The high potentiality of integrating renewable energies,such as photovoltaic,into a modern electrical microgrid system,using DC-to-DC converters,raises some issues associated with controller loop design and system sta...The high potentiality of integrating renewable energies,such as photovoltaic,into a modern electrical microgrid system,using DC-to-DC converters,raises some issues associated with controller loop design and system stability.The generalized state space average model(GSSAM)concept was consequently introduced to design a DC-to-DC converter controller in order to evaluate DC-to-DC converter performance and to conduct stability studies.This paper presents a GSSAM for parallel DC-to-DC converters,namely:buck,boost,and buck-boost converters.The rationale of this study is that modern electrical systems,such as DC networks,hybrid microgrids,and electric ships,are formed by parallel DC-to-DC converters with separate DC input sources.Therefore,this paper proposes a GSSAM for any number of parallel DC-to-DC converters.The proposed GSSAM is validated and investigated in a time-domain simulation environment,namely a MATLAB/SIMULINK.The study compares the steady-state,transient,and oscillatory performance of the state-space average model with a fully detailed switching model.展开更多
The state space average model and the large signal models of Pulse Skip Modulation （PSM） mode are given in this paper. Farther more, based on these models and simulations of PSM converter circuits, the analysis of t...The state space average model and the large signal models of Pulse Skip Modulation （PSM） mode are given in this paper. Farther more, based on these models and simulations of PSM converter circuits, the analysis of the characteristics of PSM converter is described in this paper, of which include efficiency, frequency spectrum analysis, output voltage ripple, response speed and interference rejection capability. Compared with PWM control mode, PSM converter has high efficiency, especially with fight loads, quick response, good interference rejection and good EMC characteristic. Improved PSM slightly, it could be a kind of good independent regulating mode during the whole operating process for a DC-DC converter. Finally, some experimental results are also presented in this paper.展开更多
The dual active bridge(DAB)is a widely used DC-DC topology owing to its ease of control and ability to achieve various control objectives.When designing a DAB-based system under broadband perturbations,one must model ...The dual active bridge(DAB)is a widely used DC-DC topology owing to its ease of control and ability to achieve various control objectives.When designing a DAB-based system under broadband perturbations,one must model the DAB,calculate its input impedance,and analyze the system stability.In this study,two continuous-time impedance models of the DAB,i.e.,a reduced-order model named the power-based impedance model(PBIM)and a full-order model named the generalized state-space average impedance model(GSSAM),are proposed and used to calculate the input impedance in a single-phase modulation mode.The modeling errors are analyzed,the participation factors and residuals are calculated,and a Bode diagram is constructed to illustrate the change in the input impedance with increasing leakage inductance.Simulations are conducted using various circuit parameters to verify the results.The results show that the PBIM exhibits simplicity and accuracy in the low-frequency domain,whereas the GSSAM performs better in the high-frequency domain.展开更多
文摘The high potentiality of integrating renewable energies,such as photovoltaic,into a modern electrical microgrid system,using DC-to-DC converters,raises some issues associated with controller loop design and system stability.The generalized state space average model(GSSAM)concept was consequently introduced to design a DC-to-DC converter controller in order to evaluate DC-to-DC converter performance and to conduct stability studies.This paper presents a GSSAM for parallel DC-to-DC converters,namely:buck,boost,and buck-boost converters.The rationale of this study is that modern electrical systems,such as DC networks,hybrid microgrids,and electric ships,are formed by parallel DC-to-DC converters with separate DC input sources.Therefore,this paper proposes a GSSAM for any number of parallel DC-to-DC converters.The proposed GSSAM is validated and investigated in a time-domain simulation environment,namely a MATLAB/SIMULINK.The study compares the steady-state,transient,and oscillatory performance of the state-space average model with a fully detailed switching model.
基金Supported by the National Natural Science Foundation of China (No.60436030)
文摘The state space average model and the large signal models of Pulse Skip Modulation （PSM） mode are given in this paper. Farther more, based on these models and simulations of PSM converter circuits, the analysis of the characteristics of PSM converter is described in this paper, of which include efficiency, frequency spectrum analysis, output voltage ripple, response speed and interference rejection capability. Compared with PWM control mode, PSM converter has high efficiency, especially with fight loads, quick response, good interference rejection and good EMC characteristic. Improved PSM slightly, it could be a kind of good independent regulating mode during the whole operating process for a DC-DC converter. Finally, some experimental results are also presented in this paper.
基金Supported by the National Natural Science Foundation of China(52005436).
文摘The dual active bridge(DAB)is a widely used DC-DC topology owing to its ease of control and ability to achieve various control objectives.When designing a DAB-based system under broadband perturbations,one must model the DAB,calculate its input impedance,and analyze the system stability.In this study,two continuous-time impedance models of the DAB,i.e.,a reduced-order model named the power-based impedance model(PBIM)and a full-order model named the generalized state-space average impedance model(GSSAM),are proposed and used to calculate the input impedance in a single-phase modulation mode.The modeling errors are analyzed,the participation factors and residuals are calculated,and a Bode diagram is constructed to illustrate the change in the input impedance with increasing leakage inductance.Simulations are conducted using various circuit parameters to verify the results.The results show that the PBIM exhibits simplicity and accuracy in the low-frequency domain,whereas the GSSAM performs better in the high-frequency domain.
