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The simplest electronic ballast for HID lamps
Abstract
The resonant forward-flyback (RFF) inverter is presented, analyzed
theoretically and tested experimentally. It is shown that the inverter
can be designed to operate under zero voltage switching (ZVS) conditions
and that it acts as a current source, features that are highly
compatible with HID lamp ballasting. The design guidelines and the
detailed analytical expressions developed in this study were verified by
computer simulation and hardware implementation. The experimental
results of the study demonstrate that the arc of small 35 W and 70 W
metal halide discharge lamps can be stabilized by the proposed RFF
ballast when operated in the 300 kHz to 400 kHz switching frequency
range and applying about 20% FM modulation. Considering the fact that
the proposed ballast includes only one switching device, one magnetic
component and one resonant capacitor, the RFF inverter is most likely
the simplest ballast topology possible
... Topology shown in Fig. 2c is similar to that in Fig. 2b but using a transformer instead of an inductor. A topology similar to that shown in Fig. 2c was used to supply high intensity discharge (HID) lamps in [11]. In [11] the topology shown in Fig. 2c is analyzed considering the effect of the transformer leakage inductance, but the relationship between the transistor duty cycle and load voltage and current was not clearly established. ...
... A topology similar to that shown in Fig. 2c was used to supply high intensity discharge (HID) lamps in [11]. In [11] the topology shown in Fig. 2c is analyzed considering the effect of the transformer leakage inductance, but the relationship between the transistor duty cycle and load voltage and current was not clearly established. Besides, according to [10], this topology presents an asymmetric load current waveform with high crest factor. ...
... The topology proposed to drive the lamp is shown in Fig. 3a. This topology is very similar to that presented in [11], only an extra inductor is placed in series with the lamp in order to improve the lamp CCF. The circuit shown in Fig. 3a is equivalent to the class E amplifier with only one inductor and one capacitor in the load network presented in [9] and [10]. ...
In this paper a high-power-factor electronic ballast for compact fluorescent lamps based on the class E amplifier and featuring low voltage stress across the switch is presented. The proposed ballast is obtained by integrating a buck-boost converter, used as power factor correction stage, and a class E amplifier with a parallel resonant tank, used as resonant inverter. The buck-boost converter is op-erated at constant frequency and constant duty cycle in discontinuous conduction mode (DCM) to obtain a high input power factor.
... A LOW INPUT CURRENT RIPPLE Fig. 1 shows CCFL inverters with a minimum of switches and components. The inverters are modified from the electronic ballast applied first to high intensity discharge (HID) lamps [14], [15], and they can be regarded as modified class E-type resonant inverters [1], [13]- [18]. By increasing the leakage of the transformer, we can simply use the leakage inductance of the transformer as a substitute for the input choke coil of the generic class E inverter to reduce the number of components. ...
... Given that the operation and design procedure has been fully described in [14] and [15], we merely present an outline of the operation. When the switch is turned on, the input current flows through the primary side of the transformer and the switch. ...
... Furthermore, the steady-state value of is always the same despite the varying load power under the dimming control. Therefore, by choosing sufficiently large value of and , and by assuming the voltage of is a constant voltage source, the inverter in Fig. 2 can be regarded as inverters in Fig. 1 and can be analyzed and designed similarly as in [14] and [15]. The main difference between inverters in Figs. 1 or 2 and inverters in [14] or [15] is that the resonant network in the secondary side should be considered in the design. ...
A new low-cost and efficient cold cathode fluorescent lamp (CCFL) inverter for liquid crystal display (LCD) application is suggested in this paper. The topology of the inverter is derived from modified class E-type resonant electronic ballasts and has a dc-like input current. In addition, a new sensing circuit for lamp current and transformer voltage is proposed. A simple RC-network measures the voltage of a ballasting capacitor in series with the lamp instead of the lamp current itself while the lamp is floated. Utilizing the printed circuit board capacitors for the sensing capacitors and integrating small-valued sensing resistors into a control integrated circuit make the inverter very simple, efficient, and cost-effective. The new sensing circuit can solve many problems that arise when a terminal of the lamp is grounded to sense the lamp current. The control circuits for the prototype experiments are also described in detail. The frequency control scheme with a fixed off-time and a varying on-time was chosen to maintain the operation of zero-voltage switching in the entire dimming range and to reduce the complexity of the control circuits. The control circuits have an analog dimming function using a current control loop, a low frequency pulsewidth modulation dimming, open-lamp protection and voltage regulation, and soft-on/off functions
... The average efficiency is approximately 73%, with a peak at 75%. This efficiency is higher than the commonly reported value for single-switch converter, as noted by [28], [29]. ...
... Several papers [7]- [16] discuss methods to detect and overcome acoustic resonance in HID metal halide lamps other than those used in automobiles. The ballast working in the megahertz range is proposed in [17], resulting in smaller size ballasts. A single-stage HID ballast with frequency modulation is discussed in [23] for commercial 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.
... [11] ...
In this paper, a high-power-factor electronic ballast for compact fluorescent lamps based on the class E amplifier and featuring low voltage stress across the switch is presented. The proposed ballast is obtained by integrating a buck-boost converter, used as power factor correction stage, and a class E amplifier with a parallel resonant tank, used as resonant inverter. The buck-boost converter is operated at constant frequency and constant duty cycle in discontinuous conduction mode (DCM) to obtain a high input power factor
... Therefore, it is difficult to find a frequency window that is consistently free of acoustic resonance for every lamp all the time. 5 The lamp is operated with modulation of switching frequency in the inverter [10][11][12]. This approach will expand the power spectrum of the lamp and lower the energy of the eigenfrequency that supplies the lamp. ...
A two-stage, frequency-modulated (FM), high-frequency-driven electronic ballast for metal-halide (MH) lamps is proposed. The presented ballast consists of a power-factor-correction (PFC) converter as the first stage, a half-bridge series-resonant parallel-loaded (HB-SRPL) inverter as the second stage, and a frequency-modulation controller. The advantageous features of the high-frequency-operated ballast are its compact size and reduced weight. With constant-frequency control, the switching frequency of the ballast must be carefully designed within a frequency window that is free from acoustic resonance, and the envelope of the lamp current is large owing to the DC-bus voltage ripple that occurs on the PFC output. However, if the switching frequency of the inverter is operated outside of the stable operation window or if the energy of some eigenfrequency is sufficiently higher, then acoustic resonances will exist. An FM-controlled electronic ballast for MH lamps is proposed. The switching frequency of the HB-SRPL inverter, whose centre frequency is intentionally designed at a frequency at which acoustic resonances occur, is periodically modulated by the voltage ripples of the PFC output. The presented ballast offers a lower envelope of lamp current in order to expand the power spectrum of the lamp and to decrease the energy of the eigenfrequency that supplies the lamp. Owing to its FM operation that allows for an adequately modulated index, no acoustic resonance occurs. The ballast offers cost-effectiveness, a simple control circuit without an external modulation signal, and a low crest factor (<1.45). Design guidelines and experimental results are presented for a 70 W MH lamp ballast that utilises the FM control method with universal-line input voltage
... Therefore, determination of appropriate design specifications of the ballast circuit requires an accurate analysis of the specific lamp to be supplied. Several methods to predict and prevent the acoustic resonance and several electronic ballast circuits have been presented [5]- [16]. However, these methods and circuits refer to 70 W and/or 150 W HID lamps for lighting systems and cannot be directly applied to automotive lamps. ...
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%,
High-voltage dc has a wide area of application in the military, science, and industry. Based on the energy equation, in order to produce more potential energy, due to limitations in increasing the capacitance, another parameter which is the voltage must be increased to a higher value. In the recent century, many types of high-voltage generators and voltage multipliers are introduced to do this task, and until now; their development and improvement are subject to be continued. Indeed, a charge pump is another type of voltage multiplier that can produce a dc voltage at its output. Unlike the voltage multipliers that employ to generate a low or high-voltage dc, charge pumps are generally used in low-voltage applications. In this thesis, a novel charge pump is developed for high-voltage applications. By re-designing a voltage multiplier circuit, it attempts to propose a novel charge pump configuration that can produce higher output dc voltage and stored potential energy. Since,the proposed circuit includes many energy storage components, understanding its performance and calculating the output voltage in the time-domain seems to be a very complicated and time-consuming process. Thus, a circuit theory is used to explain the performance of the circuit in a simple way. Furthermore, this theory offers an equation to explain the correlations between the output voltage and stored potential energy with the input voltage and number of stages. In order to evaluate the proposed circuit, simulation has been carried out, and its output results were compared with calculations. In order to identify a more precise behaviour of the output voltage parameters, in steady-state, and their dependence to the input voltage, number of stages and pumping frequency; an approximate mathematical model optimized for each parameter that can give an enhanced view of the circuit for better understanding of its behaviour. In addition, a new time-domain equation is suggested for the proposed charge pump. Moreover, based on the suggested time-domain equation, a suitable transfer function for both the transient and the steady-state response of the proposed charge pump is calculated. This transfer function can be used for modelling and simulating the circuit as a control system. Ultimately, a prototype circuit of the proposed charge pump with the ability of converting to the conventional circuit with the same values, and circuit parameters have been designed, optimized, and fabricated; its output results were compared with the output results of the conventional circuit; and results of calculation and simulation. In this research, the novel charge pump is successfully designed, fabricated, and validated. The results show its promised application in science and, military.
The paper proposes and analyzes an individual
automatic energy-saving device destined to the produce light
dimming in the public lighting network dominated by high
intensity discharge (HID) lamps and magnetic ballasts. The
device is based on the single-phase voltage angle regulation and
designed to switch the lamp's circuit input voltage within three
levels 230V, 190V and 170V. The selection of the level is done
automatically and depends on the time hour. The dimming device
operation was first simulated and then experimental validated
using two power levels (of 250 W and 150W) of high pressure
sodium (HPS) lamps. This device can be a relative cheap solution
for the low budget lighting systems, an opportunity for the city
manager of lighting and electricity to get better energy efficiency.
Keywords- energy-saving, energy efficiency, public lighting
systems, magnetic ballast systems, automatic dimmability
In this paper, we studied the development of the electronic ballast for 250W MH (Metal-Halide) lamps. We were able to improve the input power factor by using a PFC IC. To provide the lamp with the rated voltage required, we used the buck-type dc-dc converter. The stress of the switching devices in the inverter could be reduced by this method. To eliminate the acoustic resonance phenomena of MH lamps, the voltage of the lamp added the high frequency sine-wave to the low frequency square-wave by using the full bridge typed inverter. We have developed a simple igniter using the L and C elements. We could control the dimness of the lamp by varying the output voltage of the buck converter. The buck converter output voltage could be controlled by using a microprocessor.
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%.
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/low-frequency square-wave-driven half-bridge inverter for supplying low-frequency 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 is free of acoustic resonance. This paper analyzes the operational modes, key design guidelines and experimental results of the proposed ballast for a 70W HID lamp operating with 110V-rms input utility-line voltage.
Palm oil agricultural and industry activities generate a great amount of by product, known as palm oil mills effluent (POME). The treatment conducted using membrane bioreactor has successfully removed the heavy organic component of POME but the water that remains still contain colour as its by product. This paper proposed the use of a simple silent discharge ozonizer in colour removal of treated palm oil mill effluent (POME). The ozonizer chamber was developed from a simple planar metal dielectric barrier discharge construction. A simple high frequency power converter as power supply to the chamber was designed based on resonance phenomena. This power supply converted a direct current low voltage input into high frequency and high sinusoidal voltage output. This high voltage created micro electrical discharges inside chamber to generate ozone from oxygen molecules. At normal atmospheric pressure and ambient temperature, this ozonizer produced ozone concentration up to 1800 ppm. Ozone in a certain concentration was injected into the treated POME water through a diffuser for several minutes. As the result, the colour of treated POME water has successfully changed from 100 mg/l Pt. Co into 40 mg/l Pt. Co or lower. Visually, water colour below 40mg/l Pt. Co is considered clear. Extended the time of ozone treatment upto 15 minute has successfully reach colour abatement below 15 mL/l Pt. Co which accords to World Health Organiation (WHO) recommendation for Colour in drinking water.
This paper presents a new control technique of low-cost and high performance for a single switch zero voltage switching (ZVS) inverter with a dimming control. This paper reviews the cold cathode fluorescent lamp (CCFL) characteristics and the various inverter topologies for the CCFL and introduces a new simple E-class inverter circuit topology and its control technique. The proposed controller can ensure ZVS operation under most operating conditions and simply perform the dimming control. It is shown through experimental results that the controller of the proposed system has good performance for the LCD backlight inverter operation
This paper presents a new constant power control of high frequency electronic ballast for a metal halide lamp based on the phase-locked loop (PLL) technique. First, the PLL is employed as a feedback mechanism to improve the resonant frequency variations caused by lamps aging or an impedance difference between used lamps characteristics. The proposed system can adjust the operating frequency to sustain constant power for a metal halide lamp according to the impedance of the adopted lamps. Moreover, the control strategy also can be used to substantially reduce the warm-up process of a metal halide lamp. The design considerations and measured results are detailed to verify the validity of the proposed control strategy
A one-chip class-E inverter controller is implemented in a 0.35 mum standard CMOS process. The control IC generates a control signal to turn on or off the insulated-gate bipolar transistor switch of the class-E inverter power supply driving a magnetron load which generates 2.45 GHz microwave for heating. It provides active power factor correction, soft start, and thermal protection. The rated RF output power of the magnetron is around 1.2 kW for a 100 V AC line, and an input power factor of over 0.98 is maintained. The proposed integrated solution gives better system performance with lower cost than conventional discrete solutions.
This paper proposes a novel LCD backlight inverter using a simple control circuit of low-cost with a dimming control, which utilizes zero voltage switching (ZVS) technique. This paper reviews the cold cathode fluorescent lamp (CCFL) characteristics and the various inverter topologies for the CCFL, briefly. And it introduces a new simple E-class inverter circuit topology and its control technique. The proposed inverter can ensure ZVS operation under most operating conditions and simply perform the dimming control. It is shown through experimental results that the controller of the proposed system has good performance for the LCD backlight inverter operation.
This paper presents an LCD panel sector-dimming controlled high efficiency LED backlight drive system. The proposed LED backlight drive system is composed of a high efficiency DC-DC converter capable of operating over a universal AC input voltage (180~265 V) and a high performance LED backlight sector-dimming controller. The proposed system achieves high efficiency with a soft-switching asymmetrical half-bridge DC-DC converter using a synchronous rectifier and an LED backlight sector dimming controller using lossless power semiconductor switches (MOSFETs). In order to achieve high performance, the proposed system performs the sector -dimming and the current regulation using a low-cost microcontroller and MOSFET switching, resulting in high contrast and brightness. A 90 W laboratory prototype was built and tested. The experimental results verify the feasibility of the proposed system.
xx, 113 leaves : ill. (some col.) ; 30 cm. PolyU Library Call No.: [THS] LG51 .H577M EE 2009 Chan HID lamps on account of their high brightness and efficiency are being adopted as a replacement to the traditional Halogen lamps in automobile lighting systems. However, HID lamp produces more glares compared to Halogen lamps due to sharper cut-off point of its light pattern. The abrupt shift from the dark to bright region of its light pattern is known to cause glare to the oncoming vehicles resulting in temporary discomfort to the oncoming drivers. The present work is related to the solution to overcome the problem of glare caused by the use of HID lamps. Accordingly a system which can control the direction of the light beam from the HID lamp is developed in the current work. Power saving and high power efficiency are also the concerns for this project. In the study of Advanced Headlamp Control System, two types of drive have been examined to control the headlamps that are stepper motor and servo motor. Comparison has been made for the performance and cost. It has been found that the stepper motor provide a higher performance in response time and robustness. Lower cost in overall system is also found. . The Adaptive Front Lighting System (AFS) control is highly related to the distance of the obstacle. Different distance will trigger different operations of the AFS. Simulation of the system by Matlab has been done to examine different cases and conditions. The logic, the input and output of the system have been simulated through software. A number of cases have been done to study the operation condition in details. In automotive system, the voltage conversion from the battery voltage to other unit is important. The present system is to develop a low EMI converter that converts battery voltage 12V to 6V for the control electronics of the proposed Advanced Headlamp Control System. A new switched-capacitor resonant converter is proposed that eliminates the level-shifted gate drive. A circulation inductor is inserted to reduce the shoot-through current. A formulation of the circuit is presented. The method can be extended to other voltage conversion system and other switched-capacitor topologies. Finally, the implementation of the AFS to an electric vehicle is discussed. The design of the EV based on the total running resistance is to use design the motor drive system. The overall vehicle with the installation of the AFS is finally prototyped and demonstrated in an electric vehicle EV4. M.Phil., Dept. of Electrical Engineering, The Hong Kong Polytechnic University, 2009
It has been for a long time that in commercial product, only was a series type of HID-lamp ballasts available. Although it has the merit of simple circuit configuration, there still exist limitations, such as high conduction loss on the secondary winding of the igniter transformer or requiring a two-stage ignitor design, high follow-up current flowing through the full-bridge switches, and requiring a sophisticated L-C filter located between the full-bridge inverter and the igniter winding. This paper presents a parallel type of electronic ballast for HID lamps, which can release the aforementioned limitations. Additionally, performance comparison between these two types of ballasts will be also presented. Experimental results measured from a prototype of 35 W Xenon-lamp ballast are used to verify the analysis and discussion.
A novel two-stage, high-power-factor electronic ballast used to drive high-intensity discharge lamps is proposed in the paper. The ballast consists of a flyback-type input current shaper to achieve power factor correction and a half-bridge-type inverter to supply the lamp with low-frequency square-wave current. Owing to its low-frequency operation, no acoustic resonance occurs. The features of the ballast are cost-effective, low total-harmonic-distortion (THD), high power factor (PF>0.99). Operational principles, design equations and simulated results of one 70-W HID lamp operating at 400 Hz switching frequency with 110 V-rms line input voltage are presented.
An adaptive acoustic resonance free electronic ballast for high intensity discharge (HID) lamps is proposed. The ballast implemented a digital method to detect acoustic resonance of HID lamps. The lamp power is kept constant. Simultaneously, end of life detection is also provided. A prototype of the electronic ballast for 250 W metal halide lamp has been built, and the experimental results proved its validity.
In this paper, a new current control method is applied to a nonresonant, quasi-square wave inverter used to supply HID lamps at high frequency. The chosen control method is previously compared to several current mode and voltage mode control methods. The selection criteria in order to choose a control method are stabilization of the ballast-lamp system and low power high frequency harmonics. With current stabilization, no intermediate stages are needed between the inverter and the DC source; with low power harmonics, decreases the risk of finding acoustic resonances in the high frequency steady state operation. The proposed circuit is specially suitable for the automotive industry, because the inverter can be connected directly to a DC bus.
The paper presents a novel two-stage acoustic resonance free electronic ballast for high intensity discharge (HID) lamps. The ballast consists of a power factor correction (PFC) stage to achieve power factor correction and an inverter to supply the lamp with low frequency square wave current. Due to its low frequency operation, no acoustic resonance occurs. The proposed circuit was verified by simulation and experimental results.
The paper presents a novel two-stage acoustic resonance free electronic ballast for high intensity discharge (HID) lamps. The ballast consists of a PFC stage to achieve power factor correction and a four quadrants DC/DC converter to supply the lamp with low frequency square wave current. Due to the negative impedance characteristic of the HID lamps, the inverter must be controlled to perform as a current source. The control strategy is described in detail in the paper. The circuit is also verified experimentally.
This paper presents a driver for an HID lamp based on the
application of a high frequency current square waveform through the lamp
with the goal of avoiding acoustic resonances. The proposed ballast is
fed from a 12 V DC input voltage and is intended to be used in systems
supplied from nonconventional sources, such as back-up batteries,
photovoltaic generators and automotive applications. In order to
initiate the discharge in the lamp, a specially designed igniter
supplied from the 12 V DC voltage is used to apply high voltage ignition
peaks to the lamp. Experimental results obtained from a laboratory
prototype for a 70 W metal halide lamp supplied at 30 kHz are also shown
to evaluate the possibilities of the proposed topology
In this paper a high-power-factor electronic ballast for compact
fluorescent lamps based on the class E amplifier and featuring low
voltage stress across the switch is presented. The proposed ballast is
obtained by integrating a buck-boost converter, used as power factor
correction stage, and a class E amplifier with a parallel resonant tank,
used as a resonant inverter. The buck-boost converter is operated at
constant frequency and constant duty cycle in discontinuous conduction
mode (DCM) to obtain a high input power factor
A high power factor dimming control for high intensity discharge
lamp (HID) is presented in this paper. The system configuration consists
of a power factor pre-regulator, a full-bridge inverter, and a
series-resonant tank. The power factor pre-regulator, based on a boost
converter and diode rectifier, is controlled to produce sinusoidal line
current with high power factor and low current harmonics. The
phase-shift PWM scheme is adopted for inverter drive. In this control
approach, the constant switching frequency with variable duty cycle is
implemented for dimming control. The series-resonant parallel-loaded
circuit is used to drive the metal halide lamp (MHL), one of the high
intensity discharge lamps. Finally, experimental results of a 70 W MHL
hardware prototype are presented to verify the characteristics of high
power factor and dimming control of electronic ballast
A high-power-factor high-efficiency electronic ballast for high
intensity discharge lamp (HID) applications is presented in this paper.
The electronic ballast consists of a boost type power factor corrected
rectifier, a full bridge inverter, and a resonant tank. The power factor
pre-regulator produces sinusoidal input current in phase with mains
voltage. The phase-shift PWM scheme for full bridge inverter is adopted.
In this control scheme, the constant switching frequency with variable
duty cycle is used for dimming control. The series-resonant
parallel-loaded circuit is used to drive the metal halide lamp (MHL),
one of the high intensity discharge lamp. The over-voltage and
over-current protection circuits are also considered in a 70 W MHL
hardware prototype for safety operation. Finally, experimental results
are presented to verify the characteristics of high power factor and
dimming control of electronic ballast for metal halide lamp
A single-stage, complex frequency-modulated (CFM), high-frequency-driven electronic ballast for high-intensity-discharging (HID) lamps is proposed. The presented ballast combines a power-factor-correction (PFC) converter with a half-bridge series-resonant parallel-loaded inverter as well as a CFM controller. The switching frequency of the integrated inverter is non-periodically modulated by the CFM signal that integrates DC-bus voltage ripples with an additional high-frequency sine-wave signal. Compared with constant-frequency and frequency-modulated (FM) control, the presented ballast offers a widely continuous power spectrum of lamp current with decreased amplitude in order to effectively expand the lamp power as well as reducing sideband frequencies and allowing for a much lower energy level of the eigen frequency that supplies the lamp. Because of its CFM operation, no acoustic resonance occurs; additionally, the obtained results include a 13 dBm reduction of power spectrum at the centre switching frequency compared with FM control, and a 22 dBm reduction compared with constant-frequency control. The ballast offers high power factor (0.99), high efficiency (90%), cost-effectiveness and a simple, easy-to-implement controller. A prototype ballast utilising the CFM control method with 110 V utility-line input voltage has been built, and experimental results were carried out on three different brands of 70 W metal-halide-type HID lamps
This paper presents the design and implementation of the 2.65-MHz self-oscillating complementary electronic ballast with a constant-lamp-current control for a metal halide lamp. In order to avoid the inherent acoustic-resonance problem of metal halide lamps, the ballast's switching-frequency level was selected to be 2.65 MHz, which satisfies higher magnitudes of maximum electromagnetic interference (EMI) limitation at frequencies of between 2.5 to 3.0 MHz, within the EMI/electromagnetic compatibility frequency range ldquochimney,rdquo for RF lighting systems. With the constant-lamp-current control scheme, the lamp current can be regulated to be less dependent on the input ac voltage. Finally, a 20-W prototype ballast is implemented to demonstrate the ability to avoid the acoustic-resonance and to provide constant levels of lamp current.
The use of high frequency (HF) square waveforms is a possible metal halide (MH) lamps supply method which can be implemented by means of non-resonant electronic inverters. This strategy can successfully avoid acoustic resonances appearance in such kind of lamps (theoretically, in a perfect square waveform, no power modulation is found). The main drawbacks of this kind of inverters are the electromagnetic interference emissions and the parasitic effects of the series igniters. This effect can spoil the square waveforms on the lamp, hence injecting HF harmonics in the lamp supply power spectrum, eventually leading to acoustic resonances appearance. In this paper, this effect is studied, in order to limit the values of the parasitic elements of the series igniter compatible with a proper operation of the HF inverter. Once these values are estimated, such an igniter has been built and tested, thus obtaining a practical HF (100 kHz) square waveform inverter with series igniter for 35-W MH lamps
High intensity discharge (HID) lamps are the most suitable when both high light power levels and good color rendering are researched. Some remarkable theoretical advantages would be obtained if these kinds of lamps were driven with high frequency (HF) electronic ballasts. Nevertheless, at these frequencies, acoustic resonances (AR) phenomenon appears. Low wattage metal halide (MH) lamps are, among all HID lamps, the most affected by this phenomenon. To obtain lack of AR in HID lamps, lamp power frequency harmonics must have a lower amplitude than a certain threshold value, related to activation energy. An electronic ballast may be designed to guarantee power harmonics levels lower than this threshold level at nominal operation. Nevertheless, the equivalent resistance of HID lamps varies highly in starting and warm-up stages, as well as in the aging process. Therefore, the system must be designed to be adequate for the necessary "supplying conditions" for these load variations. In this paper, a new control strategy for a HF square-wave inverter is presented. This ballast keeps lamp power harmonics at low levels, regardless of the lamp equivalent load. The proposed ballast, along with the control strategy, is presented, as well as the built prototypes and experimental results carried out. From these experiments, it can be concluded that the proposed method supplies low wattage MH lamps with lack of acoustic resonances.
Currently, the main drawback in high-intensity discharge lamps supplied by means of high-frequency (HF) electronic ballasts are the so-called acoustic resonances. In this paper, two HF nonresonant inverters for low wattage metal halide (MH) lamps are analyzed, from the point of view of its behavior regarding the acoustic resonances' phenomenon. Thus, a HF electronic ballast, operating with a lack of acoustic resonances, is proposed. From a dc voltage bus, the inverters provide an ac waveform to the lamp. The power stage operation of the inverters is first analyzed. Then, the characteristics of these waveforms are analyzed, from the point of view of minimizing the acoustic resonances' appearance. Then, upon these theoretical results, a comparison between inverters is done, selecting the most appropriate for lighting purposes. After that, a built prototype of the chosen inverter topology is presented, and the experimental results are shown. These experiments were carried out on several 70-W MH lamps. Finally, some conclusions are presented.
This paper presents a two-stage low-frequency square-wave electronic ballast for high-intensity discharge lamps. The ballast consists of a power-factor-correction stage to achieve power-factor correction and an inverter to supply the lamp with low-frequency square-wave current. Due to its low-frequency operation, no acoustic resonance occurs. Ignition, warmup process, and end-of-life detection are analyzed in detail. The presented circuit was verified with simulation and experimental results.
Electronic ballasts for metal halide lamps of the Illuminating Calculate (Lr): IioadVin Lr = n21tfoIlamp(r.m.s) 640
- H-I Faehnrich
- E Rasch
H-I. Faehnrich and E. Rasch, °'Electronic ballasts for metal halide lamps, Journal Engineering Society, pp.131-140, Summer, 1988. of the Illuminating Calculate (Lr): IioadVin Lr = n21tfoIlamp(r.m.s) 640
Acoustic resonances in high frequency operated low wattage metal halide lamps
- J W Denneman
J. W. Denneman, "Acoustic resonances in high frequency operated low wattage metal halide lamps," Philips Journal of Research, Vol. 38, pp. 263-272,415, 1983.