共查询到20条相似文献,搜索用时 15 毫秒
1.
Calleja A.J. Alonso J.M. Lopez E. Ribas J. Martinez J.A. Rico-Secades M. 《Power Electronics, IEEE Transactions on》1999,14(6):998-1006
A new single-stage high-power-factor electronic ballast based on a flyback converter is presented in this paper. The ballast is able to supply a fluorescent lamp assuring a high-input power factor for the utility line. Other features are lamp power regulation against line voltage variations and low lamp current crest factor, both assuring long lamp life. The ballast is analyzed at steady-state operation, and design equations and characteristics are obtained. Also, a procedure for the ballast design is presented. Finally, simulation and experimental results from a laboratory prototype are shown 相似文献
2.
A single-stage high-power-factor electronic ballast is developed by making an integration of an active filter and a series resonant inverter. The function of power-factor correction is performed by adjusting the duty ratio of the inverter power switches with a simple control circuit. A prototype unit designed for a 36-W compact fluorescent lamp is built and tested to verify the predicted results 相似文献
3.
This paper proposes a novel single-stage high-power-factor high-efficiency electronic ballast with symmetrical topology for fluorescent lamps. The circuit topology originates from the integration of two half-wave rectifiers with buck-boost power-factor-correction converters and a half-bridge series-resonant parallel-loaded inverter. A high power factor at the input line is assured by operating the buck-boost converters in discontinuous conduction mode. With symmetrical operation and carefully designed circuit parameters, zero-voltage switching on the active power switches of the inverter can be retained to achieve high circuit efficiency. The design equations are derived from the analyzed results based on fundamental approximation, and then an easy-to-use design tool is provided accordingly under considerations of filament heating and ignition. A prototype circuit designed for two T9-40W rapid-start fluorescent lamps is built and tested to verify the analytical predictions. Satisfactory performance is obtained from the experimental results. 相似文献
4.
A single-stage quasi-resonant flyback converter using the synchronous rectifier (SR) is proposed for improving power factor and system efficiency. This converter operates at the critical conduction mode with the variable frequency (VF) control to reduce the switching loss of the primary switch. The bulk capacitor voltage can be independent of the output load and kept within a practical range for the universal line input. Therefore, the problem of high-voltage stress across the bulk capacitor is reduced. The proposed converter features relatively low bulk capacitor voltage in the universal line voltage and also complies with the Standard IEC 61000-3-2 Class D limits. Moreover, since it uses the voltage-driven SR, it achieves a high efficiency. The operational principle and theoretical analysis are presented. Experimental results for a 100?W (19?V/5.3?A) adapter at the VF were obtained to show the performance of the proposed converter. 相似文献
5.
A single-stage, three-phase AC-to-DC converter topology is proposed for high-frequency power supply applications. The principal features of the circuit include continuous current operation of the three AC input inductors, inherent shaping of the input currents, resulting in high power factor, a transformer isolated output, and only two active devices are required, both soft-switched. Resonant conversion techniques are used, and a high power factor is achieved by injecting high-frequency currents into the three-phase rectifier, producing a high frequency modulation of the rectifier input voltages. The current injection principle is explained and the system operation is confirmed by a combination of simulation and experimental results. 相似文献
6.
Cascade connection of a boost and a resonant converter using a common device pair produces a new topology that combines the input current shaping capabilities of the boost circuit and the soft-switching operation of the resonant converter. The circuit is suitable for high-power-factor rectification. Results are presented from a 100 W prototype 相似文献
7.
A simple and effective approach of turning an isolated hard-switched converter design into a soft-switched one is presented. By adding an auxiliary winding, switch and small capacitor to the conventional pulsewidth modulation (PWM) isolated flyback converter, all switches and diodes are softly turned on and off. No extra active or passive voltage clamp circuit is needed to suppress voltage stress on the switching devices that were usually found in classical converters. A zero-current-switching (ZCS) PWM flyback converter topology with multiple outputs is analyzed and examined. The proposal inherently utilizes the leakage inductance of the “flyback” transformer to achieve ZCS of all switching devices. A complete steady-state DC analysis and the operating principle are described. The performance of an 80 W experimental converter prototype with dual-voltage outputs is included 相似文献
8.
Neto R.M.F. Tofoli F.L. de Freitas L.C. 《Industrial Electronics, IEEE Transactions on》2005,52(5):1278-1285
This paper proposes a high-power-factor half-bridge doubler boost converter without commutation losses, which provides high output voltages, i.e., from 600 to 900 V. The voltages across the semiconductor devices are low and approximately equal to the output voltage, as doubled output voltages and reduced high-frequency ripple can be achieved. A detailed mathematical analysis concerning its operation is presented, and simulation and experimental results describe the converter performance. 相似文献
9.
Single-switch soft-switching flyback converter 总被引:3,自引:0,他引:3
A novel control method is proposed to achieve soft-switching in the single-switch flyback converter. Using the proposed scheme, circuit efficiency is increased while the simplicity of the circuit is maintained. A 200 W converter is built to verify the proposed scheme 相似文献
10.
A ZCS bidirectional flyback DC/DC converter 总被引:2,自引:0,他引:2
Chung H.S.-H. Wai-Leung Cheung Tang K.S. 《Power Electronics, IEEE Transactions on》2004,19(6):1426-1434
This paper addresses the design and analysis of a zero-current-switched (ZCS) bidirectional flyback dc/dc converter. The converter is based on extending a previously developed unidirectional ZCS flyback converter and replacing the output diode with a controlled switch, which acts as either a rectifier or a power control switch in the corresponding power flow direction. By adding an auxiliary winding in the coupled inductor, a switch, and a capacitor, the hard-switching design is converted into a soft-switching one. The technique utilizes the leakage inductance of the flyback coupled inductor to create zero-current-switching conditions for all switches in both power flow directions, leading to reduced switching losses, stresses, and electromagnetic interference. The operating principles of the converter and experimental results have been presented. 相似文献
11.
A new soft-switching technique that improves performance of the high-power-factor boost rectifier by reducing switching losses is introduced. The losses are reduced by an active snubber which consists of an inductor, a capacitor, a rectifier, and an auxiliary switch. Since the boost switch turns off with zero current, this technique is well suited for implementations with insulated-gate bipolar transistors. The reverse-recovery-related losses of the rectifier are also reduced by the snubber inductor which is connected in series with the boost switch and the boost rectifier. In addition, the auxiliary switch operates with zero-voltage switching. A complete design procedure and extensive performance evaluation of the proposed active snubber using a 1.2 kW high-power-factor boost rectifier operating from a 90 Vrms-256 Vrms input are also presented 相似文献
12.
Gang Chen Yim-Shu Lee Hui S.Y.R. Dehong Xu Yousheng Wang 《Industrial Electronics, IEEE Transactions on》2000,47(4):770-779
An actively clamped bidirectional flyback converter is proposed. The converter's operation is examined in detail. All switches in the converter have zero-voltage-switching characteristics. A low-frequency behavior model and small-signal transfer functions are derived. It is found that the flow of current is directly under the control of the duty cycle, and that the transformer's leakage inductance has a significant effect on the control characteristic of the converter. It is expected that such bidirectional converters will find wide applications in the interconnection of multiple sources of DC power to a common bus (e.g., in a DC uninterruptible power supply). Simulation and experiment results are also presented 相似文献
13.
14.
15.
Ferdowsi M. Emadi A. Telefus M. Davis C. 《Power Electronics, IEEE Transactions on》2005,20(4):798-805
Pulse regulation, a fixed frequency control technique, is introduced and applied to flyback converter operating in discontinuous conduction mode (DCM). The control parameters are designed in a way that the converter operates as close as possible to the critical conduction mode. In contrast to the conventional pulsewidth modulation control scheme, the principal idea of pulse regulation is to achieve output voltage regulation using high and low-power pulses. Pulse regulation is simple, cost effective, and enjoys a fast dynamic response. The proposed technique is applicable to any converter operating in DCM. However, this work mainly focuses on flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented. 相似文献
16.
Pulse Train control technique for flyback converter 总被引:1,自引:0,他引:1
Telefus M. Shteynberg A. Ferdowsi M. Emadi A. 《Power Electronics, IEEE Transactions on》2004,19(3):757-764
Pulse Train/spl trade/ control technique is introduced and applied to flyback converter operating in discontinuous conduction mode (DCM). In contrast to the conventional pulse width modulation (PWM) control scheme, the principal idea of Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in DCM. However, this work mainly focuses on flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented. 相似文献
17.
18.
Electronic ballasts must provide enough open circuit voltage to start the fluorescent lamp and current limiting while the lamp is running. Resonant inverters may be utilized in electronic ballasts because of their load-dependent characteristics. The three basic types of resonant inverters, the series-loaded, parallel-loaded, and the series-parallel-loaded, are compared using fundamental approximation techniques for their applicability in electronic ballasts operating from a low voltage source. A parallel-loaded resonant inverter operating slightly above its resonant frequency is selected because of the high voltage gains possible. Operation above the resonant frequency allows zero-voltage turn on of the semiconductor devices. Zero-voltage turn off can be achieved with the addition of lossless snubber capacitors. Experimental results from a lab prototype are used to verify the design procedure 相似文献
19.
A new high-power-factor three-phase AC-DC converter: analysis,design, and experimentation 总被引:4,自引:0,他引:4
This paper proposes a new high-power factor three-phase AC-DC power converter, which is composed of a line interphase transformer (LIT) and two three-phase diode rectifiers, followed by a pulsewidth modulation (PWM) DC-DC boost power converter. The active switch of the boost converter is gated at a constant frequency such that the AC input current is discontinuous. This procedure provides an input current shaping without the third, fifth and seventh harmonics. The currents that flow through the LIT and boost inductors have such a high-switching frequency that ferrite cores with a small size can be utilized. In addition, the output voltage is regulated by PWM to compensate for line voltage variations and load change. Theoretical analysis, design procedure and example, along with experimental results taken from a 6 kW laboratory prototype are given 相似文献
20.
Seidel A.R. Bisogno F.E. Pinheiro H. do Prado R.N. 《Industrial Electronics, IEEE Transactions on》2003,50(6):1267-1274
This paper presents a simple alternative for an electronic ballast operating in self-sustained oscillating mode with dimming capability for fluorescent lamps. A simple modification in one of the gate drivers side circuit allows the lamp to dim without compromising the simplicity, reliability, and low cost which characterize the self-oscillating electronic ballast (SOEB). A qualitative analysis is presented to explain the behavior of the proposed self-oscillating electronic ballast with dimming feature. In addition, the stability and the key equations for the design are derived using the extended Nyquist criterion and describing function method. Experimental results from two 40-W electronic ballasts are presented to demonstrate the performance and to validate the analysis carried out. 相似文献