Single-stage line-coupled half-bridge ballast with unity power factor and ripple-free input current using a coupled inductor

A single-stage line-coupled half-bridge ballast with unity power factor and ripple-free input current using a coupled inductor is proposed. The proposed power-factor-correction circuit can achieve unity power factor and ripple-free input current using a coupled inductor. A saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. The proposed ballast has high energy efficiency, low cost, and high reliability compared to the conventional high-power-factor electronic ballasts. Experimental results obtained on a 30-W fluorescent lamp is discussed.     

Multiinput converter with power factor correction, maximum power point tracking, and ripple-free input currents

A multiinput converter for photovoltaic (PV) power system applications with power factor correction (PFC), maximum power point tracking (MPPT), and ripple-free input currents (RFIC) is proposed in this paper. With phase-shifted pulse-width-modulation (PWM) control, the multiinput converter can draw power from the utility line and PV arrays individually or simultaneously and deliver it to the load. In addition, an almost unity power factor for the utility line and an MPPT for PV arrays can also be achieved. Moreover, the upper power switches of each input-stage circuit in the proposed converter are operated with zero-current-switching (ZCS) at turn-off transition and the lower ones are operated with zero-voltage-switching (ZVS) at turn-on transition. Hence, the switching losses of the power switches can be reduced. Experimental measurements are demonstrated to verify the performance of the proposed multiinput converter.     

Single-stage current-fed DC-DC converter with time-sharing controlof output voltage and input current

A single-stage current-fed DC/DC power converter structure and control strategy for simultaneous control of output voltage and current flowing in the input inductor are described. This configuration is suitable for high power-density applications because it results in reduced converter size and power loss. A very fast control-to-output response is obtained, together with stable operation even for large load and reference variations. Static and dynamic converter performances are investigated and design criteria given. Experimental results obtained on a prototype are also reported     

An AC/DC converter with high power factor

The television receiver often employs a capacitor-input-type rectifier. In this case, it is regulated as a class D piece of equipment. This paper presents a novel ringing-choke-converter-type switching regulator, which functions as an active filter. The proposed circuit features a simple circuit configuration and cost effectiveness. It achieves a high power factor of about 0.95 and reduces current harmonics (third, fifth, and seventh) in the AC input current to less than 40% of the limit value for class D. The voltage across the input smoothing capacitor does not show large variations and the components in the conventional ringing-choke converter can be used unmodified. Ripple content of the DC output voltage shows a slight increase and is the subject for future research.     

Control of power factor correcting boost converter withoutinstantaneous measurement of input current

This paper proposes a new control method for the constant-frequency control of power factor correcting boost power converter using a sinewave template modulated PWM signal which eliminates the need for instantaneous measurement of the line current for the switching control of the boost converter. The control strategy is based on the notion that the line current can be forced to trace a deterministic waveform such as a sinusoid by considering the implicit model of the sinewave in the boost converter controller structure. The modulating sinewave template is generated using the line voltage, the boost converter output voltage and the load current. The paper provides the analysis and the design of the controller and presents simulation and implementation results to demonstrate its effectiveness     

Single-stage power factor correction converter with parallel powerprocessing for wide line and load changes

A new single-phase single-stage power factor correction converter with a simple auxiliary circuit is proposed. Using parallel power processing, this converter can be operated in wide line and load changes while limiting the link voltage below 400 V. Experimental results show that the measured power factor and efficiency are about 0.98 and 81%, respectively, at rated condition and the auxiliary circuit to reduce the link voltage is effective     

A low-power switched-current CDMA matched filter employing MOS linear matching cell with on-chip A/D converter

A low-power switched-current matched filter (MF) for code-division multiple-access (CDMA) systems has been developed. The front-end voltage-to-current (V/I) converter has been eliminated by merging the function into each matching cell utilizing the MOS linear I-V characteristics. A low-power analog-to-digital (A/D) converter has also been developed to establish smooth interfacing to digital back-end processing for a delayed locked loop (DLL) and a RAKE receiver. A proof-of-concept chip was fabricated in a 0.35-μm standard CMOS technology with a measured power consumption of 1.65 mW at 11 Mchip/s with 2-V power supply including the A/D converter.     

三相整流桥直流侧和交流侧并联型有源电力滤波器比较研究

三相直流侧和交流侧有源电力滤波器均可用于三相不可控整流桥的谐波治理。从谐波补偿效果、有源滤波器的补偿容量、开关应力三个方面对二者进行了分析和对比。分析结果表明,由于直流侧有源电力滤波器并联在整流桥的直流侧,在换相处的负载电流变化率比交流侧小得多,因此直流侧有源电力滤波器的补偿性能优于交流侧有源电力滤波器。同时由于直流侧有源电力滤波器工作在电压电流两个象限,因此其补偿容量和开关应力远小于交流侧有源电力滤波器。     

采用LC滤波的大功率本安Buck开关变换器

随着矿井智能化的不断推进及安全级别的不断提高,本质安全型电气电子设备正被广泛推广使用,而其中的核心控制芯片所需的电压越来越低,所以对低压大功率本安电源的需求也就越来越大。为了提高本安Buck变换器的输出功率,采用了一种在基本本安Buck变换器的输出端附加LC滤波电路的方法,分析了采用LC滤波的大功率本安Buck变换器（LC-Buck变换器）的组成及工作原理,通过实验对比得出了本安LC-Buck变换器在同等条件下可以有效提高输出功率的结论。     

A high frequency AC/DC converter with unity power factor andminimum harmonic distortion

A novel forced commutated AC/DC converter and control strategy is proposed that is able to draw nearly sinusoidal currents at unity power factor from three-phase power lines. The power factor is controlled by adjusting the relative position of the fundamental component of an optimized pulse-width-modulation (PWM) type voltage with respect to the supply voltage. Current harmonic distortion is minimized by the use of optimized firing angles for the converter at a frequency where gate turn-off thyristors (GTOs) can be used. This feature makes this approach attractive at power levels of 100 kW to 600 kW. An 8096 microcontroller is used to minimize the interface hardware requirements. The theoretical analysis of the converter, the control energy, and experimental results for a low-power prototype are presented     

Single-switch AC/DC converter with power factor correction

A single-switch, one-stage power factor correction converter with output electrical isolation is proposed. To relieve the voltage spike caused by the leakage inductance of the power transformer, two bulk storage capacitors are used. The proposed converter has both a good power factor correction and excellent line and load regulation capabilities with an efficiency of 87%     

Magnetic-coupled high power factor converter with low line currentharmonic distortions for power factor correction and fast outputresponse

A new magnetic-coupled high power factor converter (MCHPFC) with a single switch/single stage is proposed. The proposed converter gives good power factor correction, low current harmonic distortions, and tight output voltage regulation. The prototype shows that the IEC555-2 requirements are met satisfactorily with nearly unity power factor. A proposed MCHPFC is particularly suited for low-power-level power supply applications     

Low power and high gain current reuse LNA with modified input matching and inter-stage inductors

In this paper we present a fully integrated current reuse CMOS LNA (low noise amplifier) with modified input matching circuitry and inductive inter-stage architecture in 0.18 μm CMOS technology. To reduce the large spiral inductors that actually require larger surface area for their fabrication, two parallel LC circuits are used with two small spiral on-chip inductors. Using cascode configuration equipped by parallel inter-stage LCs, we achieved lower power consumption with higher power gain. In this configuration we used two cascoded transistors to have a good output swing suitable for low voltage technology compared to other current reuse configurations. This configuration provides better input matching, lower noise figure and more reverse isolation which is vital in LNA design. Complete analytical simulation of the circuit results in center frequency of 5.5 GHz, with 1.9 dB NF, 50 Ω input impedance, 1 GHz 3 dB power bandwidth, 20.5 dB power gain (S₂₁), high reverse isolation (S₁₂)<−48 dB, −18.5 dB input matching (S₁₁) and −21.3 dB output matching (S₂₂), while dissipating as low power as 2 mW at 1.8 V power supply.     

Analysis and design of single-controlled switch three-phaserectifier with unity power factor and sinusoidal input current

This paper describes a new low-cost three-phase AC-DC high-power/low-harmonic-controlled rectifier and its analysis, design, and performance. The circuit consists of a three-phase diode-bridge rectifier, followed by a boost stage containing only one switch and one boost inductor. The proposed converter is used to automatically draw sinusoidal input-current waveforms with high efficiency. This is achieved with discontinuous-input voltage to the rectifier and with a discontinuous-inductor-current mode of operation of the boost converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design     

A low power current controllable single-input three-output current-mode filter using MOS transistors only

A novel circuit configuration for the realization of low power single-input three-output (SITO) current mode (CM) filters employing only MOS transistors are presented. The proposed circuit can realize low-pass (LP), band-pass (BP) and high-pass (HP) filter functions simultaneously at three high impedance outputs without changing configuration. Despite the other previously reported works, the proposed circuit is free from resistors and passive capacitors. Instead of passive capacitors; the gate-source capacitor of MOS transistor is used making the proposed circuit ideally suitable for integration. Compared to other works, the proposed filter has also the lowest number of transistors and lowest power consumption. The proposed circuit exhibits low-input and high-output impedances, which is highly desirable for cascading in CM signal processing. Moreover, it is center frequency can be electronically adjusted using a control current without a significant effect on quality factor (Q) granting it the highly desirable capability of electronic tunability. Transfer functions of the LP, BP and HP outputs are derived and the performance of the proposed circuit is proved through pre layout and post layout simulations at supply voltage of 1.8 V and using 0.18 μm CMOS process parameters. The power consumption and the required chip area are only 0.5 mW and 77.4 μm × 70.2 μm, respectively.     

Novel multiple function analog filter structures and a dual-mode multifunction filter

This paper reports three multi-function filters each of which realizes at least three basic functions without any external passive elements. Depending on the circuit, from one to four operational transconductance amplifiers (OTAs), and two operational amplifiers (OPAMPs) are employed. All three circuits are transimpedance-mode circuits; one of them can also operate as a current-mode filter. Therefore this filter represents a dual-mode, multifunction filter. The presented theory is verified with macro models in simulation program with integrated circuit emphasis (SPICE) simulations and post layout simulations, which are carried out with parasitics extracted from the layouts of the filter chips.     

A three-phase to three-phase series-resonant power converter withoptimal input current waveforms. II. Applications and results

For pt.I see ibid., vol.35, no.2, p.263-8 (1988). A 15 kW three-phase prototype series-resonant power converter is constructed. The converter features sinusoidal output voltage and sinusoidal input currents. The control concepts and necessary electronics, as well as the layout of the power circuit, are discussed. Low distortion levels are achieved for both the output voltages and the input currents, and measurements show the very fast (milliseconds) reaction capabilities of this type of equipment     

Synthesis and analysis for a novel single-stage isolated high power factor correction converter

A novel single-stage isolated high power factor correction (HPFC) converter operating in the discontinuous conduction mode is proposed in this paper. It is an integration of a buck-boost converter with a flyback converter by means of components placement and synchronous switching technology. It can achieve HPFC, tight output voltage regulation and lower voltage stress of the bulk capacitor, which is independent of the loads. The small-signal mathematical model for the proposed converter is derived separately by the averaging method and the current injected equivalent circuit approach. The IsSpice simulations and experimental results successfully verify the dynamics and performances of the proposed converter.     

Electronically tunable current-mode biquad filter employing CCCDTAs and grounded capacitors with low input and high output impedance

In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current controlled current differencing transconductance amplifier (CCCDTA) is presented. The proposed filter uses two CCCDTAs and two grounded capacitors without any external resistors, which is well suited for integrated circuit implementation. The filter simultaneously gives 3 standard transfer functions, namely, lowpass, highpass and bandpass filters with independent control of quality factor and pole frequency by electronic method. By summing of I_HP and L_LP, the notch filter can be also achieved. Moreover, the circuit has low input and high output impedance which would be an ideal choice for cascading in current-mode circuit. The PSPICE simulation results are included verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.