Novel three-phase power factor corrector suitable for charging systems

This paper proposes a three-phase power factor correction (PFC) for a three-phase induction motor (IM) drive under normal and abnormal supply voltage conditions. A new technique of PFC based on a positive sequence components method is introduced. The PFC circuit uses a SEPIC converter with a single switch, which needs only one control signal. The PFC control method with the proposed technique provides nearly sinusoidal supply currents maintaining a high power factor under different supply voltage conditions. Furthermore, the PFC method maintains DC bus voltage at the desired value. The regulated DC voltage feeds a four-switch inverter of the three-phase IM drive system. Mathematical analysis of the equivalent circuits based on operation modes of the SEPIC converter is introduced. The performance of the proposed technique is evaluated under ideal and non-ideal supply voltage conditions. The results are analyzed in terms of reduction in the THD of supply currents and improvement of power factor. System validation performed in simulation and experiment has shown the effectiveness of the proposed system under different supply voltage conditions.

Bridgeless Cuk PFC converter with full load range soft switching operation by using a simple auxiliary circuit

In more electric aircraft (MEA), three-phase power factor correction (PFC) rectifiers of several kilowatts are required. In this paper, a three-phase buck–boost derived PFC converter with three switches and with input inductors connected in delta configuration for use in MEA is presented. The proposed converter is operated in a discontinuous conduction mode to achieve PFC at ac input. This avoids the inner current control loop which further eliminates the current sensors. It requires only one output voltage sensor unlike five sensors in conventional PFC converter for its control implementation. This makes the system cost effective, more reliable, and robust. A simple voltage control loop is used to generate the gate signals. The steady state operation of the converter and detailed design calculations are presented. For each power component, the analytical expressions for calculating the average and rms current ratings are derived to facilitate the converter design. The small-signal model of the converter is presented to aid the controller design. The experimental results from a 2 kW laboratory prototype are presented to confirm the operation of the proposed converter. An input power factor of 0.999, an input current total harmonic distortion of as low as 2.76%, and a high conversion efficiency of 96% are achieved from the prototype.

Hızlı DA şarj için elektrikli araç şarj istasyonu, araç dışında AA-DA dönüşümü gerçekleştirir. Son yıllarda, üç fazlı AA-DA güç faktörü düzelten (GFD) dönüştürücüler hızlı şarj cihazı ile birlikte ele alınmaktadır. Bu dönüştürücüler, tek yönlü ve çift yönlü güç akışı yapısı kullanılarak geliştirilmiştir. Bu çalışmada, çift yönlü güç akışı sağlayan üç fazlı AA-DA GFD dönüştürücü topolojileri performans açısından değerlendirilmiştir. Amaç, elektrikli araç hızlı şarjı için en yeni üç fazlı çift yönlü çok seviyeli AA-DA GFD dönüştürücü teknolojisini sunmaktır. Bu makale, elektrikli araçlar için hızlı şarj altyapısıyla ilgilenen araştırmacılar için kapsamlı ve pratik bir inceleme sunmaktadır.

The inherent dead angles of the input line current in buck power factor correction (PFC) converter deteriorates the power factor (PF). This article introduces a new bridgeless single-phase buck (PFC) converter with reduced components. This converter is designed to operate in discontinuous conduction mode (DCM) to achieve inherent PFC with a simple structure. The DCM operation gives additional advantages, such as low turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> losses and reduced complexity of the control circuitry. Unlike the buck PFCs, in which dead angle is the main drawback, in the proposed converter the PF is improved and the dead angle is eliminated by applying an auxiliary switch. Besides, the efficiency is further improved by employing the bridgeless structure. The switching losses are eliminated due to achieved zero current switching (ZCS) at the turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> of the main switches, and also ZCS at the turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and zero voltage switching at turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> of the auxiliary switch. The proposed topology is successfully implemented on a 120 W prototype converter at 110 Vrms input voltage and 48 V output voltages, and its performance is experimentally verified. The results show the total harmonic distortion of 5.3% and efficiency of 93.1% at the rated load.

This paper presents a systematic and comprehensive approach for differential mode (DM) electromagnetic interference (EMI) filter design in a three-phase boost-type power factor correction (PFC) rectifier. Since the DM EMI filter forms a significant portion of the overall filter as well as converter volume, the reduction of DM filter component size is kept as a major objective in the filter design process in order to improve the power density. In addition to the objectives of volume optimization and conducted emission attenuation requirement to comply with the EMI standard, the filter design process also ensures a near-unity power factor operation with the optimal set of EMI filter parameters. To accomplish this, the paper analyzes the effect of EMI filter component selection on the overall lower order (1-100 kHz) frequency response, which is important for evaluating the dynamic response and stability. The results from the proposed design approach are validated through simulation, the DM Bode plot, and frequency response of the input current with and without EMI filter. As a proof-of-concept verification, the proposed EMI filter is implemented in a 4-kW three-phase boost-PFC prototype, which demonstrates minimal phase displacement (<;5°) of the input current.

본 논문에서는 영전압 스위칭(ZVS)과 전류불연속 모드(DCM)에 의한 새로운 고효율의 DC-DC 컨버터에 대해 연구된다. 일반적으로 고효율의 컨버터를 만들기 위해서는 전력변환기내에 사용된 반도체 스위칭 소자의 손실을 최소화하여 이루어진다. 제안한 컨버터는 DCM에 의하여 스위치의 턴-온 동작을 영전류 스위칭(ZCS)으로 만들고, 또한 새로운 유사공진 회로를 접목하여 컨버터의 고효율을 실현시킨다. 제안한 컨버터에 사용된 제어용 스위칭 소자들은 유사공진 기법에 의해 소프트 스위칭, 즉 ZVS와 ZCS으로 동작시키고, 이에 따른 제어용 스위칭 소자들은 전압과 전류의 스트레스 없이 동작한다. 그 결과 제안한 컨버터는 스위칭 손실의 저감에 의해 고효율로 구동된다. 제안한 DCM-ZVS 컨버터의 소프트 스위칭 동작과 시스템 효율은 디지털 시뮬레이션과 실험결과를 통해 그 타당성이 입증된다. This paper is study on a new high efficiency DC-DC converter of discontinuous conduction mode (DCM) with zero voltage switching (ZVS). The converters of high efficiency are generally made that the power loss of the used semiconductor switching devices is minimized. The proposed converter is accomplished that the turn-on operation of switches is on zero current switching (ZCS) by DCM. The converter is also applicable to a new quasi-resonant circuit to achieve high efficiency converter. The control switches using in the converter are operated with soft switching, that is, ZVS and ZCS by quasi-resonant method. The control switches are operated without increasing their voltage and current stresses by the soft switching technology. The result is that the switching loss is very low and the efficiency of the converter is high. The soft switching operation and the system efficiency of the proposed DCM-ZVS converter are verified by digital simulation and experimental results.

A novel three-phase major circuit topology is proposed in this paper and its circuit design is also given. Its characteristic is that specific PFC integrated circuit is not applied in this AC-DC converter, there are less circuit components and its power factor is very high. Moreover, its operation principle and power factor correction principle are discussed and analyzed in detail. Its simulation results operating in different duties using MATLAB/SIMULINK are also given. The rationality and correctness of its circuit topology and principle are explained and verified by theory analysis and simulation results.

A new integrated single-stage zero current switched (ZCS) quasi-resonant converter (QRC) for the power factor correction (PFC) converter is introduced in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of an input current. The proposed converter has the characteristics of the good power factor, low line current harmonics, and tight output regulation. Furthermore, the ringing effect due to the output capacitance of the main switch can be eliminated by use of active clamp circuit. A prototype converter has been designed and experimented based on design equations. The line current waveform of the prototype shows about 15% of total harmonic distortion at rated condition. Also, the efficiency and the power factor can be obtained about 87% and 0.985, respectively at rated condition. The proposed converter is suitable for a low power level applications with a tightly regulated output voltage and a high switching frequency.

An AC -DC converter with power factor correction (PFC) function is proposed in this paper. In the proposed converter, the boost PFC stage and the active-clamp DC-DC converter stage are merged into a single converter to reduce the overall cost and improve the power density. An active-clamp DC-DC converter stage can suppress the switch voltage stresses and provide zero-voltage-switching (ZVS) operation of the switches. The boost converter in PFC stage operates in discontinuous conduction mode (DCM) and it provides naturally high power factor. Due to the ZVS operation, the switching losses of the proposed converter are significantly reduced and the efficiency is improved. Steady-state analysis is performed. Simulation results are also provided to verify the effectiveness of the proposed converter.

As a significant ecological corridor from west to east across China, the Yangtze River Economical Belt (YREB) is in great need of green development and transformation. Rather than only focusing on the overall growth of green productivity, it is important to identify whether the technical change is biased towards economic performance or green performance in promoting green productivity. By employing the biased technical change theory and Malmquist index decomposition method, we analyze the green biased technical change in terms of industrial water resources in YREB at the output side and the input side respectively. We find that the green biased technical change varies during 2006–2015 at both the input side and output side in YREB. At the input side, water-saving biased technical change is generally dominant compared to water-using biased technical change during 2006–2015, presenting the substitution effects of non-water production factors. At the output side, the economy-growth biased technical change is the main force to promote green productivity, whereas the role of water-conservation biased technical change is insufficient. The green performance at the output side needs to be strengthened compared to the economic performance in YREB. A series of water-related environmental policies introduced in China since 2008 have promoted the green biased technical change both at the input side and the output side in YREB, but the policy effects at the output side is still inadequate compared to that at the input side. The technological innovation in sewage treatment and control need to catch up with the economic growth in YREB. Our research gives insights to enable a deeper understanding of the green biased technical change in YREB and will benefit more focused policy-making of green innovation.

This paper presents how the Electric Vehicle (EV) bidirectional chargers can help the Distribution Systems. In addition to the battery charge and the Vehicle-to-Grid functions (V2G), the reactive power can be compensated according to an established reactive power reference. A three-phase bidirectional power factor correction (PFC) with a DC link is connected to an isolated DC/DC bidirectional converter is utilized in the topology. The virtual flux control algorithm used in assigning the amount of the injected reactive power is presented in this paper. The required mitigation for this functionality does not require any additional hardware, and it can be implemented on the existing electric vehicles with only a firmware update. Simulation results demonstrate how the reactive power is being compensated and the saturation of the reactive current is used to keep the power under predefined limits.

In this paper, performance of voltage source inverter.(VSI) fed Permanent Magnet Brushless DC Motor(PMBLDCM) with Power Factor Correction (PFC) is discussed. A power factor correction converter is suggested at the input to correct the power factor on the input side. The conventional circuit is improved by introducing double boost converter at the input side. The Pulse Width Modulation (PWM) inverter fed Permanent Magnet Brushless DC motor system with L-filter, T-filter and double boost converter are simulated and the results are presented. The performance of PMBLDCM operating with the above mentioned converters is studied. By digital simulation, the characteristics of the PMBLDCM system are investigated. FFT analysis for various converters is presented. The simulation results indicate improved performance. Key words : VSI; Double boost converter; PMBLDC; Harmonic reduction; PWM; PFC; Sim power systems DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9591 BJSIR 2011; 46(4): 457-464

The buck-boost power factor corrected (PFC) converter has the wide range of the dc output voltage. A new non-isolated three-phase hard-switching buck-boost PFC converter and a new non-isolated three-phase soft-switching buck-boost PFC converter are proposed. Their structures are very compact and the low cost is achieved by removing the three-phase transformer. They are operated in the discontinuous current mode (DCM) and controlled by a new control method to achieve the high power factor. The new control method based on the PWM technique is presented in this paper.

The novel zero-current switching (ZCS) and zero-voltage switching (ZVS) high power factor single-phase AC to DC converters for the power factor correction are proposed in this paper. Merits of the proposed converters include higher power density, simpler control stage, zero switch loss, less harmonic control contents, unity power factor and unidirectional power flow. Optional principle, design analysis and conditions achieving zero switching loss for the proposed converters are described. Finally, some experimental results are discussed.