A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measur...A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values.展开更多
Due to the decrease in the number of switches for the four-switch three-phase alternating current-direct current(FSTP AC-DC)converter,it can easily lead to DC-link capacitor voltage imbalance and the system stability ...Due to the decrease in the number of switches for the four-switch three-phase alternating current-direct current(FSTP AC-DC)converter,it can easily lead to DC-link capacitor voltage imbalance and the system stability reduction.In order to solve these problems,a finite control set model predictive control(FCS-MPC)for FSTP AC-DC converters with DC-link capacitor voltage balancing is proposed.In this strategy,in order to facilitate calculation,theαβcoordinate system model is established and all voltage vectors are evaluated by establishing a cost function.During the whole process,phase locked loop(PLL)and complex modulation strategy are not required.In the new established cost function,the additional objective term of suppressing capacitor voltage fluctuation is to eliminate effectively the capacitor voltages oscillations and deviations and improve the system reliability.The simulation results show that the proposed strategy can keep the capacitor voltage balancing and has good dynamic and static performance.展开更多
并联有源电力滤波器SAPF(shunt active power filter)是当前谐波治理的主趋势。为获得高品质的SAPF谐波补偿性能,提出具有鲁棒性的单相数字锁相环,通过乘法鉴相、环路低通滤波、无静差控制、积分取余等环节实现对网侧电压相位的检测;并...并联有源电力滤波器SAPF(shunt active power filter)是当前谐波治理的主趋势。为获得高品质的SAPF谐波补偿性能,提出具有鲁棒性的单相数字锁相环,通过乘法鉴相、环路低通滤波、无静差控制、积分取余等环节实现对网侧电压相位的检测;并设计具有高稳定性的直流侧电压控制器,应用极点配置法确定控制器参数。文中提出的锁相环相位跟踪结果不受电网电压畸变影响,锁相准确,电压控制器相角裕度大、响应速度快,能够兼顾稳态与暂态性能,因此该SAPF系统对电网具有良好的适应性。仿真与实验验证了所提方案的正确性与有效性。展开更多
This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this con...This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.展开更多
电动汽车电气系统需要为常规低压电器及辅助部件供电,为确保整车电量平衡,需对供电系统进行详细的计算和选型。通过对汽车低压电器用电量及电器使用频率系数的分析,计算出DC/DC电压转换器满足纯电动轿车在各工况下所需的功率及蓄电池所...电动汽车电气系统需要为常规低压电器及辅助部件供电,为确保整车电量平衡,需对供电系统进行详细的计算和选型。通过对汽车低压电器用电量及电器使用频率系数的分析,计算出DC/DC电压转换器满足纯电动轿车在各工况下所需的功率及蓄电池所需容量。经过对整车低压用电器用电量的计算,为满足电动汽车对铅酸蓄电池的要求,最终选取功率为2.16 k W的DC/DC电压转换器和容量为20 A·h的铅酸蓄电池。经3万km的可靠性试验,证明该低压供电系统的选型和分析方法可靠有效。展开更多
This paper presents a power supply solution for fully integrated passive radio-frequency identification （RFID） transponder IC, which has been implemented in 0.35μm CMOS technology with embedded EEPROM from Chartere...This paper presents a power supply solution for fully integrated passive radio-frequency identification （RFID） transponder IC, which has been implemented in 0.35μm CMOS technology with embedded EEPROM from Chartered Semiconductor. The proposed AC/DC and DC/DC charge pumps can generate stable output for RFID applications with quite low power dissipation and extremely high pumping efficiency. An analytical model of the voltage multiplier, comparison with other charge pumps, simulation results, and chip testing results are presented.展开更多
By using the output inductors and body capacitances without adding any component compared with hard switching synchronous rectifier,the topology of a soft switched synchronous rectifier with phase-shifted full bridge ...By using the output inductors and body capacitances without adding any component compared with hard switching synchronous rectifier,the topology of a soft switched synchronous rectifier with phase-shifted full bridge zero voltage switching DC/DC converter is proposed. The converter efficiency is maximized due to soft switching of the full bridge MOSFETs and the synchronous MOSFETs, and also the low conduction loss of synchronous MOSFET. The operation principles of the circuit are analyzed in detail and the small-signal model is derived, also the converter dynamic characteristics are analyzed. Frequency responses of transfer functions under different values of transformer primary leakage inductance are discussed. The experimental results were obtained from a 400 V input and 100 A/12 V output DC/DC converter operating at 100 kHz. The results show that the converter efficiency is 2% higher in rated power than traditional diode rectifier.展开更多
文摘A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values.
基金National Natural Science Foundation of China(No.61741508)
文摘Due to the decrease in the number of switches for the four-switch three-phase alternating current-direct current(FSTP AC-DC)converter,it can easily lead to DC-link capacitor voltage imbalance and the system stability reduction.In order to solve these problems,a finite control set model predictive control(FCS-MPC)for FSTP AC-DC converters with DC-link capacitor voltage balancing is proposed.In this strategy,in order to facilitate calculation,theαβcoordinate system model is established and all voltage vectors are evaluated by establishing a cost function.During the whole process,phase locked loop(PLL)and complex modulation strategy are not required.In the new established cost function,the additional objective term of suppressing capacitor voltage fluctuation is to eliminate effectively the capacitor voltages oscillations and deviations and improve the system reliability.The simulation results show that the proposed strategy can keep the capacitor voltage balancing and has good dynamic and static performance.
文摘并联有源电力滤波器SAPF(shunt active power filter)是当前谐波治理的主趋势。为获得高品质的SAPF谐波补偿性能,提出具有鲁棒性的单相数字锁相环,通过乘法鉴相、环路低通滤波、无静差控制、积分取余等环节实现对网侧电压相位的检测;并设计具有高稳定性的直流侧电压控制器,应用极点配置法确定控制器参数。文中提出的锁相环相位跟踪结果不受电网电压畸变影响,锁相准确,电压控制器相角裕度大、响应速度快,能够兼顾稳态与暂态性能,因此该SAPF系统对电网具有良好的适应性。仿真与实验验证了所提方案的正确性与有效性。
文摘This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.
文摘电动汽车电气系统需要为常规低压电器及辅助部件供电,为确保整车电量平衡,需对供电系统进行详细的计算和选型。通过对汽车低压电器用电量及电器使用频率系数的分析,计算出DC/DC电压转换器满足纯电动轿车在各工况下所需的功率及蓄电池所需容量。经过对整车低压用电器用电量的计算,为满足电动汽车对铅酸蓄电池的要求,最终选取功率为2.16 k W的DC/DC电压转换器和容量为20 A·h的铅酸蓄电池。经3万km的可靠性试验,证明该低压供电系统的选型和分析方法可靠有效。
文摘This paper presents a power supply solution for fully integrated passive radio-frequency identification （RFID） transponder IC, which has been implemented in 0.35μm CMOS technology with embedded EEPROM from Chartered Semiconductor. The proposed AC/DC and DC/DC charge pumps can generate stable output for RFID applications with quite low power dissipation and extremely high pumping efficiency. An analytical model of the voltage multiplier, comparison with other charge pumps, simulation results, and chip testing results are presented.
文摘By using the output inductors and body capacitances without adding any component compared with hard switching synchronous rectifier,the topology of a soft switched synchronous rectifier with phase-shifted full bridge zero voltage switching DC/DC converter is proposed. The converter efficiency is maximized due to soft switching of the full bridge MOSFETs and the synchronous MOSFETs, and also the low conduction loss of synchronous MOSFET. The operation principles of the circuit are analyzed in detail and the small-signal model is derived, also the converter dynamic characteristics are analyzed. Frequency responses of transfer functions under different values of transformer primary leakage inductance are discussed. The experimental results were obtained from a 400 V input and 100 A/12 V output DC/DC converter operating at 100 kHz. The results show that the converter efficiency is 2% higher in rated power than traditional diode rectifier.
