直流微电网以其可靠性高、便于控制、损耗低等优点成为未来家庭的主要供电结构。本研究针对目前已有直流微电网控制策略的不足,研究了基于直流母线信号(DC Bus Signaling,DBS)的控制策略,该控制策略可以最大程度地提高新能源的利用率,...直流微电网以其可靠性高、便于控制、损耗低等优点成为未来家庭的主要供电结构。本研究针对目前已有直流微电网控制策略的不足,研究了基于直流母线信号(DC Bus Signaling,DBS)的控制策略,该控制策略可以最大程度地提高新能源的利用率,采用直流母线信号实现直流微电网的最优控制;通过研究直流微电网的下垂控制实现了同一个电压等级下多个微源的功率分配及电压控制;通过研究各微源变换器的输出特性,实现了储能单元及并网变换器的下垂控制与恒功率平滑切换的控制方法;最后在MATLAB/Simulink中搭建了基于平均模型的直流微电网的仿真模型,对孤岛运行时的控制策略进行了验证,仿真结果表明所设计的控制算法能够实现直流微电网的协调控制。展开更多
A low-power high-linearity linear-in-dB variable gain amplifier（VGA） with novel DC offset calibration loop for direct-conversion receiver（DCR） is proposed.The proposed VGA uses the differential-ramp based techniqu...A low-power high-linearity linear-in-dB variable gain amplifier（VGA） with novel DC offset calibration loop for direct-conversion receiver（DCR） is proposed.The proposed VGA uses the differential-ramp based technique,a digitally programmable gain amplifier（PGA） can be converted to an analog controlled dB-linear VGA. An operational amplifier（OPAMP） utilizing an improved Miller compensation approach is adopted in this VGA design.The proposed VGA shows a 57 dB linear range.The DC offset cancellation（DCOC） loop is based on a continuous-time feedback that includes the Miller effect and a linear range operation MOS transistor to realize high-value capacitors and resistors to solve the DC offset problem,respectively.The proposed approach requires no external components and demonstrates excellent DCOC capability in measurement.Fabricated using SMIC 0.13μm CMOS technology,this VGA dissipates 4.5 mW from a 1.2 V supply voltage while occupying 0.58 mm^2 of chip area including bondpads.In addition,the DCOC circuit shows 500 Hz high pass cutoff frequency（HPCF） and the measured residual DC offset at the output of VGA is less than 2 mV.展开更多
在我国 DC 型企业补充养老保险计划开始建立之时,国际社会正进行着一场对 DC 计划的反思浪潮。DC计划运营效率低下、存在偿付能力风险、降低养老保障覆盖率、加剧养老金收入分配差距等诸多问题开始暴露。多头委托的运作模式、养老金风...在我国 DC 型企业补充养老保险计划开始建立之时,国际社会正进行着一场对 DC 计划的反思浪潮。DC计划运营效率低下、存在偿付能力风险、降低养老保障覆盖率、加剧养老金收入分配差距等诸多问题开始暴露。多头委托的运作模式、养老金风险责任的转移、养老保障的刚性需求是导致 DC 计划产生问题的原因。国际社会普遍认为,DB、DC 两种养老计划,各有利弊,互为补充。鼓励两种模式共同发展、分别对两种计划进行改进、综合使用两种计划是国际上解决养老金问题的三条途径。我国应全面考虑养老金治理结构、偿付能力风险、成本效率、计划流动性、资本市场发展、养老收入分配,以及"历史债务"等因素,建立以 DB 计划为主、DC 计划为辅,鼓励综合创新的企业补充养老保险制度。展开更多
A high-linearity PGA（programmable gain amplifier） with a DC offset calibration loop is proposed.The PGA adopts a differential degeneration structure to vary voltage gain and uses the closed-loop structure including ...A high-linearity PGA（programmable gain amplifier） with a DC offset calibration loop is proposed.The PGA adopts a differential degeneration structure to vary voltage gain and uses the closed-loop structure including the input op-amps to enhance the linearity.A continuous time feedback based DC offset calibration loop is also designed to solve the DC offset problem.This PGA is fabricated by TSMC 0.13μm CMOS technology.The measurements show that the receiver PGA（RXPGA） provides a 64 dB gain range with a step of 1 dB,and the transmitter PGA（TXPGA） covers a 16 dB gain.The RXPGA consumes 18 mA and the TXPGA consumes 7 mA （I and Q path） under a 3.3 V supply.The bandwidth of the multi-stage PGA is higher than 20 MHz.In addition,the DCOC（DC offset cancellation） circuit shows 10 kHz of HPCF（high pass cutoff frequency） and the DCOC settling time is less than 0.45μs.展开更多
文摘直流微电网以其可靠性高、便于控制、损耗低等优点成为未来家庭的主要供电结构。本研究针对目前已有直流微电网控制策略的不足,研究了基于直流母线信号(DC Bus Signaling,DBS)的控制策略,该控制策略可以最大程度地提高新能源的利用率,采用直流母线信号实现直流微电网的最优控制;通过研究直流微电网的下垂控制实现了同一个电压等级下多个微源的功率分配及电压控制;通过研究各微源变换器的输出特性,实现了储能单元及并网变换器的下垂控制与恒功率平滑切换的控制方法;最后在MATLAB/Simulink中搭建了基于平均模型的直流微电网的仿真模型,对孤岛运行时的控制策略进行了验证,仿真结果表明所设计的控制算法能够实现直流微电网的协调控制。
文摘A low-power high-linearity linear-in-dB variable gain amplifier（VGA） with novel DC offset calibration loop for direct-conversion receiver（DCR） is proposed.The proposed VGA uses the differential-ramp based technique,a digitally programmable gain amplifier（PGA） can be converted to an analog controlled dB-linear VGA. An operational amplifier（OPAMP） utilizing an improved Miller compensation approach is adopted in this VGA design.The proposed VGA shows a 57 dB linear range.The DC offset cancellation（DCOC） loop is based on a continuous-time feedback that includes the Miller effect and a linear range operation MOS transistor to realize high-value capacitors and resistors to solve the DC offset problem,respectively.The proposed approach requires no external components and demonstrates excellent DCOC capability in measurement.Fabricated using SMIC 0.13μm CMOS technology,this VGA dissipates 4.5 mW from a 1.2 V supply voltage while occupying 0.58 mm^2 of chip area including bondpads.In addition,the DCOC circuit shows 500 Hz high pass cutoff frequency（HPCF） and the measured residual DC offset at the output of VGA is less than 2 mV.
文摘在我国 DC 型企业补充养老保险计划开始建立之时,国际社会正进行着一场对 DC 计划的反思浪潮。DC计划运营效率低下、存在偿付能力风险、降低养老保障覆盖率、加剧养老金收入分配差距等诸多问题开始暴露。多头委托的运作模式、养老金风险责任的转移、养老保障的刚性需求是导致 DC 计划产生问题的原因。国际社会普遍认为,DB、DC 两种养老计划,各有利弊,互为补充。鼓励两种模式共同发展、分别对两种计划进行改进、综合使用两种计划是国际上解决养老金问题的三条途径。我国应全面考虑养老金治理结构、偿付能力风险、成本效率、计划流动性、资本市场发展、养老收入分配,以及"历史债务"等因素,建立以 DB 计划为主、DC 计划为辅,鼓励综合创新的企业补充养老保险制度。
文摘A high-linearity PGA（programmable gain amplifier） with a DC offset calibration loop is proposed.The PGA adopts a differential degeneration structure to vary voltage gain and uses the closed-loop structure including the input op-amps to enhance the linearity.A continuous time feedback based DC offset calibration loop is also designed to solve the DC offset problem.This PGA is fabricated by TSMC 0.13μm CMOS technology.The measurements show that the receiver PGA（RXPGA） provides a 64 dB gain range with a step of 1 dB,and the transmitter PGA（TXPGA） covers a 16 dB gain.The RXPGA consumes 18 mA and the TXPGA consumes 7 mA （I and Q path） under a 3.3 V supply.The bandwidth of the multi-stage PGA is higher than 20 MHz.In addition,the DCOC（DC offset cancellation） circuit shows 10 kHz of HPCF（high pass cutoff frequency） and the DCOC settling time is less than 0.45μs.
