With the rapid scaling of superconducting quantum processors,electronic control systems relying on commercial off-the-shelf instruments face critical bottlenecks in signal density,power consumption,and crosstalk mitig...With the rapid scaling of superconducting quantum processors,electronic control systems relying on commercial off-the-shelf instruments face critical bottlenecks in signal density,power consumption,and crosstalk mitigation.Here we present a custom dual-channel direct current(DC)source module(QPower)dedicated to large-scale superconducting quantum processors.The module delivers a voltage range of±7 V with 200 m A maximum current per channel,while achieving the following key performance benchmarks:noise spectral density of√Hz at 10 k Hz,output ripple<500μV_(pp)within 20 MHz bandwidth,and long-term voltage drift<5μVpp over 12 hours.Integrated into the control electronics of a 66-qubit quantum processor,QPower enables qubit coherence time of T_(1)=87.6μs and Ramsey dephasing time of T_(2)=5.1μs,with qubit resonance frequency drift constrained to±40 k Hz during 12-hour operation.This modular design is compact in size and efficient in energy consumption,providing a scalable DC source solution for intermediate-scale quantum processors with stringent noise and stability requirements,with potential extensions to other quantum hardware platforms and precision measurement systems.展开更多
This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availa...This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.展开更多
Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number...Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number of separated DC sources is presented in this paper. Three-phase output voltages of this inverter can easily be balanced because they are synthesized by using the same DC sources. A harmonic reduction method eliminating both the 5th and 7th harmonics is proposed. Finally, comparison results and spectral analysis are presented. Key words multilevel inverter - topology - DC source - harmonic reduction - spectrum Project supported by the Postdoctoral Science Foundation of Shanghai (Grant No. kO7)展开更多
3.SWITCHING ANGLES If the nominal capacitor voltage is chosen as Vdc/2, then one can compute the switching anglesθ1,θ2,andθ3.Following the development,the Fourier series expan- sion of the(staircase)output voltage ...3.SWITCHING ANGLES If the nominal capacitor voltage is chosen as Vdc/2, then one can compute the switching anglesθ1,θ2,andθ3.Following the development,the Fourier series expan- sion of the(staircase)output voltage waveform of the multilevel inverter as shown in Fig.2(a)展开更多
Asymmetric three-phase cascading Trinary-DC source Multilevel Inverter which can achieve reduced harmonics and superior root mean square (RMS) values of the output voltage is proposed. This topology can achieve cascad...Asymmetric three-phase cascading Trinary-DC source Multilevel Inverter which can achieve reduced harmonics and superior root mean square (RMS) values of the output voltage is proposed. This topology can achieve cascaded full bridge inverter operation with dissimilar (unequal) DC Source and it is fired by using variable frequency pulse with modulation technique as a switching strategy. This pulse width modulation switching strategy has a newly adopted multicarrier single reference technique. The performance parameter factors like Form Factor (FF), Crest Factor (CF), Total Harmonic Distortion (THD) and fundamental RMS output voltage (V<sub>RMS</sub>) are estimated by using proposed asymmetrical three-phase cascading multilevel inverter for several modulation indices (0.8 - 1). The research study carries with MATLAB/SIMULINK based simulation and experimental results obtained using appropriate prototype (test board) to prove the viability of the proposed concept.展开更多
为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力...为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力纳入安全约束机组组合(security-constrained unit commitment,SCUC)问题中进行调控。设计日前机组组合、短期实时调节和滚动重调节三段式配合的调度框架,并基于列与约束生成算法(column-andconstraint generation,C&CG)设计三层迭代求解方法。通过该方法解决了传统二阶段鲁棒性机组组合偏于保守的弊端,有效提高了风电消纳。为了充分利用VSC换流站能独立调节有功、无功的优势,在SCUC结果的基础上进行无功电压优化,并基于Benders分解算法进行求解,有效降低了系统网损。最后,将所提模型应用于改进IEEE 30节点系统算例,验证模型的有效性和可行性。展开更多
A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of th...A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.展开更多
为提高风电场交直流混合输电并网的系统性能,提出一种更加灵活的电压源换流器高压直流(voltage source converter based high voltage direct current,VSC-HVDC)控制策略。对于风电场侧电压源换流器,设计了一种新的交流电压–功角控制...为提高风电场交直流混合输电并网的系统性能,提出一种更加灵活的电压源换流器高压直流(voltage source converter based high voltage direct current,VSC-HVDC)控制策略。对于风电场侧电压源换流器,设计了一种新的交流电压–功角控制方法。对于交直流混合输电模式,该方法通过调节风电场交流母线电压与电压源换流器输出电压间的功角来实现定有功功率控制。对于纯柔性直流输电模式,风电场交流母线电压自动被调节为具有恒幅恒频的交流电压,实现了对波动风电的同步输送。该方法中输电模式的变化无需切换控制;另外,通过附加电流高通滤波器增强了对系统谐振的阻尼作用。对电网侧电压源换流器,采用一种新的直接电流矢量控制,使直流电压稳定在参考值上。运用PSCAD/EMTDC仿真软件对分别接入笼型感应发电机(squirrel cage induction generator,SCIG)风电场和双馈感应发电机(doubly fed induction generator,DFIG)风电场的交直流混合输电系统建模仿真。一系列运行条件下的仿真结果验证了控制方法的有效性与可行性。展开更多
直流系统的定有功控制方式牺牲了交流侧系统在发生事故时相互支援的能力。根据电压源型换流器高度可控、灵活高效的特点,提出一种适用于多端柔性直流输电(voltage sourced converter based multi-terminal high voltage direct current,...直流系统的定有功控制方式牺牲了交流侧系统在发生事故时相互支援的能力。根据电压源型换流器高度可控、灵活高效的特点,提出一种适用于多端柔性直流输电(voltage sourced converter based multi-terminal high voltage direct current,VSC-MTDC)互联系统的频率稳定控制策略。该策略不需要站间通信,通过附加频率控制使换流站可对交流侧系统的频率做出响应,通过直流电压斜率控制使多个换流站共同分担直流网络中的不平衡功率,从而实现了一侧交流系统频率发生较大变化时,其余交流系统可通过VSC-MTDC进行功率支援,缓解事故系统的有功不平衡状况。最后通过仿真软件PSCAD/EMTDC进行仿真验证,结果表明所提策略充分利用了VSC-MTDC互联系统的频率调整能力,减小了故障端系统的频率变化量。展开更多
基金Project supported by the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.KQTD20210811090049034)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301703)。
文摘With the rapid scaling of superconducting quantum processors,electronic control systems relying on commercial off-the-shelf instruments face critical bottlenecks in signal density,power consumption,and crosstalk mitigation.Here we present a custom dual-channel direct current(DC)source module(QPower)dedicated to large-scale superconducting quantum processors.The module delivers a voltage range of±7 V with 200 m A maximum current per channel,while achieving the following key performance benchmarks:noise spectral density of√Hz at 10 k Hz,output ripple<500μV_(pp)within 20 MHz bandwidth,and long-term voltage drift<5μVpp over 12 hours.Integrated into the control electronics of a 66-qubit quantum processor,QPower enables qubit coherence time of T_(1)=87.6μs and Ramsey dephasing time of T_(2)=5.1μs,with qubit resonance frequency drift constrained to±40 k Hz during 12-hour operation.This modular design is compact in size and efficient in energy consumption,providing a scalable DC source solution for intermediate-scale quantum processors with stringent noise and stability requirements,with potential extensions to other quantum hardware platforms and precision measurement systems.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.91126004)
文摘This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.
文摘Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number of separated DC sources is presented in this paper. Three-phase output voltages of this inverter can easily be balanced because they are synthesized by using the same DC sources. A harmonic reduction method eliminating both the 5th and 7th harmonics is proposed. Finally, comparison results and spectral analysis are presented. Key words multilevel inverter - topology - DC source - harmonic reduction - spectrum Project supported by the Postdoctoral Science Foundation of Shanghai (Grant No. kO7)
文摘3.SWITCHING ANGLES If the nominal capacitor voltage is chosen as Vdc/2, then one can compute the switching anglesθ1,θ2,andθ3.Following the development,the Fourier series expan- sion of the(staircase)output voltage waveform of the multilevel inverter as shown in Fig.2(a)
文摘Asymmetric three-phase cascading Trinary-DC source Multilevel Inverter which can achieve reduced harmonics and superior root mean square (RMS) values of the output voltage is proposed. This topology can achieve cascaded full bridge inverter operation with dissimilar (unequal) DC Source and it is fired by using variable frequency pulse with modulation technique as a switching strategy. This pulse width modulation switching strategy has a newly adopted multicarrier single reference technique. The performance parameter factors like Form Factor (FF), Crest Factor (CF), Total Harmonic Distortion (THD) and fundamental RMS output voltage (V<sub>RMS</sub>) are estimated by using proposed asymmetrical three-phase cascading multilevel inverter for several modulation indices (0.8 - 1). The research study carries with MATLAB/SIMULINK based simulation and experimental results obtained using appropriate prototype (test board) to prove the viability of the proposed concept.
文摘为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力纳入安全约束机组组合(security-constrained unit commitment,SCUC)问题中进行调控。设计日前机组组合、短期实时调节和滚动重调节三段式配合的调度框架,并基于列与约束生成算法(column-andconstraint generation,C&CG)设计三层迭代求解方法。通过该方法解决了传统二阶段鲁棒性机组组合偏于保守的弊端,有效提高了风电消纳。为了充分利用VSC换流站能独立调节有功、无功的优势,在SCUC结果的基础上进行无功电压优化,并基于Benders分解算法进行求解,有效降低了系统网损。最后,将所提模型应用于改进IEEE 30节点系统算例,验证模型的有效性和可行性。
基金supported by National Natural Science Foundation of China(No.61903291)Shaanxi Province Key R&D Program(No.2022GY-134)。
文摘A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.
文摘为提高风电场交直流混合输电并网的系统性能,提出一种更加灵活的电压源换流器高压直流(voltage source converter based high voltage direct current,VSC-HVDC)控制策略。对于风电场侧电压源换流器,设计了一种新的交流电压–功角控制方法。对于交直流混合输电模式,该方法通过调节风电场交流母线电压与电压源换流器输出电压间的功角来实现定有功功率控制。对于纯柔性直流输电模式,风电场交流母线电压自动被调节为具有恒幅恒频的交流电压,实现了对波动风电的同步输送。该方法中输电模式的变化无需切换控制;另外,通过附加电流高通滤波器增强了对系统谐振的阻尼作用。对电网侧电压源换流器,采用一种新的直接电流矢量控制,使直流电压稳定在参考值上。运用PSCAD/EMTDC仿真软件对分别接入笼型感应发电机(squirrel cage induction generator,SCIG)风电场和双馈感应发电机(doubly fed induction generator,DFIG)风电场的交直流混合输电系统建模仿真。一系列运行条件下的仿真结果验证了控制方法的有效性与可行性。
文摘直流系统的定有功控制方式牺牲了交流侧系统在发生事故时相互支援的能力。根据电压源型换流器高度可控、灵活高效的特点,提出一种适用于多端柔性直流输电(voltage sourced converter based multi-terminal high voltage direct current,VSC-MTDC)互联系统的频率稳定控制策略。该策略不需要站间通信,通过附加频率控制使换流站可对交流侧系统的频率做出响应,通过直流电压斜率控制使多个换流站共同分担直流网络中的不平衡功率,从而实现了一侧交流系统频率发生较大变化时,其余交流系统可通过VSC-MTDC进行功率支援,缓解事故系统的有功不平衡状况。最后通过仿真软件PSCAD/EMTDC进行仿真验证,结果表明所提策略充分利用了VSC-MTDC互联系统的频率调整能力,减小了故障端系统的频率变化量。
