scispace - formally typeset
Search or ask a question

Showing papers on "Flyback converter published in 2010"


Journal ArticleDOI
TL;DR: A DC-DC converter topology is proposed, which combines the boost converter and the switched capacitor function to provide different output voltages and a self-balanced voltage using only one driven switch, one inductor, 2 diodes and 2 capacitors for an Nx MBC.
Abstract: A DC-DC converter topology is proposed. The DC-DC multilevel boost converter (MBC) is a pulse-width modulation (PWM)-based DC-DC converter, which combines the boost converter and the switched capacitor function to provide different output voltages and a self-balanced voltage using only one driven switch, one inductor, 2 N -1 diodes and 2 N -1 capacitors for an Nx MBC. It is proposed to be used as DC link in applications where several controlled voltage levels are required with self-balancing and unidirectional current flow, such as photovoltaic (PV) or fuel cell generation systems with multilevel inverters; each device blocks only one voltage level, achieving high-voltage converters with low-voltage devices. The major advantages of this topology are: a continuous input current, a large conversion ratio without extreme duty cycle and without transformer, which allow high switching frequency. It can be built in a modular way and more levels can be added without modifying the main circuit. The proposed converter is simulated and prototyped; experimental results prove the proposition's principle.

437 citations


Journal ArticleDOI
TL;DR: In this article, a dual-bridge series resonant dc/dc converter with high frequency isolation is analyzed with two simple modified ac equivalent circuit analysis methods for both voltage source load and resistive load.
Abstract: Bidirectional dual-bridge dc/dc converter with high frequency isolation is gaining more attentions in renewable energy system due to small size and high-power density. In this paper, a dual-bridge series resonant dc/dc converter is analyzed with two simple modified ac equivalent circuit analysis methods for both voltage source load and resistive load. In both methods, only fundamental components of voltages and currents are considered. All the switches may work in either zero-voltage-switching or zero-current-switching for a wide variation of voltage gain, which is important in renewable energy generation. It is also shown in the second method that the load side circuit could be represented with an equivalent impedance. The polarity of cosine value of this equivalent impedance angle reveals the power flow direction. The analysis is verified with computer simulation results. Experimental data based on a 200 W prototype circuit is included for validation purpose.

402 citations


Journal ArticleDOI
TL;DR: The main reasons why the conventional method for converter analysis fails are described and the different steps required to predict the power losses more accurately are documents.
Abstract: An accurate power loss model for a high-efficiency dual active bridge converter, which provides a bidirectional electrical interface between a 12-V battery and a high-voltage (HV) dc bus in a fuel cell car, is derived. The nominal power is 2 kW, the HV dc bus varies between 240 and 450 V, and the battery voltage range is between 11 and 16 V. Consequently, battery currents of up to 200 A occur at nominal power. In automotive applications, high converter efficiency and high power densities are required. Thus, it is necessary to accurately predict the dissipated power for each power component in order to identify and to properly design the heavily loaded parts of the converter. In combination with measured efficiency values, it is shown that conventional converter analysis predicts substantially inaccurate efficiencies for the given converter. This paper describes the main reasons why the conventional method fails and documents the different steps required to predict the power losses more accurately. With the presented converter prototype, an efficiency of more than 92% is achieved at an output power of 2 kW in a wide input/output voltage range.

388 citations


Journal ArticleDOI
TL;DR: In this paper, a flyback-based electrolytic capacitor-less light-emitting diode (LED) driver is proposed, which converts the commercial ac voltage to a pulsating current with twice the line frequency driving high-brightness LEDs.
Abstract: This paper proposes a concept of electrolytic capacitor-less light-emitting diode (LED) driver, which converts the commercial ac voltage to a pulsating current with twice the line frequency driving high-brightness LEDs. As no electrolytic capacitor is used, this driver possesses the unique advantage of long lifetime to match with that of LEDs. A method of injecting the third and fifth harmonics into the input current to reduce the peak-to-average ratio of the output current is also proposed. While ensuring that the input power factor is higher than 0.9 to meet regulation standards such as ENERGY STAR, the proposed method allows the peak-to-average ratio of the output current to be reduced to 1.34 theoretically, which is beneficial for the safe operation of the LEDs. As an example, a flyback-based electrolytic capacitor-less LED driver is proposed, and its operation is analyzed. In order to inject the third and fifth harmonics into the input current, the function of the duty cycle in a half-line cycle is derived. It is then simplified to a fitting function, which can be easily implemented with the input voltage sensing. A 25 V, 0.35 A output prototype is built and tested in the laboratory, and the experimental results are presented to verify the effectiveness of the electrolytic capacitor-less LED driver and its control method.

332 citations


Journal ArticleDOI
TL;DR: In this article, a novel interleaved high step-up converter with voltage multiplier cell is proposed to avoid the extremely narrow turn-off period and to reduce the current ripple, which flows through the power devices compared with the conventional interleaving boost converter in high stepup applications.
Abstract: A novel interleaved high step-up converter with voltage multiplier cell is proposed in this paper to avoid the extremely narrow turn-off period and to reduce the current ripple, which flows through the power devices compared with the conventional interleaved boost converter in high step-up applications. Interleaved structure is employed in the input side to distribute the input current, and the voltage multiplier cell is adopted in the output side to achieve a high step-up gain. The voltage multiplier cell is composed of the secondary windings of the coupled inductors, a series capacitor, and two diodes. Furthermore, the switch voltage stress is reduced due to the transformer function of the coupled inductors, which makes low-voltage-rated MOSFETs available to reduce the conduction losses. Moreover, zero-current-switching turn- on soft-switching performance is realized to reduce the switching losses. In addition, the output diode turn-off current falling rate is controlled by the leakage inductance of the coupled inductors, which alleviates the diode reverse recovery problem. Additional active device is not required in the proposed converter, which makes the presented circuit easy to design and control. Finally, a 1-kW 40-V-input 380-V-output prototype operating at 100 kHz switching frequency is built and tested to verify the effectiveness of the presented converter.

245 citations


Journal ArticleDOI
TL;DR: A novel high step-up converter is proposed for fuel-cell system applications to achieve a much higher voltage conversion ratio and avoid operating at extreme duty ratio and to adopt lower voltage rating devices to further reduce both switching and conduction losses.
Abstract: In this paper, a novel high step-up converter is proposed for fuel-cell system applications. As an illustration, a two-phase version configuration is given for demonstration. First, an interleaved structure is adapted for reducing input and output ripples. Then, a C?uk-type converter is integrated to the first phase to achieve a much higher voltage conversion ratio and avoid operating at extreme duty ratio. In addition, additional capacitors are added as voltage dividers for the two phases for reducing the voltage stress of active switches and diodes, which enables one to adopt lower voltage rating devices to further reduce both switching and conduction losses. Furthermore, the corresponding model is also derived, and analysis of the steady-state characteristic is made to show the merits of the proposed converter. Finally, a 200-W rating prototype system is also constructed to verify the effectiveness of the proposed converter. It is seen that an efficiency of 93.3% can be achieved when the output power is 150-W and the output voltage is 200-V with 0.56 duty ratio.

207 citations


Journal ArticleDOI
TL;DR: In this article, an isolated bidirectional full-bridge dc-dc converter with high conversion ratio, high output power, and soft start-up capability is proposed, where the use of a capacitor, a diode, and a flyback converter can clamp the voltage spike caused by the current difference between the current-fed inductor and leakage inductance of the isolation transformer.
Abstract: An isolated bidirectional full-bridge dc-dc converter with high conversion ratio, high output power, and soft start-up capability is proposed in this paper. The use of a capacitor, a diode, and a flyback converter can clamp the voltage spike caused by the current difference between the current-fed inductor and leakage inductance of the isolation transformer, and can reduce the current flowing through the active switches at the current-fed side. Operational principle of the proposed converter is first described, and then, the design equation is derived. A 1.5-kW prototype with low-side voltage of 48 V and high-side voltage of 360 V has been implemented, from which experimental results have verified its feasibility.

198 citations


Journal ArticleDOI
TL;DR: In this article, a sepic-integrated boost (SIB) converter was proposed to supplement the insufficient step-up ratio and distribute a voltage stress of a classical boost converter.
Abstract: For a nonisolated high step-up converter, the combination of a boost converter with a series output module is investigated in this paper. As a solution to supplement the insufficient step-up ratio and distribute a voltage stress of a classical boost converter, a sepic-integrated boost (SIB) converter, which provides an additional step-up gain with the help of an isolated sepic converter, is proposed. Since the boost converter and the sepic converter share a boost inductor and a switch, its structure is simple. Moreover, the SIB converter needs no current snubber for the diodes, since the transformer leakage inductor alleviates the reverse recovery. The operational principle and characteristics of SIB converter are presented, and verified experimentally with a 200 W, 42 V input, 400 V output prototype converter.

197 citations


Journal ArticleDOI
TL;DR: In this article, the voltage regulation problem is addressed with a detailed analysis that starts with the modelling of the PV array and the converter, followed by study, design, simulation and practical experiments of three closed-loop control strategies for the buck converter.
Abstract: This study deals with the regulation of the output voltage of photovoltaic (PV) arrays. As a case study, the DC-DC buck converter is used as an interface between the PV array and the load, but other types of converters can be used for the same purpose. The input voltage of the converter is controlled in order to regulate the operating point of the array. Besides reducing losses and stress because of the bandwidth-limited regulation of the converter duty cycle, controlling the converter input voltage reduces the settling time and avoids oscillation and overshoot, making easier the functioning of maximum power point tracking (MPPT) methods. The voltage regulation problem is addressed with a detailed analysis that starts with the modelling of the PV array and the converter. This analysis is followed by study, design, simulation and practical experiments of three closed-loop control strategies for the buck converter. Control stability and implementation considerations are presented.

191 citations


Journal ArticleDOI
TL;DR: Simulation and experimental results are shown to prove the ability of the indirect three-level sparse matrix converter to generate multilevel output voltages as well as to maintain a set of sinusoidal balanced input currents.
Abstract: A matrix converter is an ac-ac power converter topology that has received extensive research attention as an alternative to traditional ac-dc-ac converter. A matrix converter is able to convert energy from an ac source to an ac load without the need of a bulky and limited-lifetime energy-storage elements. The indirect three-level sparse matrix converter (I3SMC) is a new topology from this family that can synthesize three-level voltage in order to improve the output performance in terms of reduced harmonic content. This paper discusses the operating principles and a space-vector-modulation scheme for this topology. Simulation and experimental results are shown to prove the ability of this topology to generate multilevel output voltages as well as to maintain a set of sinusoidal balanced input currents. The performance of the converter is compared with the conventional matrix converter and an alternative multilevel matrix-converter topology in order to demonstrate the advantages and disadvantages of the I3SMC.

190 citations


Journal ArticleDOI
TL;DR: In this article, a flyback converter with a non-complementary active clamp control method is proposed, where the absorbed leakage energy is transferred to the output and input side.
Abstract: This paper proposes a flyback converter with a new noncomplementary active clamp control method. With the proposed control method, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. Compared to the conventional active clamp technique, the proposed methods can achieve high efficiency both for heavy-load and light-load condition, and the efficiency is almost not affected by the leakage inductance. The detailed operation principle and design considerations are presented. Performance of the proposed circuit is validated by the experimental results from a 16 V/4 A prototype.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a DC-DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low and high power applications.
Abstract: This study presents a new DC-DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low- and high-power applications. This configuration can be utilised instead of several single output power supplies. This is a compatible topology for a diode-clamed inverter in the grid connection systems, where boosting low rectified output-voltage and series DC link capacitors is required. To verify the proposed topology, steady-state and dynamic analyses of a MOB converter are examined. A simple control strategy has been proposed to demonstrate the performance of the proposed topology for a double-output boost converter. The topology and its control strategy can easily be extended to offer multiple outputs. Simulation and experimental results are presented to show the validity of the control strategy for the proposed converter.

Patent
16 Aug 2010
TL;DR: In this article, the authors provide power converter circuitry including an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform.
Abstract: According to one aspect, embodiments of the invention provide power converter circuitry including an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform, a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage; a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the plurality of DC buses during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and a second power converter coupled to the input and configured to supply power from the multiphase AC power source to at least some of the plurality of DC buses during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.

Journal ArticleDOI
TL;DR: In this paper, a single-phase quasi-Z-source ac-ac converter was proposed, which can realize buck-boost, reversing, or maintaining the phase angle.
Abstract: This paper deals with a new family of single-phase ac-ac converters called single-phase quasi-Z-source ac-ac converters. The proposed converter inherits all the advantages of the traditional single-phase Z-source ac-ac converter, which can realize buck-boost, reversing, or maintaining the phase angle. In addition, the proposed converter has the unique features that the input voltage and output voltage share the same ground and the operation is in the continuous current mode. The operating principles of the proposed converter are described, and a circuit analysis is provided. In order to verify the performance of the proposed converter, a laboratory prototype was constructed with a voltage of 84 Vrms/60 Hz. The simulation and experimental results verified that the converter has a lower input current total harmonic distortion and higher input power factor in comparison with the conventional single-phase Z-source ac-ac converter.

Proceedings ArticleDOI
14 Mar 2010
TL;DR: In this article, a 7.2 kV, 7.5 MVA converter model of the Modular Multilevel Converter (M2C) is presented and the cause of the circulating currents is investigated.
Abstract: The Modular Multilevel Converter (M2C) is an emerging multilevel converter for HVDC and FACTS as well as for future AC-fed traction vehicles or medium voltage drives (MVD). A suitable converter model of the Modular Multilevel Converter (M2C) is presented. A 7.2 kV, 7.5 MVA converter is taken as an example to analyze characteristic waveforms of the converter. The cause of the circulating currents — a phenomenon unique to this topology — is investigated. Furthermore, particular attention is paid to the current distribution in the converter cells for characteristic load phase angles.

Journal ArticleDOI
TL;DR: In this paper, a DC-DC converter with high step-up voltage gain is presented, which uses the coupled inductor and the voltage-lift technique to achieve high step up voltage gain.
Abstract: A DC-DC converter with high step-up voltage gain is presented. The proposed converter uses the coupled inductor and the voltage-lift technique to achieve high step-up voltage gain. Additionally, the voltage on the active switch is clamped, and the energy stored in the leakage inductor is recycled in the proposed converter. Therefore the voltage stress on the active switch is reduced, and the conversion efficiency is improved. Finally, a laboratory prototype circuit with input voltage 12-V, output voltage 100-V and output power 35-W is implemented to demonstrate the performance of the proposed converter.

Journal ArticleDOI
TL;DR: The proposed ZVZCS PWM combined three-level dc/dc converter has the following advantages: all power switches suffer only half of the input voltage; the voltage across the output filter is very close to the output voltage, which can reduce the outputfilter inductance significantly; and the voltage stress of the rectifier diodes is reduced too, so that the converter is very suitable for high input voltage and wide input voltage range applications.
Abstract: This paper proposes a zero-voltage and zero-current-switching (ZVZCS) PWM combined three-level (TL) dc/dc converter, which is a combination of a ZVZCS PWM TL converter with a ZVZCS PWM full-bridge converter. The proposed converter has the following advantages: all power switches suffer only half of the input voltage; the voltage across the output filter is very close to the output voltage, which can reduce the output filter inductance significantly; and the voltage stress of the rectifier diodes is reduced too, so that the converter is very suitable for high input voltage and wide input voltage range applications. The converter also can achieve zero-voltage-switching for the leading switches and ZCS for the lagging switches in a wide load range to achieve higher efficiency. The design considerations and procedures are presented in this paper. The operation principle and characteristics of the proposed converter are analyzed and verified on a 400-800-V input and 54-V/20-A output prototype.

Patent
10 Feb 2010
TL;DR: A photovoltaic device as mentioned in this paper includes at least one PV cell and a DC/DC converter electrically coupled to the PV cell, and the converter is integrated into a PV package.
Abstract: A photovoltaic device includes at least one photovoltaic cell and a DC/DC converter electrically coupled to the at least one photovoltaic cell. The at least one photovoltaic cell and the DC/DC converter are integrated into a photovoltaic package.

Journal ArticleDOI
TL;DR: In this paper, a full-order small-signal modeling and dynamic analysis of zero-voltage-switching (ZVS) phase-shift bidirectional DC-DC converters is studied.
Abstract: Full-order small-signal modelling and dynamic analysis of zero-voltage-switching (ZVS) phase-shift bidirectional DC-DC converters is studied. A general modelling method is proposed to develop the discrete-time average model. This full-order model takes into account the leakage inductance current and the resonant transition intervals in order to realise ZVS. Both the leakage inductance current and the resonant transition intervals are the key to accurately predict the dynamic behaviour of the converter. A control-to-output-voltage transfer function is derived for the dual active bridge DC-DC converter, which is taken as an example to illustrate the modelling procedure. Experimental results confirm that the new model correctly predicts the small-signal frequency response up to one-third of the switching frequency and is more accurate than the previously presented models.

Journal ArticleDOI
TL;DR: A zero-voltage- and zero-current-switching full-bridge (FB) converter with secondary resonance with high efficiency, minimum number of devices, and low cost is presented and analyzed.
Abstract: A zero-voltage- and zero-current-switching full-bridge (FB) converter with secondary resonance is presented and analyzed. The primary side of the converter is composed of FB insulated-gate bipolar transistors, which are driven by phase-shift control. The secondary side is composed of a resonant tank and a half-wave rectifier. Without an auxiliary circuit, zero-voltage switching (for leading-leg switches) and zero-current switching (for lagging-leg switches) are achieved in the entire operating range. To implement the converter without an additional inductor, the leakage inductance of the transformer is utilized as the resonant inductor. Due to its many advantages, including high efficiency, minimum number of devices, and low cost, this converter is attractive for high-voltage and high-power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 5-kW output power, an input-voltage range varying from 250 to 350 V, and a 350-V output voltage. The experimental results obtained from a prototype verify the analysis. The prototype's efficiency at full load is over 95.5%.

Journal ArticleDOI
TL;DR: In this article, the optimal topology for multilevel converters is investigated for various objectives such as minimum number of switches and dc voltage sources and minimum standing voltage on the switches for producing the maximum output voltage steps.
Abstract: The general function of a multilevel converter is to synthesize a desired output voltage from several levels of dc voltages as inputs. In order to increase the steps in the output voltage, a new topology is recommended in [1], which benefits from a series connection of sub-multilevel converters. In the procedure described in this reference, despite all the advantages, it is not possible to produce all the steps (odd and even) in the output. In addition, for producing an output voltage with a constant number of steps, there are different configurations with a different number of components. In this paper, the optimal structures for this topology are investigated for various objectives such as minimum number of switches and dc voltage sources and minimum standing voltage on the switches for producing the maximum output voltage steps. Two new algorithms for determining the dc voltage sources magnitudes have been proposed. Finally, in order to verify the theoretical issues, simulation and experimental results for a 49-level converter with a maximum output voltage of 200V are presented.

Journal ArticleDOI
TL;DR: In this article, a two-stage power converter consisting of a boost converter in parallel with a buck-boost converter is proposed to directly convert the low AC input voltage to the required high dc output voltage at a higher efficiency.
Abstract: The conventional two-stage power converters with bridge rectifiers are inefficient and may not be practical for the low-voltage microgenerators. This paper presents an efficient ac-to-dc power converter that avoids the bridge rectification and directly converts the low AC input voltage to the required high dc output voltage at a higher efficiency. The proposed converter consists of a boost converter in parallel with a buck-boost converter, which are operated in the positive half cycle and negative half cycle, respectively. Detailed analysis of the converter is carried out to obtain relations between the power, circuit parameters, and duty cycle of the converter. Based on the analysis, control schemes are proposed to operate the converter. Design guidelines are presented for selecting the converter component and control parameters. A self-starting circuit is proposed for independent operation of the converter. Detailed loss calculation of the converter is carried out. Simulation and experimental results are presented to validate the proposed converter topology and control schemes.

Journal ArticleDOI
TL;DR: The design, realization, and performance evaluation of a single-phase 3-kW dc/ac power converter, using an active-bridge dc/dc converter and a full-bridge DC/ac, are introduced, presenting a novel solution on the industrial scenario for the considered application.
Abstract: In this paper, the design, realization, and performance evaluation of a single-phase 3-kW dc/ac power converter, using an active-bridge dc/dc converter and a full-bridge dc/ac, are introduced, presenting a novel solution on the industrial scenario for the considered application. Control algorithms, including the maximum power point tracking, paralleling to the grid, and converter switching signals, are digitally implemented on a standard microcontroller.

Journal ArticleDOI
TL;DR: In this paper, a soft-switching dc/dc converter with high voltage gain is proposed, which provides a continuous input current and high voltage gains, and reduces switching loss of active power switches.
Abstract: A soft-switching dc/dc converter with high voltage gain is proposed in this paper. It provides a continuous input current and high voltage gain. Moreover, soft-switching characteristic of the proposed converter reduces switching loss of active power switches and raises the conversion efficiency. The reverse-recovery problem of output rectifiers is also alleviated by controlling the current changing rates of diodes with the use of the leakage inductance of a coupled inductor. Experimental results obtained on 200 W prototype are discussed.

Journal ArticleDOI
TL;DR: An improved soft-switching full-bridge phase-shifted pulsewidth modulation converter using insulated-gate bipolar transistors with a special auxiliary transformer with new significant feature in suppression of circulating current also in short-circuit conditions is presented.
Abstract: An improved soft-switching full-bridge phase-shifted pulsewidth modulation converter using insulated-gate bipolar transistors with a special auxiliary transformer is presented in this paper. Zero-voltage switching for leading leg and zero-current switching for lagging leg switches in the converter are achieved for full-load range from no load to short circuit by adding an active energy recovery clamp and auxiliary circuits. The new significant feature of the converter consists in suppression of circulating current also in short-circuit conditions. The proposed converter is very attractive for applications where short circuit and no load are the normal states of the converter operation, e.g., arc welding. The principle of operation is explained and analyzed, and experimental results are presented on a 3-kW 50-kHz laboratory converter model.

Journal ArticleDOI
TL;DR: In this paper, a new soft-switching boost converter is proposed, which utilizes a soft switching method using an auxiliary circuit with a resonant inductor and capacitor, auxiliary switch, and diodes.
Abstract: A new soft-switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn on and off, and this causes a reduction in the whole system's efficiency. The proposed boost converter utilizes a soft-switching method using an auxiliary circuit with a resonant inductor and capacitor, auxiliary switch, and diodes. Therefore, the proposed soft-switching boost converter reduces switching losses more than the conventional hard-switching converter. The efficiency, which is about 91% in hard switching, increases to about 96% in the proposed soft-switching converter. In this paper, the performance of the proposed soft-switching boost converter is verified through the theoretical analysis, simulation, and experimental results.

Journal ArticleDOI
Hao Ma1, Yue Ji1, Ye Xu1
TL;DR: In this article, a single-stage power factor correction (SSPFC) converter is proposed for the adapter application, which is composed of a flyback converter, a feedback winding and a front-end input current shaper.
Abstract: A new single-stage power factor correction (SSPFC) converter is proposed for the adapter application, which is composed of a flyback converter, a feedback winding and a front-end input current shaper. Through the feedback winding, a direct energy transfer path is configured to improve the conversion efficiency and alleviate the voltage stress across the bulk capacitor. Moreover, the feedback winding is connected to the input through only two diodes, which results in low conduction losses. Equations and configurations are given to design the input current-shaping inductor and the magnetizing inductor of the transformer, which are operated in the discontinuous conduction mode (DCM) and the DCM/ continuous conduction mode boundary mode respectively for well-shaped current waveform and reduced bulk capacitor voltage. The theoretical analysis of the converter is verified by two SSPFC prototype circuits with 19 V/90 W output. One prototype achieves a high efficiency of 90.3%, while complying with IEC 61000-3-2 Class D standard. With a different turns ratio design, the power factor can be further improved to 0.97 in another prototype.

Proceedings ArticleDOI
01 Nov 2010
TL;DR: In this article, the authors presented a DC-AC converter that merges a DCDC converter and an inverter in a single-stage topology to be used as an interface converter between photovoltaic systems and the electrical AC grid.
Abstract: This paper presents a DC-AC converter that merges a DC-DC converter and an inverter in a single-stage topology to be used as an interface converter between photovoltaic systems and the electrical AC grid. This topology is based on a full bridge converter with three levels output voltage, where two diodes and one inductor have been added in order to create a Boost converter. The control system of the proposed converter is based on two hysteretic controllers: one for the grid injected current and the other for controlling the panel current. A prototype of the proposed converter including power and control circuits was developed. The MPPT algorithm is not yet implemented and, therefore, to obtain experimental results an additional power supply is used to emulate the PV panel. Theoretical analysis and design criteria are presented together with simulated results to validate the proposed concepts. Experimental results are obtained in a lab prototype to evidence the feasibility and performance of the converter.

Journal ArticleDOI
TL;DR: In this paper, a synchronously rectified (SR) boost converter was proposed for low-ripple applications, which is the combination of the traditional synchronous rectified boost converter and the traditional Ky converter.
Abstract: In this letter, a KY boost converter is presented, which is the KY converter combined with the traditional synchronously rectified (SR) boost converter. Such a converter has continuous input and output inductor currents, different from the traditional SR boost converter, and has a larger voltage conversion ratio than the traditional SR boost converter does, and hence, this converter is very suitable for low-ripple applications. A detailed description of the proposed converter is presented herein along with a mathematical deduction and some experimental results.

Proceedings ArticleDOI
01 Nov 2010
TL;DR: In this paper, it is shown that the anticipated interaction will not result in any problems neither for the converter nor for the motor control itself, and that the interaction of these controllers with an external motor current controller is not a problem.
Abstract: The modular multilevel converter (M2C) is a promising converter technology for various high-voltage high-power applications. The reason to this is that low-distortion output quantities can be achieved with low average switching frequencies per switch and without output filters. With the M2C the output voltage has such a low harmonic content that high-power motors can be operated without any derating. However, the apparent large number of devices, requires more complex converter control techniques than a two-level counterpart. Even though there have been several ways suggested to control the converter itself, it is still a challenge to investigate the interaction of these controllers with an external motor current controller. It is shown in the paper that the anticipated interaction will not result in any problems neither for the converter nor for the motor control itself.