Power Factor Electronic Ballast Research Articles

High power factor electronic ballast using resonant converter for compact fluorescent lamp

SummaryThis paper proposes a novel single stage single switch resonant inverter with high power factor for electronic ballast. The power factor correction circuit is at the input side. It is designed to operate at discontinuous conduction mode. The lamp power is controlled by adjusting the duty ratio of the active switch of the power factor correction circuit. The circuit operation is analyzed in detail to derive the design equations. Circuit parameters are designed based on design considerations. Finally, prototype electronic ballast for a 40‐W compact fluorescent lamp is built and tested. The efficiency and the performance of the proposed converter are verified for the designed prototype. Copyright © 2016 John Wiley & Sons, Ltd.

Structures of Single-stage and High Power Factor Electronic Ballasts Integrating the Boost and Ballast Inductors


 This paper presents a new family of high power factor for electronic ballasts applied to fluorescent lamps. From the proposed structures, two topologies are presented without the ballast inductor, because the boost inductor, in addition to performing power factor correction, also has the function of limiting and stabilizing the lamp current, besides making it to start. The main characteristics of these topologies are the reduction in the production costs owing to fewer components, the low harmonic distortion in the input current, the lower current in the switches, and the lower DC bus voltage. To verify the proposed design methodology and to provide the condition of unity power factor and stabilization of the lamp current, the experimental results of one prototype is presented.

Analysis and Implementation of an HPF Electronic Ballast for HID Lamps With LFSW Voltage

In this paper, a novel high power-factor electronic ballast for metal-halide (MH) lamps based on integration of a buck-boost converter, a buck converter, and a full-bridge inverter is proposed. The buck-boost converter that serves as a power-factor corrector (PFC) is designed to operate at discontinuous conduction mode to achieve a high power factor at the input line. A bidirectional buck converter formed by a full-bridge inverter, an inductor, and a capacitor drives an MH lamp with a low-frequency square-wave voltage to prevent the lamp from acoustic resonance. The lamp power is controlled by adjusting the duty ratio of the active switches of the PFC. The circuit operation is analyzed in detail to derive the design equations. Circuit parameters are designed based on design considerations in practical applications. Finally, a prototype electronic ballast for a 70-W MH lamp is built and tested. Satisfactory performances are obtained from the experimental results.

Single-Stage Half-Bridge Electronic Ballast Using a Single Coupled Inductor

This paper proposes a single-stage half-bridge electronic ballast with a high power factor using only a single coupled inductor. Compared to conventional high power factor electronic ballasts, the proposed ballast is a simpler circuit with a low cost and a high reliability. The proposed ballast is made up of a power-factor-correction (PFC) circuit and a self-oscillating class-D inverter. The PFC and inverter stages of the proposed ballast are simplified by sharing only a single coupled inductor and two common switches. The proposed PFC circuit can achieve a high power factor and low voltage stresses of the switches. A saturable transformer in the self-oscillating class-D inverter determines the switching frequency of the ballast. Experimental results obtained on a 30W fluorescent lamp are discussed.

A High-Power-Factor Single-Stage Single-Switch Electronic Ballast for Compact Fluorescent Lamps

A very high power factor electronic ballast that uses a single switch in the power circuit is proposed in this paper for compact fluorescent lamps (CFLs). The proposed power circuit is designed by integrating a SEPIC power factor corrector with a novel single-switch current-fed resonant inverter. The advantage of this single-switch electronic ballast is that it greatly simplifies the gate-drive circuit design due to the elimination of isolation devices that are otherwise required in the conventional half-bridge totem pole configuration. This topology features a reduction of at least two switches in the power stage compared to conventional two-stage approach for high-power-factor electronic ballasts. In addition, the proposed circuit is also able to achieve close-to-unity power factor by operating the integrated SEPIC power factor corrector in discontinuous conduction mode. The conduction loss of the switch in the proposed circuit is also significantly reduced compared to the conventional class-E single-switch resonant inverter. Experimental results are provided to justify all the theoretical analysis and highlight the features of the proposed circuit on a 13-W CFL.

A Modified Valley Fill Electronic Ballast Having a Current Source Resonant Inverter With Improved Line-Current Total Harmonic Distortion (THD), High Power Factor, and Low Lamp Crest Factor

In this paper, a modified valley fill (VF) circuit is employed to combine with a current-fed resonant inverter as a passive high power factor (PF) electronic ballast. A conventional VF circuit limits the line current to conduct when the conduction angles are: 30deg les omegat les 150deg and 210deg les omegat les 330deg during the line period, which results in high total harmonic distortion (THD). The modified VF circuit has the following advantage: When the capacitors are connected in parallel, the voltage across the capacitors is one-third of the peak voltage, which allows the conduction angle of the line current to be further extended to 19.5deg les omegat les 160.5deg and 199.5deg les omegat les 340.5deg, so that a lower THD can be achieved. The high lamp crest factor (CF) problem generated by the high ripple voltage from the modified VF circuit is improved in the proposed ballast as variable frequency control is employed to continuously regulate the lamp current. An experimental prototype is then built in the laboratory to verify the feasibility of the proposed work for a 26-W compact fluorescent lamp. The final results confirm that a PF of 0.986 and a lamp CF of 1.49 are achieved with the proposed circuit, whereas a PF of 0.96 is achieved with the conventional VF ballast.

High Power Factor Electronic Ballast for Fluorescent Lamps With Reduced Input Filter and Low Cost of Implementation

An electronic ballast employing the voltage source-charge pump power factor correction concept is presented in this paper. Such characteristics as reliability, simplicity, and a small number of components are found in this electronic ballast. From the developed mathematical analysis, the unity power factor condition is obtained. Experimental results for a prototype applying the developed methodology to two 40-W lamps, using a fixed frequency drive, and to a second prototype with two 40-W lamps, using a self-oscillating drive, prove the efficiency of the proposed electronic ballast.

A high power factor ballast using a single switch with both power stages integrated

This paper presents a high power factor electronic ballast used to startup fluorescent lamps employing a single power stage and a single-switch. This topology was obtained combining of a Boost converter and a new inverter topology with coupled inductors. The use of a single active switch reduces the number of components used in the control and power circuits. The equations used for designing the proposed reactor and for choosing the semiconductor devices are presented. A prototype operating at 50kHz was built and used to startup 40-W fluorescent lamps.

Single Stage Self-Oscillating HPF Electronic Ballast

This paper presents a single stage self-oscillating high power factor (HPF) electronic ballast more suitable for both low power levels (because it operates in discontinuous conduction mode) and low AC mains applications (since it employs an input doubler rectifier). The electronic ballast is based on a high frequency dither signal, which shapes the input current in a sinusoidal waveform. In order to reduce the electronic ballast components the self-oscillation technique has been employed. An electronic ballast prototype operating at 25 kHz has been implemented to drive two 40 W straight-type fluorescent lamps from a 127 V utility line. High power factor is achieved even though the electronic ballast drives just one fluorescent lamp. The experimental results demonstrated the electronic ballast operation.

High Power Factor Self-Oscillating Electronic Ballast to Supply Four Fluorescent Lamps

This paper presents an innovative modification in the conventional self-oscillating driver, in order to supply variable loads. This modification consists of adding an auxiliary output filter supplying a small power resistor, which also includes the primary winding of the self-oscillating transformer. The analysis for self-sustained oscillations is performed by extended Nyquist criterion, which defines the design equations for the ballast component values. A design example is presented, using the proposed circuit in a high power factor electronic ballast supplying four independent lamps. A passive circuit named valley charge pump is used to perform the power factor correction. The ballast supplies four lamps independently, without considerable frequency changes, with an efficiency of 93%, and reaching IEC 61000-3-2 requirements for the input current distortion.

Design and experimental results of an input-current-shaper based electronic ballast

This paper presents some design issues and experimental results regarding the use of the input current shaper (ICS) technique to implement high power factor electronic ballasts. The ICS is placed between main rectifier and bulk capacitor to increase the conduction angle of the main rectifier diodes up to a minimum value to obtain low current harmonics injected to the mains. Two possibilities to implement ICS-based ballast are considered in this paper: the forward-based ICS and the flyback-based ICS. Experimental results obtained from two 40-W fluorescent lamp ballasts are also presented.

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.