The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
M M Jovanovic - One of the best experts on this subject based on the ideXlab platform.
-
review and stability analysis of pll based interleaving control of dcm ccm boundary boost pfc converters
IEEE Transactions on Power Electronics, 2009Co-Authors: Laszlo Huber, Brian T Irving, M M JovanovicAbstract:In this paper, a systematic review of phase-locked Loop (PLL)-based closed-Loop control Methods for interleaved discontinuous conduction mode/continuous conduction mode (DCM/CCM) boundary boost power factor correction (PFC) converters is presented. A detailed analysis of the stability of the PLL with instant averaging filter is performed and verified by simulation. The stability of the PLL with instant averaging filter and with RC filter is compared by simulation. Based on the simulation results, it is concluded that the PLL-based closed-Loop Methods always provide stable operation, unlike the open-Loop control Methods, where the only Method that results in stable operation is the slave synchronization to the turn- on instant of the master with current-mode control. It is also shown that the dynamic response of the PLL-based closed-Loop Methods with master-slave approach and democratic approach is almost identical. Experimental results obtained on a 300-W, universal input, 400-V output, interleaved DCM/CCM boundary boost PFC prototype circuit with a dedicated controller IC utilizing a democratic, PLL-based closed-Loop Method are also provided.
-
closed Loop control Methods for interleaved dcm ccm boundary boost pfc converters
Applied Power Electronics Conference, 2009Co-Authors: Laszlo Huber, Brian T Irving, M M JovanovicAbstract:In this paper, a systematic overview of PLL-based closed-Loop control Methods for interleaved DCM/CCM boundary boost PFC converters is presented. It is shown that the PLL-based closed-Loop Methods always provide stable operation, unlike the open-Loop control Methods, where the only Method which results in stable operation is the slave synchronization to the turn-on instant of the master with current-mode control. It is also shown that the dynamic response of the PLL-based closed-Loop Methods with master-slave approach and democratic approach is almost identical. Experimental results obtained on a 300-W, universal input, 400-V output, interleaved DCM/CCM boundary boost PFC prototype circuit with a dedicated controller IC utilizing a democratic, PLL-based closed-Loop Method is also provided.
Brad Lehman - One of the best experts on this subject based on the ideXlab platform.
-
control Loop design for two stage dc dc converters with low voltage high current output
IEEE Transactions on Power Electronics, 2005Co-Authors: Julian Yan Zhu, Brad LehmanAbstract:This work presents a general analysis framework for control Loop design of two-stage converters. The results yield a thorough explanation of various Loop design approaches. A three-Loop Method to extend the system bandwidth is proposed. The new control design algorithm is applied to a 48 V/3.3 V two-stage converter. Experiments verify the effectiveness of the control Loop design approach.
-
control Loop design for two stage dc dc converters with low voltage high current output
Applied Power Electronics Conference, 2003Co-Authors: Julian Yan Zhu, Brad LehmanAbstract:This paper presents a general analysis framework for control Loop design of two-stage converters. The results yield a thorough explanation of various Loop design approaches. A three-Loop Method to extend the system bandwidth is proposed. The new control design algorithm is applied to a 48 V/3.3 V two-stage converter. Experiments verify the effectiveness of the control Loop design approach.
Benni Reznik - One of the best experts on this subject based on the ideXlab platform.
-
quantum simulations of gauge theories with ultracold atoms local gauge invariance from angular momentum conservation
Physical Review A, 2013Co-Authors: Erez Zohar, Ignacio J Cirac, Benni ReznikAbstract:Quantum simulations of High Energy Physics, and especially of gauge theories, is an emerging and exciting direction in quantum simulations. However, simulations of such theories, compared to simulations of condensed matter physics, must satisfy extra restrictions, such as local gauge and Lorentz invariance. In this paper we discuss these special requirements, and present a new Method for quantum simulation of lattice gauge theories using ultracold atoms. This Method allows to include local gauge invariance as a fundamental symmetry of the atomic Hamiltonian, arising from natural atomic interactions and conservation laws (and not as a property of a low energy sector). This allows us to implement elementary gauge invariant interactions for three lattice gauge theories: compact QED (U(1)), SU(N) and Z_N, which can be used to build quantum simulators in 1+1 dimensions. We also present a new Loop Method, which uses the elementary interactions as building blocks in the effective construction of quantum simulations for d+1 dimensional lattice gauge theories (d>1), without having to use Gauss's law as a constraint, as in previous proposals. We discuss in detail the quantum simulation of 2+1 dimensional compact QED and provide a numerical proof of principle. The simplicity of the already gauge invariant elementary interactions of this model suggests it may be useful for future experimental realizations.
-
quantum simulations of gauge theories with ultracold atoms local gauge invariance from angular momentum conservation
Physical Review A, 2013Co-Authors: Erez Zohar, Ignacio J Cirac, Benni ReznikAbstract:Quantum simulations of high-energy physics, and especially of gauge theories, is an emerging and exciting direction in quantum simulations. However, simulations of such theories, compared to simulations of condensed matter physics, must satisfy extra restrictions, such as local gauge invariance and relativistic structure. In this paper we discuss these special requirements, and present a Method for quantum simulation of lattice gauge theories using ultracold atoms. This Method allows us to include local gauge invariance as a fundamental symmetry of the atomic Hamiltonian, arising from natural atomic interactions and conservation laws (and not as a property of a low-energy sector). This allows us to implement elementary gauge invariant interactions for three lattice gauge theories: U(1) (compact QED), ${\mathbb{Z}}_{N}$ and SU$(N)$ (Yang-Mills), which can be used to build quantum simulators in $1+1$ dimensions. We also present a Loop Method, which uses the elementary interactions as building blocks in the effective construction of quantum simulations for $d+1$ dimensional lattice gauge theories ($dg1$), but unlike in previous proposals, here gauge invariance and Gauss's law are natural symmetries, which do not have to be imposed as a constraint. We discuss in detail the quantum simulation of $2+1$ dimensional compact QED and provide a numerical proof of principle. The simplicity of the already gauge-invariant elementary interactions of this model suggests it may be useful for future experimental realizations.
Hyeongseok Ko - One of the best experts on this subject based on the ideXlab platform.
-
analysis and synthesis of facial expressions with hand generated muscle actuation basis
International Conference on Computer Graphics and Interactive Techniques, 2005Co-Authors: Byoungwon Choe, Hyeongseok KoAbstract:We present a performance-driven facial animation system for analyzing captured expressions to find muscle actuation and synthesizing expressions with the actuation values. Significantly different approach of our work is that we let artists sculpt the initial draft of the actuation basis---the basic facial shapes corresponding to the isolated actuation of individual muscles, instead of calculating skin surface deformation entirely relying on the mathematical models such as finite element Methods. We synthesize expressions by linear combinations of the basis elements, and analyze expressions by finding the weights for the combinations. Even though the hand-generated actuation basis represents the essence of the subject's characteristic expressions, it is not accurate enough to be used in the subsequent computational procedures. We also describe an iterative algorithm to increase the accuracy of the actuation basis. The experimental results suggest that our artist-in-the-Loop Method produces more predictable and controllable outcome than pure mathematical models, thus can be a quite useful tool in animation productions.
-
analysis and synthesis of facial expressions with hand generated muscle actuation basis
Proceedings Computer Animation 2001. Fourteenth Conference on Computer Animation (Cat. No.01TH8596), 2001Co-Authors: Byoungwon Choe, Hyeongseok KoAbstract:We present a performance-driven facial animation system for analyzing captured expressions to find muscle actuation and synthesizing expressions with the actuation values. A significantly different approach of our work is that we let artists sculpt the initial draft of the actuation basis: the basic facial shapes corresponding to the isolated actuation of individual muscles, instead of calculating skin surface deformation entirely, relying on mathematical models such as finite element Methods. We synthesize expressions by linear combinations of the basis elements, and analyze expressions by finding the weights for the combinations. Even though the hand-generated actuation basis represents the essence of the subject's characteristic expressions, it is not accurate enough to be used in the subsequent computational procedures. We also describe an iterative algorithm to increase the accuracy of the actuation basis. The experimental results suggest that our artist-in-the-Loop Method produces a more predictable and controllable outcome than pure mathematical models, and thus can be a quite useful tool in animation productions.
Laszlo Huber - One of the best experts on this subject based on the ideXlab platform.
-
review and stability analysis of pll based interleaving control of dcm ccm boundary boost pfc converters
IEEE Transactions on Power Electronics, 2009Co-Authors: Laszlo Huber, Brian T Irving, M M JovanovicAbstract:In this paper, a systematic review of phase-locked Loop (PLL)-based closed-Loop control Methods for interleaved discontinuous conduction mode/continuous conduction mode (DCM/CCM) boundary boost power factor correction (PFC) converters is presented. A detailed analysis of the stability of the PLL with instant averaging filter is performed and verified by simulation. The stability of the PLL with instant averaging filter and with RC filter is compared by simulation. Based on the simulation results, it is concluded that the PLL-based closed-Loop Methods always provide stable operation, unlike the open-Loop control Methods, where the only Method that results in stable operation is the slave synchronization to the turn- on instant of the master with current-mode control. It is also shown that the dynamic response of the PLL-based closed-Loop Methods with master-slave approach and democratic approach is almost identical. Experimental results obtained on a 300-W, universal input, 400-V output, interleaved DCM/CCM boundary boost PFC prototype circuit with a dedicated controller IC utilizing a democratic, PLL-based closed-Loop Method are also provided.
-
closed Loop control Methods for interleaved dcm ccm boundary boost pfc converters
Applied Power Electronics Conference, 2009Co-Authors: Laszlo Huber, Brian T Irving, M M JovanovicAbstract:In this paper, a systematic overview of PLL-based closed-Loop control Methods for interleaved DCM/CCM boundary boost PFC converters is presented. It is shown that the PLL-based closed-Loop Methods always provide stable operation, unlike the open-Loop control Methods, where the only Method which results in stable operation is the slave synchronization to the turn-on instant of the master with current-mode control. It is also shown that the dynamic response of the PLL-based closed-Loop Methods with master-slave approach and democratic approach is almost identical. Experimental results obtained on a 300-W, universal input, 400-V output, interleaved DCM/CCM boundary boost PFC prototype circuit with a dedicated controller IC utilizing a democratic, PLL-based closed-Loop Method is also provided.
