The Experts below are selected from a list of 258966 Experts worldwide ranked by ideXlab platform
Danwei Wang - One of the best experts on this subject based on the ideXlab platform.
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high performance grid simulator using Parallel Structure fractional repetitive control
IEEE Transactions on Power Electronics, 2016Co-Authors: Tianqi Liu, Danwei Wang, Keliang ZhouAbstract:In this paper, a high-performance grid simulator based on a Parallel Structure fractional repetitive control scheme is employed to emulate various operation scenarios of power grids for testing power products. In this paper, a simple fractional repetitive control scheme is proposed for grid simulators to achieve high-accuracy tracking performance. Using Parallel branches, the proposed repetitive controller can flexibly select the interested harmonics for compensation, and independently, tune the convergency rate at selective harmonic frequencies. Compared with the conventional repetitive control, the proposed control scheme achieves faster transient response. Moreover, the number of delay units required in the proposed repetitive controller is reduced to at least half of that in a conventional repetitive controller. Design process and stability criteria are presented in details. A set of experimental results is provided to verify the effectiveness of the proposed approach.
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Parallel Structure Fractional Repetitive Control for PWM Inverters
IEEE Transactions on Industrial Electronics, 2015Co-Authors: Tianqi Liu, Danwei WangAbstract:In this paper, a Parallel Structure fractional repetitive control (RC) scheme is proposed to improve the performance of pulsewidth-modulation (PWM) inverters in fractional cases where the sampling rate of the digital control system is not an integral multiple of the fundamental frequency. By introducing a correction factor, the new control scheme increases the control gains for all harmonics and locates poles accurately at targeted harmonic frequencies. As a result, the proposed control scheme achieves better tracking and rejection performance than conventional RC. Moreover, the Parallel Structure fractional repetitive controller requires less data memory. Dynamic response is also improved. The stability and convergence of this method are proved. Experimental results on a single-phase PWM inverter illustrate the advantages of this control scheme.
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A General Parallel Structure Repetitive Control Scheme for Multiphase DC–AC PWM Converters
IEEE Transactions on Power Electronics, 2013Co-Authors: Keliang Zhou, Danwei Wang, Ming ChengAbstract:This paper presents a general Parallel Structure repetitive control (PSRC) scheme for multiphase dc-ac pulse-width modulation (PWM) converters to cancel output total harmonic distortion more efficiently. With Parallel Structure, categorized harmonic frequency internal models are connected in Parallel. Each categorized internal model has its own independent control gain and PSRC can optimize the total convergence rate by tuning the control gains independently according to the harmonic distribution. Compared with a multiresonant controller, PSRC has more compact Structure and yields much less computation burden. Compared with conventional repetitive control (CRC), PSRC can achieve a much faster dynamic response without any loss of tracking accuracy or any added data memory. Moreover, PSRC is a general Parallel Structure RC for housing various existing RC, such as CRC, odd-harmonic RC, and dual-mode-Structure RC. Experimental results of the PSRC-controlled three-phase dc-ac PWM converters show the validity and advantages of the proposed PSRC scheme.
Tianqi Liu - One of the best experts on this subject based on the ideXlab platform.
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high performance grid simulator using Parallel Structure fractional repetitive control
IEEE Transactions on Power Electronics, 2016Co-Authors: Tianqi Liu, Danwei Wang, Keliang ZhouAbstract:In this paper, a high-performance grid simulator based on a Parallel Structure fractional repetitive control scheme is employed to emulate various operation scenarios of power grids for testing power products. In this paper, a simple fractional repetitive control scheme is proposed for grid simulators to achieve high-accuracy tracking performance. Using Parallel branches, the proposed repetitive controller can flexibly select the interested harmonics for compensation, and independently, tune the convergency rate at selective harmonic frequencies. Compared with the conventional repetitive control, the proposed control scheme achieves faster transient response. Moreover, the number of delay units required in the proposed repetitive controller is reduced to at least half of that in a conventional repetitive controller. Design process and stability criteria are presented in details. A set of experimental results is provided to verify the effectiveness of the proposed approach.
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Parallel Structure Fractional Repetitive Control for PWM Inverters
IEEE Transactions on Industrial Electronics, 2015Co-Authors: Tianqi Liu, Danwei WangAbstract:In this paper, a Parallel Structure fractional repetitive control (RC) scheme is proposed to improve the performance of pulsewidth-modulation (PWM) inverters in fractional cases where the sampling rate of the digital control system is not an integral multiple of the fundamental frequency. By introducing a correction factor, the new control scheme increases the control gains for all harmonics and locates poles accurately at targeted harmonic frequencies. As a result, the proposed control scheme achieves better tracking and rejection performance than conventional RC. Moreover, the Parallel Structure fractional repetitive controller requires less data memory. Dynamic response is also improved. The stability and convergence of this method are proved. Experimental results on a single-phase PWM inverter illustrate the advantages of this control scheme.
Young Jin Suh - One of the best experts on this subject based on the ideXlab platform.
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Real hypersurfaces in the complex hyperbolic quadric with Reeb Parallel Structure Jacobi operator.
Mathematical Physics Analysis and Geometry, 2020Co-Authors: Hyunjin Lee, Young Jin SuhAbstract:We introduce the notion of Reeb Parallel Structure Jacobi operator for real hypersurfaces in the complex hyperbolic quadric ${Q^*}^m=SO^0_{2,m}/SO_2 SO_m$, $m \geq 3$, and give a classification theory for real hypersurfaces in ${{Q^*}^m}$, $m \geq 3$, with Reeb Parallel Structure Jacobi operator.
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Real hypersurfaces in the complex quadric with Parallel Structure Jacobi operator
Differential Geometry and its Applications, 2017Co-Authors: Young Jin SuhAbstract:Abstract First we introduce the notion of Parallel Structure Jacobi operator for real hypersurfaces in the complex quadric Q m = S O m + 2 / S O m S O 2 . Next we give a complete classification of real hypersurfaces in Q m = S O m + 2 / S O m S O 2 with Parallel Structure Jacobi operator.
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Hopf hypersurfaces in complex two-plane Grassmannians with generalized Tanaka-Webster \mathfrak{D}^ \bot-Parallel Structure Jacobi operator
Open Mathematics, 2014Co-Authors: Eunmi Pak, Young Jin SuhAbstract:Regarding the generalized Tanaka-Webster connection, we considered a new notion of $$\mathfrak{D}^ \bot$$ -Parallel Structure Jacobi operator for a real hypersurface in a complex two-plane Grassmannian G 2(ℂ m+2) and proved that a real hypersurface in G 2(ℂ m+2) with generalized Tanaka-Webster $$\mathfrak{D}^ \bot$$ -Parallel Structure Jacobi operator is locally congruent to an open part of a tube around a totally geodesic quaternionic projective space ℍP n in G 2(ℂ m+2), where m = 2n.
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REAL HYPERSURFACES IN COMPLEX TWO-PLANE GRASSMANNIANS WITH 𝔇⊥-Parallel Structure JACOBI OPERATOR
International Journal of Mathematics, 2011Co-Authors: Imsoon Jeong, Juan De Dios Pérez, Carlos J. G. Machado, Young Jin SuhAbstract:In this paper we give some non-existence theorems for Hopf real hypersurfaces in complex two-plane Grassmannians G2(ℂm+2) with 𝔇⊥-Parallel Structure Jacobi operator, where 𝔇⊥ = Span {ξ1, ξ2, ξ3}.
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REAL HYPERSURFACES IN COMPLEX TWO-PLANE GRASSMANNIANS WITH
International Journal of Mathematics, 2011Co-Authors: Imsoon Jeong, Juan De Dios Pérez, Carlos J. G. Machado, Young Jin SuhAbstract:In this paper we give some non-existence theorems for Hopf real hypersurfaces in complex two-plane Grassmannians G2(ℂm+2) with
Keliang Zhou - One of the best experts on this subject based on the ideXlab platform.
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high performance grid simulator using Parallel Structure fractional repetitive control
IEEE Transactions on Power Electronics, 2016Co-Authors: Tianqi Liu, Danwei Wang, Keliang ZhouAbstract:In this paper, a high-performance grid simulator based on a Parallel Structure fractional repetitive control scheme is employed to emulate various operation scenarios of power grids for testing power products. In this paper, a simple fractional repetitive control scheme is proposed for grid simulators to achieve high-accuracy tracking performance. Using Parallel branches, the proposed repetitive controller can flexibly select the interested harmonics for compensation, and independently, tune the convergency rate at selective harmonic frequencies. Compared with the conventional repetitive control, the proposed control scheme achieves faster transient response. Moreover, the number of delay units required in the proposed repetitive controller is reduced to at least half of that in a conventional repetitive controller. Design process and stability criteria are presented in details. A set of experimental results is provided to verify the effectiveness of the proposed approach.
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A General Parallel Structure Repetitive Control Scheme for Multiphase DC–AC PWM Converters
IEEE Transactions on Power Electronics, 2013Co-Authors: Keliang Zhou, Danwei Wang, Ming ChengAbstract:This paper presents a general Parallel Structure repetitive control (PSRC) scheme for multiphase dc-ac pulse-width modulation (PWM) converters to cancel output total harmonic distortion more efficiently. With Parallel Structure, categorized harmonic frequency internal models are connected in Parallel. Each categorized internal model has its own independent control gain and PSRC can optimize the total convergence rate by tuning the control gains independently according to the harmonic distribution. Compared with a multiresonant controller, PSRC has more compact Structure and yields much less computation burden. Compared with conventional repetitive control (CRC), PSRC can achieve a much faster dynamic response without any loss of tracking accuracy or any added data memory. Moreover, PSRC is a general Parallel Structure RC for housing various existing RC, such as CRC, odd-harmonic RC, and dual-mode-Structure RC. Experimental results of the PSRC-controlled three-phase dc-ac PWM converters show the validity and advantages of the proposed PSRC scheme.
Eunmi Pak - One of the best experts on this subject based on the ideXlab platform.
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Hopf Hypersurfaces in Complex Two-plane Grassmannians with Generalized Tanaka-Webster Reeb-Parallel Structure Jacobi Operator
Kyungpook Mathematical Journal, 2019Co-Authors: Byung-hak Kim, Hyunjin Lee, Eunmi PakAbstract:Regarding the generalized Tanaka-Webster connection, we considered a new notion of \(\mathfrak{D}^ \bot\)-Parallel Structure Jacobi operator for a real hypersurface in a complex two-plane Grassmannian G2(ℂm+2) and proved that a real hypersurface in G2(ℂm+2) with generalized Tanaka-Webster \(\mathfrak{D}^ \bot\)-Parallel Structure Jacobi operator is locally congruent to an open part of a tube around a totally geodesic quaternionic projective space ℍPn in G2(ℂm+2), where m = 2n.
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Hopf hypersurfaces in complex two-plane Grassmannians with generalized Tanaka-Webster \mathfrak{D}^ \bot-Parallel Structure Jacobi operator
Open Mathematics, 2014Co-Authors: Eunmi Pak, Young Jin SuhAbstract:Regarding the generalized Tanaka-Webster connection, we considered a new notion of $$\mathfrak{D}^ \bot$$ -Parallel Structure Jacobi operator for a real hypersurface in a complex two-plane Grassmannian G 2(ℂ m+2) and proved that a real hypersurface in G 2(ℂ m+2) with generalized Tanaka-Webster $$\mathfrak{D}^ \bot$$ -Parallel Structure Jacobi operator is locally congruent to an open part of a tube around a totally geodesic quaternionic projective space ℍP n in G 2(ℂ m+2), where m = 2n.
