The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presen...The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presented. The large-signal model of it is also derived. Based on the comprehensive analysis of the system model, the compensator is designed to make the system match better and to improve its dynamic performance and the stability under perturbations. Finally, the design methods and the analysis are verified by simulation and experimental results.展开更多
The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control sy...The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.展开更多
The UPS （uninterruptible power supplies） are essential power infrastructure components of systems designed for critical application, including data centers. High availability achievement is a very important factor r...The UPS （uninterruptible power supplies） are essential power infrastructure components of systems designed for critical application, including data centers. High availability achievement is a very important factor related to UPS performance, consequently to proper critical application functionality. Generally, UPS have a limited input voltage window, referring to the nominal input voltage value. Goal of this paper is to prove larger voltage window, without affecting normal UPS operation. Larger window will result on less commutation, backup and normal mode reduction, and consequently duty time of batteries reduction, too. Thus, under these conditions, it is to be expected availability improvement. The stabilizing node model, applied at UPS＇s control part through this paper is presented. UPS＇s behavior with an implemented stabilizing node is observed at few sites. In order to analyze and conclude about UPS＇s performance under these technical conditions, simulation results are further presented.展开更多
The AC electric arc furnace(EAF)is becoming a core apparatus of the modern steel industry.Nevertheless,it used to be a major threat of power quality in the traditional power supply system.In this paper,a flexible powe...The AC electric arc furnace(EAF)is becoming a core apparatus of the modern steel industry.Nevertheless,it used to be a major threat of power quality in the traditional power supply system.In this paper,a flexible power supply system of the AC EAF is proposed,which is expected to completely alter its inherent cognition of impact load in the power grid.The basics of the power supply for EAF are first reviewed and the novel techniques to enhance the operation flexibility of EAF are introduced.The power circuit and the control structure are then presented,followed by the detailed strategies of various operations fully considering the features of EAF.A large disturbance stability criterion based on the mixed potential theory is also established for the practical application.Both electromagnetic transient simulations using PSCAD and benefit analyses verify the feasibility of the proposed system.展开更多
Purpose In order to make BEPC-II to run at a higher energy,the Institute of High Energy Physics undertook an upgrading project.One of the important factors limiting the energy boost is the power and performance of the...Purpose In order to make BEPC-II to run at a higher energy,the Institute of High Energy Physics undertook an upgrading project.One of the important factors limiting the energy boost is the power and performance of the dipole magnet power supplies;therefore,these four magnet power supplies are developed for the BEPC-II upgrading.Methods The power supplies adopt topologies of thyristor rectifiers to realize a high-power output.In the control unit of each power supply,a digital current closed loop is adopted,and the key components in the feedback loop are thermostatically controlled.In order to improve the performances of the power supplies,analog voltage regulators are added to the inner control loops.Results These four power supplies have been tested and have already been officially used in BEPC-II,and their powers have reached the requirements of the upgrading.The test results of the current stability are described and shown in this paper,which testifies that the stabilities meet the design parameters.Conclusions A digital control is applied to each SCR rectifier control.The performances of the power supplies are improved by the combination of digital current control loops and the analog voltage control loops,which makes the performances of the dipole magnet power supplies meet the requirements of the upgrading project.展开更多
Purpose The high energy photon source(HEPS)uses the on-axial injection scheme.There are two designs in this injection scheme that are critical to the performance of the HEPS injection system.One is the strip line kick...Purpose The high energy photon source(HEPS)uses the on-axial injection scheme.There are two designs in this injection scheme that are critical to the performance of the HEPS injection system.One is the strip line kicker and another is the high voltage fast pulse power supply system.In the high voltage fast pulse power supply system,the design of high voltage power supply is very important.The output voltage stability of high voltage power supply directly affects the stability of the pulse amplitude of the injection system.Methods A high voltage power supply with high output voltage stability is designed in this paper,and the scheme is given.The correctness of the design scheme is verified by simulation experiments.Result A prototype is built for full test.The test results showed that the output voltage stability is lower than 58 ppm.The output voltage is 6.4 mV(f≤3 kHz)/113.2 mV(f>3 kHz).Conclusions The designed high voltage power supply can fully meet the requirements of the HEPS injection system.展开更多
Purpose High Energy Photon Source(HEPS)requires high quality,high energy beam and ultra-low emittance of 0.1 nm·rad,which puts forward high demand for power supply.In this paper,a high-performance corrector magne...Purpose High Energy Photon Source(HEPS)requires high quality,high energy beam and ultra-low emittance of 0.1 nm·rad,which puts forward high demand for power supply.In this paper,a high-performance corrector magnet power supply is developed to calibrate and adjust beam track within a certain bandwidth range to ensure the stability of beam track.Methods The prototype of power supply adopts the new"One control Two"control mode,which adjusts the performance of two power supplies simultaneously based on digital control.Results The experimental results show that the stability of the power supply is lower than 20 ppm,which is far better than the design index.Voltage ripple is less than 10 mV,and other performance indexes meet the physical design requirements,which can well meet the requirements of HEPS construction.Conclusions After a lot of experiments and tests,all the parameters passed the design indicators.The successful development of this power supply has laid a foundation for the successful application of HEPS.展开更多
Purpose This power supply prototype is developed for the quadrupole magnets in the storage ring of HEPS.The project requires a high current stability of these power supplies,in order to master the key technology of th...Purpose This power supply prototype is developed for the quadrupole magnets in the storage ring of HEPS.The project requires a high current stability of these power supplies,in order to master the key technology of this type of power supply in advance,a prototype is made in the project of HEPS test facility.Methods Modularization is used in the prototype’s topology and a combination of digital and analog control is adopted in the closed-loop control.Three control loops are used to improve the output current’s quality.In order to improve the current stability,the key devices in the circuit are under thermostatical controlled.Results The acceptance test results for the NDRC are given in details,which show that all the parameters are better than the design indexes.Conclusions After a lot of experiments and tests,all the parameters of this prototype passed the acceptance test.Among the results,the stability of this prototype achieved 5.2 ppm,the repeatability is 3.2 ppm,and the low-frequency voltage ripples are lower than the requirements of Physicists.The success of this prototype means that the requirements of power supplies in physical design can be met.展开更多
文摘The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presented. The large-signal model of it is also derived. Based on the comprehensive analysis of the system model, the compensator is designed to make the system match better and to improve its dynamic performance and the stability under perturbations. Finally, the design methods and the analysis are verified by simulation and experimental results.
基金supported in part by the ITER Program of China(973 Program)(No.2011GB109002)National Natural Science Foundation of China(No.11275056)
文摘The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.
文摘The UPS （uninterruptible power supplies） are essential power infrastructure components of systems designed for critical application, including data centers. High availability achievement is a very important factor related to UPS performance, consequently to proper critical application functionality. Generally, UPS have a limited input voltage window, referring to the nominal input voltage value. Goal of this paper is to prove larger voltage window, without affecting normal UPS operation. Larger window will result on less commutation, backup and normal mode reduction, and consequently duty time of batteries reduction, too. Thus, under these conditions, it is to be expected availability improvement. The stabilizing node model, applied at UPS＇s control part through this paper is presented. UPS＇s behavior with an implemented stabilizing node is observed at few sites. In order to analyze and conclude about UPS＇s performance under these technical conditions, simulation results are further presented.
基金supported in part by the National Natural Science Foundation of China (No.U1866601)。
文摘The AC electric arc furnace(EAF)is becoming a core apparatus of the modern steel industry.Nevertheless,it used to be a major threat of power quality in the traditional power supply system.In this paper,a flexible power supply system of the AC EAF is proposed,which is expected to completely alter its inherent cognition of impact load in the power grid.The basics of the power supply for EAF are first reviewed and the novel techniques to enhance the operation flexibility of EAF are introduced.The power circuit and the control structure are then presented,followed by the detailed strategies of various operations fully considering the features of EAF.A large disturbance stability criterion based on the mixed potential theory is also established for the practical application.Both electromagnetic transient simulations using PSCAD and benefit analyses verify the feasibility of the proposed system.
文摘Purpose In order to make BEPC-II to run at a higher energy,the Institute of High Energy Physics undertook an upgrading project.One of the important factors limiting the energy boost is the power and performance of the dipole magnet power supplies;therefore,these four magnet power supplies are developed for the BEPC-II upgrading.Methods The power supplies adopt topologies of thyristor rectifiers to realize a high-power output.In the control unit of each power supply,a digital current closed loop is adopted,and the key components in the feedback loop are thermostatically controlled.In order to improve the performances of the power supplies,analog voltage regulators are added to the inner control loops.Results These four power supplies have been tested and have already been officially used in BEPC-II,and their powers have reached the requirements of the upgrading.The test results of the current stability are described and shown in this paper,which testifies that the stabilities meet the design parameters.Conclusions A digital control is applied to each SCR rectifier control.The performances of the power supplies are improved by the combination of digital current control loops and the analog voltage control loops,which makes the performances of the dipole magnet power supplies meet the requirements of the upgrading project.
文摘Purpose The high energy photon source(HEPS)uses the on-axial injection scheme.There are two designs in this injection scheme that are critical to the performance of the HEPS injection system.One is the strip line kicker and another is the high voltage fast pulse power supply system.In the high voltage fast pulse power supply system,the design of high voltage power supply is very important.The output voltage stability of high voltage power supply directly affects the stability of the pulse amplitude of the injection system.Methods A high voltage power supply with high output voltage stability is designed in this paper,and the scheme is given.The correctness of the design scheme is verified by simulation experiments.Result A prototype is built for full test.The test results showed that the output voltage stability is lower than 58 ppm.The output voltage is 6.4 mV(f≤3 kHz)/113.2 mV(f>3 kHz).Conclusions The designed high voltage power supply can fully meet the requirements of the HEPS injection system.
基金supported byNationalNatural Science Foundation of China(12005236).
文摘Purpose High Energy Photon Source(HEPS)requires high quality,high energy beam and ultra-low emittance of 0.1 nm·rad,which puts forward high demand for power supply.In this paper,a high-performance corrector magnet power supply is developed to calibrate and adjust beam track within a certain bandwidth range to ensure the stability of beam track.Methods The prototype of power supply adopts the new"One control Two"control mode,which adjusts the performance of two power supplies simultaneously based on digital control.Results The experimental results show that the stability of the power supply is lower than 20 ppm,which is far better than the design index.Voltage ripple is less than 10 mV,and other performance indexes meet the physical design requirements,which can well meet the requirements of HEPS construction.Conclusions After a lot of experiments and tests,all the parameters passed the design indicators.The successful development of this power supply has laid a foundation for the successful application of HEPS.
文摘Purpose This power supply prototype is developed for the quadrupole magnets in the storage ring of HEPS.The project requires a high current stability of these power supplies,in order to master the key technology of this type of power supply in advance,a prototype is made in the project of HEPS test facility.Methods Modularization is used in the prototype’s topology and a combination of digital and analog control is adopted in the closed-loop control.Three control loops are used to improve the output current’s quality.In order to improve the current stability,the key devices in the circuit are under thermostatical controlled.Results The acceptance test results for the NDRC are given in details,which show that all the parameters are better than the design indexes.Conclusions After a lot of experiments and tests,all the parameters of this prototype passed the acceptance test.Among the results,the stability of this prototype achieved 5.2 ppm,the repeatability is 3.2 ppm,and the low-frequency voltage ripples are lower than the requirements of Physicists.The success of this prototype means that the requirements of power supplies in physical design can be met.
