Reliable electricity infrastructure is critical for modern society,highlighting the importance of securing the stability of fundamental power electronic systems.However,as such systems frequently involve high-current ...Reliable electricity infrastructure is critical for modern society,highlighting the importance of securing the stability of fundamental power electronic systems.However,as such systems frequently involve high-current and high-voltage conditions,there is a greater likelihood of failures.Consequently,anomaly detection of power electronic systems holds great significance,which is a task that properly-designed neural networks can well undertake,as proven in various scenarios.Transformer-like networks are promising for such application,yet with its structure initially designed for different tasks,features extracted by beginning layers are often lost,decreasing detection performance.Also,such data-driven methods typically require sufficient anomalous data for training,which could be difficult to obtain in practice.Therefore,to improve feature utilization while achieving efficient unsupervised learning,a novel model,Densely-connected Decoder Transformer(DDformer),is proposed for unsupervised anomaly detection of power electronic systems in this paper.First,efficient labelfree training is achieved based on the concept of autoencoder with recursive-free output.An encoder-decoder structure with densely-connected decoder is then adopted,merging features from all encoder layers to avoid possible loss of mined features while reducing training difficulty.Both simulation and real-world experiments are conducted to validate the capabilities of DDformer,and the average FDR has surpassed baseline models,reaching 89.39%,93.91%,95.98%in different experiment setups respectively.展开更多
New electric power systems characterized by a high proportion of renewable energy and power electronics equipment face significant challenges due to high-frequency(HF)electromagnetic interference from the high-speed s...New electric power systems characterized by a high proportion of renewable energy and power electronics equipment face significant challenges due to high-frequency(HF)electromagnetic interference from the high-speed switching of power converters.To address this situation,this paper offers an in-depth review of HF interference problems and challenges originating from power electronic devices.First,the root cause of HF electromagnetic interference,i.e.,the resonant response of the parasitic parameters of the system to high-speed switching transients,is analyzed,and various scenarios of HF interference in power systems are highlighted.Next,the types of HF interference are summarized,with a focus on common-mode interference in grounding systems.This paper thoroughly reviews and compares various suppression methods for conducted HF interference.Finally,the challenges involved and suggestions for addressing emerging HF interference problems from the perspective of both power electronics equipment and power systems are discussed.This review aims to offer a structured understanding of HF interference problems and their suppression techniques for researchers and practitioners.展开更多
As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devic...As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devices,particularly transformers in switched-mode power supplies.Testing flyback converters with transformers under strong background magnetic fields highlights electromagnetic compatibility(EMC)issues for such switched-mode power supplies.This study utilizes finite element analysis software to simulate the electromagnetic environment of switched-mode power supply transformers and investigates the impact of variations in different magnetic field parameters on the performance of switched-mode power supplies under strong stray magnetic fields.The findings indicate that EMC issues are associated with transformer core saturation and can be alleviated through appropriate configurations of the core size,air gap,fillet radius,and installation direction.This study offers novel solutions for addressing EMC issues in high magnetic field environments.展开更多
Cu nanoparticles exhibit excellent properties as high-temperature-resistant,conductive,heat-dissipating,and connecting materials.However,their susceptibility to oxidation poses a major challenge to the production of h...Cu nanoparticles exhibit excellent properties as high-temperature-resistant,conductive,heat-dissipating,and connecting materials.However,their susceptibility to oxidation poses a major challenge to the production of high-quality sintered bodies in the air,severely limiting their widespread adoption in power electronics packaging.This study presents a novel approach to the synthesis of Cu nanoparticles capped with oleylamine ligands.By employing a simple solvent-cleaning process,effective control of the density of oleylamine ligands on particle surfaces was achieved,resulting in high-performance Cu nanoparticles with both oxidation resistance and air-sintering susceptibility.Moreover,through our research,the solvent-cleaning mechanism was clarified,a model for the oleylamine ligand decomposition was developed,the air-sintering behavior of Cu nanoparticles was analyzed,and the impacts of both the sintered bodies and interfaces on the sintering performance were explained.Additionally,Cu nanoparticles subjected to 5 cleaning rounds followed by sintering at 280℃and 5 MPa in air were confirmed to be able to produce the highest shear strength(49.2±3.51 MPa)and lowest resistivity(6.15±0.32μΩ·cm).Based on these results,flexible capacitive pressure sensors with Cu sintered electrodes were fabricated and demonstrated a stable pressure-capacitance response over the temperature range of 25-250℃.These findings underscore the impressive robustness and durability of sintered structures and the potential for high-temperature applications of oleylamine-capped Cu nanoparticles.Our study provides reliable application demonstrations for the low-cost manufacture of high-performance power electronics packaging structures that can operate in high-current-density,high-heat-flow-density,high-temperature,and high-stress environments.展开更多
The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building elec...The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building electrical engineering and power electronics technology,investigates the main power electronics technology used in building electrical engineering,introduces the teaching content of current power electronics course,analyzes the insufficiency of current teaching content related to the practice of electrical engineering,and proposes the principles and directions for the reformation and innovation of the teaching content of the course of power electronics for the major of building electricity and intelligence.展开更多
Reliability is a persistent challenge in power electronics, with component failures significantly compromising system performance. Capacitors, widely used in power converters for filtering, contribute to approximately...Reliability is a persistent challenge in power electronics, with component failures significantly compromising system performance. Capacitors, widely used in power converters for filtering, contribute to approximately 30% of failures, predominantly due to electrochemical corrosion leading to capacitance degradation and catastrophic breakdowns. This paper presents a novel capacitor-free solid-state power filter(SSPF) for three-phase inverters, offering a transformative approach to mitigate reliability issues associated with conventional inductor-capacitor(LC) and active output filters(AOFs). Unlike AOFs, which depend on compact LC structures, the SSPF eliminates capacitors entirely, circumventing their inherent failure modes. Leveraging advanced solid-state devices and transformer technology, the SSPF achieves superior filtering performance, enhances system reliability, and significantly reduces component count, utilizing half the metal-oxidesemiconductor field effect transistor(MOSFET) switches required by AOFs. This design not only lowers costs but also improves efficiency. Simulation and experimental results demonstrate the SSPF's capability to deliver a sinusoidal output voltage at the fundamental frequency. These attributes position the SSPF as a robust, cost-effective, and innovative solution for modern power electronics applications.展开更多
The dynamics of network power response play a crucial role in system stability.However,the integration of power electronic equipment leads to amplitude and angular frequency(abbreviated as"frequency")time-va...The dynamics of network power response play a crucial role in system stability.However,the integration of power electronic equipment leads to amplitude and angular frequency(abbreviated as"frequency")time-varying characteristics of the node voltage during dynamic processes.As a result,traditional calcu-lation methods for and characteristics of the power response of the network based on phasor and impe-dance lose their validity.Therefore,this paper undertakes mathematical calculations to reveal the power response of a network under excitation by voltage with time-varying amplitude and frequency(TVAF),relying on the original mathematical relationships and superimposed step response.Then,the multi-timescale characteristics of both the active and reactive power of the network are explored physically.Additionally,this paper reveals a new phenomenon of storing and releasing the active and reactive power of the network.To meet practical engineering requirements,a simplified power expression is presented.Finally,the theoretical analysis is validated through time-domain simulations.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
The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a s...The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a sample.Finite element method is used to evaluate the temperature distribution in power modules.The precise electrothermal model is obtained by fitting the curve of transient thermal impedance with a finite series of exponential terms,in which,the thermal-coupling effect among chips is considered as a prediction of the highest transient temperature of the chips.This model can be used in many thermal monitoring systems.Both ANSYS and PSPICE si- mulation software have been employed,and the simulation results agree with the experimental ones very well.展开更多
This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched disturbances.The aim of this paper is to present a review of SMC describing the k...Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched disturbances.The aim of this paper is to present a review of SMC describing the key developments and examining the new trends and challenges for its application to power electronic systems.The fundamental theory of SMC is briefly reviewed and the key technical problems associated with the implementation of SMC to power converters and drives,such chattering phenomenon and variable switching frequency,are discussed and analyzed.The recent developments in SMC systems,future challenges and perspectives of SMC for power converters are discussed.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
In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its i...In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its internal components affects the performance of the system.The stability and reliability of an energy system can be improved by studying the fault diagnosis of power electronic circuits.Therefore,an algorithm based on adaptive simulated annealing particle swarm optimization(ASAPSO)was used in the present study to optimize a backpropagation(BP)neural network employed for the online fault diagnosis of a power electronic circuit.We built a circuit simulation model in MATLAB to obtain its DC output voltage.Using Fourier analysis,we extracted fault features.These were normalized as training samples and input to an unoptimized BP neural network and BP neural networks optimized by particle swarm optimization(PSO)and the ASAPSO algorithm.The accuracy of fault diagnosis was compared for the three networks.The simulation results demonstrate that a BP neural network optimized with the ASAPSO algorithm has higher fault diagnosis accuracy,better reliability,and adaptability and can more effectively diagnose and locate faults in power electronic circuits.展开更多
Through the inspiration of the reliability mechanism of human body, it is obvious that the bionic methods can be used as a reference for the optimized design of high power plasma inverter. On this basis, the high powe...Through the inspiration of the reliability mechanism of human body, it is obvious that the bionic methods can be used as a reference for the optimized design of high power plasma inverter. On this basis, the high power plasma inverter can be composed of several high power density intelligent power electric building blocks （ IPEBB ） , which are controlled by intelligent controller with the capability of self-management and can be regarded as the cell of the inverter. All of these IPEBB can be controllable and cooperative through distributed communication structure with digital control. This structure can be regarded as the nerve of the inverter. In each IPEBB, the advance mechanical feedback mechanism is adopted to suppress the magnetic bins, over-current protection and gate driving for the high power switches. A 75 kW Prototype constructed by IPEBBs was built to test the performance. Experimental results verify the feasibility of the proposed approach, and the bionic design methods can benefit the optimized design of high power plasma inverter.展开更多
At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important i...At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important indicator of power electronic device designing,losses have always been the focus of attention.At present,the losses are generally measured through experiments,but it takes a lot of time and is difficult to quantitatively analyze the internal distribution of PET losses.To solve the above problems,this article first qualitatively analyzes the losses of power electronic devices and proposes a loss calculation method based on pure simulation.This method uses the Discrete State Event Driven(DSED)modeling method to solve the problem of slow simulation speed of large-capacity power electronic devices and uses a loss calculation method that considers the operating conditions of the device to improve the calculation accuracy.For the PET prototype in this article,a losses model of the PET is established.The comparison of experimental and simulation results verifies the feasibility of the losses model.Then the losses composition of PET was analyzed to provide reference opinions for actual operation.It can help pre-analyze the losses distribution of PET,thereby providing a potential method for improving system efficiency.展开更多
For building Global Energy Interconnection(GEI), it is necessary to implement new breakthroughs on largepower system simulation. Key routes for implementing full electromagnetic transient simulation of large-power sys...For building Global Energy Interconnection(GEI), it is necessary to implement new breakthroughs on largepower system simulation. Key routes for implementing full electromagnetic transient simulation of large-power systems are described in this paper, and a top framework is designed. A combination of the new large time step algorithm and the traditional small-time step algorithm is proposed where both parts A and B are calculated independently. The method for integrating the Norton equivalence of the power electronic system to the entire power grid is proposed. A two-level gird division structure is proposed, which executes a multi-rate parallel calculation among subsystems and element parallel calculation in each subsystem. The initialization method of combining load flow derivation and automatic trial-and-error launching is introduced. The feasibility of the method is demonstrated through a practical power grid example, which lays a foundation for further research.展开更多
A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correl...A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correlative double sampling(CDS),pixel FPN is cancelled and column FPN is stored and eliminated by the sampleand-hold operation of digitally programmable gain amplifier(DPGA).The bandwidth balance technology based on operational amplifier(op-amp) sharing is also introduced to decrease the power dissi...展开更多
Recently,power electronic transformers(PETs)have received widespread attention owing to their flexible networking,diverse operating modes,and abundant control objects.In this study,we established a steady-state model ...Recently,power electronic transformers(PETs)have received widespread attention owing to their flexible networking,diverse operating modes,and abundant control objects.In this study,we established a steady-state model of PETs and applied it to the power flow calculation of AC-DC hybrid systems with PETs,considering the topology,power balance,loss,and control characteristics of multi-port PETs.To address new problems caused by the introduction of the PET port and control equations to the power flow calculation,this study proposes an iterative method of AC-DC mixed power flow decoupling based on step optimization,which can achieve AC-DC decoupling and effectively improve convergence.The results show that the proposed algorithm improves the iterative method and overcomes the overcorrection and initial value sensitivity problems of conventional iterative algorithms.展开更多
The AC/DC hybrid distribution network is one of the trends in distribution network development, which poses great challenges to the traditional distribution transformer. In this paper, a new topology suitable for AC/D...The AC/DC hybrid distribution network is one of the trends in distribution network development, which poses great challenges to the traditional distribution transformer. In this paper, a new topology suitable for AC/DC hybrid distribution network is put forward according to the demands of power grid, with advantages of accepting DG and DC loads, while clearing DC fault by blocking the clamping double sub-module(CDSM) of input stage. Then, this paper shows the typical structure of AC/DC distribution network that is hand in hand. Based on the new topology, this paper designs the control and modulation strategies of each stage, where the outer loop controller of input stage is emphasized for its twocontrol mode. At last, the rationality of new topology and the validity of control strategies are verified by the steady and dynamic state simulation. At the same time, the simulation results highlight the role of PET in energy regulation.展开更多
This paper presents a current control method for a shunt hybrid active power filter （HAPF） using recursive integral PI algorithm. The method improves the performance of the HAPF system by reducing the influence of d...This paper presents a current control method for a shunt hybrid active power filter （HAPF） using recursive integral PI algorithm. The method improves the performance of the HAPF system by reducing the influence of detection accuracy, time delay of instruction current calculation and phase displacement of output filter. Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability. The proposed algorithm is easy to implement for engineering applications and easy to compute. Experiment results have verified the validity of the proposed controller. Furthermore, the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant 62303090,U2330206in part by the Postdoctoral Science Foundation of China under Grant 2023M740516+1 种基金in part by the Natural Science Foundation of Sichuan Province under Grant 2024NSFSC1480in part by the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Reliable electricity infrastructure is critical for modern society,highlighting the importance of securing the stability of fundamental power electronic systems.However,as such systems frequently involve high-current and high-voltage conditions,there is a greater likelihood of failures.Consequently,anomaly detection of power electronic systems holds great significance,which is a task that properly-designed neural networks can well undertake,as proven in various scenarios.Transformer-like networks are promising for such application,yet with its structure initially designed for different tasks,features extracted by beginning layers are often lost,decreasing detection performance.Also,such data-driven methods typically require sufficient anomalous data for training,which could be difficult to obtain in practice.Therefore,to improve feature utilization while achieving efficient unsupervised learning,a novel model,Densely-connected Decoder Transformer(DDformer),is proposed for unsupervised anomaly detection of power electronic systems in this paper.First,efficient labelfree training is achieved based on the concept of autoencoder with recursive-free output.An encoder-decoder structure with densely-connected decoder is then adopted,merging features from all encoder layers to avoid possible loss of mined features while reducing training difficulty.Both simulation and real-world experiments are conducted to validate the capabilities of DDformer,and the average FDR has surpassed baseline models,reaching 89.39%,93.91%,95.98%in different experiment setups respectively.
基金supported by the science and technology project of State Grid Shanghai Municipal Electric Power Company(No.52094023003L).
文摘New electric power systems characterized by a high proportion of renewable energy and power electronics equipment face significant challenges due to high-frequency(HF)electromagnetic interference from the high-speed switching of power converters.To address this situation,this paper offers an in-depth review of HF interference problems and challenges originating from power electronic devices.First,the root cause of HF electromagnetic interference,i.e.,the resonant response of the parasitic parameters of the system to high-speed switching transients,is analyzed,and various scenarios of HF interference in power systems are highlighted.Next,the types of HF interference are summarized,with a focus on common-mode interference in grounding systems.This paper thoroughly reviews and compares various suppression methods for conducted HF interference.Finally,the challenges involved and suggestions for addressing emerging HF interference problems from the perspective of both power electronics equipment and power systems are discussed.This review aims to offer a structured understanding of HF interference problems and their suppression techniques for researchers and practitioners.
基金supported by the Natural Science Foundation of Anhui Province(No.228085ME142)the Comprehensive Research Facility for the Fusion Technology Program of China(No.20180000527301001228)the Open Fund of the Magnetic Confinement Fusion Laboratory of Anhui Province(No.2024AMF04003)。
文摘As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devices,particularly transformers in switched-mode power supplies.Testing flyback converters with transformers under strong background magnetic fields highlights electromagnetic compatibility(EMC)issues for such switched-mode power supplies.This study utilizes finite element analysis software to simulate the electromagnetic environment of switched-mode power supply transformers and investigates the impact of variations in different magnetic field parameters on the performance of switched-mode power supplies under strong stray magnetic fields.The findings indicate that EMC issues are associated with transformer core saturation and can be alleviated through appropriate configurations of the core size,air gap,fillet radius,and installation direction.This study offers novel solutions for addressing EMC issues in high magnetic field environments.
基金supported by the Natural Science Foundation of Fujian Province(No.2022J01044)the Digital Twin and Intelligent Transportation Maintenance Engineering Research Centre of Genting Applied Technology R&D Platform at Xiamen City University.
文摘Cu nanoparticles exhibit excellent properties as high-temperature-resistant,conductive,heat-dissipating,and connecting materials.However,their susceptibility to oxidation poses a major challenge to the production of high-quality sintered bodies in the air,severely limiting their widespread adoption in power electronics packaging.This study presents a novel approach to the synthesis of Cu nanoparticles capped with oleylamine ligands.By employing a simple solvent-cleaning process,effective control of the density of oleylamine ligands on particle surfaces was achieved,resulting in high-performance Cu nanoparticles with both oxidation resistance and air-sintering susceptibility.Moreover,through our research,the solvent-cleaning mechanism was clarified,a model for the oleylamine ligand decomposition was developed,the air-sintering behavior of Cu nanoparticles was analyzed,and the impacts of both the sintered bodies and interfaces on the sintering performance were explained.Additionally,Cu nanoparticles subjected to 5 cleaning rounds followed by sintering at 280℃and 5 MPa in air were confirmed to be able to produce the highest shear strength(49.2±3.51 MPa)and lowest resistivity(6.15±0.32μΩ·cm).Based on these results,flexible capacitive pressure sensors with Cu sintered electrodes were fabricated and demonstrated a stable pressure-capacitance response over the temperature range of 25-250℃.These findings underscore the impressive robustness and durability of sintered structures and the potential for high-temperature applications of oleylamine-capped Cu nanoparticles.Our study provides reliable application demonstrations for the low-cost manufacture of high-performance power electronics packaging structures that can operate in high-current-density,high-heat-flow-density,high-temperature,and high-stress environments.
基金Cloud Course of Beijing University of Civil Engineering and Architecture at Super Star Learning(YC240109)。
文摘The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building electrical engineering and power electronics technology,investigates the main power electronics technology used in building electrical engineering,introduces the teaching content of current power electronics course,analyzes the insufficiency of current teaching content related to the practice of electrical engineering,and proposes the principles and directions for the reformation and innovation of the teaching content of the course of power electronics for the major of building electricity and intelligence.
基金curruntly supported by the Purdue University Office of Technology Commercialization under Track Code (PRF 71167-01)。
文摘Reliability is a persistent challenge in power electronics, with component failures significantly compromising system performance. Capacitors, widely used in power converters for filtering, contribute to approximately 30% of failures, predominantly due to electrochemical corrosion leading to capacitance degradation and catastrophic breakdowns. This paper presents a novel capacitor-free solid-state power filter(SSPF) for three-phase inverters, offering a transformative approach to mitigate reliability issues associated with conventional inductor-capacitor(LC) and active output filters(AOFs). Unlike AOFs, which depend on compact LC structures, the SSPF eliminates capacitors entirely, circumventing their inherent failure modes. Leveraging advanced solid-state devices and transformer technology, the SSPF achieves superior filtering performance, enhances system reliability, and significantly reduces component count, utilizing half the metal-oxidesemiconductor field effect transistor(MOSFET) switches required by AOFs. This design not only lowers costs but also improves efficiency. Simulation and experimental results demonstrate the SSPF's capability to deliver a sinusoidal output voltage at the fundamental frequency. These attributes position the SSPF as a robust, cost-effective, and innovative solution for modern power electronics applications.
基金supported in part by the National Natural Science Fundation of China(52225704 and 52107096).
文摘The dynamics of network power response play a crucial role in system stability.However,the integration of power electronic equipment leads to amplitude and angular frequency(abbreviated as"frequency")time-varying characteristics of the node voltage during dynamic processes.As a result,traditional calcu-lation methods for and characteristics of the power response of the network based on phasor and impe-dance lose their validity.Therefore,this paper undertakes mathematical calculations to reveal the power response of a network under excitation by voltage with time-varying amplitude and frequency(TVAF),relying on the original mathematical relationships and superimposed step response.Then,the multi-timescale characteristics of both the active and reactive power of the network are explored physically.Additionally,this paper reveals a new phenomenon of storing and releasing the active and reactive power of the network.To meet practical engineering requirements,a simplified power expression is presented.Finally,the theoretical analysis is validated through time-domain simulations.
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.
文摘The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a sample.Finite element method is used to evaluate the temperature distribution in power modules.The precise electrothermal model is obtained by fitting the curve of transient thermal impedance with a finite series of exponential terms,in which,the thermal-coupling effect among chips is considered as a prediction of the highest transient temperature of the chips.This model can be used in many thermal monitoring systems.Both ANSYS and PSPICE si- mulation software have been employed,and the simulation results agree with the experimental ones very well.
文摘This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
基金supported in part by the National Key R&D Program of China(2019YFB1312000)the National Natural Science Foundation of China(62022030 and 62033005)+2 种基金the Fundamental Research Funds for the Central Universities(HIT.OCEF.2021005)the Heilongjiang Provincial Natural Science Foundation of China(62033005)the SelfPlanned Task of State Key Laboratory of Advanced Welding and Joining(HIT)。
文摘Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched disturbances.The aim of this paper is to present a review of SMC describing the key developments and examining the new trends and challenges for its application to power electronic systems.The fundamental theory of SMC is briefly reviewed and the key technical problems associated with the implementation of SMC to power converters and drives,such chattering phenomenon and variable switching frequency,are discussed and analyzed.The recent developments in SMC systems,future challenges and perspectives of SMC for power converters are discussed.
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.
基金supported by the 2022 Project for Improving the Basic Research Ability of Young and Middle-aged Teachers in Guangxi Universities(Grant No.2022KY0209).
文摘In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its internal components affects the performance of the system.The stability and reliability of an energy system can be improved by studying the fault diagnosis of power electronic circuits.Therefore,an algorithm based on adaptive simulated annealing particle swarm optimization(ASAPSO)was used in the present study to optimize a backpropagation(BP)neural network employed for the online fault diagnosis of a power electronic circuit.We built a circuit simulation model in MATLAB to obtain its DC output voltage.Using Fourier analysis,we extracted fault features.These were normalized as training samples and input to an unoptimized BP neural network and BP neural networks optimized by particle swarm optimization(PSO)and the ASAPSO algorithm.The accuracy of fault diagnosis was compared for the three networks.The simulation results demonstrate that a BP neural network optimized with the ASAPSO algorithm has higher fault diagnosis accuracy,better reliability,and adaptability and can more effectively diagnose and locate faults in power electronic circuits.
基金Supported by National Natural Science Foundation of China （50805051）, and Guangzhou Support Science and Technology Project （10A41071568）
文摘Through the inspiration of the reliability mechanism of human body, it is obvious that the bionic methods can be used as a reference for the optimized design of high power plasma inverter. On this basis, the high power plasma inverter can be composed of several high power density intelligent power electric building blocks （ IPEBB ） , which are controlled by intelligent controller with the capability of self-management and can be regarded as the cell of the inverter. All of these IPEBB can be controllable and cooperative through distributed communication structure with digital control. This structure can be regarded as the nerve of the inverter. In each IPEBB, the advance mechanical feedback mechanism is adopted to suppress the magnetic bins, over-current protection and gate driving for the high power switches. A 75 kW Prototype constructed by IPEBBs was built to test the performance. Experimental results verify the feasibility of the proposed approach, and the bionic design methods can benefit the optimized design of high power plasma inverter.
基金the National Key Research and Development Program of China(2017YFB0903200).
文摘At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important indicator of power electronic device designing,losses have always been the focus of attention.At present,the losses are generally measured through experiments,but it takes a lot of time and is difficult to quantitatively analyze the internal distribution of PET losses.To solve the above problems,this article first qualitatively analyzes the losses of power electronic devices and proposes a loss calculation method based on pure simulation.This method uses the Discrete State Event Driven(DSED)modeling method to solve the problem of slow simulation speed of large-capacity power electronic devices and uses a loss calculation method that considers the operating conditions of the device to improve the calculation accuracy.For the PET prototype in this article,a losses model of the PET is established.The comparison of experimental and simulation results verifies the feasibility of the losses model.Then the losses composition of PET was analyzed to provide reference opinions for actual operation.It can help pre-analyze the losses distribution of PET,thereby providing a potential method for improving system efficiency.
基金supported by key project of smart grid technology and equipment of national key research and development plan of China (2016YFB0900601)
文摘For building Global Energy Interconnection(GEI), it is necessary to implement new breakthroughs on largepower system simulation. Key routes for implementing full electromagnetic transient simulation of large-power systems are described in this paper, and a top framework is designed. A combination of the new large time step algorithm and the traditional small-time step algorithm is proposed where both parts A and B are calculated independently. The method for integrating the Norton equivalence of the power electronic system to the entire power grid is proposed. A two-level gird division structure is proposed, which executes a multi-rate parallel calculation among subsystems and element parallel calculation in each subsystem. The initialization method of combining load flow derivation and automatic trial-and-error launching is introduced. The feasibility of the method is demonstrated through a practical power grid example, which lays a foundation for further research.
基金Supported by National Natural Science Foundation of China (No.60806010,No.60976030)Tianjin Innovation Special Funds for Science and Technology (No.05FZZDGX00200)
文摘A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correlative double sampling(CDS),pixel FPN is cancelled and column FPN is stored and eliminated by the sampleand-hold operation of digitally programmable gain amplifier(DPGA).The bandwidth balance technology based on operational amplifier(op-amp) sharing is also introduced to decrease the power dissi...
基金supported by the National Key Research and Development Program of China(2017YFB0903300).
文摘Recently,power electronic transformers(PETs)have received widespread attention owing to their flexible networking,diverse operating modes,and abundant control objects.In this study,we established a steady-state model of PETs and applied it to the power flow calculation of AC-DC hybrid systems with PETs,considering the topology,power balance,loss,and control characteristics of multi-port PETs.To address new problems caused by the introduction of the PET port and control equations to the power flow calculation,this study proposes an iterative method of AC-DC mixed power flow decoupling based on step optimization,which can achieve AC-DC decoupling and effectively improve convergence.The results show that the proposed algorithm improves the iterative method and overcomes the overcorrection and initial value sensitivity problems of conventional iterative algorithms.
基金supported by National Key Research and Development Program of China (2016YFB0900500,2017YFB0903100)the State Grid Science and Technology Project (SGRI-DL-F1-51-011)
文摘The AC/DC hybrid distribution network is one of the trends in distribution network development, which poses great challenges to the traditional distribution transformer. In this paper, a new topology suitable for AC/DC hybrid distribution network is put forward according to the demands of power grid, with advantages of accepting DG and DC loads, while clearing DC fault by blocking the clamping double sub-module(CDSM) of input stage. Then, this paper shows the typical structure of AC/DC distribution network that is hand in hand. Based on the new topology, this paper designs the control and modulation strategies of each stage, where the outer loop controller of input stage is emphasized for its twocontrol mode. At last, the rationality of new topology and the validity of control strategies are verified by the steady and dynamic state simulation. At the same time, the simulation results highlight the role of PET in energy regulation.
基金supported by the National Natural Science Foundation of China (No.60774043)
文摘This paper presents a current control method for a shunt hybrid active power filter （HAPF） using recursive integral PI algorithm. The method improves the performance of the HAPF system by reducing the influence of detection accuracy, time delay of instruction current calculation and phase displacement of output filter. Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability. The proposed algorithm is easy to implement for engineering applications and easy to compute. Experiment results have verified the validity of the proposed controller. Furthermore, the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.
