High-Performance Digital Resonant Controllers Implemented With Two Integrators

• Published in: IEEE transactions on power electronics Vol. 26; no. 2; pp. 563 - 576
• Main Authors: Yepes, A G, Freijedo, F D, Lopez, Óscar, Doval-Gandoy, Jesús
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Active filters; Applied sciences; Circuit properties; Circuits of signal characteristics conditioning (including delay circuits); Control systems; Controllers; Current control; Delay systems; Digital circuits; Digital control; Electric currents; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electrical machines; Electronic circuits; Electronics; Exact sciences and technology; Frequencies; power conditioning; Power electronics, power supplies; Prototypes; pulse width-modulated power converters; Regulation and control; Regulators; Resonance; Resonant frequency; Stability; Steady-state; Voltage control; Performance evaluation; Stability margin; High performance; Positioning; PWM power convertors; Prototype; Control system; Power electronics; pulse width-modulated power converters; Experimental study; Synchronization; Voltage control; power conditioning; Implementation; Current control; Digital control; Discretization; Power control; Resonance frequency; Power conditioning circuits; Discrete time; Integrator; Alternating current
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2010.2066290

Resonant controllers are one of the highest performance alternatives for ac current/voltage control. The implementations based on two integrators are widely employed to achieve frequency adaptation without substantial computational burden. However, the discretization of these schemes causes a significant error both in the resonant frequency and in the phase lead provided by the delay compensation. Therefore, perfect tracking is not assured, and stability may be compromised. This paper proposes solutions for both problems without adding a significant resource consumption by correction of the roots placement. A simple expression to calculate the target leading angle, in delay compensation schemes, is also proposed to improve stability margins by means of a better accuracy than previous approaches. Experimental results obtained with a laboratory prototype corroborate the theoretical analysis and the improvement achieved by the proposed discrete-time implementations.