Demchenko Y. High frequency power factor correctors in power supplies with transformerless input

Demchenko Yu.S. High frequency power factor correctors in power supplies with transformerless input. – Manuscript. Dissertation for the degree of the candidate of technical sciences (doctor of philosophy) in specialty 05.09.12 "Semiconductor power converters". ‒ National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Kyiv, 2019. The dissertation is devoted to solving the scientific and technical problem of improving the existing control methods of active high-frequency power factor correctors in power supplies with transformerless input for increasing the level of electromagnetic compatibility of semiconductor power converters with the power supply network. The dissertation analyzes the literary sources devoted to the methods of increasing the power factor of semiconductor power converters: the borderline control method, the peak current control method and the average current control method. Analog and digital correction control systems are investigated. To eliminate the distortion of the input current and extend the operating range of the corrector the scheme of additional transistor switching was developed. To improve the spectrum of the corrector with peak current control method it is proposed to introduce an additional corrective influence into the control system. The developed third-harmonic filtering control method allows to reduce the magnitude of third harmonic and greatly improves the input current spectrum. Digital peak current control with the correction of a derivative reference signal is developed, which allows to simplify the structure of the control system. The paper presents a digital system that implements the adaptive control of the power factor corrector and provides the required compensating sawtooth voltage slope over the entire range of input and output voltage. Keywords: control method, control system, current quality rate, electromagnetic compatibility, power factor corrector, semiconductor converter, total harmonic distortion.