In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effec...In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems.展开更多
We demonstrate superb large-area verticalβ-Ga_(2)O_(3)SBDs with a Schottky contact area of 1×1 mm^(2)and obtain a high-efficiency DC-DC converter based on the device.Theβ-Ga_(2)O_(3)SBD can obtain a forward cur...We demonstrate superb large-area verticalβ-Ga_(2)O_(3)SBDs with a Schottky contact area of 1×1 mm^(2)and obtain a high-efficiency DC-DC converter based on the device.Theβ-Ga_(2)O_(3)SBD can obtain a forward current of 8 A with a forward volt-age of 5 V,and has a reverse breakdown voltage of 612 V.The forward turn-on voltage(VF)and the on-resistance(Ron)are 1.17 V and 0.46Ω,respectively.The conversion efficiency of theβ-Ga_(2)O_(3)SBD-based DC-DC converter is 95.81%.This work indicates the great potential of Ga_(2)O_(3)SBDs and relevant circuits in power electronic applications.展开更多
This paper proposes the new cascaded series parallel design for improved dynamic performance of DC-DC buck boost converters by a new Sliding Mode Control (SMC) method. The converter is controlled using Sliding Mode Co...This paper proposes the new cascaded series parallel design for improved dynamic performance of DC-DC buck boost converters by a new Sliding Mode Control (SMC) method. The converter is controlled using Sliding Mode Control method that utilizes the converter’s duty ratio to determine the skidding surface. System modeling and simulation results are presented. The results also showed an improved overall performance over typical PID controller, and there was no overshoot or settling time, tracking the desired output nicely. Improved converter performance and robustness were expected.展开更多
Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous perfo...Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous performance test under normal weather conditions. This paper proposes an experimental evaluation of MPPT algorithms according to DC-DC converters topologies, under normal operation conditions. Four widely used MPPT algorithms <i><i><span>i.e.</span></i><span></span></i> Perturb and Observe (P & O), Hill Climbing (HC), Fixed step Increment of Conductance (INCF) and Variable step Increment of Conductance (INCV) are implemented using two topologies of DC-DC converters <i><span>i.e.</span></i><span> buck and boost converters. As input variables to the PV systems, recorded irradiance and temperature, and extracted photovoltaic parameters (ideality factor, series resistance and reverse saturation current) were used. The obtained results show that buck converter has a lot of power losses when controlled by each of the four MPPT algorithms. Meanwhile, boost converter presents a stable output power during the whole day. Once more, the results show that INCV algorithm has the best performance.</span>展开更多
The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module wh...The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module when climatic conditions change with different resistive load values. So DC-DC converters must be used with MPPT controller in order to reduce losses in the global PV system. This article focuses on the effect of climatic conditions on design of two components (inductance, capacitance) for three topologies of DC-DC converters commonly used in PV systems. When climatic conditions change, the boundary of inductance and capacitance parameters of DC-DC converter will change. These two parameters must be properly sized to achieve optimal efficiency for each converter. The design optimization is based on two principles: 1) for a steady-state operation in a continuous conduction mode, the inductance value for all choppers must be greater than the maximum value of boundary inductance, and 2) in order to limit the output voltage ripple of DC-DC converter below a desired value, the filter capacitance must be larger than the maximum value of boundary capacitance.展开更多
Wide bandgap(WBG)semiconductors,such as silicon carbide(SiC)and gallium nitride(GaN),exhibit superior physical properties and demonstrate great potential for replacing conventional silicon(Si)semiconductors with WBG t...Wide bandgap(WBG)semiconductors,such as silicon carbide(SiC)and gallium nitride(GaN),exhibit superior physical properties and demonstrate great potential for replacing conventional silicon(Si)semiconductors with WBG technology,pushing the boundaries of power devices to handle higher blocking voltages,switching frequencies,output power levels,and operating temperatures.However,tradeoffs in switching performance and converter efficiency when substituting GaN devices for Si and SiC counterparts are not well-defined,especially in a cascode configuration.Additional research with further detailed investigation and analysis is necessitated for medium-voltage GaN devices in power converter applications.Therefore,the aim of this research is to experimentally investigate the impact of emerging 650/900 V cascode GaN devices on bidirectional dc-dc converters that are suitable for energy storage and distributed renewable energy systems.Dynamic characteristics of Si,SiC,and cascode GaN power devices are examined through the double-pulse test(DPT)circuit at different gate resistance values,device currents,and DC bus voltages.Furthermore,the switching behavior and energy loss as well as the rate of voltage and current changes over the time are studied and analyzed at various operating conditions.A 500 W experimental converter prototype is implemented to validate the benefits of cascode GaN devices on the converter operation and performance.Comprehensive analysis of the power losses and efficiency improvements for Si-based,SiC-based,and GaN-based converters are performed and evaluated as the switching frequency,working temperature,and output power level are in-creased.The experimental results reveal significant improvements in switching performance and energy efficiency from the emerging cascode GaN devices in the bidirectional converters.展开更多
针对输入串联输出并联双有源桥(dual active bridge,DAB)变换器子模块内部参数不匹配导致的功率不平衡,以及单移相(single phase shift,SPS)控制下变换器工作效率低的问题,该文基于拓展移相(extended phase shift,EPS)控制提出一种扰动...针对输入串联输出并联双有源桥(dual active bridge,DAB)变换器子模块内部参数不匹配导致的功率不平衡,以及单移相(single phase shift,SPS)控制下变换器工作效率低的问题,该文基于拓展移相(extended phase shift,EPS)控制提出一种扰动均压(disturbance voltage sharing,DVS)控制策略。通过建立EPS控制下的电流应力解析模型,求解最优电流应力对应下的内外移相比组合。进一步,设计逐级扰动方案,通过扰动模块的外移相比,对各模块内部参数失配时的输入电压进行补偿。DVS控制策略在实现串并联模块间功率平衡的前提下,降低变换器电流应力,从而提升变换器的工作效率。此外,由于无需在每个控制环路中增设输入电压传感器,系统结构更为简化,硬件成本更低。最后,通过仿真和实验验证了所提控制策略的正确性和有效性。展开更多
In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A ...In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A two-loop control is employed for a buck converter. The robustness of the sliding mode controlled buck converter system is tested for step load changes and input voltage variations. The theoretical predictions are validated by means of simulations. Matlab/Simulink is used for the simulations. The simulation results are presented. The buck converter is tested with operating point changes and parameter uncertainties. Fast dynamic response of the output voltage and robustness to load and input voltage variations are obtained.展开更多
Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circui...Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circuit response;moreover it is convenient for controller design purpose. Due to simple and effective methodology, average state space is the most common method among the modelling methods. In this paper a bidirectional full bridge converter is modelled by average state space and for each mode of operations a controller is designed. Attained mathematical model results are in a close agreement with detailed circuit simulation.展开更多
This paper presents a simple and systematic approach to design second order sliding mode controller for buck converters.The second order sliding mode control(SOSMC)based on twisting algorithm has been implemented to c...This paper presents a simple and systematic approach to design second order sliding mode controller for buck converters.The second order sliding mode control(SOSMC)based on twisting algorithm has been implemented to control buck switch mode converter.The idea behind this strategy is to suppress chattering and maintain robustness and finite time convergence properties of the output voltage error to the equilibrium point under the load variations and parametric uncertainties.In addition,the influence of the twisting algorithm on the performance of closed-loop system is investigated and compared with other algorithms of first order sliding mode control such as adaptive sliding mode control(ASMC),nonsingular terminal sliding mode control(NTSMC).In comparative evaluation,the transient response of the output voltage with the step change in the load and the start-up response of the output voltage with the step change in the input voltage of buck converter were compared.Experimental results were obtained from a hardware setup constructed in laboratory.Finally,for all of the surveyed control methods,the theoretical considerations,numerical simulations,and experimental measurements from a laboratory prototype are compared for different operating points.It is shown that the proposed twisting method presents an improvement in steady state error and settling time of output voltage during load changes.展开更多
Traditional DC-DC converter topologies interface two power terminals: a source and a load. The construction of diverse and flexible power management and distribution (PMAD) systems with such topologies is governed by ...Traditional DC-DC converter topologies interface two power terminals: a source and a load. The construction of diverse and flexible power management and distribution (PMAD) systems with such topologies is governed by a tight compromise between converter count, efficiency, and control complexity. The broader impact of the current research activity is the development of enhanced power converter systems suitable for a wide range of applications. Potential users of this technology include the designers of portable and stand-alone systems such as laptops, hand-held electronics, and communication repeater stations. High power topology options support the evolution of clean power technologies such as hybrid-electric vehicles (HEV’s) and solar vehicles. DC-DC converter is considered as an advanced environmental issue since it is a greenhouse emission eliminator. By utilizing the advancement of these renewable energy sources, we minimize the use of fossil fuel. Thus, we will have a cleaner and pollution free environment. In this paper, a three-port DC-DC converter is designed and discussed. The converter was built and tested at the energy research laboratory at Taibah University, Al Madinah, KSA.展开更多
As a number of switch combinations are involved in operation of multi converter system, conventional methods for obtaining discrete time large signal model of these converter systems result in a very complex solution....As a number of switch combinations are involved in operation of multi converter system, conventional methods for obtaining discrete time large signal model of these converter systems result in a very complex solution. A simple sampled data technique for modeling distributed dc dc PWM converters system (DCS) was proposed. The resulting model is nonlinear and can be linearized for analysis and design of DCS. These models are also suitable for fast simulation of these networks. As the input and output of dc dc converters are slow varying, suitable model for DCS was obtained in terms of the finite order input/output approximation.展开更多
The multiphase boost DC-DC converter with stable control strategy is presented. Multi- phase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of v...The multiphase boost DC-DC converter with stable control strategy is presented. Multi- phase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of voltage doubler rectifiers on the secondary side of high frequency transformers. The stable control strategy for three phase boost DC-DC converter has been utilized during simulation in this study and this strategy can be extend to N-number of phases. The stable control strategy consists of only three voltage loops, which are sufficient for appropriate and efficient operation of three phase boost DC-DC converter. With the stable control strategy, the equal power balance sharing can be obtained between input and output. The stability of control strategy has been evaluated by simulating the multiphase boost DC-DC converter for the same and mismatch turn ratios of high frequency transformers. The simulation result is good and the objective of the strategy is a- chieved.展开更多
基金This work was supported by China Railway Corporation Science and Technology Research and Development Project(P2021J038).
文摘In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems.
基金supported by the National Natural Science Foundation of China (NSFC) under Grant Nos. 61925110, 61821091, 62004184 and 62234007the Key-Area Research and Development Program of Guangdong Province under Grant No. 2020B010174002
文摘We demonstrate superb large-area verticalβ-Ga_(2)O_(3)SBDs with a Schottky contact area of 1×1 mm^(2)and obtain a high-efficiency DC-DC converter based on the device.Theβ-Ga_(2)O_(3)SBD can obtain a forward current of 8 A with a forward volt-age of 5 V,and has a reverse breakdown voltage of 612 V.The forward turn-on voltage(VF)and the on-resistance(Ron)are 1.17 V and 0.46Ω,respectively.The conversion efficiency of theβ-Ga_(2)O_(3)SBD-based DC-DC converter is 95.81%.This work indicates the great potential of Ga_(2)O_(3)SBDs and relevant circuits in power electronic applications.
文摘This paper proposes the new cascaded series parallel design for improved dynamic performance of DC-DC buck boost converters by a new Sliding Mode Control (SMC) method. The converter is controlled using Sliding Mode Control method that utilizes the converter’s duty ratio to determine the skidding surface. System modeling and simulation results are presented. The results also showed an improved overall performance over typical PID controller, and there was no overshoot or settling time, tracking the desired output nicely. Improved converter performance and robustness were expected.
文摘Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous performance test under normal weather conditions. This paper proposes an experimental evaluation of MPPT algorithms according to DC-DC converters topologies, under normal operation conditions. Four widely used MPPT algorithms <i><i><span>i.e.</span></i><span></span></i> Perturb and Observe (P & O), Hill Climbing (HC), Fixed step Increment of Conductance (INCF) and Variable step Increment of Conductance (INCV) are implemented using two topologies of DC-DC converters <i><span>i.e.</span></i><span> buck and boost converters. As input variables to the PV systems, recorded irradiance and temperature, and extracted photovoltaic parameters (ideality factor, series resistance and reverse saturation current) were used. The obtained results show that buck converter has a lot of power losses when controlled by each of the four MPPT algorithms. Meanwhile, boost converter presents a stable output power during the whole day. Once more, the results show that INCV algorithm has the best performance.</span>
文摘The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module when climatic conditions change with different resistive load values. So DC-DC converters must be used with MPPT controller in order to reduce losses in the global PV system. This article focuses on the effect of climatic conditions on design of two components (inductance, capacitance) for three topologies of DC-DC converters commonly used in PV systems. When climatic conditions change, the boundary of inductance and capacitance parameters of DC-DC converter will change. These two parameters must be properly sized to achieve optimal efficiency for each converter. The design optimization is based on two principles: 1) for a steady-state operation in a continuous conduction mode, the inductance value for all choppers must be greater than the maximum value of boundary inductance, and 2) in order to limit the output voltage ripple of DC-DC converter below a desired value, the filter capacitance must be larger than the maximum value of boundary capacitance.
文摘Wide bandgap(WBG)semiconductors,such as silicon carbide(SiC)and gallium nitride(GaN),exhibit superior physical properties and demonstrate great potential for replacing conventional silicon(Si)semiconductors with WBG technology,pushing the boundaries of power devices to handle higher blocking voltages,switching frequencies,output power levels,and operating temperatures.However,tradeoffs in switching performance and converter efficiency when substituting GaN devices for Si and SiC counterparts are not well-defined,especially in a cascode configuration.Additional research with further detailed investigation and analysis is necessitated for medium-voltage GaN devices in power converter applications.Therefore,the aim of this research is to experimentally investigate the impact of emerging 650/900 V cascode GaN devices on bidirectional dc-dc converters that are suitable for energy storage and distributed renewable energy systems.Dynamic characteristics of Si,SiC,and cascode GaN power devices are examined through the double-pulse test(DPT)circuit at different gate resistance values,device currents,and DC bus voltages.Furthermore,the switching behavior and energy loss as well as the rate of voltage and current changes over the time are studied and analyzed at various operating conditions.A 500 W experimental converter prototype is implemented to validate the benefits of cascode GaN devices on the converter operation and performance.Comprehensive analysis of the power losses and efficiency improvements for Si-based,SiC-based,and GaN-based converters are performed and evaluated as the switching frequency,working temperature,and output power level are in-creased.The experimental results reveal significant improvements in switching performance and energy efficiency from the emerging cascode GaN devices in the bidirectional converters.
文摘针对输入串联输出并联双有源桥(dual active bridge,DAB)变换器子模块内部参数不匹配导致的功率不平衡,以及单移相(single phase shift,SPS)控制下变换器工作效率低的问题,该文基于拓展移相(extended phase shift,EPS)控制提出一种扰动均压(disturbance voltage sharing,DVS)控制策略。通过建立EPS控制下的电流应力解析模型,求解最优电流应力对应下的内外移相比组合。进一步,设计逐级扰动方案,通过扰动模块的外移相比,对各模块内部参数失配时的输入电压进行补偿。DVS控制策略在实现串并联模块间功率平衡的前提下,降低变换器电流应力,从而提升变换器的工作效率。此外,由于无需在每个控制环路中增设输入电压传感器,系统结构更为简化,硬件成本更低。最后,通过仿真和实验验证了所提控制策略的正确性和有效性。
文摘In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A two-loop control is employed for a buck converter. The robustness of the sliding mode controlled buck converter system is tested for step load changes and input voltage variations. The theoretical predictions are validated by means of simulations. Matlab/Simulink is used for the simulations. The simulation results are presented. The buck converter is tested with operating point changes and parameter uncertainties. Fast dynamic response of the output voltage and robustness to load and input voltage variations are obtained.
文摘Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circuit response;moreover it is convenient for controller design purpose. Due to simple and effective methodology, average state space is the most common method among the modelling methods. In this paper a bidirectional full bridge converter is modelled by average state space and for each mode of operations a controller is designed. Attained mathematical model results are in a close agreement with detailed circuit simulation.
文摘This paper presents a simple and systematic approach to design second order sliding mode controller for buck converters.The second order sliding mode control(SOSMC)based on twisting algorithm has been implemented to control buck switch mode converter.The idea behind this strategy is to suppress chattering and maintain robustness and finite time convergence properties of the output voltage error to the equilibrium point under the load variations and parametric uncertainties.In addition,the influence of the twisting algorithm on the performance of closed-loop system is investigated and compared with other algorithms of first order sliding mode control such as adaptive sliding mode control(ASMC),nonsingular terminal sliding mode control(NTSMC).In comparative evaluation,the transient response of the output voltage with the step change in the load and the start-up response of the output voltage with the step change in the input voltage of buck converter were compared.Experimental results were obtained from a hardware setup constructed in laboratory.Finally,for all of the surveyed control methods,the theoretical considerations,numerical simulations,and experimental measurements from a laboratory prototype are compared for different operating points.It is shown that the proposed twisting method presents an improvement in steady state error and settling time of output voltage during load changes.
文摘Traditional DC-DC converter topologies interface two power terminals: a source and a load. The construction of diverse and flexible power management and distribution (PMAD) systems with such topologies is governed by a tight compromise between converter count, efficiency, and control complexity. The broader impact of the current research activity is the development of enhanced power converter systems suitable for a wide range of applications. Potential users of this technology include the designers of portable and stand-alone systems such as laptops, hand-held electronics, and communication repeater stations. High power topology options support the evolution of clean power technologies such as hybrid-electric vehicles (HEV’s) and solar vehicles. DC-DC converter is considered as an advanced environmental issue since it is a greenhouse emission eliminator. By utilizing the advancement of these renewable energy sources, we minimize the use of fossil fuel. Thus, we will have a cleaner and pollution free environment. In this paper, a three-port DC-DC converter is designed and discussed. The converter was built and tested at the energy research laboratory at Taibah University, Al Madinah, KSA.
文摘As a number of switch combinations are involved in operation of multi converter system, conventional methods for obtaining discrete time large signal model of these converter systems result in a very complex solution. A simple sampled data technique for modeling distributed dc dc PWM converters system (DCS) was proposed. The resulting model is nonlinear and can be linearized for analysis and design of DCS. These models are also suitable for fast simulation of these networks. As the input and output of dc dc converters are slow varying, suitable model for DCS was obtained in terms of the finite order input/output approximation.
文摘The multiphase boost DC-DC converter with stable control strategy is presented. Multi- phase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of voltage doubler rectifiers on the secondary side of high frequency transformers. The stable control strategy for three phase boost DC-DC converter has been utilized during simulation in this study and this strategy can be extend to N-number of phases. The stable control strategy consists of only three voltage loops, which are sufficient for appropriate and efficient operation of three phase boost DC-DC converter. With the stable control strategy, the equal power balance sharing can be obtained between input and output. The stability of control strategy has been evaluated by simulating the multiphase boost DC-DC converter for the same and mismatch turn ratios of high frequency transformers. The simulation result is good and the objective of the strategy is a- chieved.