The dependence of the Recombination- Generation( R- G) current on the bulk trap characteristics and sili- con film structure in SOI lateral p+ p- n+ diode has been analyzed num erically by using the simulation tool,D...The dependence of the Recombination- Generation( R- G) current on the bulk trap characteristics and sili- con film structure in SOI lateral p+ p- n+ diode has been analyzed num erically by using the simulation tool,DESSIS- ISE.By varying the bulk trap characteristics such as the trap density and energy level spectrum systematically,the dependence of the R- G current on both of them has been dem onstrated in details.Moreover,the silicon film doping concentration and thickness are changed to make silicon body varies from the fully- depletion m ode into the partial- ly- depletion one.The influence of the transfer of silicon body characteristics on the R- G currenthas also been care- fully examined.A better understanding is obtained of the behavior of bulk trap R- G current in the SOI lateral gat- ed- diode.展开更多
Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is propose...Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.展开更多
Thyristor control phase shifter (TCPS) is one of the new facilities implemented in power network, leading to the development of economically efficient and technically reliable system. This paper introduces the functio...Thyristor control phase shifter (TCPS) is one of the new facilities implemented in power network, leading to the development of economically efficient and technically reliable system. This paper introduces the function of TCPS in power system, describes its working principle and structure, and suggests some simple models used in its study and briefly presents the comparison between different types of TCPSs and their applications.展开更多
The effectiveness of a combination of fault current limiter and thyristor controlled braking resistor on power system stability enhancement and damping turbine shaft torsional oscillations has been studied. If both de...The effectiveness of a combination of fault current limiter and thyristor controlled braking resistor on power system stability enhancement and damping turbine shaft torsional oscillations has been studied. If both devices operate at the same bus, the stabilization control scheme can be carried out continuously and with flexibility. As a result, the fault currents are limited, and the generator disturbances and the turbine shaft torsional oscillations are converged quickly. In this paper, the effectiveness of the combination of both devices has been demonstrated by considering 3LG (three-lines-to-ground) fault in a two-machine infinite bus system. Also, temperature rise effect of both devices with various resistance values and weights has been demonstrated. Simulation results indicate a significant power system stability enhancement and damping turbine shaft torsional oscillations as well as with allowable temperature rise.展开更多
This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Br...This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Braking Resistor (TCBR). This coordination will enhance the stability of the inertial and torsional oscillatory modes. The study is performed on system-I of the second IEEE benchmark for simulation of Sub-Synchronous Oscillations, using eigenvalue analysis and verified by detailed digital simulation. A dynamic fundamental frequency model for TCBR is developed. The pole placement technique is used to design the control system of TCBR and PSS. The shaft torque's following a disturbance is computed and analyzed. The obtained results indicate that substantial damping is achieved by the proposed coordination.展开更多
This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabiliz...This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabilized current. For achieving zero-voltage switching, a transition-mode driver L6561 is utilized to detect the ending of transformer resonance and drive an insulated-gate-bipolar-transistor. As transistor is conducted, rectified direct-current voltage drives the transformer. While transistor is cut off, transformer resonates with a parallel capacitor. Transistor conduction time and magnetron power are controlled with a 16-bit digital signal controller dsPIC30F4011. For widening the working range, transistor conduction time is set to be inversely changed with line-frequency input voltage. To demonstrate the analysis and design of this paper, a 1 kW inverter circuit is built. Experimental results show the feasibility and usefulness of the designed magnetron power supply.展开更多
This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor (TCSC) and based on fault component integr...This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor (TCSC) and based on fault component integrated impedance (FCII) calculated for a transmission line with TCSC and controllable shunt reactor (CSR). The FCII is defined as the ratio of the sum of the fault component voltage phasors of a transmission line with TCSC and CSR to the sum of the fault component current phasors where all the phasors are determined at both line's terminals. It can be used to distinguish internal faults occurring on the line from external ones. If the fault is an external one the FCII reflects the line's capacitive impedance and has large value. If the fault is an internal one on the line the FCII reflects the impedance of the equivalent system and the line and is relatively small. The new pilot protection scheme can be easily set and has the fault phase selection ability and also it is not affected by the capacitive current and the fault transition resistance. It is not sensitive to compensation level and dynamics of TCSC and CSR. The effectiveness of the new scheme is validated against data obtained in ATP simulations and Northwest China 750 kV Project.展开更多
High-resolution flexible electronic devices are widely used in the fields of soft robotics,smart human-machine interaction,and intelligent e-healthcare monitoring due to their mechanical flexibility,ductility,and comp...High-resolution flexible electronic devices are widely used in the fields of soft robotics,smart human-machine interaction,and intelligent e-healthcare monitoring due to their mechanical flexibility,ductility,and compactness.The electrohydrodynamic jet printing(e-jet printing)technique is used for constructing high-resolution and cross-scale flexible electronic devices such as field-effect transistors(FETs),flexible sensors,and flexible displays.As a result,researchers are paying close attention to e-jet printing flexible electronic devices.In this review,we focused on the latest advancements in high-resolution flexible electronics made by e-jet printing technology,including various materials used in e-jet printing inks,the process control of e-jet printing,and their applications.First,we summarized various functional ink materials available for e-jet printing,including organic,inorganic,and hybrid materials.Then,the interface controlling the progress of e-jet printing was discussed in detail,including the physical and chemical properties of the functional ink,the interfacial wettability between the ink and substrate,and the microdroplet injection behavior in a high-voltage field.Additionally,various applications of e-jet printing in the fields of flexible electrodes,FETs,flexible sensors,and flexible displays were demonstrated.Finally,the future problems and potential associated with the development of next generation e-jet printing technology for flexible electronic devices were also presented.展开更多
基金摩托罗拉和北京大学的联合研究项目!"Gated-Diode Method Application Development and Sensitivity Analysis"的资助 (合同号 :MSPSESTL
文摘The dependence of the Recombination- Generation( R- G) current on the bulk trap characteristics and sili- con film structure in SOI lateral p+ p- n+ diode has been analyzed num erically by using the simulation tool,DESSIS- ISE.By varying the bulk trap characteristics such as the trap density and energy level spectrum systematically,the dependence of the R- G current on both of them has been dem onstrated in details.Moreover,the silicon film doping concentration and thickness are changed to make silicon body varies from the fully- depletion m ode into the partial- ly- depletion one.The influence of the transfer of silicon body characteristics on the R- G currenthas also been care- fully examined.A better understanding is obtained of the behavior of bulk trap R- G current in the SOI lateral gat- ed- diode.
基金supported by Program for New Century Excellent Talents in University(NCET)(2008)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality+1 种基金 (PHR(IHLB)) and Beijing Novel Research Star(2005B01)Ministry of Beijing Science and Technology
文摘Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.
文摘Thyristor control phase shifter (TCPS) is one of the new facilities implemented in power network, leading to the development of economically efficient and technically reliable system. This paper introduces the function of TCPS in power system, describes its working principle and structure, and suggests some simple models used in its study and briefly presents the comparison between different types of TCPSs and their applications.
文摘The effectiveness of a combination of fault current limiter and thyristor controlled braking resistor on power system stability enhancement and damping turbine shaft torsional oscillations has been studied. If both devices operate at the same bus, the stabilization control scheme can be carried out continuously and with flexibility. As a result, the fault currents are limited, and the generator disturbances and the turbine shaft torsional oscillations are converged quickly. In this paper, the effectiveness of the combination of both devices has been demonstrated by considering 3LG (three-lines-to-ground) fault in a two-machine infinite bus system. Also, temperature rise effect of both devices with various resistance values and weights has been demonstrated. Simulation results indicate a significant power system stability enhancement and damping turbine shaft torsional oscillations as well as with allowable temperature rise.
文摘This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Braking Resistor (TCBR). This coordination will enhance the stability of the inertial and torsional oscillatory modes. The study is performed on system-I of the second IEEE benchmark for simulation of Sub-Synchronous Oscillations, using eigenvalue analysis and verified by detailed digital simulation. A dynamic fundamental frequency model for TCBR is developed. The pole placement technique is used to design the control system of TCBR and PSS. The shaft torque's following a disturbance is computed and analyzed. The obtained results indicate that substantial damping is achieved by the proposed coordination.
文摘This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabilized current. For achieving zero-voltage switching, a transition-mode driver L6561 is utilized to detect the ending of transformer resonance and drive an insulated-gate-bipolar-transistor. As transistor is conducted, rectified direct-current voltage drives the transformer. While transistor is cut off, transformer resonates with a parallel capacitor. Transistor conduction time and magnetron power are controlled with a 16-bit digital signal controller dsPIC30F4011. For widening the working range, transistor conduction time is set to be inversely changed with line-frequency input voltage. To demonstrate the analysis and design of this paper, a 1 kW inverter circuit is built. Experimental results show the feasibility and usefulness of the designed magnetron power supply.
基金supported by the National Natural Science Foundation of China (Grant Nos.50877061 and 51037005)
文摘This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor (TCSC) and based on fault component integrated impedance (FCII) calculated for a transmission line with TCSC and controllable shunt reactor (CSR). The FCII is defined as the ratio of the sum of the fault component voltage phasors of a transmission line with TCSC and CSR to the sum of the fault component current phasors where all the phasors are determined at both line's terminals. It can be used to distinguish internal faults occurring on the line from external ones. If the fault is an external one the FCII reflects the line's capacitive impedance and has large value. If the fault is an internal one on the line the FCII reflects the impedance of the equivalent system and the line and is relatively small. The new pilot protection scheme can be easily set and has the fault phase selection ability and also it is not affected by the capacitive current and the fault transition resistance. It is not sensitive to compensation level and dynamics of TCSC and CSR. The effectiveness of the new scheme is validated against data obtained in ATP simulations and Northwest China 750 kV Project.
基金supported by the Ministry of Science and Technology of China(2018YFA0703200)the National Natural Science Foundation of China(51973154)the Natural Science Foundation of Tianjin(20JCZDJC00680)。
文摘High-resolution flexible electronic devices are widely used in the fields of soft robotics,smart human-machine interaction,and intelligent e-healthcare monitoring due to their mechanical flexibility,ductility,and compactness.The electrohydrodynamic jet printing(e-jet printing)technique is used for constructing high-resolution and cross-scale flexible electronic devices such as field-effect transistors(FETs),flexible sensors,and flexible displays.As a result,researchers are paying close attention to e-jet printing flexible electronic devices.In this review,we focused on the latest advancements in high-resolution flexible electronics made by e-jet printing technology,including various materials used in e-jet printing inks,the process control of e-jet printing,and their applications.First,we summarized various functional ink materials available for e-jet printing,including organic,inorganic,and hybrid materials.Then,the interface controlling the progress of e-jet printing was discussed in detail,including the physical and chemical properties of the functional ink,the interfacial wettability between the ink and substrate,and the microdroplet injection behavior in a high-voltage field.Additionally,various applications of e-jet printing in the fields of flexible electrodes,FETs,flexible sensors,and flexible displays were demonstrated.Finally,the future problems and potential associated with the development of next generation e-jet printing technology for flexible electronic devices were also presented.