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Marian K. Kazimierczuk - One of the best experts on this subject based on the ideXlab platform.
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modeling and analysis of class e amplifier with a shunt inductor at sub nominal opeRation for any Duty Ratio
IEEE Transactions on Circuits and Systems, 2014Co-Authors: Mohsen Hayati, Marian K. Kazimierczuk, Ali Lotfi, Hiroo SekiyaAbstract:This paper presents analytical expressions for the sub-nominal opeRation, which is only the zero current switching (ZCS) condition, of the class-E power amplifier with a shunt inductor at any Duty Ratio. The Duty Ratio is considered not only as a design specification but also as an adjustment parameter. In the sub-nominal opeRation with any Duty Ratio, both the peak switch voltage and the peak switch current can be set as design specifications due to two more degrees of design freedom in comparison with the class-E nominal amplifier at the fixed Duty Ratio. Additionally, it is also seen that the Duty Ratio affects the maximum operating frequency and the output power capability with ZCS condition. A design example of the class-E ZCS amplifier with a shunt inductor under the specifications of peak switch voltage and peak switch current is given. The measurement and a simulation by circuit simulator results agreed with the analytical expressions quantitatively, which show the validity of our analytical expressions.
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comparison of wide and high frequency Duty Ratio to inductor current transfer functions of dc dc pwm buck converter in ccm
IEEE Transactions on Industrial Electronics, 2012Co-Authors: N. Kondrath, Marian K. KazimierczukAbstract:Wide- (WF) and high-frequency (HF) small-signal models are presented for pulsewidth-modulated dc-dc buck converter power stage. An exact Duty-Ratio-to-inductor-current transfer function is derived using the WF model and compared to an approximate transfer function derived using the HF model for the buck converter power stage in continuous conduction mode. The theoretical results are validated using experimental results.
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control to output and Duty Ratio to inductor current transfer functions of peak current mode controlled dc dc pwm buck converter in ccm
International Symposium on Circuits and Systems, 2010Co-Authors: N. Kondrath, Marian K. KazimierczukAbstract:The control-to-output and the Duty Ratio-to-inductor current transfer functions of peak current-mode controlled PWM dc-dc buck converter in CCM are derived and illustrated. The closed inner-current loop and the power stage inductor current-to-output voltage transfer functions are used to derive the control-to-output transfer function of the peak current-mode controlled buck converter in CCM, which is essential for the outer-voltage loop controller design. A small-signal model including parasitic components and delay is used to derive the power stage transfer function, necessary for proper analysis of the power stage. The loop gain of the inner-current loop is derived and is shown that it is independent of converter topology.
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Analysis of Class DE Amplifier With Nonlinear Shunt Capacitances at Any Grading Coefficient for High $\displaystyle Q$ and 25 $\displaystyle $ % Duty Ratio
IEEE Transactions on Power Electronics, 2010Co-Authors: Hiroo Sekiya, Natsumi Sagawa, Marian K. KazimierczukAbstract:This paper gives analytical expressions for the class disruptive effect (DE) amplifier with nonlinear shunt capacitances at any grading coefficient m of the MOSFET body junction diode at a high value of the loaded quality factor Q of the output resonant circuit, zero equivalent series resistance of all the components, and switch-on Duty Ratio D=0.25. No external shunt capacitance is used in the analysis of the class DE amplifier. The grading coefficient determines the degree of nonlinearity of the MOSFET shunt capacitances. When the grading coefficient is different from the design specifications, the waveforms of the switch voltages do not satisfy the class E switching conditions, reducing the power conversion efficiency. Therefore, the grading coefficient m is an important parameter to satisfy the class E switching conditions. It is shown analytically that the dc supply voltage and current are always proportional to the amplitude of the output voltage and current. The output power capability is never affected by any nonlinearity of the shunt capacitances. We obtain analytical design equations, which are validated by PSPICE simulations and laboratory experiments considered with the gate-drain capacitance effect.
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maximum operating frequency of class e amplifier at any Duty Ratio
IEEE Transactions on Circuits and Systems Ii-express Briefs, 2008Co-Authors: Tadashi Suetsugu, Marian K. KazimierczukAbstract:This paper shows that the maximum operating frequency of the class-E power amplifier depends on the transistor Duty Ratio. The maximum operating frequency increases as the Duty Ratio decreases under zero-voltage switching and zero-derivative switching conditions at fixed values of the output power, dc supply voltage, and shunt capacitance.
Raja Ayyanar - One of the best experts on this subject based on the ideXlab platform.
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sensor less current sharing over wide operating range for extended Duty Ratio boost converter
IEEE Transactions on Power Electronics, 2017Co-Authors: Raja AyyanarAbstract:An extended-Duty-Ratio (EDR) boost converter is studied extensively in this paper for high voltage gain applications with a wide input (and/or output) voltage range. The EDR is a unique combination of an interleaved, multiphase boost converter and switched capacitor configuRation that achieves high voltage gain with significantly lower switch voltage stress and switching losses compared to conventional high-gain solutions. Most of the switches in the multiphase EDR experience only a fixed fraction of the output voltage ( $1/M, 2/M$ , etc., where $M$ is the number of phases). Through extensive analysis over a wide operating range, it is shown here that the EDR boost converter has inherent current sharing among the phases only in a limited range of Duty Ratio— $(M-1)/M \leq D \leq 1$ . As the Duty Ratio reduces beyond this range as required in wide input voltage applications, inherent current sharing property is lost. In this paper, techniques to ensure current sharing under all operating zones without requiring current sensors are presented. Instead of having equal Duty Ratio for each phase, it is adjusted for each phase according to the operating region of the converter. Extensive analysis is presented to derive the required Duty Ratio changes for the different phases. The proposed concept is validated with experimental results from a 250 W, 3-phase EDR boost, and GaN-based hardware prototype.
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gan based high gain non isolated dc dc stage of microinverter with extended Duty Ratio boost
European Conference on Cognitive Ergonomics, 2016Co-Authors: Raja AyyanarAbstract:Microinverter is attracting more attention due to its compact size, plug and play concept, easy installation, and higher power yield under partial shading condition. This paper explores a converter for the DC-DC stage of a non-isolated microinverter. The topology termed as extended-Duty-Ratio (EDR) boost, is a hybrid of the interleaved boost and switched capacitor concept which has the advantage of providing high gain but simultaneously maintaining reduced voltage and current stress on most of the switches. The inductor current is interleaved, reducing the equivalent ripple on the converter input current and the inductor power loss. The converter opeRation is identified to be divided into different zones depending on the Duty Ratio of the phases. The operating principles along with the details of the component design and loss analysis as a function of converter phases has been studied. A 250 W GaN based 3-level EDR prototype with input from 20 V–40 V and 225 V output and operating at switching frequency of 200 kHz has been developed to validate converter's opeRation in hardware.
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voltage regulator optimization using multiwinding coupled inductors and extended Duty Ratio mechanisms
IEEE Transactions on Power Electronics, 2009Co-Authors: B Oraw, Raja AyyanarAbstract:This paper examines design optimization of voltage regulators (VRs) for microprocessor applications. Optimality of competing VR topologies, such as conventional (Conv) buck, coupled inductor, and extended Duty Ratio converters, is examined using efficiency norms and a new cost-per-watt metric to compare the amount of output capacitance (which is strongly correlated to the VR cost) to the efficiency. Coupled inductors provide a higher steady-state inductance than transient inductance. Lower transient inductance allows for smaller output capacitance. However, lower output capacitance requires a higher switching frequency and thus yields greater switching losses and lower efficiency. Extended Duty Ratio mechanisms reduce the switching voltage, and hence, reduce switching losses and increase efficiency. Experimental data are provided that the coupled inductor extended Duty Ratio converter has the same average efficiency, has higher light-load efficiency, and uses one-third of the output capacitance as the Conv multiphase buck converter. Hence, the combination of multiwinding coupled inductors and extended Duty Ratio mechanisms is shown to be the optimal VR configuRation. The optimality concepts contributed in this paper resolve the ambiguity between VR cost and efficiency, and are essential for selecting the best solution among several competing VR designs.
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common Duty Ratio control of input series connected modular dc dc converters with active input voltage and load current sharing
IEEE Transactions on Industry Applications, 2006Co-Authors: Ramesh Giri, Raja Ayyanar, V K Choudhary, Ned MohanAbstract:This paper proposes a simple control method to achieve active sharing of input voltage and load current among modular converters that are connected in series at the input and in parallel at the output. The input-series connection enables a fully modular power-system architecture, where low voltage and low power modules can be connected in any combination at the input and/or at the output, to realize any given specifications. Further, the input-series connection enables the use of low-voltage MOSFETs that are optimized for very low RDSON , thus, resulting in lower conduction losses. In the proposed scheme, the Duty Ratio to all the converter modules connected in input-series and output-parallel (ISOP) configuRation is made common. This scheme does not require a dedicated input-voltage or load-current-share controller. It relies on the inherent self-correcting characteristic of the ISOP connection when the Duty Ratio of all the converters is the same. The proposed scheme is analyzed using the average model of a forward converter. The stability and performance of the scheme are verified through numerical simulation, both in frequency domain and in time domain. The proposed control method is also validated on an experimental prototype ISOP system comprising of two forward converters
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common Duty Ratio control of input series connected modular dc dc converters with active input voltage and load current sharing
Applied Power Electronics Conference, 2003Co-Authors: Ramesh Giri, Raja Ayyanar, Ned MohanAbstract:In this paper, active input voltage and load current sharing of DC-DC converter modules connected in series at the input and parallel at the output employing a novel common Duty Ratio control concept, is proposed. An appropriate analysis and experimental results are presented to verify the proposed concepts.
J A Melkebeek - One of the best experts on this subject based on the ideXlab platform.
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Duty Ratio feedforward for digitally controlled boost pfc converters
IEEE Transactions on Industrial Electronics, 2005Co-Authors: D M Van De Sype, Koen De Gusseme, A Van Den Bossche, J A MelkebeekAbstract:When a "classical" current control scheme is applied, the line current of a boost power-factor-correction (PFC) converter leads the line voltage, resulting in a nonunity fundamental displacement power factor and in important zero-crossing distortion in applications with a high line frequency (e.g., 400-Hz power systems on commercial aircraft). To resolve this problem, a current-control scheme is proposed using Duty-Ratio feedforward. In this paper, the input impedance of the boost PFC converter for both the classical current-loop controller and the controller using Duty-Ratio feedforward are derived theoretically. A comparison reveals the advantages of the proposed control scheme: a low total harmonic distortion of the line current, a resistive input impedance, virtually no zero-crossing distortion, and a fundamental displacement power factor close to unity. The theoretical results obtained are verified using an experimental setup of a digitally controlled boost PFC converter.
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Duty Ratio feedforward for digitally controlled boost pfc converters
Applied Power Electronics Conference, 2003Co-Authors: D M V De Sype, Koen De Gusseme, A Van Den Bossche, J A MelkebeekAbstract:When a 'classical' current control scheme is applied, the input current of a boost power factor correction (PFC) converter leads the input voltage, resulting in a nonunity fundamental displacement factor and in important zero-crossing distortion in applications with a high grid frequency (e.g. 400 Hz power systems on commercial aircraft). To resolve this problem, a current-control scheme is proposed using Duty-Ratio feedforward. In this paper, the input impedance of the boost PFC converter for both the classical current-loop controller and the controller using Duty-Ratio feedforward are derived theoretically. A comparison reveals the advantages of the proposed control scheme: a low total-harmonic-distortion (THD) of the input current, a resistive input impedance, virtually no zero-crossing distortion and a fundamental displacement power factor close to unity. The theoretical results obtained are verified using an experimental setup of a digitally controlled boost PFC converter.
Jianjiang Shi - One of the best experts on this subject based on the ideXlab platform.
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common Duty Ratio control of input parallel output parallel ipop connected dc dc converter modules with automatic sharing of currents
IEEE Transactions on Power Electronics, 2012Co-Authors: Jianjiang Shi, Lingbing ZhouAbstract:Input-parallel output-parallel (IPOP) connected converter systems allow the use of low-power converter modules for high-power applications, with interleaving control scheme resulting in smaller filter size, better dynamic performance, and higher power density. In this paper, a new IPOP converter system is proposed, which consists of multiple dual-active half-bridge (DAHB) dc-dc converter modules. Moreover, by applying a common-Duty-Ratio control scheme, without a dedicated current-sharing controller, the automatic sharing of input currents or load currents is achieved in the IPOP converter even in the presence of substantial differences of 10% in various module parameters. The current-sharing performance of the proposed control method is analyzed using both a small-signal model and a steady-state dc model of the IPOP system. It is concluded that the equal sharing of currents among modules can be achieved by reducing the mismatches in various module parameters, which is achievable in practice. The current-sharing performance of the IPOP converter is also verified by Saber simulation and a 400-W experimental prototype consisting of two DAHB modules. The common-Duty-Ratio control method can be extended to any IPOP system that consists of three or more converter modules, including traditional dual-active bridge dc-dc converters, which have a characteristic of current source.
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Common-Duty-Ratio Control of Input-Series Output-Parallel Connected Phase-shift Full-Bridge DC–DC Converter Modules
IEEE Transactions on Power Electronics, 2011Co-Authors: Jianjiang Shi, Jie Luo, Xiangning HeAbstract:Input-series output-parallel (ISOP)-connected converters allow the use of low-voltage and low-power converter modules for high input-voltage and high-power applications. Further, the use of high-frequency, low-voltage MOSFETs, which are optimized for very low on-resistance, is enabled, resulting in lower conduction losses and higher power density. In this paper, a common-Duty-Ratio control scheme is proposed for an ISOP converter consisting of multiple phase-shift full-bridge (PS-FB) converter modules. The proposed control method achieves stable sharing of the input voltage and load current by applying a common Duty Ratio to all converter modules, without a dedicated input-voltage sharing controller. The control method is analyzed by using both a small-signal averaged model and a steady-state dc model of the ISOP converter, and it is concluded that the equal sharing of input voltage and load current among converter modules can be achieved through reducing the mismatches in various module parameters, which is practically achievable. The stability and performance of the control scheme are verified by Saber simulation and a 500 W experimental prototype consisting of two PS-FB converter modules.
Xiangning He - One of the best experts on this subject based on the ideXlab platform.
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Common-Duty-Ratio Control of Input-Series Output-Parallel Connected Phase-shift Full-Bridge DC–DC Converter Modules
IEEE Transactions on Power Electronics, 2011Co-Authors: Jianjiang Shi, Jie Luo, Xiangning HeAbstract:Input-series output-parallel (ISOP)-connected converters allow the use of low-voltage and low-power converter modules for high input-voltage and high-power applications. Further, the use of high-frequency, low-voltage MOSFETs, which are optimized for very low on-resistance, is enabled, resulting in lower conduction losses and higher power density. In this paper, a common-Duty-Ratio control scheme is proposed for an ISOP converter consisting of multiple phase-shift full-bridge (PS-FB) converter modules. The proposed control method achieves stable sharing of the input voltage and load current by applying a common Duty Ratio to all converter modules, without a dedicated input-voltage sharing controller. The control method is analyzed by using both a small-signal averaged model and a steady-state dc model of the ISOP converter, and it is concluded that the equal sharing of input voltage and load current among converter modules can be achieved through reducing the mismatches in various module parameters, which is practically achievable. The stability and performance of the control scheme are verified by Saber simulation and a 500 W experimental prototype consisting of two PS-FB converter modules.
