Real-Time Implementation of a Discrete Nonlinearity Compensating Multiloops Control Technique for a 1.5-kW Three-Phase/Switch/Level Vienna Converter

This paper presents and analyzes experimental results of a new discrete multiloop nonlinear control scheme, applied to a 1.5-kW laboratory prototype of a three-phase/level/switch boost-type Vienna rectifier. As for most split dc-bus voltage switched-mode rectifiers, the proposed control technique aims to ensure ac line currents shaping, output dc-bus voltage regulation and dc load unbalance compensation. The proposed technique is based on the dq nonlinear averaged model of the converter. To cancel the inherent nonlinearity of the converter, an input- to-output transform is applied to both inner and outer loops, thus linearizing the system and allowing the application of conventional linear pole placement method for controller tuning. The rectifier performance, during both nominal and severe operating conditions, are then evaluated in real-time using the dSPACE DS 1104 controller board, supported by a Matlab/Simulink real-time workshop environment.