Ballast For High Intensity Discharge Lamps Research Articles

A Generalized Dynamic Conductance Model for High Intensity Discharge Lamps and its Prospective Application to Design Dimmable Electronic Ballast

A generalized model for high intensity discharge (HID) lamp is developed based on the Francis-Damelincourt dynamic conductance model of electric discharge by replacing the model constants A, B, C, D with four experimentally determined coefficient functions of rated lamp power and root mean square supply voltage. Experimental validation of this model is done, which shows a maximum deviation of about 5 %. Moreover, sensitivity analysis for the model coefficients is also performed, results of which conform to the physical behaviour of high pressure sodium (HPS) and metal halide (MH) lamps. This model is capable to simulate electrical characteristics of HPS and MH lamps of wide range of commercially available rated power (70–400) W fed by a wide range of supply voltage (180–250) V, 50 Hz. As a prospective application, the model is applied to design dimmable low frequency square wave electronic ballast for HID lamps. A design algorithm is proposed for this purpose. Performance analysis of the designed ballast is conducted in Matlab-Simulink environment, which shows fairly good performance of the circuit in terms of dimming accuracy (maximum deviation 2.64 %), lamp power factor (≥ 0.993), and lamp current crest factor (equal to 1.0). The model can also be utilized for designing electronic ballasts of other topologies.

Behaviour of a high-intensity discharge lamp fed by a high-frequency dimmable electronic ballast

The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.

Current Phase Surveillance in Resonant Converters for Electric Discharge Applications to Assure Operation in Zero-Voltage-Switching Mode

A digital approach to provide phase surveillance in resonant converters is proposed. The approach provides a mechanism for controllers in resonant inverters to maintain zero-voltage-switching (ZVS) mode operation despite large and abrupt changes in load behavior. Applications are focused on but not limited to generation and control of electrical discharges. The phase surveillance provides effective arc ignition, prevents the eventual arc extinction and assures ZVS in MOSFET turn-on transients. The proposed circuit and control approach makes the converter robust to distorted waveforms associated with either low Q operation, the use of nonlinear soft-saturation core inductors or any other cause that jeopardizes ZVS in high-frequency resonant inverters, including component tolerance, aging, and temperature effects. Two practical circuits are used to demonstrate the phase surveillance operation. A two-phase resonant inverter controlling a welding arc shows how the phase surveillance assures ZVS operation and a single-phase resonant electronic ballast for high-intensity discharge lamps shows how the phase surveillance solves the problem of arc generation. Phase surveillance maintains the frequency dependent characteristics of the resonant inverter, such as the high output impedance that stabilizes the arc beyond the control loop bandwidth, while achieving robust operation for any combination of load, component tolerances, and driver dead times.

Teaching Resonant Converters: Properties and Applications for Variable Loads

This paper summarizes a lesson on resonant converters included in the new course, Advanced Power Conversion Techniques, within the M.Sc. program in electrical engineering at the University of Cantabria, Spain. The course has recently received the National Accreditation for official programs. The M.Sc. program, along with the Ph.D. thesis, forms a Ph.D. program in industrial engineering. The contents motivate the students to find suitable resonant converter applications of industrial interest. A new approach to teaching resonant converters is presented that focused on their properties at certain frequencies, such as for voltage sources, current sources, or sink and power source operation with very variable loads. The analysis of the converters enables the identification of these operating points and, by means of a sensitivity analysis with respect to the components of the resonant tank, explains the robustness of their behavior. Using as a starting point the fulfillment of the desired property, we propose that the students develop open-loop designs, with stable behavior, or closed-loop designs, with very small variation in the operating point. Two practical application examples are shown: electronic ballasts for high-intensity discharge lamps and power supplies for electrical discharge machining.

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.

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.

Design of a two-stage low-frequency square-wave electronic ballast for HID lamps

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.

A high-frequency electronic ballast for HID lamps based on a /spl lambda//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 /spl lambda/ (/spl lambda//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.

Analysis, design, and optimization of the LCC resonant inverter as a high-intensity discharge lamp ballast

A complete study of the clamped-mode (CM) series-parallel (LCC) resonant inverter together with some of the control-to-output characteristics are presented in this paper. Also, a new control method for the CM LCC resonant inverter is introduced. With this method, the inverter is forced to operate with optimum commutations and without handling reactive energy, thus minimizing both switching and conduction losses. The corresponding design procedure is illustrated with a design example. Finally, some experimental results obtained from a prototype at the laboratory are also shown to validate the analysis and evaluate the proposed control method.