Papers by Keyword: Power Factor Correction (PFC)

Abstract: A new-type LED switching power supply circuit using flyback converter is designed based on current-mode PFC controller chip L6562. The circuit has some characteristics such as simple structure, wide input voltage range, output stability and reliable operation. The experimental results show that the system efficiency is up to 89.46% when the input voltage changes from 85V to 265V(AC), meanwhile the system works stably with constant current and constant voltage output.

Abstract: Power electronic devices with front-end rectifier are widely used in industry, commerce and transportation, which result in low power factor. Though there are several proposed solutions to this, Single Ended Primary Inductance Converter (SEPIC) converter was the most successful one. But the conventional SEPIC converters suffer from high switching losses. Hence in this paper, a modified SEPIC converter is used to improve the power factor at the mains side. This paper presents the simulation and analysis of single phase single-switch, converter topologies of AC-DC SEPIC converter and modified SEPIC converter for Continuous Conduction Mode (CCM) of operation with 48V, 100W output power. The results of SEPIC converter and modified SEPIC converter are compared for closed loop analysis in simulation which is done in PSIM. It is found that modified SEPIC converter has high regulated output voltage and high power factor.

Abstract: This paper proposes the single phase ac-dc three-level boost converter with controller circuit such as sliding mode controller, proportional integral controller and employs three-level pulse width modulation technique. Solid state switched mode three-level boost converter along with the control methods achieve unity power factor, high efficiency, precisely regulated dc output in boost converter, reduced output voltage ripple and less than 5% of total harmonic distortion with unidirectional power flow. The outstanding feature of proposed control scheme is line current is driven to follow sinusoidal reference current command which is in phase with sinusoidal input voltage and guaranteeing dc-link capacitor voltage balance in every switching cycle. Comparative analysis of PI controller and sliding mode controller is carried out. The performances of converter under load variation, unbalanced load condition and sudden change in load condition for various control strategies were verified.

Abstract: This paper presents a Hardware implementation of single-stage solar based DC-DC converter for inductive load application. Solar model is connected in the input side. The circuit has two full wave converter connected to boost the voltage and also for the power factor correction. Switch-utilization factor is improved by using two active switches to serve in the PFC circuits. Controlled converter is used to load side along with pi filter. Finally inductive load is connected to output side. In the hardware circuit solar panel output voltage, transformer primary, secondary voltage and load voltage is measured. In the circuit used with all the component parameters to operate at zero-voltage switching which retains the high circuit efficiency. A circuit is designed for an 80v dc output and tested.

Abstract: Principles of traditional Boost PFC circuit are introduced. Based on average current control, a large signal model is obtained and turned into small signal model carrying constant load. And current regulator and voltage regulator are designed accordingly. Directing at strong non-linear characteristics of the circuit, this paper adopts double average method to analyze its low frequency stability. This converter can achieve high power factor in wide range of input and load power and simulation result shows that power factor is above 0.99.

Abstract: A PV power system with bi-directional inverter is proposed in this paper. The system is divided into two stages, one is power stage, which contains DC/DC converter and bi-directional inverter, the other is control stage. Both stages control schemes are by a micro-controller dsPIC30F4011. For preventing from high current harmonic caused by the two stages, a predictive current control and modulation principle are designed and operated in high frequency to reduce the current harmonic. The bi-directional inverter can operate in grid-connection (GC) mode or power factor correction (PFC) mode. But the core material of inductance will result in violent current ripple change when the inductor current promoted. So, a gain modulation is used to compensate various inductances used to reduce grid-connection current ripple. Finally, the system is implemented to verify the feasibility and performance of the proposed system.

Abstract: In the design of laptop power adapter, the former stage is the power factor correction PFC converter; the after stage is DC/DC converter. The control part controls chip through an integrated PFC and PFM control integrated. In this two structures, the former stage PFC often using traditional inductor current critical conduction mode Boost converter to achieve sinusoidal input current to the whole form, thus reducing input current harmonics with a high power factor, keep a long time , simple structure and low cost.

Abstract: Considering the distortion factor, the large power resistance spot welding (RSW) inverter power supplys actual power factor (PF) is very low. In this paper, the 3-phase 4-wire three-phase/switch/level (VIENNA) rectifier is proposed to realize the power factors correction (PFC). Firstly, an equivalent load model of the back-stage in the RSW inverter power supply is established, thus the real load of this PFC circuit can be archived. Then, the 3-phase 4-wire VIENNA rectifier PFC circuit is analyzed with the simulation software of Pspice. Finally, an experimental circuit power of 3kW is designed. Experimental results show that the PF of this system can be increased to 98.6% that demonstrates the practicability of the 3-phase 4-wire VIENNA rectifier in RSW inverter power supply.

Abstract: This paper designs a kind of new electrolytic capacitor-less LED (light-emitting diode) driver, which converts the commercial ac voltage to a pulsating current with twice the line frequency driving high-brightness LEDs. As no electrolytic capacitor is used, this driver possesses the unique advantage of long lifetime to match with that of LEDs. A method of injecting the third and fifth harmonics into the input current to reduce the peak-to-average ratio of the output current is also proposed. A 25V, 0.35A output prototype is built and tested in the laboratory, and the experimental results are presented to verify the effectiveness of the electrolytic capacitor-less LED driver and its control method.

Abstract: When nonlinear load is powered by DC grid, harmonic currents and distortion power are produced. At first, the concept of the DC active power filter (DC-APF) is presented in this paper after the analysis of instantaneous power and power factor in the DC network. The DC-APF includes the parallel type, the series type and the series-parallel type, etc. The circuit topologies and the working principles of two kinds of DC-APF are proposed and analyzed: (1) the general type, which can compensate harmonic currents and reactive currents; (2) the correction type, which can track the DC voltage. The comprehensive simulation analysis of the double-bridge half-controlled DC-APF by means of MATLAB/SIMULINK and the experiment of the correction type prove the validity and the feasibility of these topologies and operating principles.