Compensation Methods for Regulating Parameters of Switch Voltage Converters

Abstract

Introduction. Approaches to the introduction of negative feedback in pulse control systems regulating the parameters of electricity flow with pulse-width modulation (PWM) continue to attract research attention in the field of switch power amplifiers (SPA) and switch voltage converters (SVC). Evaluation of the potential of compensation methods is of importance when selecting power electronics devices for various purposes.Aim. To review compensation methods for parameter regulation and to investigate conditions for the operational stability of SVC with feedback on output voltage and current.Materials and methods. The research methodology included the theory of pulsed automatic control systems, the method of harmonic linearization with stability assessment according to Nyquist criteria, and the generating filter method based on multiple frequencies.Results. An analysis of operational stability conditions was carried out.  Analytical dependences and graphical representation of the limit feedback values from the modulation parameters and the switch transformation scheme were proposed.Conclusion. The conducted study of the feedback depth in SVC, limited by the penetration of high-frequency components into the path of a width-modulated signal and its delay, due to the peculiarities of the terminal stage of the SPA, demonstrates that the limit value of the voltage feedback depth at typical circuit parameters does not exceed 12 dB, while the depth of the current feedback of the filter choke of the low frequencies can be fundamentally (more than 20 dB) higher. At the same time, the implementation of voltage stabilization and output current limitation modes for maintaining reliable operation in start-up and overload modes is possible only with the use of combined feedback.