Design and analysis of automotive high intensity discharge lamp ballast using micro controller unit

A new scheme of the automotive high intensity discharge (HID) lamp ballast systems is proposed. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter as same as conventional HID ballast system. However this system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, which results in the use of the lower voltage rating power devices for HID lamp ballast system compared with conventional system. As a result, proposed system has a lower cost or a higher efficiency. For the improvement of the efficiency, the proposed ballast controller using micro-controller unit (MCU), controls the frequency to operate the DC-DC converter in critical conduction mode. This paper presents the design and analysis of the proposed ballast and some experimental results.     

一种数字控制HID灯电子镇流器的研制

介绍了一种单片机数字控制车用前照明高强度气体放电灯（high intensity discharge，HID）电子镇流器。镇流器系统主要由高频DC／DC开关电源、DC／AC逆变器、高压启动电路和单片机控制电路组成。它通过单片机软件编程，实现精确的数字控制，确保HID灯启动复杂的时序控制和恒功率控制过程，而且可以很好地处理各种故障模式，具有输入过压／欠压保护，输入反接保护，输出短路、开路保护等功能。     

Acoustic-resonance-free electronic ballast for automotive HID lamps

A novel cost-effective and acoustic-resonance-free electronic ballast used to drive automotive high intensity discharging (HID) lamps that utilise a constant lamp power control scheme is proposed. The presented ballast is comprised of a buck-boost flyback converter to provide negative DC voltages and a half-bridge-type inverter to supply the lamp with low-frequency, square-wave AC voltage/ current. Owing to its low-frequency operation, no acoustic resonance occurs on the automotive HID lamps. Design guidelines and experimental results are demonstrated for a 35 Wautomotive HID lamp prototype ballast operating at 400 Hz switching frequency with battery input DC voltage of 12 V.     

Novel Design of HID Lamp Electronic Ballast for Automotive Systems

This paper presents a high intensity discharge（HID） lamp for automotive illumination. A novel type of ballast for HID is proposed without an acoustic resonance. The system consists of high frequency DC/DC converter,DC/AC inverter（SLA2403M）, high voltage igniter and a microcontroller unit（MCU）. The proposed ballast controls the complex start-up process and constant power process by programming on the rnicrocontroller. It is verified that experimental results agree well with the calculated ones. The ballast features such functions as failure protection, line under-voltage, line over-voltage, output short circuit and disconnection protections.     

A Novel Constant Power Control Circuit for HID Electronic Ballast

This paper presents a constant power control circuit for a three-stage high-intensity discharge (HID) electronic ballast. The three-stage electronic ballast is composed of a boost pre-regulator to achieve a high power factor, a DC/DC buck converter to regulate lamp current with constant lamp power, and a full-bridge inverter to drive the HID lamp with a low-frequency ac squarewave current. The buck converter operating in current mode utilizes current sense level-shift technique to achieve constant power output. The proposed constant power control circuit is easily designed and implemented for the three-stage HID electronic ballast. Finally, a laboratory prototype of a 70 W HID electronic ballast is implemented. The measured results show that the proposed ballast can be applied for various HID lamps with low lamp power variation (less than 0.6%).     

Low-cost high power-density electronic ballast for automotive HIDlamp

A low-cost high-efficiency high power-density electronic ballast for 35 W automotive high intensity discharge (HID) is presented along with the results of theoretical computations and experimental tests. The ballast circuits is based on a 100 kHz resonant inverter, a half-wave rectifier and a 400 Hz operated square-wave inverter. The converter operates at zero turn on losses, nearly zero turn off losses, and at a reduced electromagnetic interference level. The ballast circuit is designed to prevent inappropriate operations due to the acoustic resonances. The lamp voltage waveform has limited dv/dt and no DC component contributing to a long operating life of the lamp. A breadboard of the electronic ballast was designed and experimentally tested on a 35 W lamp, for a DC input voltage ranging from 9 V to 16 V. The electronic ballast performs all the features required to turn-on, warm-up and drive at the steady state a 35 W HID lamp and operates at a maximum steady state efficiency η=84%,     

A high-frequency electronic ballast for HID lamps based on aλ/4-long distributed constant line

A novel type of solid-state ballast, which operates in the megahertz-range frequency, is presented in this paper. A circuit composed of a voltage-source half-bridge inverter, a distributed constant line and a parallel LC resonant circuit has been developed for this purpose. The high-intensity discharge (HID) lamp is connected to the output terminal of the inverter through the distributed constant line. Here, since the length of the line is adjusted to 1/4 of the propagation wavelength λ (λ/4 condition), the output voltage of the voltage-source inverter can be converted to a current source on the load side. Therefore, the ballast can supply not only high voltage to the HID lamp for initiating discharge, but also stable current to it during discharge condition. The modification of the proposed circuit is also proposed in order to expand the operating frequency without increasing the undesirable harmonic current. The experimental results from a prototype system verify the theoretical procedure     

TRIAC dimmable ballast with power equalization

A two-stage, two-wire TRIAC dimmable electronic ballast for fluorescent lamps is presented in this paper. It is constructed by using a flyback converter as the input power factor corrector to supply a half-bridge series-resonant parallel-loaded inverter to ballast the lamp. The flyback converter is operated in discontinuous conduction mode so that the filtered input current profile is the same as the TRIAC-controlled voltage waveform. The switches in the inverter are switched at a constant frequency slightly higher than the resonant frequency of the resonant tank. Based on the constant average input current characteristics of the inverter, the dimming operation is simply achieved by pulsewidth modulation control of the magnitude of the flyback converter output voltage. No synchronization network is required between the input and output stages. In addition, a linear power equalization scheme is developed so that the dc-link voltage (and hence the lamp power) is in a linear relationship with the firing angle of the TRIAC. The average output voltage of the dimmer controls the equalized flyback converter output voltage. Modeling, analysis, and design of the ballast will be described. A prototype was implemented to verify the experimental measurements with the theoretical predictions.     

Low Frequency Architecture for Multi-Lamp CCFL Systems With Capacitive Ignition

A low frequency architecture is proposed for driving parallel cold cathode fluorescent lamps (CCFLs) in large screen liquid crystal display (LCD) TV backlighting applications. Key to the architecture is a proposed capacitive coupling approach for aiding lamp ignition. A dc voltage is applied to the lamp electrodes while an ac voltage is applied to an external plate for capacitive coupling. The result is reliable, simultaneous ignition of parallel lamps with a required applied dc voltage near the lamp steady-state operating voltage. The complete system architecture includes a single high voltage converter, a pulse lamp ignition circuit, current control circuits and a single backlight controller. The topology is capable of driving a large number of parallel lamps with independent lamp current regulation, while avoiding ac coupling losses in steady-state operation and achieving significant reduction in reactive components when compared to typical high frequency ac ballast designs. Experimental results are presented for a system of four parallel 250 mm length lamps, demonstrating simultaneous parallel lamp ignition and dc current regulation.     

数模双环路HID安定器的设计

HID氙气灯必须工作在恒定功率条件下,通常采用功率误差检测环路来实现。在分析了35 W车用HID氙气灯工作特性和市场上HID氙气灯安定器设计特点的基础上,提出了一种新颖的HID安定器的设计方案,其特点是同时采用了数字和模拟两个功率误差检测环路。实验表明,采用以此结构设计的安定器既保证了很好的瞬态特性,又保证了进入稳态后输出功率的稳定性。     

Analysis and Improvement of Automotive High Intensity Discharge Lamp Ballast Based on Microcontroller Unit

The superior performance of high intensity discharge（HID） headlamp is clearly shown for luxury sedans, and the lamp luminescence properties are analyzed. The principle of its ballast technology is analyzed in detail. For against the disadvantage of current ballast technology for sedans lamp, a novel type of electronic ballast for HID is designed based on programmable intelligent computer（PIC） microcontroller unit（MCU） and S1A2410M inverter and it provides guidance and can be easily used in control configuration selection and design. The feasibility and superiority of the system are proved.     

A boost-type converter for DC-supply of fluorescent lamps

A boost type converter is described that is suitable for low-voltage DC-supply of fluorescent lamps. It has inherent lamp current limitation (ballast action) and provides the high voltage pulses and electrode heating that are required for igniting the lamp. The proposed circuit is applicable in automotive, emergency, and portable light sources.<>     

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%.     

Single-stage electronic ballast with dimming feature and unitypower factor

Analysis, design, and practical consideration of a single-stage electronic ballast with dimming feature and unity power factor are presented in this paper. The proposed single-stage ballast is the combination of a boost converter and a half-bridge series-resonant parallel-loaded inverter. The boost semistage working in the discontinuous conduction mode functions as a power factor corrector and the inverter semistage operated above resonance are employed to ballast the lamp. Replacing the lamp with the plasma model, analysis of the ballast is fulfilled. The dimming feature is carried out by pulse-width modulation (PWM) and variable-frequency controls simultaneously. The proposed single-stage ballast is suitable for applications with moderate power level and low-line voltage while requiring a high-output voltage. It can save a controller, an active switch and its driver, reduce size, and possibly increase system reliability while requiring two additional diodes over a conventional two-stage system. A prototype was implemented to verify the theoretical discussion. The hardware measurements have shown that the desired performance can be achieved feasibly     

Investigation of a New Control Strategy for Electronic Ballasts Based on Variable Inductor

In this paper, a new control method for electronic ballasts based on the use of a variable inductor is presented. The main goal is to perform the complete control of the electronic ballast by maintaining the switching frequency constant and without using other parameters of the power converter, such as input voltage or duty cycle. The magnetic regulator is controlled by means of a dc current, which allows performing both lamp soft starting and lamp dimming. Apart from the important advantage of keeping a constant frequency during full electronic ballast operation, the proposed method presents additional advantages when compared to other control methods, such as inherent isolated control, more linear control characteristics, constant electrode power, and higher efficiency. Experimental results from a 36-W linear fluorescent lamp prototype are presented.     

Small-signal analysis of a low-cost power control for LCC series-parallel inverters with resonant current mode control for HID lamps

In this paper, a low-cost power control for LCC series-parallel inverters with resonant current mode control for high intensity discharge (HID) lamps is presented. These resonant inverters require controlling the power supplied to the lamp in order to avoid exceeding the maximum lamp power recommended by the lamp manufacturer. The classical control method measures the lamp voltage and current and they are multiplied analogically, obtaining the lamp power consumption measure. This control circuitry results very complex due to the lamp voltage and current wide variations range during ignition and discharge processes. Assuming a regulated input dc voltage (bus voltage) provided by the power factor correction (PFC) pre-regulator and an inverter constant efficiency along the lamp aging, the lamp power consumption may be estimated and regulated properly measuring the inverter average input current. Also, the small-signal analysis performed allows obtaining the small-signal resonant inverter input impedance and studying the connection stability between PFC pre-regulator and inverter. The inverter small-signal analysis has been performed and an electronic ballast prototype for 250-W HPS lamps has been implemented and tested verifying the low-cost lamp power control method proposed.     

A high-power-factor electronic ballast using a flyback push-pullintegrated converter

This paper describes a high-power-factor electronic ballast for fluorescent lamps. The converter offers a high power factor and a high-frequency supply to the lamp using a single switch. In spite of its simplicity, an excellent performance concerning load and supply is achieved, ensuring a sinusoidal and in-phase supply current. High power factor is achieved by using a flyback converter operating in discontinuous conduction mode. Operating principle, design equations, component stress, and efficiency are presented. Experimental results have been obtained for one 40-W fluorescent lamp operating at 50-kHz switching frequency and 220-V line voltage     

Implementation of a Voltage Multiplier Integrated HID Ballast Circuit With Dimming Control for Automotive Application

High-intensity discharge (HID) lamps are becoming popular substitutes for halogen lamps in automotive headlamps because of the high lumen/watt ratio and the color of the light. In this paper, a ballast (integrated with a voltage multiplier circuit in the secondary winding of the dc converter transformer) with dimming control is presented. The proposed circuit not only eliminates one auxiliary winding but also reduces the voltage across the switch on the primary side and consequently permits the selection of switches with a lower rating. A brief review of the HID circuits is done and compared with the proposed circuit. Experimental results from the prototype are presented. This paper also presents different methods of dimming the automotive HID lamps based on analog and digital control and discusses the relative merits of each of the methods. The dimming control is implemented using both the methods, and experimental results are presented. It is envisaged that the dimming control will provide some flexibility to drivers in the control of HID lamps to suit the driving conditions in the modern cities that are very well lit at night. This paper investigates the merits of each method and discusses the practical issues for implementing such controls.      

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.     

Power factor correction converter using delay control

A low cost universal input voltage single-controller power factor correction converter for a 200 W power supply is proposed. It consists of the PFC part followed by a DC-DC converter as in a conventional two-stage scheme. However a single PWM controller is used as in a single-stage PFC scheme. The switch in the PFC part is synchronized with the switch in the DC-DC converter and has a fixed frequency. Employing an adaptive delay scheme, the PPC switch is controlled to limit the capacitor voltage within a desired range for optimum efficiency and to reduce input current harmonic distortion. The design procedures of the delay scheme, the feedback loop, and experimented results are presented to verify the performance