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 $eta = 84%$.      

Analysis and design of single-controlled switch three-phaserectifier with unity power factor and sinusoidal input current

This paper describes a new low-cost three-phase AC-DC high-power/low-harmonic-controlled rectifier and its analysis, design, and performance. The circuit consists of a three-phase diode-bridge rectifier, followed by a boost stage containing only one switch and one boost inductor. The proposed converter is used to automatically draw sinusoidal input-current waveforms with high efficiency. This is achieved with discontinuous-input voltage to the rectifier and with a discontinuous-inductor-current mode of operation of the boost converter. By using a simplified single-phase model and symbolic analysis method, analytical equations are obtained and used for design     

Analysis of a ripple-free input-current boost converter withdiscontinuous conduction characteristics

Coupled inductor techniques supply a method to reduce the power converter size and weight and achieve ripple-free current. The boost power converter is a very popular topology in industry. However, the input-current ripple hinders efforts to meet electromagnetic interference (EMI) requirements. In particular, the input current becomes discontinuous and pulsating when the conventional boost power converter operates in the discontinuous inductor-current mode. This paper describes a boost power converter which has the same discontinuous properties as the conventional boost power converter. However, the proposed boost topology has continuous or ripple-free input current when it operates with discontinuous inductor-current. The proposed topology is compared with traditional converter topologies, such as the Sepic and Cuk power converters. Simulation results are presented. The prototype is built to demonstrate the theoretical prediction. The proposed boost topology is simple, with straightforward control [the same as pulse-width modulation (PWM)]     

A novel active snubber for high-power boost converters

A technique which improves the performance of the boost converter by reducing the reverse-recovery-related losses in the boost switch and rectifier with an active snubber that is implemented with a minimum number of components is presented. This minimum-component-count snubber consists of a snubber inductor, an auxiliary switch, and a rectifier. The proposed technique reduces the reverse-recovery-related losses by controlling the turn-off di/dt rate of the rectifier current with the snubber inductor connected in series with the boost switch and rectifier. The voltage and current stresses of the components in the proposed active-snubber boost converter are similar to those in its conventional “hard-switched” counterpart     

A quasi-resonant quadratic boost converter using a single resonant network

This paper presents a quadratic boost converter using a single quasi-resonant network to reach soft commutation. A resonant inductor, a resonant capacitor, and an auxiliary switch form the resonant network and the main switch operates in a zero-current-switching way. A complete analysis of this converter is presented. According to the simulation and experimental results, this quadratic boost converter provides a larger conversion ratio than that provided by the conventional boost converter (for a given duty ratio D), and presents optimum performance, which operates with soft-switch commutation using a single resonant network.     

New single-stage PFC regulator using the Sheppard-Taylor topology

This paper describes a new usage of the DC/DC converter developed by D.I. Sheppard and B.E. Taylor in 1983 for achieving high power factor and output regulation. This converter may be viewed as a cascade of a modified boost stage and a buck stage, with the two stages sharing the same active switch. Two possible operation regimes are described. In the first regime, the converter's input part, which is a modified boost converter, operates in discontinuous mode, and the output part, which is a buck converter, operates in continuous mode. In this regime, high power factor is naturally achieved, and the output voltage is regulated by duty-cycle modulation via a simple output feedback. In the second regime, the input part operates in continuous mode, and the output part operates in discontinuous mode, with duty-cycle modulation maintaining a high power factor and frequency modulation regulating the output. Some comparisons between the Sheppard-Taylor converter and conventional boost and buck cascade are given in the paper     

A simple and effective method to alleviate the rectifierreverse-recovery problem in continuous-current-mode boostconverters

Rectifier reverse-recovery problems cause a significant efficiency reduction as well as severe electromagnetic interference (EMI) in continuous-current-mode (CCM) boost converters. To alleviate these problems, this paper presents a simple and effective solution that involves shifting the original rectifier current to a new branch, which consists of a rectifier and a coupled winding of the boost inductor. When the active switch turns on, the current through the original boost rectifier is zero and the current decrease rate di/dt in the new branch is controlled by the leakage inductor. Based on the operation analysis, design issues to guarantee complete current shift are also addressed. Applying the proposed concept to a 500 W CCM DC/DC boost converter and a 500 W CCM power factor correction (PFC) boost converter with universal-line input generates a 2% efficiency improvement. The same concept can be easily extended to other basic DC/DC and CCM PFC converters     

A new soft-switched PFC boost rectifier with integrated flyback converter for stand-by power

This paper presents a magnetic integration approach that reduces the number of magnetic components in a power supply by integrating magnetic components in two conversion stages. Specifically, in the proposed approach, a single transformer is used to implement the continuous-conduction-mode boost power-factor-corrected (PFC) converter and the dc/dc flyback converter. The integrated boost and flyback converters offer soft switching of all semiconductor switches including a controlled di/dt turn-off rate of the boost rectifier. The performance of the proposed approach was evaluated on a 150-kHz, 450-W, universal-line range boost PFC converter with 12-V/2.2-A integrated stand-by flyback converter.     

Implementation of single-phase boost power-factor-correctioncircuits in three-phase applications

A three-phase rectifier employing three single-phase boost power-factor-correction circuits is analyzed. Each converter operates in the continuous conduction mode (CCM), which allows a high power factor and a small EMI filter. Current sharing is ensured by a common voltage loop driving the individual current loops of the three converters. A suitable circuit arrangement is devised to limit phase interaction. The zero-voltage-transition technique (ZVT) is successfully applied to each converter, in order to obtain zero turn on losses and soft turnoff of the freewheeling diodes. Results of a 1800-W 100-kHz experimental prototype are reported, which confirm the theoretical forecasts     

An improvement technique for the efficiency of high-frequencyswitch-mode rectifiers

A new technique for improving the efficiency of single-phase high-frequency switch-mode boost rectifiers is proposed. This rectifier includes an additional boost converter that follows the main high-frequency switching device. The additional converter, which is controlled at lower frequencies, bypasses almost all the current in the main switch and the high frequency switching loss is greatly reduced accordingly. Both switching devices are controlled by a simple method; each controller consists of a one-shot multivibrator, a comparator and an AND gate, and the maximum switching frequency can be limited without any clock generator. The rectifier works cooperatively in high efficiency and acts as though it were a conventional high-frequency switch-mode rectifier with one switching device. The proposed method is verified by experiment. This paper describes the rectifier configuration and design, and discusses the steady-state performance concerning the switching loss reduction and efficiency improvement. Transient performance is also included     

A new, soft-switched, high-power-factor boost converter with IGBTs

A new soft-switching technique that improves performance of the high-power-factor boost rectifier by reducing switching losses is introduced. The losses are reduced by an active snubber which consists of an inductor, a capacitor, a rectifier, and an auxiliary switch. Since the boost switch turns off with zero current, this technique is well suited for implementations with insulated-gate bipolar transistors. The reverse-recovery-related losses of the rectifier are also reduced by the snubber inductor which is connected in series with the boost switch and the boost rectifier. In addition, the auxiliary switch operates with zero-voltage switching. A complete design procedure and extensive performance evaluation of the proposed active snubber using a 1.2 kW high-power-factor boost rectifier operating from a 90 V_rms-256 V_rms input are also presented     

A new ZVS semiresonant high power factor rectifier with reducedconduction losses

This paper presents a novel single-phase unity power factor rectifier, which features critical conduction mode and zero-voltage switching. The reduced conduction losses are achieved by the employment of a single converter, instead of the typical configuration composed of a front-end rectifier followed by a boost converter. Theoretical analysis, a design example, and experimental results of a 300 W converter with 127 V_rms input voltage and 400 V_DC output voltage are presented     

A technique for reducing rectifier reverse-recovery-related lossesin high-power boost converters

A circuit technique that reduces the boost power converter losses caused by the reverse-recovery current of the rectifier is described. The losses are reduced by inserting an inductor in the series path of the boost switch and a rectifier to control the di/dt rate of the rectifier during its turn off. The energy from the inductor after the boost switch turn off is returned to the input or delivered to the output via an active snubber     

Digital implementation of a line current shaping algorithm for three phase high power factor boost rectifier without input voltage sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase boost rectifier is described. The indicated objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses the concept of resistance emulation for shaping of input current like input voltage in digital implementation. Two decoupled fixed frequency current mode controllers calculate the switching instants for equivalent single phase boost rectifiers. A combined switching strategy is developed in the form of space vectors to simultaneously satisfy the timing requirements of both the current mode controllers in a switching period. Conventional phase locked loop (PLL) is not required as converter switching is self-synchronized with the input voltage. Analytical formula is derived to obtain the steady state stability condition of the converter. A linear, low frequency, small signal model of the three phase boost rectifier is developed and verified by measurement of the voltage control transfer function. In implementation Texas Instruments's DSP TMS320F240F is used as the digital controller. The algorithm is tested on a 10-kW, 700-V dc, three phase boost rectifier.     

High static gain single-phase PFC based on a hybrid boost converter

In this paper, a single-phase unity power factor rectifier, based on a hybrid boost converter, resulting from the integration of a conventional dc–dc boost converter and a switched-capacitor voltage doubler is proposed, analysed, designed and tested. The high-power rectifier is controlled by two feedback loops with the same control strategy employed in the conventional boost-based rectifier. The main feature of the proposed rectifier is its ability to output a dc voltage larger than the double of the peak value of the input line voltage, while subjecting the power switches to half of the dc-link voltage, which contributes to reducing the cost and increasing the efficiency. Experimental data were obtained from a laboratory prototype with an input voltage of 220 Vrms, line frequency of 60 Hz, output voltage of 800 Vdc, load power of 1000 W and switching frequency of 50 kHz. The efficiency of the prototype, measured in the laboratory, was 96.5% for full load and 97% for half load.     

Analysis and Implementation of a Hybrid High-Power-Factor Three-Phase Unidirectional Rectifier

This paper describes the conception and analysis of a unidirectional hybrid three-phase rectifier suitable for medium- and high-power applications. The rectifier is composed of a single-switch diode bridge boost-type rectifier in parallel with a pulsewidth modulation (PWM) three-phase unidirectional boost rectifier. The objective is to obtain a structure capable of providing sinusoidal input currents with low harmonic distortion and dc output voltage regulation. The diode rectifier operates at low frequency and has a higher output power rating. Therefore, the PWM unidirectional rectifier is designed to operate with a small power rating and at a high switching frequency. The total harmonic distortion of the proposed structure varies between 0% and 32%, depending only on the amount of power processed by the PWM three-phase unidirectional rectifier. The rectifier topology conception, principle of operation, control scheme, and simulation and experimental results of a 20-kW laboratory prototype are also presented in this paper.     

A zero-voltage-switched PWM boost converter with an energyfeedforward auxiliary circuit

A zero-voltage-switched (ZVS) pulsewidth-modulated (PWM) boost converter with an energy feedforward auxiliary circuit is proposed in this paper. The auxiliary circuit, which is a resonant circuit consisting of a switch and passive components, ensures that the converter's main switch and boost diode operate with soft switching. This converter can function with PWM control because the auxiliary resonant circuit operates for a small fraction of the switching cycle. Since the auxiliary circuit is a resonant circuit, the auxiliary switch itself has both a soft turn on and turn off, resulting in reduced switching losses and electromagnetic interference (EMI). This is unlike other proposed ZVS boost converters with auxiliary circuits where the auxiliary switch has a hard turn off. Peak switch stresses are only slightly higher than those found in a conventional PWM boost converter because part of the energy that would otherwise circulate in the auxiliary circuit and drastically increase peak switch stresses is fed to the load. In this paper, the operation of the converter is explained and analyzed, design guidelines are given, and experimental results obtained from a prototype are presented. The proposed converter is found to be about 2%-3% more efficient than the conventional PWM boost converter     

Performance Evaluation of a Novel Hybrid Multipulse Rectifier for Utility Interface of Power Electronic Converters

This paper presents an improved analysis of a novel programmable power-factor-corrected-based hybrid multipulse power rectifier (PFC-HMPR) for utility interface of power electronic converters. The proposed hybrid multipulse rectifier is composed of an ordinary three-phase six-pulse diode-bridge rectifier (Graetz bridge) with a parallel connection of single-phase switched converters in each three-phase rectifier leg. In this paper, the authors present a complete discussion about the controlled rectifiers' power contribution and also a complete analysis concerning the total harmonic distortion of current that can be achieved when the proposed converter operates as a conventional 12-pulse rectifier. The mathematical analysis presented in this paper corroborate, with detailed equations, the experimental results of two 6-kW prototypes implemented in a laboratory.     

A low-distortion three-phase multiresonant boost rectifier withzero-current switching

A new three-phase high-quality boost rectifier system is introduced in this paper. The single switch and input-diode bridge in this rectifier operate with zero-current switching (ZCS) while the DC-side diode operates with zero-voltage switching (ZVS). The semiconductor stresses are constant and independent of load-current variations. A multiresonant scheme is used to achieve this property. Line-current waveforms of low-harmonic content are obtained naturally by these rectifiers. Simulation and experimental results are supplied to confirm the validity of the proposed concept     

Soft-Switched PFC Boost Rectifier With Integrated ZVS Two-Switch Forward Converter

A soft-switched continuous-conduction-mode boost power factor correction front-end converter with an integrated zero-voltage-switched two-switch forward second-stage converter is introduced. In the proposed approach, a single transformer is commonly used by the two stages to provide isolation of the power supply and soft switching of all semiconductor switches including a controlled di/dt turn-off rate of the boost rectifier. The performance of the proposed approach was evaluated on a 150-kHz, 430-W/12-V, universal-line range prototype converter