Modeling and design of non-linear hybrid current controller suitable for high dynamic current loops

Groupe de Recherche en Électrotechnique et Électronique de Nancy (GREEN-INPL), 2 avenue de la Forêt de Haye, 54516 Vandœuvre-lès-Nancy Cedex, France

Corresponding author: Serge.Pierfederici@ensem.inpl-nancy.fr

Received: 17 February 2007
Revised: 17 April 2007
Accepted: 25 May 2007
Published online: 28 June 2007

Abstract

In this paper, the modeling and study of a new non-linear hybrid current controller is presented. It ensures high dynamic response of the current loop with a fixed switching frequency operation mode, a zero static error and high robustness properties as regard to system parameters variations. To model the proposed non-linear current controller, different tools are developed. In a first step a high frequency average model is proposed. It allows studying the average dynamic properties such as bandwidth, time response and overflow. To investigate the behavior of the current ripple due to the switching effect, a second model, based on the construction of a three-dimensional bifurcation diagram and the definition of a form function is established. This model allows studying the nature of the cycle described by the state trajectory and proving that the system operates with a fixed switching frequency. Design rules of the control parameters of this controller are explained and its robustness properties are tested by numerical simulations and experimental tests.