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
The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink e...The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.展开更多
A microgrid is defined as a local electric power distribution system with diverse DG （distributed generation） units, energy storage systems, and loads, which can operate as a part of the distribution system or when ...A microgrid is defined as a local electric power distribution system with diverse DG （distributed generation） units, energy storage systems, and loads, which can operate as a part of the distribution system or when needed can operate in an islanded mode. Energy storage systems play a key role in improving security, stability, and power quality of the microgrid. During grid-connected mode, these storage units are charged from various DG sources as well as the main grid. During islanded mode, DG sources along with the storage units need to supply the load. Power electronic interfaces between the microgrid buses and the storage units should be able to detect the mode of operation, allow seamless transition between the modes, and allow power flow in both directions, while maintaining stability and power quality. An overview of bidirectional converter topologies relevant to microgrid energy storage application and their control strategies will be presented in this paper.展开更多
The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modif...The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modified bi directional class-E resonant dc-dc converter is introduced here in this proposed topology for the application in electric vehicles. The advantages of soft switching techniques have been utilized for making analysis simple. The main advantage here in this system is that it can operate in a wide range of frequencies with minimal switching loss in transistors. This paper elaborates a detailed analysis on converter design and the same has been simulated and verified in Matlab/Simulink.展开更多
In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers pro...In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers process and transmit information,stability and reliability are important.Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability.For the smooth operation of a data center,the power supply must be reliable and uninterrupted.In this study,we summarize the basic principle,topology,switch conversion strategy,and control technology of the existing isolated bidirectional DC-DC converters.Subsequently,existing research results and problems with isolated bidirectional DC-DC converters are reviewed.Finally,future trends in the development of isolated bidirectional DC-DC converters for data centers are presented,which offer valuable insights for solving engineering obstacles and future research directions in the field.展开更多
This paper introduces a tri-state modulation technique for a soft-switching bidirectional DC-DC converter (BDC). This method maintains the soft-switching condition and introduces a freewheeling interval that reduces t...This paper introduces a tri-state modulation technique for a soft-switching bidirectional DC-DC converter (BDC). This method maintains the soft-switching condition and introduces a freewheeling interval that reduces the rise and fall times of the inductor current, effectively suppressing inductor current ripples. Additionally,the tri-state modulation provides an extra degree of freedom, enabling optimization for reduced operating losses. The paper details the operation principles of tri-state modulation in both buck and boost modes and discusses optimization strategies for minimizing losses. An experimental setup is developed to validate the tri-state modulation approach, where switching waveforms and efficiency are measured. The experimental results confirm that the proposed method achieves soft-switching conditions, suppresses inductor current ripples, and provides higher efficiency compared to conventional hard-switching BDC and typical soft-switching BDC.展开更多
This paper presents a quasi-Z-source based isolated bidirectional DC-DC converter(qZIBDC)for renewable energy applications.The converter utilizes a dual active bridge circuit with a quasi-Z-source network on both side...This paper presents a quasi-Z-source based isolated bidirectional DC-DC converter(qZIBDC)for renewable energy applications.The converter utilizes a dual active bridge circuit with a quasi-Z-source network on both sides,so the converter works as buck/boost converter from either side.It has a wider input/output voltage operating range,soft-switching capabilities without additional devices,and higher boost capability than a traditional dual active bridge circuit.Apart from that,shoot-through states are incorporated in its operating cycle to boost the input voltage resulting in high reliability of the proposed converter.Due to the symmetrical structure of the circuit,there is no defined high voltage or low voltage side as in traditional isolated bidirectional DC-DC converter.The operating principle and control strategy of the proposed converter are presented.Simulation and experimental results are provided to verify the effectiveness of the proposed converter topology and its control strategy.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
The primary challenge in renewable-energy utilization is an energy-storage system involving its power converter.The systems have to promise high efficiency,reliability and durability.Also,all of these can be realized ...The primary challenge in renewable-energy utilization is an energy-storage system involving its power converter.The systems have to promise high efficiency,reliability and durability.Also,all of these can be realized at an economical cost.Buck and boost converters connected in parallel can convert power in both directions.It is the basic non-isolated bidirectional topology commonly used with energy-storage systems.The primary issue with the buck-boost non-isolated bidirectional converter is how to enhance its performance,so the modification involving this topology is still conducted.This paper examines 29 proposed converters from 30 research publications published in the last 10 years,the most recent of which focuses on modified non-isolated bidirectional converters based on the buck-boost topology.These are classified into eight modification schemes,which involve adding new components or circuits to the base topology.Each is evaluated against six parameters:the number of components,control complexity,power-rating applications,soft-switching ability,efficiency outcome and capacity to minimize losses.Moreover,each modified non-isolated bidirectional converter was compared from the renewable-energy-based power-generation-source perspective utilized.Based on these studies,researchers might think of ways to improve the buck-boost converter by changing it to make a new non-isolated bidirectional converter that can be used in systems that need it.展开更多
In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law t...In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law that brings the output voltage to the desired level. Due to infinite switching occurring at the desired level, we enhanced the switching control law by allowing a sizeable output voltage ripple. We derived mathematical models that allow one to choose the desired switching frequency. In practice, the existence of the non-ideal properties of the Zeta converter results in steady-state output voltage error. By analyzing the power loss in the zeta converter, we proposed an improved switching control law that eliminates the steady-state output voltage error. The effectiveness of the proposed method is illustrated with simulation results.展开更多
This paper explores pole placement techniques for the 4th order C1 DC-to-DC Buck converter focusing on optimizing various performance metrics. Refinements were made to existing ITAE (Integral of Time-weighted Absolute...This paper explores pole placement techniques for the 4th order C1 DC-to-DC Buck converter focusing on optimizing various performance metrics. Refinements were made to existing ITAE (Integral of Time-weighted Absolute Error) polynomials. Additionally, metrics such as IAE (Integral Absolute Error), ISE (Integral of Square Error), ITSE (Integral of Time Squared Error), a MaxMin metric as well as LQR (Linear Quadratic Regulator) were evaluated. PSO (Particle Swarm Optimization) was employed for metric optimization. Time domain response to a step disturbance input was evaluated. The design which optimized the ISE metric proved to be the best performing, followed by IAE and MaxMin (with equivalent results) and then LQR.展开更多
To prevent sub-harmonic oscillation and improve the stability and load capacity of the system,a piecewise linear slope compensation circuit is designed. Compared with the traditional design, this circuit provides a co...To prevent sub-harmonic oscillation and improve the stability and load capacity of the system,a piecewise linear slope compensation circuit is designed. Compared with the traditional design, this circuit provides a compensation signal whose slope varies from different duty cycles at - 40-85℃ ,and reduces the negative effect of slope compensation on the system＇s load capacity and transient response. A current mode PWM Boost DC-DC converter employing this slope compensation circuit is implemented in a UMC 0.6μm-BCD process. The results indicate that the circuit works well and effectively,and the load capacity is increased by 20%. The chip area of the piecewise linear slope compensation circuit is 0.01mm^2 ,which consumes only 8μA quiescent current,and the efficiency ranges up to 93%.展开更多
The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss a...The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has been designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.展开更多
A current-mode DC-DC buck converter with high stability is presented. The loop gain＇s expression of the current-mode converter is derived by employing an advanced model of a current-mode control converter. After anal...A current-mode DC-DC buck converter with high stability is presented. The loop gain＇s expression of the current-mode converter is derived by employing an advanced model of a current-mode control converter. After analyzing the loop gain＇s expression, which illustrates the method of selecting suitable frequency compensation for the control loop,a novel pole-zero tracking frequency compensation is proposed. Based on theoretical analysis, a DC-DC buck converter with high stability is designed with 0.5μm-CMOS technology. The simulated results reveal that the stability of the converter is independent of the load current and the input voltage. Moreover,the converter provides a full load transient response setting time of less than 5μs and overshoots and undershoots of less than 30mV.展开更多
An integrated 3.3V/1.2V SC DC-DC converter operating under 10MHz with a fixed duty radio of 0.5 is presented.To improve the output current of the converter,CMOS technology is adopted to fabricate the switching devices...An integrated 3.3V/1.2V SC DC-DC converter operating under 10MHz with a fixed duty radio of 0.5 is presented.To improve the output current of the converter,CMOS technology is adopted to fabricate the switching devices,and mutually compensatory circuitry technology is also employed to double the output current furthermore.The simulation results using Hspice simulation software,show that the output currents of a single unit circuit and two unit circuits connected in a mutually compensatory manner of the improved converter is about 12.5mA and 26mA,respectively.The power conversion efficiency of the mutually compensatory circuit can amount to 73%,while its output voltage ripple is less than 1.5%.The converter is fabricated in standard Rohm 0.35μm CMOS technology in Tokyo University of Japan.The test result indicates that the output current of 9.8mA can be obtained from a single unit circuit of the improved converter.展开更多
We present a new hybrid digital pulse-width modulator （DPWM） for digital DC-DC converters that employs a ring-oscillator/counter structure. Based on a temperature/process compensation technique and a novel digital c...We present a new hybrid digital pulse-width modulator （DPWM） for digital DC-DC converters that employs a ring-oscillator/counter structure. Based on a temperature/process compensation technique and a novel digital controller, the proposed DPWM can not only offer temperature/process-independent pulse widths, but also operate at a much higher clock frequency than the existing delay-line/counter DPWM structure. Post-simulation results show that with our DPWM, the system clock frequency reaches 156.9MHz while the worst variation,in a temperature range of 0 to 100℃under all process corners,is only± 9.4%.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
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
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
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The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.
文摘A microgrid is defined as a local electric power distribution system with diverse DG （distributed generation） units, energy storage systems, and loads, which can operate as a part of the distribution system or when needed can operate in an islanded mode. Energy storage systems play a key role in improving security, stability, and power quality of the microgrid. During grid-connected mode, these storage units are charged from various DG sources as well as the main grid. During islanded mode, DG sources along with the storage units need to supply the load. Power electronic interfaces between the microgrid buses and the storage units should be able to detect the mode of operation, allow seamless transition between the modes, and allow power flow in both directions, while maintaining stability and power quality. An overview of bidirectional converter topologies relevant to microgrid energy storage application and their control strategies will be presented in this paper.
文摘The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modified bi directional class-E resonant dc-dc converter is introduced here in this proposed topology for the application in electric vehicles. The advantages of soft switching techniques have been utilized for making analysis simple. The main advantage here in this system is that it can operate in a wide range of frequencies with minimal switching loss in transistors. This paper elaborates a detailed analysis on converter design and the same has been simulated and verified in Matlab/Simulink.
基金Supported by the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province(2022B1515020002).
文摘In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers process and transmit information,stability and reliability are important.Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability.For the smooth operation of a data center,the power supply must be reliable and uninterrupted.In this study,we summarize the basic principle,topology,switch conversion strategy,and control technology of the existing isolated bidirectional DC-DC converters.Subsequently,existing research results and problems with isolated bidirectional DC-DC converters are reviewed.Finally,future trends in the development of isolated bidirectional DC-DC converters for data centers are presented,which offer valuable insights for solving engineering obstacles and future research directions in the field.
基金supported by the National Natural Science Foundation of China(No.52207076)the Natural Science Foundation of Hunan Province(No.2023JJ50025).
文摘This paper introduces a tri-state modulation technique for a soft-switching bidirectional DC-DC converter (BDC). This method maintains the soft-switching condition and introduces a freewheeling interval that reduces the rise and fall times of the inductor current, effectively suppressing inductor current ripples. Additionally,the tri-state modulation provides an extra degree of freedom, enabling optimization for reduced operating losses. The paper details the operation principles of tri-state modulation in both buck and boost modes and discusses optimization strategies for minimizing losses. An experimental setup is developed to validate the tri-state modulation approach, where switching waveforms and efficiency are measured. The experimental results confirm that the proposed method achieves soft-switching conditions, suppresses inductor current ripples, and provides higher efficiency compared to conventional hard-switching BDC and typical soft-switching BDC.
文摘This paper presents a quasi-Z-source based isolated bidirectional DC-DC converter(qZIBDC)for renewable energy applications.The converter utilizes a dual active bridge circuit with a quasi-Z-source network on both sides,so the converter works as buck/boost converter from either side.It has a wider input/output voltage operating range,soft-switching capabilities without additional devices,and higher boost capability than a traditional dual active bridge circuit.Apart from that,shoot-through states are incorporated in its operating cycle to boost the input voltage resulting in high reliability of the proposed converter.Due to the symmetrical structure of the circuit,there is no defined high voltage or low voltage side as in traditional isolated bidirectional DC-DC converter.The operating principle and control strategy of the proposed converter are presented.Simulation and experimental results are provided to verify the effectiveness of the proposed converter topology and its control strategy.
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.
基金supported and funded by the Higher Education Leading Applied Research(PTUPT)programme of the Ministry of Education,Culture,Research,and Technology of the Republic of Indonesia under contract number 011/PL.PTUPT/BRIn.LPPM/VI/2022the Indonesia Endowment Funds for Education(LPDP),Ministry of Finance of the Republic of Indonesia[number:20200811214083].
文摘The primary challenge in renewable-energy utilization is an energy-storage system involving its power converter.The systems have to promise high efficiency,reliability and durability.Also,all of these can be realized at an economical cost.Buck and boost converters connected in parallel can convert power in both directions.It is the basic non-isolated bidirectional topology commonly used with energy-storage systems.The primary issue with the buck-boost non-isolated bidirectional converter is how to enhance its performance,so the modification involving this topology is still conducted.This paper examines 29 proposed converters from 30 research publications published in the last 10 years,the most recent of which focuses on modified non-isolated bidirectional converters based on the buck-boost topology.These are classified into eight modification schemes,which involve adding new components or circuits to the base topology.Each is evaluated against six parameters:the number of components,control complexity,power-rating applications,soft-switching ability,efficiency outcome and capacity to minimize losses.Moreover,each modified non-isolated bidirectional converter was compared from the renewable-energy-based power-generation-source perspective utilized.Based on these studies,researchers might think of ways to improve the buck-boost converter by changing it to make a new non-isolated bidirectional converter that can be used in systems that need it.
文摘In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law that brings the output voltage to the desired level. Due to infinite switching occurring at the desired level, we enhanced the switching control law by allowing a sizeable output voltage ripple. We derived mathematical models that allow one to choose the desired switching frequency. In practice, the existence of the non-ideal properties of the Zeta converter results in steady-state output voltage error. By analyzing the power loss in the zeta converter, we proposed an improved switching control law that eliminates the steady-state output voltage error. The effectiveness of the proposed method is illustrated with simulation results.
文摘This paper explores pole placement techniques for the 4th order C1 DC-to-DC Buck converter focusing on optimizing various performance metrics. Refinements were made to existing ITAE (Integral of Time-weighted Absolute Error) polynomials. Additionally, metrics such as IAE (Integral Absolute Error), ISE (Integral of Square Error), ITSE (Integral of Time Squared Error), a MaxMin metric as well as LQR (Linear Quadratic Regulator) were evaluated. PSO (Particle Swarm Optimization) was employed for metric optimization. Time domain response to a step disturbance input was evaluated. The design which optimized the ISE metric proved to be the best performing, followed by IAE and MaxMin (with equivalent results) and then LQR.
文摘To prevent sub-harmonic oscillation and improve the stability and load capacity of the system,a piecewise linear slope compensation circuit is designed. Compared with the traditional design, this circuit provides a compensation signal whose slope varies from different duty cycles at - 40-85℃ ,and reduces the negative effect of slope compensation on the system＇s load capacity and transient response. A current mode PWM Boost DC-DC converter employing this slope compensation circuit is implemented in a UMC 0.6μm-BCD process. The results indicate that the circuit works well and effectively,and the load capacity is increased by 20%. The chip area of the piecewise linear slope compensation circuit is 0.01mm^2 ,which consumes only 8μA quiescent current,and the efficiency ranges up to 93%.
文摘The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has been designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.
文摘A current-mode DC-DC buck converter with high stability is presented. The loop gain＇s expression of the current-mode converter is derived by employing an advanced model of a current-mode control converter. After analyzing the loop gain＇s expression, which illustrates the method of selecting suitable frequency compensation for the control loop,a novel pole-zero tracking frequency compensation is proposed. Based on theoretical analysis, a DC-DC buck converter with high stability is designed with 0.5μm-CMOS technology. The simulated results reveal that the stability of the converter is independent of the load current and the input voltage. Moreover,the converter provides a full load transient response setting time of less than 5μs and overshoots and undershoots of less than 30mV.
文摘An integrated 3.3V/1.2V SC DC-DC converter operating under 10MHz with a fixed duty radio of 0.5 is presented.To improve the output current of the converter,CMOS technology is adopted to fabricate the switching devices,and mutually compensatory circuitry technology is also employed to double the output current furthermore.The simulation results using Hspice simulation software,show that the output currents of a single unit circuit and two unit circuits connected in a mutually compensatory manner of the improved converter is about 12.5mA and 26mA,respectively.The power conversion efficiency of the mutually compensatory circuit can amount to 73%,while its output voltage ripple is less than 1.5%.The converter is fabricated in standard Rohm 0.35μm CMOS technology in Tokyo University of Japan.The test result indicates that the output current of 9.8mA can be obtained from a single unit circuit of the improved converter.
文摘We present a new hybrid digital pulse-width modulator （DPWM） for digital DC-DC converters that employs a ring-oscillator/counter structure. Based on a temperature/process compensation technique and a novel digital controller, the proposed DPWM can not only offer temperature/process-independent pulse widths, but also operate at a much higher clock frequency than the existing delay-line/counter DPWM structure. Post-simulation results show that with our DPWM, the system clock frequency reaches 156.9MHz while the worst variation,in a temperature range of 0 to 100℃under all process corners,is only± 9.4%.
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.
