Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters...Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.展开更多
Due to the impact of the novel coronavirus outbreak,universities have adopted online teaching and carried out remote teaching.With the improvement of the epidemic and the approaching of the new school year,the organic...Due to the impact of the novel coronavirus outbreak,universities have adopted online teaching and carried out remote teaching.With the improvement of the epidemic and the approaching of the new school year,the organic connection between online teaching during the epidemic and offline course construction after the epidemic is not only a challenge for tertiary education teachers,but also an urgent issue to be addressed.Therefore,the power electronics course is taken as an example to explore this connection.展开更多
High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-...High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-IPEM）, consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management.展开更多
Modeling and simulation have emerged as an indispensable approach to create numerical experiment platforms and study engineering systems.However,the increasingly complicated systems that engineers face today dramatica...Modeling and simulation have emerged as an indispensable approach to create numerical experiment platforms and study engineering systems.However,the increasingly complicated systems that engineers face today dramatically challenge state-of-the-art modeling and simulation approaches.Such complicated systems,which are composed of not only continuous states but also discrete events,and which contain complex dynamics across multiple timescales,are defined as generalized hybrid systems(GHSs)in this paper.As a representative GHS,megawatt power electronics(MPE)systems have been largely integrated into the modern power grid,but MPE simulation remains a bottleneck due to its unacceptable time cost and poor convergence.To address this challenge,this paper proposes the numerical convex lens approach to achieve state-discretized modeling and simulation of GHSs.This approach transforms conventional time-discretized passive simulations designed for pure-continuous systems into state-discretized selective simulations designed for GHSs.When this approach was applied to a largescale MPE-based renewable energy system,a 1000-fold increase in simulation speed was achieved,in comparison with existing software.Furthermore,the proposed approach uniquely enables the switching transient simulation of a largescale megawatt system with high accuracy,compared with experimental results,and with no convergence concerns.The numerical convex lens approach leads to the highly efficient simulation of intricate GHSs across multiple timescales,and thus significantly extends engineers’capability to study systems with numerical experiments.展开更多
Out of many renewable energy resources, solar energy is one of the conspicuous sources of energy which can supply the increasing demand of energy. As of May 2014, India has an installed PV capacity of 2.5 GW. The sola...Out of many renewable energy resources, solar energy is one of the conspicuous sources of energy which can supply the increasing demand of energy. As of May 2014, India has an installed PV capacity of 2.5 GW. The solar photovoltaic project includes power electronics with high quality performance devices, incorporated with smart energy management principles. Power electronics is used to improve the energy efficiency of apparatus, and help the generation of environmentally clean energy. In this article the explanation of role of power electronics and the discussion about similar and future concepts in solar photovoltaic systems related to reliability and advancement of each technology in India has been presented.展开更多
Power electronics is a new technology of power transmission and control.Compared with the traditional power transmission,non-contact power transmission has the advantages of low wear rate,safety,reliability,convenienc...Power electronics is a new technology of power transmission and control.Compared with the traditional power transmission,non-contact power transmission has the advantages of low wear rate,safety,reliability,convenience and flexibility.In this way,it avoids the problems of friction,wear,aging and so on in the traditional power supply mode,saves a lot of wires,makes up for the shortcomings of the traditional power transmission mode,and has a wider application range.Therefore,it is of great practical significance to study the key technology of power electronic information transmission for promoting the intelligent development of power transmission in China.展开更多
A new structure of integrated low-pass LC filter of DC-DC power converter is proposed in this paper. This filter consists in a circular planar coil enclosed between two ferrites substrates. Mn-Zn ferrite has been chos...A new structure of integrated low-pass LC filter of DC-DC power converter is proposed in this paper. This filter consists in a circular planar coil enclosed between two ferrites substrates. Mn-Zn ferrite has been chosen because of its high permeability and permittivity. In this filter Mn-Zn substrates act not only as a magnetic core but also as a capacitor. In order to reduce the conduction losses in the part of the ferrite used as a capacitor, a particular topology using a blocking layer is proposed. A modelling of the dielectric behaviour of the materials has been performed and injected in a simulation in order to find the resulting LC filter performances and its power range of use. In order to increase the filter efficiency, different solutions have been explored. In particular the inter-turn gap evolution has been optimized to reduce the inter-turn losses. Regarding the bulk losses, BaTiO3?blocking layers have?been added, either upon the ground or the conductor. In this last case a co-firing ferrite tape has been inserted between turns to increase the LC product. Finally the use of low losses Mn-Zn and BaTiO3?has been proposed and the final characteristics (both electrical and dimensional) of our filter have been compared toconventional ones.展开更多
In this paper power electronics used in PV power generation systems have been reviewed and modelled. PV systems need converters for maximum power point tracking, power conditioning, voltage step-up/down as necessary, ...In this paper power electronics used in PV power generation systems have been reviewed and modelled. PV systems need converters for maximum power point tracking, power conditioning, voltage step-up/down as necessary, and for storage charge-controlling. Inverters are needed for AC loads and for utility grid interfacing. The four basic DC-DC converters commonly used with PV systems have been reviewed and modelled. Different DC-AC inverter types and operational architectures have also been reviewed with the two-stage DC-AC inverter, with the point of common coupling (PCC) at the inverter input, suggested as the most cost-effective and efficient architecture for PV-based communal grids. This is because only one inverter is used for the entire system as opposed to an inverter for every module string, resulting in higher efficiencies, low cost, and low harmonic distortions when compared to systems with PCC at AC terminal. The aim of power conversion/inversion is to extract maximum power possible from the PV system and where necessary, to invert it at close to 100% as possible. Highlight: 1) DC-DC converters are necessary for power conditioning in PV systems;2) DC-AC inverters are necessary for AC loads and for utility grid interfacing;3) DC-AC inverters are also used to control the PV systems when grid connected;4) Best inverter configuration cost-effectively and efficiently allows easy system modifications.展开更多
Abstract： This paper presents results from an on-going research project on pressure tolerant power electronics at SINTEF Energy Research, Norway. The driving force for this research is to enable power electronic comp...Abstract： This paper presents results from an on-going research project on pressure tolerant power electronics at SINTEF Energy Research, Norway. The driving force for this research is to enable power electronic components to operate in pressurized dielectric environment. The intended application is the converters for operation down to 3,000 meters ocean depth, primarily for subsea oil and gas processing. The paper focuses on the needed modifications to a general purpose gate driver for IGBT （insulated gate bipolar transistors） that will give pressure tolerance. Adaptations and modifications of the individual driver components are presented.The results from preliminary testing are promising, which shows that the considered adaptations give feasible solutions.展开更多
In the analysis of power electronics system,it is necessary to simulate ordinary differential equations(ODEs)with discontinuities and stiffness.However,there are many difficulties in using traditional discrete-time al...In the analysis of power electronics system,it is necessary to simulate ordinary differential equations(ODEs)with discontinuities and stiffness.However,there are many difficulties in using traditional discrete-time algorithms to solve such equations.Kofman and others presented the quantized state systems(QSS)algorithm in the discrete event system specification(DEVS)formalism.The discretization is applied to the state variables instead of time range in QSS.QSS is efficient to solve ODEs,but it is difficulty to be used when simulating actual power electronics systems with controller’s and other events.Based on the idea of this numerical algorithm and discrete event,a Discrete State Event Driven(DSED)simulation method is presented in this paper,which is fit for simulation of power electronics system.The method is developed to deal with non-linearity,stiffness and multi-time scale of power electronics systems.The DSED simulation method includes event definition,module seperation and modeling,event-driven mechanisms,numerical computation based on QSS,and some other operations.Simulation results verified the effectiveness and validity of the proposed method.展开更多
The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling meth...The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling method but unfortunately water is often undesired due to high voltages or costumer requirements. Two-phase cooling is a promising technology for electronics cooling. It allows using dielectric fluids in passive systems and still benefits from very high heat transfer coefficients. Thermosyphons are a particularly interesting technology in the field of power electronics because it is entirely passive and a simple equipment. ABB has developed a compact thermosyphon heat exchanger based on automotive technology, which uses numerous multi-port extruded tubes with capillary sized channels disposed in parallel and brazed to a heated base plate in order to achieve the desired compactness. The experimental performances of this novel power electronics cooling system are presented with R134a as a working fluid. The influence of several parameters on the performances was studied experimentally： coolant flow rate, coolant temperature, heat load and fluid filling.展开更多
The rapid pace of change in the wide band gap(WBG)power semiconductor area has led to an explosion in potential uses for WBG devices in a huge variety of applications.The applications include automotive,aerospace and ...The rapid pace of change in the wide band gap(WBG)power semiconductor area has led to an explosion in potential uses for WBG devices in a huge variety of applications.The applications include automotive,aerospace and traction applications,as well as grid related or charging systems,with the potential to provide paradigm shifts in performance and efficiency over Silicon devices in current use today.Despite these exciting developments,however,there are still many outstanding challenges for both researchers and industry to solve before WBG technology becomes pervasive.In this paper we will explore some of these challenges and highlight the strengths of WBG devices,some of the specific issues for machine drives and develop some potential solutions for future developments in power electronics.展开更多
Today, new applications of power electronics systems appear in many domains like transport: more electric aircrafts or electric cars. In order to combine power and electronic systems in the same environment or to take...Today, new applications of power electronics systems appear in many domains like transport: more electric aircrafts or electric cars. In order to combine power and electronic systems in the same environment or to take into account norma- tive constraints in term of electromagnetic field exposure for humans, electromagnetic compatibility (EMC) has to be integrated early in the design flow of the complete system (aircraft or car). The shielding is one of the most used solu- tions to avoid unwanted couplings between power systems and their environment. This paper presents a new experi- mental solution to determine the shielding efficiency of new material (composite material or association of different materials) in the frequency range of power electronic systems.展开更多
To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existi...To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existing small-signal stability analysis methods.On this basis,guidance can be provided on determining suitable analysis methods to solve relevant small-signal stability problems in power electronics-dominated power systems(PEDPSs).Various mature methods have been developed to analyze the small-signal stability of PEDPSs,including eigenvalue-based methods,Routh stability criterion,Nyquist/Bode plot based methods,passivity-based methods,positive-net-damping method,lumped impedance-based methods,bifurcation-based methods,etc.In this paper,the application conditions,advantages,and limitations of these criteria in identifying oscillation frequencies and stability margins are reviewed and compared to reveal and explain connections and discrepancies among them.Especially,efforts are devoted to mathematically proving the equivalence between these small-signal stability criteria.Finally,the performance of these criteria is demonstrated and compared in a 4-machine 2-area power system with a wind farm and an IEEE 39-bus power system with 3 wind farms.展开更多
With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of th...With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of this paper is to review the performance of power semiconductor devices,passive components,gate drivers,sensors,and eventually power electronics converters at cryogenic temperatures.By comparing the physical properties of semiconductor materials and the electrical performance of commercial power semiconductor devices,silicon carbide switches show obvious disadvantages due to the increased on-resistance and switching time at cryogenic temperature.In contrast,silicon and gallium nitride devices exhibit improved performance when tem-perature is decreased.The performance ceiling of power semiconductor devices can be influenced by gate drivers,within which the commercial alternatives show deteriorated performance at cryogenic temperature compared to room temperature.Moreover,options for voltage and current sense in cryogenic environments are justified.Based on the cryogenic performance of the various components afore-discussed,this paper ends by presenting an overview of the published converter,which are either partially or fully tested in a cryogenic environment.展开更多
The markedly increased integration of renewable energy in the power grid is of significance in the transition to a sustainable energy future.The grid integration of renewables will be continuously enhanced in the futu...The markedly increased integration of renewable energy in the power grid is of significance in the transition to a sustainable energy future.The grid integration of renewables will be continuously enhanced in the future.According to the International Renewable Energy Agency(IRENA),renewable technology is the main pathway to reach zero carbon dioxide(CO_(2))emissions by 2060.Power electronics have played and will continue to play a significant role in this energy transition by providing efficient electrical energy conversion,distribution,transmission,and utilization.Consequently,the development of power electronics technologies,i.e.,new semiconductor devices,flexible converters,and advanced control schemes,is promoted extensively across the globe.Among various renewables,wind energy and photovoltaic(PV)are the most widely used,and accordingly these are explored in this paper to demonstrate the role of power electronics.The development of renewable energies and the demands of power electronics are reviewed first.Then,the power conversion and control technologies as well as grid codes for wind and PV systems are discussed.Future trends in terms of power semiconductors,reliability,advanced control,grid-forming operation,and security issues for largescale grid integration of renewables,and intelligent and full user engagement are presented at the end.展开更多
Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and systems.Since there is no energy transfer during the course of the usage,r...Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and systems.Since there is no energy transfer during the course of the usage,real-time simulation has a lot of advantages in the process of development and experimentation.From the perspective of real-time simulation,this paper focuses on the main problems in modeling accuracy,system bandwidth and stability,limitations on communication interface and energy interface,and the cost of platform construction.Finally,we provide further research directions.展开更多
Electrifying the transport sector requires new possibilities for power electronics converters to attain reliable and efficient charging solutions for electric vehicles(EVs).With the continuous development in power ele...Electrifying the transport sector requires new possibilities for power electronics converters to attain reliable and efficient charging solutions for electric vehicles(EVs).With the continuous development in power electronics converters,the desire to reduce gasoline consumption and to increase the battery capacity for more electric range is achievable for EVs in the near future.The main interface between the power network and EV battery system is a power electronics converter,therefore,there is a considerable need of new power converters with low cost and high reliability for the advance charging mechanism of EVs.The rapid growth in power converter topologies brings substantial opportunities in EV charging process.In view of this fact,this paper investigates the significant aspects,current progress,and challenges associated with several power converters to suggest further improvements in charging systems of EVs.In particular,an extensive analysis of front-end as well as back-end converter configurations is presented.Moreover,the comparative properties of resonant converter topologies along with other DCDC converters are discussed in detail.Additionally,isolated,and non-isolated topologies with soft switching techniques are classified and rigorously analyzed with a view to their respective issues and benefits.It is foreseen that this paper would be a valuable addition and a worthy source of information for researchers exploring the area of power converter topologies for charging solutions of EVs.展开更多
The concept of a flexible power electronics substation(FPES)was first applied in the Zhangbei DC distribution network demonstration project.As a multi-port power electronics transformer(PET)with different AC and DC vo...The concept of a flexible power electronics substation(FPES)was first applied in the Zhangbei DC distribution network demonstration project.As a multi-port power electronics transformer(PET)with different AC and DC voltage levels,the FPES has adopted a novel topology integrating modular multilevel converter(MMC)and four-winding medium frequency transformer(FWMFT)based multiport DC-DC converter,which can significantly reduce capacitance in each sub-module(SM)of a MMC and also save space and cost.In this paper,in order to accelerate speed of electromagnetic transient(EMT)simulations of FPES based hybrid AC/DC distribution systems,an averaged-value model(AVM)is proposed for efficient and accurate representation of FPES.Assume that all SM capacitor voltages are perfectly balanced in the MMC,then the MMC behavior can be modeled using controlled voltage sources based on modulation voltages from control systems.In terms of the averaged current transfer characteristics among the windings of the FWMFT,we consider that all multiport DC-DC converters are controlled with the same dynamics,a lumped averaged model using controlled current and voltage sources has been developed for these four-port DC-DC converters connected to the upper or lower arms of the MMC.The presented FPES AVM model has been tested and validated by comparison with a detailed IGBT-based EMT model.Results show that the AVM is significantly more efficient while maintaining its accuracy in an EMT simulation.展开更多
文摘Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.
基金the Research and Practice of“Power Electronics Technology”Online Course Construction(kczx202007)the Research of“Power Electronics Technology”Course Blended Teaching Reform(2020yb06)Oriented to the New Engineering Discipline by Higher-Order Learning,which is a university-level project of Qilu University of Technology(Shandong Academy of Sciences).
文摘Due to the impact of the novel coronavirus outbreak,universities have adopted online teaching and carried out remote teaching.With the improvement of the epidemic and the approaching of the new school year,the organic connection between online teaching during the epidemic and offline course construction after the epidemic is not only a challenge for tertiary education teachers,but also an urgent issue to be addressed.Therefore,the power electronics course is taken as an example to explore this connection.
基金Fok Ying Tung Education Foundation(No.91058)the Natural Science Foundation of High Education Institutions of Jiangsu Province(No.08KJD470004)Qing Lan Project of Jiangsu Province of 2008
文摘High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-IPEM）, consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management.
基金the Major Program of National Natural Science Foundation of China(51490683).
文摘Modeling and simulation have emerged as an indispensable approach to create numerical experiment platforms and study engineering systems.However,the increasingly complicated systems that engineers face today dramatically challenge state-of-the-art modeling and simulation approaches.Such complicated systems,which are composed of not only continuous states but also discrete events,and which contain complex dynamics across multiple timescales,are defined as generalized hybrid systems(GHSs)in this paper.As a representative GHS,megawatt power electronics(MPE)systems have been largely integrated into the modern power grid,but MPE simulation remains a bottleneck due to its unacceptable time cost and poor convergence.To address this challenge,this paper proposes the numerical convex lens approach to achieve state-discretized modeling and simulation of GHSs.This approach transforms conventional time-discretized passive simulations designed for pure-continuous systems into state-discretized selective simulations designed for GHSs.When this approach was applied to a largescale MPE-based renewable energy system,a 1000-fold increase in simulation speed was achieved,in comparison with existing software.Furthermore,the proposed approach uniquely enables the switching transient simulation of a largescale megawatt system with high accuracy,compared with experimental results,and with no convergence concerns.The numerical convex lens approach leads to the highly efficient simulation of intricate GHSs across multiple timescales,and thus significantly extends engineers’capability to study systems with numerical experiments.
文摘Out of many renewable energy resources, solar energy is one of the conspicuous sources of energy which can supply the increasing demand of energy. As of May 2014, India has an installed PV capacity of 2.5 GW. The solar photovoltaic project includes power electronics with high quality performance devices, incorporated with smart energy management principles. Power electronics is used to improve the energy efficiency of apparatus, and help the generation of environmentally clean energy. In this article the explanation of role of power electronics and the discussion about similar and future concepts in solar photovoltaic systems related to reliability and advancement of each technology in India has been presented.
文摘Power electronics is a new technology of power transmission and control.Compared with the traditional power transmission,non-contact power transmission has the advantages of low wear rate,safety,reliability,convenience and flexibility.In this way,it avoids the problems of friction,wear,aging and so on in the traditional power supply mode,saves a lot of wires,makes up for the shortcomings of the traditional power transmission mode,and has a wider application range.Therefore,it is of great practical significance to study the key technology of power electronic information transmission for promoting the intelligent development of power transmission in China.
文摘A new structure of integrated low-pass LC filter of DC-DC power converter is proposed in this paper. This filter consists in a circular planar coil enclosed between two ferrites substrates. Mn-Zn ferrite has been chosen because of its high permeability and permittivity. In this filter Mn-Zn substrates act not only as a magnetic core but also as a capacitor. In order to reduce the conduction losses in the part of the ferrite used as a capacitor, a particular topology using a blocking layer is proposed. A modelling of the dielectric behaviour of the materials has been performed and injected in a simulation in order to find the resulting LC filter performances and its power range of use. In order to increase the filter efficiency, different solutions have been explored. In particular the inter-turn gap evolution has been optimized to reduce the inter-turn losses. Regarding the bulk losses, BaTiO3?blocking layers have?been added, either upon the ground or the conductor. In this last case a co-firing ferrite tape has been inserted between turns to increase the LC product. Finally the use of low losses Mn-Zn and BaTiO3?has been proposed and the final characteristics (both electrical and dimensional) of our filter have been compared toconventional ones.
文摘In this paper power electronics used in PV power generation systems have been reviewed and modelled. PV systems need converters for maximum power point tracking, power conditioning, voltage step-up/down as necessary, and for storage charge-controlling. Inverters are needed for AC loads and for utility grid interfacing. The four basic DC-DC converters commonly used with PV systems have been reviewed and modelled. Different DC-AC inverter types and operational architectures have also been reviewed with the two-stage DC-AC inverter, with the point of common coupling (PCC) at the inverter input, suggested as the most cost-effective and efficient architecture for PV-based communal grids. This is because only one inverter is used for the entire system as opposed to an inverter for every module string, resulting in higher efficiencies, low cost, and low harmonic distortions when compared to systems with PCC at AC terminal. The aim of power conversion/inversion is to extract maximum power possible from the PV system and where necessary, to invert it at close to 100% as possible. Highlight: 1) DC-DC converters are necessary for power conditioning in PV systems;2) DC-AC inverters are necessary for AC loads and for utility grid interfacing;3) DC-AC inverters are also used to control the PV systems when grid connected;4) Best inverter configuration cost-effectively and efficiently allows easy system modifications.
文摘Abstract： This paper presents results from an on-going research project on pressure tolerant power electronics at SINTEF Energy Research, Norway. The driving force for this research is to enable power electronic components to operate in pressurized dielectric environment. The intended application is the converters for operation down to 3,000 meters ocean depth, primarily for subsea oil and gas processing. The paper focuses on the needed modifications to a general purpose gate driver for IGBT （insulated gate bipolar transistors） that will give pressure tolerance. Adaptations and modifications of the individual driver components are presented.The results from preliminary testing are promising, which shows that the considered adaptations give feasible solutions.
基金This work was supported by a grant from the National Nature Science Foundation of China(No 51490680,No 51490683)。
文摘In the analysis of power electronics system,it is necessary to simulate ordinary differential equations(ODEs)with discontinuities and stiffness.However,there are many difficulties in using traditional discrete-time algorithms to solve such equations.Kofman and others presented the quantized state systems(QSS)algorithm in the discrete event system specification(DEVS)formalism.The discretization is applied to the state variables instead of time range in QSS.QSS is efficient to solve ODEs,but it is difficulty to be used when simulating actual power electronics systems with controller’s and other events.Based on the idea of this numerical algorithm and discrete event,a Discrete State Event Driven(DSED)simulation method is presented in this paper,which is fit for simulation of power electronics system.The method is developed to deal with non-linearity,stiffness and multi-time scale of power electronics systems.The DSED simulation method includes event definition,module seperation and modeling,event-driven mechanisms,numerical computation based on QSS,and some other operations.Simulation results verified the effectiveness and validity of the proposed method.
文摘The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling method but unfortunately water is often undesired due to high voltages or costumer requirements. Two-phase cooling is a promising technology for electronics cooling. It allows using dielectric fluids in passive systems and still benefits from very high heat transfer coefficients. Thermosyphons are a particularly interesting technology in the field of power electronics because it is entirely passive and a simple equipment. ABB has developed a compact thermosyphon heat exchanger based on automotive technology, which uses numerous multi-port extruded tubes with capillary sized channels disposed in parallel and brazed to a heated base plate in order to achieve the desired compactness. The experimental performances of this novel power electronics cooling system are presented with R134a as a working fluid. The influence of several parameters on the performances was studied experimentally： coolant flow rate, coolant temperature, heat load and fluid filling.
文摘The rapid pace of change in the wide band gap(WBG)power semiconductor area has led to an explosion in potential uses for WBG devices in a huge variety of applications.The applications include automotive,aerospace and traction applications,as well as grid related or charging systems,with the potential to provide paradigm shifts in performance and efficiency over Silicon devices in current use today.Despite these exciting developments,however,there are still many outstanding challenges for both researchers and industry to solve before WBG technology becomes pervasive.In this paper we will explore some of these challenges and highlight the strengths of WBG devices,some of the specific issues for machine drives and develop some potential solutions for future developments in power electronics.
文摘Today, new applications of power electronics systems appear in many domains like transport: more electric aircrafts or electric cars. In order to combine power and electronic systems in the same environment or to take into account norma- tive constraints in term of electromagnetic field exposure for humans, electromagnetic compatibility (EMC) has to be integrated early in the design flow of the complete system (aircraft or car). The shielding is one of the most used solu- tions to avoid unwanted couplings between power systems and their environment. This paper presents a new experi- mental solution to determine the shielding efficiency of new material (composite material or association of different materials) in the frequency range of power electronic systems.
基金supported in part by the National Natural Science Foundation of China for the Research Project(No.52077188)in part by the Hong Kong Research Grant Council for the Research Project(No.15219619).
文摘To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existing small-signal stability analysis methods.On this basis,guidance can be provided on determining suitable analysis methods to solve relevant small-signal stability problems in power electronics-dominated power systems(PEDPSs).Various mature methods have been developed to analyze the small-signal stability of PEDPSs,including eigenvalue-based methods,Routh stability criterion,Nyquist/Bode plot based methods,passivity-based methods,positive-net-damping method,lumped impedance-based methods,bifurcation-based methods,etc.In this paper,the application conditions,advantages,and limitations of these criteria in identifying oscillation frequencies and stability margins are reviewed and compared to reveal and explain connections and discrepancies among them.Especially,efforts are devoted to mathematically proving the equivalence between these small-signal stability criteria.Finally,the performance of these criteria is demonstrated and compared in a 4-machine 2-area power system with a wind farm and an IEEE 39-bus power system with 3 wind farms.
文摘With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of this paper is to review the performance of power semiconductor devices,passive components,gate drivers,sensors,and eventually power electronics converters at cryogenic temperatures.By comparing the physical properties of semiconductor materials and the electrical performance of commercial power semiconductor devices,silicon carbide switches show obvious disadvantages due to the increased on-resistance and switching time at cryogenic temperature.In contrast,silicon and gallium nitride devices exhibit improved performance when tem-perature is decreased.The performance ceiling of power semiconductor devices can be influenced by gate drivers,within which the commercial alternatives show deteriorated performance at cryogenic temperature compared to room temperature.Moreover,options for voltage and current sense in cryogenic environments are justified.Based on the cryogenic performance of the various components afore-discussed,this paper ends by presenting an overview of the published converter,which are either partially or fully tested in a cryogenic environment.
文摘The markedly increased integration of renewable energy in the power grid is of significance in the transition to a sustainable energy future.The grid integration of renewables will be continuously enhanced in the future.According to the International Renewable Energy Agency(IRENA),renewable technology is the main pathway to reach zero carbon dioxide(CO_(2))emissions by 2060.Power electronics have played and will continue to play a significant role in this energy transition by providing efficient electrical energy conversion,distribution,transmission,and utilization.Consequently,the development of power electronics technologies,i.e.,new semiconductor devices,flexible converters,and advanced control schemes,is promoted extensively across the globe.Among various renewables,wind energy and photovoltaic(PV)are the most widely used,and accordingly these are explored in this paper to demonstrate the role of power electronics.The development of renewable energies and the demands of power electronics are reviewed first.Then,the power conversion and control technologies as well as grid codes for wind and PV systems are discussed.Future trends in terms of power semiconductors,reliability,advanced control,grid-forming operation,and security issues for largescale grid integration of renewables,and intelligent and full user engagement are presented at the end.
基金supported by the National Natural Science Foundation of China(No.51707053)the Anhui Provincial Natural Science Foundation(No.1808085QE155)the Fundamental Research Funds for the Central Universities(No.JZ2019HGTB0080)
文摘Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and systems.Since there is no energy transfer during the course of the usage,real-time simulation has a lot of advantages in the process of development and experimentation.From the perspective of real-time simulation,this paper focuses on the main problems in modeling accuracy,system bandwidth and stability,limitations on communication interface and energy interface,and the cost of platform construction.Finally,we provide further research directions.
文摘Electrifying the transport sector requires new possibilities for power electronics converters to attain reliable and efficient charging solutions for electric vehicles(EVs).With the continuous development in power electronics converters,the desire to reduce gasoline consumption and to increase the battery capacity for more electric range is achievable for EVs in the near future.The main interface between the power network and EV battery system is a power electronics converter,therefore,there is a considerable need of new power converters with low cost and high reliability for the advance charging mechanism of EVs.The rapid growth in power converter topologies brings substantial opportunities in EV charging process.In view of this fact,this paper investigates the significant aspects,current progress,and challenges associated with several power converters to suggest further improvements in charging systems of EVs.In particular,an extensive analysis of front-end as well as back-end converter configurations is presented.Moreover,the comparative properties of resonant converter topologies along with other DCDC converters are discussed in detail.Additionally,isolated,and non-isolated topologies with soft switching techniques are classified and rigorously analyzed with a view to their respective issues and benefits.It is foreseen that this paper would be a valuable addition and a worthy source of information for researchers exploring the area of power converter topologies for charging solutions of EVs.
基金This work was supported in part by the National Nature Science Foundation of China(51977142)。
文摘The concept of a flexible power electronics substation(FPES)was first applied in the Zhangbei DC distribution network demonstration project.As a multi-port power electronics transformer(PET)with different AC and DC voltage levels,the FPES has adopted a novel topology integrating modular multilevel converter(MMC)and four-winding medium frequency transformer(FWMFT)based multiport DC-DC converter,which can significantly reduce capacitance in each sub-module(SM)of a MMC and also save space and cost.In this paper,in order to accelerate speed of electromagnetic transient(EMT)simulations of FPES based hybrid AC/DC distribution systems,an averaged-value model(AVM)is proposed for efficient and accurate representation of FPES.Assume that all SM capacitor voltages are perfectly balanced in the MMC,then the MMC behavior can be modeled using controlled voltage sources based on modulation voltages from control systems.In terms of the averaged current transfer characteristics among the windings of the FWMFT,we consider that all multiport DC-DC converters are controlled with the same dynamics,a lumped averaged model using controlled current and voltage sources has been developed for these four-port DC-DC converters connected to the upper or lower arms of the MMC.The presented FPES AVM model has been tested and validated by comparison with a detailed IGBT-based EMT model.Results show that the AVM is significantly more efficient while maintaining its accuracy in an EMT simulation.
