Research On Power Converter Based Starter-Generator System Emulator

The starter-generator controller is the core component of starter-generator system in modern electrified vehicles.Before the starter-generator controller is put into actual operation,its control algorithms and power converters must undergo various tests to ensure its reliability.Conventional digital off-line simulation makes many assumptions and ignores some key conditions in actual physical situation,and it is impossible to undergo full power test for power converters.Real-time physical simulation considers the actual physical environment,and power hardware-in-the-loop simulation can verify control algorithms of the starter-generator controller and undergo full power test for power converters.Therefore,the paper proposes a starter-generator system emulator based on power hardware-in-the-loop simulation to test the starter-generator controller.Firstly,the paper analyzes and compares the composition of power stage hardware-in-theloop simulation technology and interface algorithms in detail,and obtains the characteristics of different interface algorithms and power converter interfaces,which provides a theoretical basis for the establishment of the starter-generator system emulator.Secondly,in order to establish a starter-generator emulator based on permanent magnet synchronous motor,four steps of interface algorithm selection,power interface control,digital discrete algorithm and zero sequence current control are proposed.Thirdly,a transfer function model including a startergenerator controller and a starter-generator simulator is proposed to study the influence of the starter-generator controller current loop bandwidth on the starter-generator system.The stability of the system is improved with current-loop bandwidth of the starter-generator emulator improved,which makes the transfer-function characteristics of the starter-generator system emulator approach that of the original system.Finally,dual test platforms for the startergenerator system emulator and the starter-generator system are built to perform dynamic comparison test and bandwidth sweep test.The relevant test results can verify the effectiveness of the starter-generator system simulator.