A PFC voltage regulator with low input current distortion derived from a rectifierless topology

Abstract

Abstract-This paper presents an ac-dc converter topology for realization of power factor correction (PFC) voltage regulators for applications where the mains frequency is high and a low input current harmonic is required, e.g., in aircraft power systems. The proposed converter represents a minimal configuration consisting of two basic converters, which can be systematically derived from a previously proposed general synthesis procedure for rectifierless ac-dc converters. The proposed PFC converter has incorporated a control method which drastically reduces the circulating power and hence raises the efficiency to a level comparable to existing PFC converters. The proposed PFC converter can completely eliminate any crossover distortion, which can be significant for supply systems having a high mains frequency. In addition, the proposed converter allows bidirectional energy flow ensuring all inductors work in continuous conduction mode hence eliminating the distortion due to the abrupt change of dynamic response when the operating mode changes. Analysis and design of the power and control circuits will be given and discussed. An experimental system will be presented for verification purposes.

Design and implementation of power factor corrected circuits without using inductor‐current sensors

“…In order to estimate the inductor-current, an inductor-current estimator is first proposed here, and a DSP is used to estimate the inductor-current. To our best knowledge, no previous papers have investigated this issue [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The basic principle of the inductor-current estimation method is discussed as follows.…”

“…Li proposed a novel four-switch for three-phase PFC circuit, which reduced its power devices by two [15]. Liu implemented a PFC regulator with low input current distortion that was derived from a rectifier-less topology [16], which could eliminate crossover distortion and allow bidirectional energy flow. Hui et al proposed a single-phase, three-level, flying capacitor PFC circuit without using an electrolytic capacitor [17].…”

“…Recently, predictive control has been widely used in power electronics. However, these previously published papers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], did not discuss this issue. In addition, the sensorless-current control algorithms of inductor-voltage estimation and inductorcurrent estimation were not compared.…”

“…In addition, two predictive controllers are used for this sensorless PFC circuit to effectively improve its dynamic responses. To the authors' best knowledge, the ideas of these two sensorless methods and the use of predictive control are original and have not been published in previous papers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These are the main contributions of this paper are discussed as follows:…”

“…FIGURE16 The voltage waveforms using estimated inductor-voltage at 400 W. (a) Voltage after rectifying, (b) inductor-voltage, (c) voltage command across the MOSFET.…”