous suppression of zero-sequence current and common-mode leakage current under the combination of dual inverters switches,a multi-performance pulse width modulation strategy is proposed,and the basic principle and process of its implementation are deduced.On the basis of the proposed modulation scheme,a low-frequency zerosequence current suppression scheme based on PR controller is given.In addition,according to the selected power module device conduction loss parameters,the least squares method is used to fit the data,and the conduction loss of the dual inverters is analyzed.Finally,in order to better verify the validity and feasibility of the proposed modulation scheme,a simulation model is built using MATLAB and PLECS to simulate and experiment.The phase current,common mode voltage,high and low frequency zero sequence current and conduction loss of OW-PMSM drive system are analyzed by comparison.Simulations and experiments show that the proposed scheme is feasible and effective for multi-performance collaborative optimization of OW-PMSM drive system.By making full use of redundant space vectors,two sets of inverters generate small and identical sub-common mode voltage,which reduces the system common mode voltage amplitude by two-thirds compared with the traditional modulation scheme without introducing high frequency zero-sequence current ripple in the zero-sequence circuit.In addition,the frequency doubling effect of the motor phase current carrier harmonics can be achieved by selecting and ordering the appropriate vector positions.Total Harmonic Distortion(THD)of motor phase current is optimized,and the conductor loss of dual inverters is balanced better.In addition,low-frequency zero-sequence current suppression scheme based on multiperformance pulse width modulation strategy can achieve lowfrequency zero-sequence current suppression while maintaining low-amplitude commonmode voltage.