Single-stage Electronic Ballast Research Articles

Single‐stage single‐switch high power factor driving circuit for lighting applications

Although compact fluorescent lamps (CFLs) have been in the market for a long time, many of them do not achieve the same power factor as the incandescent lamps do, which appears to be a significant problem for the utility with the current widespread use of CFLs for household lightings. A single-stage single-switch electronic ballast with active power factor correction is presented in this study for CFL applications. Unlike other single-switch ballast circuits, the presented integrated dual-boost converter circuit can produce a symmetric bipolar square-wave voltage, thus generating a near-pure high-frequency sinusoidal voltage on the lamp, which is beneficial to the CFL lifetime. Moreover, its soft-switching variant can achieve the ZVZC turn-on and ZV turn-off for the MOSFET to improve the conversion efficiency. Detailed operating principles and circuit analysis of the proposed circuit have been provided in this study. Simulation and experimental results on a prototype of a 15 W CFL validate the theoretical analysis and highlight the merits of the presented work.

A Novel Single-Stage HPF Electronic Ballast With Coupled Inductors for Fluorescent Lamps

This paper proposes a novel single-stage electronic ballast with high power factor (HPF) for supplying fluorescent lamps. The presented electronic ballast integrates a dual boost converter with coupled inductors and a half-bridge series-resonant parallel-loaded inverter into a single-stage power conversion topology. The features of the ballast are cost-effectiveness, HPF (PF > 0.98), high circuit efficiency (>90%), low input current total harmonic distortion (THD <; 7%), low level of crest factor (CF <; 1.4), and zero-voltage switching obtained on both two power switches. Operational principles, design equations, and experimental results of one T5-type fluorescent lamp with a rated power of 21 W operating at 50 kHz switching frequency with 110 V-RMS line input voltage are presented. Satisfactory results demonstrate the feasibilities of the proposed ballast.

Implementation of a DC-Side Class-DE Low-&lt;formula formulatype="inline"&gt;&lt;tex Notation="TeX"&gt;$\bm{d\upsilon/ dt}$&lt;/tex&gt; &lt;/formula&gt; Rectifier as a PFC for Electronic Ballast Application

An analysis and design of a single-stage electronic ballast with a dc-side Class-DE low- $d\upsilon/dt$ resonant rectifier is studied in this paper to improve a poor power-factor and low line harmonic. The power-factor correction is achieved by utilize an output characteristics of a Class-DE rectifier, which is inserted between the front-end bridge rectifier and the bulk-filter capacitor. The design procedure is based on the principle of the Class-DE rectifier, which also ensures more accurate results and the proposed scheme provided a more systematic and feasible analysis methodology. The active switches can be operated under the soft-switching condition. By employing an electromagnetic interference filter after bridge rectifier, the standard-recovery diode for bridge rectifier can be employed, the cost can be reduced, the conduction angle of the bridge-rectifier diode current was increased, and low line harmonic distortion and a power factor near unity were achieved. The dc-side Class-DE rectifier is driven by a high-frequency current source, which is obtained from the square-wave output voltage of the Class-D series–parallel resonant inverter through an LC-series circuit. A prototype of the ballast, operating at an 84-kHz fixed frequency and a 220-V $_{\rm rms}$ , 50-Hz line voltage, was utilized to drive a T8–36 W fluorescent lamp. The validity of this approach was confirmed by simulation and experimental results.

Design and Implementation of a Single-Stage Acoustic-Resonance-Free HID Lamp Ballast With PFC

High-intensity-discharge (HID) lamps are widely utilized in a variety of lighting circumstances that need high luminance. This paper proposes a single-stage electronic ballast for HID lamps; the ballast offers power factor correction and is acoustic resonance free. The presented HID lamp ballast integrates a discontinuous-conduction-mode (DCM)-operated bridgeless power factor correction (PFC) converter for shaping the input utility-line current with a high-frequency (36 kHz)/low-frequency (60 Hz) square-wave-driven half-bridge inverter for supplying low-frequency (60 Hz) square-wave sources to the HID lamp. The features of the proposed ballast are high power factor, low total harmonic distortion (THD) of the input current, cost effectiveness, and that it avoids acoustic resonance. The operational modes, key design guidelines, and a design example are included. A 70 W prototype HID lamp ballast circuit operating with 110 V-rms input utility-line voltage has been implemented and testified. The functionalities of the presented ballast are demonstrated by satisfactorily experimental results with a maximum efficiency of 90.8%, a maximum power factor of 0.998, and a minimum current THD of 11.13%.

Single-stage electronic ballast with high-power factor

This article proposes a single-stage electronic ballast circuit with high-power factor. The proposed circuit was derived by sharing the switches of the power factor correction (PFC) and the half-bridge LCC resonant inverter. This integration of switches forms the proposed single-stage electronic ballast, which provides an almost unity power factor and a ripple-free input current by using a coupled inductor without increasing the voltage stress. In addition, it realises zero-voltage-switching (ZVS) by employing the self-oscillation technique. The saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Therefore, the proposed single-stage ballast has the advantage of high-power factor, high efficiency, low cost and high reliability. Steady-state analysis of the PFC and the half-bridge LCC resonant inverter are described. The results of experiments performed using a 30 W fluorescent lamp are also presented to confirm the performance of the proposed ballast.

Single‐stage high‐power‐factor low‐frequency square‐wave‐driven high‐intensity‐discharge lamp ballast

This study presents a single-stage electronic ballast for the high-intensity-discharge (HID) lamp with high-power factor. The presented ballast consists of a discontinuous-conduction-mode operated dual-boost converter to achieve input current shaping, and a high-frequency combined with a low-frequency square-wave-driven half-bridge-type inverter for supplying the HID lamp with low-frequency square-wave sources. The attractive features of the proposed ballast are high-power factor (> 0.99), low total harmonic distortion of input utility-line current (< 10%), high efficiency (> 90%), cost-effectiveness and freedom from acoustic resonance. The operational principles, design guidelines and a design example are included in this paper. A prototype ballast circuit has been successfully implemented and tested for supplying three different brands of 70W HID lamps operating with 110 V-root-mean-square input utility-line voltage. Satisfactory experimental results demonstrate the functionalities of the proposed ballast.

A Sepic-Type Single-Stage Electronic Ballast for High Line Voltage Applications

In this paper, a sepic-type single-stage electronic ballast (STSSEB) is proposed, which is derived from the combination of a sepic converter and a half-bridge inverter. The ballast can not only step down input voltage directly but achieve high power factor, reduce voltage stress, improve efficiency and lower cost. Since component stress is reduced significantly, the presented ballast can be applied to high voltage mains. Derivation of the STSSEB is first presented. Then, analysis, design and practical consideration for the STSSEB are discussed. A 347Vac 60W prototype has been simulated and implemented. Simulations and experimental results have verified the feasibility of the proposed STSSEB.

A Novel Single-Stage High-Power-Factor Electronic Ballast for Metal-Halide Lamps Free of Acoustic Resonance

This paper proposes a novel single-stage high-power-factor electronic ballast for metal-halide lamps. By integrating two buck-boost converters, a full-bridge inverter and a bidirectional buck converter, a single-stage electronic ballast with symmetrical circuit topology is derived. The circuit component count can be effectively reduced and circuit energy-conversion efficiency is improved. With a tactful control scheme, the proposed electronic ballast can output a low-frequency square-wave voltage to drive metal-halide lamps. The problematic phenomena of acoustic resonance can be eliminated. Both the buck-boost converters serve as power-factor correction (PFC) circuits, which are operated at discontinuous conduction mode (DCM) to obtain a unity power factor at the input line. The operation modes, design equations, and design steps for the circuit parameters are proposed. A prototype circuit designed for a 70-W metal-halide lamp was built and tested to verify the analytical predictions. Satisfactory performances are obtained from the experimental results.

Novel Single-Stage Self-Oscillating Dimmable Electronic Ballast With High Power Factor Correction

A novel self-oscillating electronic ballast with dimming capability and high power factor correction (PFC) is proposed in this paper. The single-stage electronic ballast integrates a buck-boost PFC stage with a half-bridge LCC series-parallel resonant inverter. The buck-boost semistage operating in discontinuous conduction mode inherently has high PFC. The inverter is dimmable in self-oscillation mode, which is achieved using pulsewidth modulation and variable-frequency controls. The dimming circuit is simple and low cost. The self-sustained oscillation of the dimmable electronic ballast for fluorescent lamps was verified using the dual-input describing function method. A prototype of a 10-W dimmable electronic ballast was implemented to verify the theoretical analysis.

A Novel High-Power-Factor Single-Switch Electronic Ballast

A novel single-stage single-switch electronic ballast topology with a unity power factor is presented in this paper. The proposed circuit consists of an integrated buck-boost stage that operates in the discontinuous conduction mode to provide a high power factor and a single-switch current-fed resonant inverter to stabilize the lamp current. The proposed topology presents a low cost and compact electronic ballast design method. The detailed descriptions of the circuit's operating principles are provided in this paper. The design equations and mathematical analysis regarding the proposed circuit are discussed in this paper. The proposed ballast has been tested with an 18-W compact fluorescent lamp, and the experimental results confirmed that a very high power factor of 0.995 and an efficiency of 83.4% have been achieved.

HID Lamp Electronic Ballast With Reduced Component Number

A reduced-component-number single-stage power-processing electronic ballast to drive high-intensity discharge lamps is presented in this paper. A dc-dc buck converter, which controls the current and the power of the lamp, a power factor preregulator based on a discontinuous conduction mode boost converter, and the inverter are combined in a boost integrated with buck rectifier/energy storage/dc-dc converter. It operates with a line-frequency square-wave current driving the lamp. The signals of the power stages are provided by a dedicated microcontroller. Ballast for sodium vapor lamps of 70 W without acoustic resonance was implemented, resulting in a pf = 0.97 with 22% total harmonic distortion and eta = 84%.

A Dimmable Electronic Ballast With Unity Power Factor Based on a Single-Stage Current-Fed Resonant Inverter

A single-stage dimmable electronic ballast with very high power factor and high efficiency is presented in this paper. A compact lamp power circuit is designed by integrating a buck-boost power factor corrector with a current-fed resonant inverter. This integration produces a single power-processing unit that minimizes the number of circuit components. The proposed resonant inverter reduces the circulating current in the resonant tank and allows simple gate drivers to be used so that isolation devices can be eliminated. With the buck-boost stage operating in the discontinuous conduction mode (DCM), a close-to-unity power factor is achieved for different lamp-power conditions. A small-signal analysis is presented, and a simple variable frequency controller is developed using the modified 555 timer to provide dimming operations. Simulation and experimental waveforms are provided to highlight the merits of the proposed circuit for a 40-W compact fluorescent lamp.

A Single-Stage High-Power-Factor Electronic Ballast Based on Integrated Buck Flyback Converter to Supply Metal Halide Lamps

In this paper, a novel single-stage electronic ballast with a high power factor is presented. The ballast circuit is based on the integration of a buck converter to provide the power factor correction, and a flyback converter to control the lamp power and to supply the lamp with a low-frequency square-waveform current. Both converters work in discontinuous conduction mode, which simplifies the control. In spite of being an integrated topology, the circuit does not present additional stress of voltage or current in the main switch, which handles only the flyback or buck current, depending on the operation mode. To supply the lamp with a low-frequency square-wave current to avoid acoustic resonances, the flyback has two secondary windings that operate complementarily at a low frequency. The design procedure of the converters is also detailed. Experimental results from a 35-W metal halide lamp are presented, where the proposed ballast reached a power factor of 0.95, a total harmonic distortion of 30% (complying with IEC 61000-3-2), and an efficiency of 90%.

Design and Implementation of a Single-Stage High-Frequency HID Lamp Electronic Ballast

We present a single-stage electronic ballast with a high power factor feature for driving high-intensity discharge (HID) lamps. A new frequency-modulation technique is proposed to eliminate the acoustic resonance problem in HID lamps under high-frequency operation. The proposed method has the merits of simple circuit and low cost; thus, it is suitable for use in commercial applications. The conducted emission caused by the high-frequency electronic ballast can be also effectively reduced. The operating principles and design considerations of the proposed electronic ballast are analyzed and discussed in detail. A 35-W laboratory prototype is designed and implemented. Simulation and experimental waveforms are given to verify the feasibility of the proposed method. The results are satisfactory.

Single-Stage Voltage Source Charge-Pump Electronic Ballast With Switched-Capacitor Dimmer for Multiple Fluorescent Lamps

This paper presents a single-stage electronic ballast for driving multiple fluorescent lamps in which a dimming control scheme is proposed to regulate the lamp current. A laboratory prototype is built and tested, and it is found that the unity power factor can remain under individual lamp brightness control. The experimental results are therefore shown to verify the feasibility of the proposed method.

Single-stage electronic ballast with class-E rectifier as power-factor corrector

A single-stage high-power-factor electronic ballast with a Class-E rectifier as a power-factor corrector is proposed. A Class-E rectifier is inserted between the front-end bridge rectifier and the bulk filter capacitor to increase the conduction angle of the bridge-rectifier diode current for obtaining low line-current harmonics. The Class-E rectifier is driven by a high-frequency sinusoidal current source, which is obtained from the square-wave output voltage of the Class-D inverter through an LC series resonant circuit. A high-frequency transformer is used for impedance matching. The experimental results for a 32-W prototype ballast are given. The switching frequency was 61.3 kHz. At full power, the power factor was 0.992 and the total ballast efficiency was 88.3%. The lamp-current crest factor was about 1.36. The simulated and experimental results were in very good agreement.

Analysis and design of a high power factor, single-stage electronic ballast for high-intensity discharge lamps

This paper proposes a single-stage electronic ballast for high-intensity discharge lamps. The ballast consists of the integration of a boost converter in discontinuous conduction mode (DCM) and a full-bridge LCC resonant inverter. The boost semi-stage working in DCM functions as a power factor corrector and the inverter semi-stage operated above resonance is employed to drive the lamp. The sine-wave approximation is used to design the inverter at steady-state. The proposed electronic ballast can save a controller, reduce size and possibly increase system reliability compared to conventional two-stage system. The proposed ballast is analyzed, simulated and experimentally verified with a 125 W HPS lamp.

Single-stage electronic ballast with unity power factor

A single-stage electronic ballast with unity power factor is proposed. 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 conventional high-power-factor (HPF) electronic ballasts. Experimental results obtained on two 40 W fluorescent lamps are discussed.

A novel single-stage push-pull electronic ballast with high input power factor

A novel single-stage push-pull electronic ballast with high input power factor is presented in this paper. The proposed electronic ballast combines the front-end power-factor corrector and push-pull converter into a single-stage power converter. Compared to the single-stage class-D electronic ballast, the proposed circuit does not require an isolated driver. The control of the circuit is easier and the cost less. The circuit of the ballast is analyzed and the design guidelines are listed. The experimental results verify the theoretical derivation.

Single-stage high power factor electronic ballast for fluorescent lamps with constant power operation

A single-stage high power factor electronic ballast is designed to operate fluorescent lamps at a constant power over a very wide input voltage range. The electronic ballast performs the constant power operation by adjusting the duty-ratio of the embedded power regulation circuit. With duty-ratio control, a preheating period for the cathode filaments can be provided before igniting the lamp. The operation of the electronic ballast is discussed by an illustrative example with experimental results.