Natural Power Factor Correction Research Articles

Instantaneous-Power-Balance-Based Modulation With Natural Power Factor Correction for Single-Stage Bidirectional AC–DC DAB Converter

Instantaneous-Power-Balance-Based Modulation With Natural Power Factor Correction for Single-Stage Bidirectional AC–DC DAB Converter

Power factor preregulation in power supplies using modified single stage non-isolated interleaved Sepic converter with minimal part count

This paper pontificates on design and realization of low-cost single phase single stage modified interleaved Sepic (MILS) converter for power supplies. On contrary to the classical Sepic power converters, the introduced active power factor correction (APFC) converter involves simple idea of paralleling that enables low input and output ripples with minimal device count. The interleaving conceptualization also lessens current stresses and static losses. Also, this modified power processing converter reveals natural power factor correction (PFC) and zero current switching (ZCS) features by discontinuous conduction mode (DCM) operation. Furthermore, the practical corroboration of the proposed converter is built and tested for 250 W hardware model to affirm benefits with 92 % efficiency and their relevant outcomes are reported in this scope. Finally, the power quality (PQ) attributes like, input power factor (PF), total harmonic distortion (THD) over input current under stable and transient cases are disclosed to prove bettered PQ limits at the AC mains as prescribed by various IEEE-519 and IEC 61,000–3-2 standards.

Natural Power Factor Correction and Soft Switching Design for a Single-Stage Bidirectional Dual Active Bridge AC–DC Converter

Natural Power Factor Correction and Soft Switching Design for a Single-Stage Bidirectional Dual Active Bridge AC–DC Converter

Long Life Power Factor Corrected LED Driver with Capacitive Energy Mechanism for Street Light Applications

Conventional switch-mode LED drivers have problems such as poor performance in harmonic distortion, flickering, power factor correction, stresses on the switches, high switching losses, large size, and high cost. To resolve these problems, we propose a long-life LED driver with the ability of power factor correction. The proposed system is based on the integration of a half-bridge LLC resonant converter and two boundary-conducted boost converters. Both boost converters share a common inductor designed in such a way that both boost converters work in boundary conduction mode to attain the natural power factor correction. Half-bridge LLC resonant converter has soft switching characteristics, which assure the zero-voltage switching (ZVS) of primary-side switches and zero-current switching (ZCS) of diodes on the secondary side. This significantly reduces switching losses and improves the overall efficiency of the system. Voltage divider capacitors are used on the input side, which minimizes the bus voltages. The proposed system has two identical secondary windings with a coupled inductor to eliminate the mismatch between them, which powers two independent LED strings. The simulation of a 100-watt 240 V AC converter yields the approximate sinusoidal shape of the input current. It shows that the switches on the primary side are operated in ZVS and the diodes in ZCS. At 240-volt AC input, the efficiency is 87.4%, the total harmonics distortion (THD) is 10.98%, and the power factor (PF) is 0.98.

A Modulation Scheme With Full Range ZVS and Natural Power Factor Correction for Bridgeless Single-Stage Isolated AC–DC Converter

The ac side structure of a bridgeless single-stage isolated ac–dc converter reduces the number of components by sharing power switches between the bridgeless rectifier and the dual-active-bridge (DAB) dc–dc converter. However, it also makes it more difficult to achieve zero-voltage switching (ZVS) for the ac side switches. Therefore, a modulation scheme is proposed to achieve ZVS for all switches over the full ranges of the grid voltage and load. A quasi-fixed switching frequency control method is also applied, in which the switching frequency is constant during a half-cycle of the grid voltage. By adjusting the switching frequency, the grid side inductor can operate in critical conduction mode without a zero-current-detection circuit, which facilitates the ZVS realization of the ac side switches. In addition, a natural power factor correction can be realized without the grid-side current sensors. Finally, a 500 W prototype was built to validate the theoretical analysis and the effectiveness of the proposed modulation scheme.

A Single-Stage Natural Power Factor Corrector Based on Dual Active Bridge DC–DC Converter Without Inner Current Tracking Loop

In this article, a single-stage ac-dc based on the dual active bridge with natural power factor correction is proposed. A modulation strategy and a control technique have been given to achieve the unity power factor of the ac side without inner current tracking loops and lookup tables. A notch filter is used in the output voltage feedback path to reduce the influence from the low-frequency output-voltage ripple to the regulator. All of the input-side power devices can achieve zero voltage switching (ZVS) on and all of the output-side power devices can achieve ZVS under certain load conditions with the proposed control strategy. The ZVS conditions and parameter design are given in this article. A 1.4-kW prototype has been fabricated to verify the effectiveness of the proposed converter and control strategy.

DCM-Based Bridgeless PFC Converter for EV Charging Application

This article proposes a single-phase switched-mode bridgeless ac–dc buck–boost derived converter that can serve as a front-end converter for the on-board electric vehicle (EV) charging application. The bridgeless scheme rules out the orthodox bridge rectifier and the affiliated losses. The proposed converter operates in discontinuous current conduction mode (DCM), thus achieving natural power factor correction for variable ac input. In addition to this, sensing of input voltage and input current is fended off because of DCM operation making the converter reliable, cost-effective, and robust compared with conventional continuous current conduction mode converters. Furthermore, the control becomes simple with the employment of a single sensor and the elimination of the phase-locked loop. The proposed front-end converter is well suited for low-voltage battery chargers ranging between 1.0 and 3.3 kW installed in golf-carts and E-rickshaws. A comprehensive steady-state analysis for one switching cycle and the design equations of the proposed converter are presented. The small-signal model of the proposed converter is presented for the implementation of the closed-loop control. Experimental results from a 1.0-kW concept-proof hardware prototype have been demonstrated, which upholds the converter analysis.

A Bridgeless Resonant Pseudoboost PFC Rectifier

In this paper, a new bridgeless single-phase ac-dc converter with a natural power factor correction (PFC) is proposed. Compared with existing single-phase bridgeless topologies, the proposed topology has the merits of less component counts. The absence of an input diode bridge and the presence of only one diode in the current path during each stage of the switching cycle result in higher power density and less conduction losses; hence, improved thermal management compared to existing PFC rectifiers is obtained. The proposed topology is designed to work in resonant mode to achieve an automatic PFC close to unity in a simple and effective manner. The resonant mode operation gives additional advantages such as zero-current turn-on in the active power switches, zero-current turn-off in the output diode and reduces the complexity of the control circuitry. Principle of operation and the feasibility of the proposed converter are provided. Detailed experimental and simulation results are presented.

STUDI PENGGUNAAN PENYEARAH 18 PULSA DENGAN TRANSFORMATOR 3 FASA KE 9 FASA HUBUNGAN SEGIENAM

The 18-pulse converter, using Y or D -connected differential autotransformer, is very interesting since it allows natural high power factor correction. The lowest input current harmonic components are the 17 th and 19 th . The Transformer is designed to feed three six-pulse bridge rectifiers displaced in phase by 20 0 . This paper present a high power factor three-phase rectifier bases on 3-phase to 9-phase transformer and 18-pulse rectifier. The 9-phase polygon-connected transformer followed by 18-pulse diode rectifiers ensures the fundamental concept of natural power factor correction. Simulation results to verify the proposed concept are shown in this paper.

Three-phase single-stage AC/DC boost integrated series resonant converter

A new ac/dc 3-/spl phi/ single-stage converter is proposed integrating a 3-/spl phi/ discontinuous current mode (DCM) boost with a dc/dc fixed frequency series resonant converter (SRC). This converter has the following features: natural power factor correction, soft switching, high-frequency (HF) transformer isolation with the series resonant tank operating in above resonance mode, etc. A new complementary gating control scheme is used for simultaneous control of boost converter and the SRC. Modes of operation are presented and analyzed. Based on the analysis, design curves are obtained. An optimum design is given and a design example is presented. Results obtained from SPICE simulation for the designed converter are given to verify the performance of the proposed converter for varying load as well as line voltage. Experimental results obtained from a laboratory prototype converter are presented to verify the theory.

A Novel Soft-Switching High-Frequency Transformer Isolated Three-Phase AC-to-DC Converter With Low Harmonic Distortion

A high-frequency transformer isolated, fixed-frequency, 3-/spl phi/ single-stage ac-to-dc converter using a boost-integrated bridge converter that employs a new gating scheme is proposed. This converter enjoys natural power factor correction with low line current harmonic distortion and symmetric high frequency voltage and current waveforms while ensuring zero-voltage switching for all the switches for a wide variation in load and line voltage. Various operating modes of the converter are presented and analyzed. Based on the analysis, design curves are obtained and an optimum design is given. A design example is presented. Results obtained from SPICE simulation and a 500 W output experimental prototype are given to verify the performance of the proposed converter for varying load as well as line voltage.

Soft-switching single-stage AC-to-DC converter with low harmonic distortion

A 1 /spl phi/ high-frequency (HF) transformer isolated, soft-switching single-stage ac-dc converter with low line-current harmonic distortion is presented. Its operation is explained with equivalent circuits for the various intervals. The converter is analyzed and design curves are obtained. An optimization parameter is introduced and a systematic design procedure is illustrated with a design example. Detailed SPICE simulation and experimental results of a 500 W converter with load as well as line voltage variation are given to verify theory. The proposed converter employs a zero-voltage transition (ZVT) network to ensure zero-voltage switching (ZVS) at all loads, and natural power factor correction is ensured using a simple control circuit.