A monochromator is important to a beamline for desired monochromatic light. There are three water-cooled double crystal monochromators(DCMs) commissioned in the phase-I beamlines of Shanghai Synchrotron Radiation Faci...A monochromator is important to a beamline for desired monochromatic light. There are three water-cooled double crystal monochromators(DCMs) commissioned in the phase-I beamlines of Shanghai Synchrotron Radiation Facility(SSRF). In this paper, the mechanical principle of the DCMs is introduced. A control system for the monochromator based on the standard architecture for SSRF beamlines is described. To achieve the control requirement precisely, the hardware includes VME(Versa Module Eurocard)-based controller for stepper motors, RS-232-based controllers for micropositioning and piezoelectric actuators. The software is developed with EPICS(Experimental Physics and Industrial Control System) package. Test results have revealed the stability and reliability of the system.展开更多
为了提升电感电流断续模式(discontinuousconductionmode,DCM)下开关电源转换器的瞬态响应性能,提出了一种基于电荷平衡原理和平均电流的差分外推控制方法.以Boost转换器为例,该方法利用采样的输出电压进行差分外推(differential extrap...为了提升电感电流断续模式(discontinuousconductionmode,DCM)下开关电源转换器的瞬态响应性能,提出了一种基于电荷平衡原理和平均电流的差分外推控制方法.以Boost转换器为例,该方法利用采样的输出电压进行差分外推(differential extrapolation,DE),预估负载对电荷的影响,进而通过平衡算法得到电流控制量.相较传统的使用电荷平衡原理的电流控制方法(charge balance principle based current control,CBPC),差分外推控制方法缩短了负载估计的延迟,减小了负载估计误差,为DCM转换器的控制设计提供了有效参考.通过Boost样机实验对比了CBPC控制与DE控制在输入、负载和参考电压发生扰动时的响应波形,结果表明,本文提出的DE控制对扰动的响应更加优异.展开更多
In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (...In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (DCM) is presented. In spite of the many benefits viz. the high voltage transfer gain, the high efficiency, and the reduced inductor current and the capacitor voltage ripples, it natured with non-minimum phase. This characteristic makes the control of NOESLLC cumbersome. Any attempt of direct controlling the output voltage may erupt to instability. To overcome this problem, indirect regulation of the output voltage based on the two-loop controller is devised. The savvy in the inductor current control improves the dynamic response of the output voltage. The FLC is designed for the outer (voltage) loop while the inner (current) loop is controlled by the PIC. For the developed ?19.6 V NOESLLC, the dynamic performances for different perturbations (line, load and component variations) are obtained for PIC plus FLC and compared with PIC plus PIC. The study of two cases is performed at various operating regions by developing the MATLAB/Simulink model.展开更多
基金Supported by the National Facility for Protein Science in Shanghaithe National Natural Science Foundation of China(No.U1232115)
文摘A monochromator is important to a beamline for desired monochromatic light. There are three water-cooled double crystal monochromators(DCMs) commissioned in the phase-I beamlines of Shanghai Synchrotron Radiation Facility(SSRF). In this paper, the mechanical principle of the DCMs is introduced. A control system for the monochromator based on the standard architecture for SSRF beamlines is described. To achieve the control requirement precisely, the hardware includes VME(Versa Module Eurocard)-based controller for stepper motors, RS-232-based controllers for micropositioning and piezoelectric actuators. The software is developed with EPICS(Experimental Physics and Industrial Control System) package. Test results have revealed the stability and reliability of the system.
文摘为了提升电感电流断续模式(discontinuousconductionmode,DCM)下开关电源转换器的瞬态响应性能,提出了一种基于电荷平衡原理和平均电流的差分外推控制方法.以Boost转换器为例,该方法利用采样的输出电压进行差分外推(differential extrapolation,DE),预估负载对电荷的影响,进而通过平衡算法得到电流控制量.相较传统的使用电荷平衡原理的电流控制方法(charge balance principle based current control,CBPC),差分外推控制方法缩短了负载估计的延迟,减小了负载估计误差,为DCM转换器的控制设计提供了有效参考.通过Boost样机实验对比了CBPC控制与DE控制在输入、负载和参考电压发生扰动时的响应波形,结果表明,本文提出的DE控制对扰动的响应更加优异.
文摘In this paper, the design of a proportional integral controller (PIC) plus fuzzy logic controller (FLC) for the negative output elementary super lift Luo converter (NOESLLC) operated in discontinuous conduction mode (DCM) is presented. In spite of the many benefits viz. the high voltage transfer gain, the high efficiency, and the reduced inductor current and the capacitor voltage ripples, it natured with non-minimum phase. This characteristic makes the control of NOESLLC cumbersome. Any attempt of direct controlling the output voltage may erupt to instability. To overcome this problem, indirect regulation of the output voltage based on the two-loop controller is devised. The savvy in the inductor current control improves the dynamic response of the output voltage. The FLC is designed for the outer (voltage) loop while the inner (current) loop is controlled by the PIC. For the developed ?19.6 V NOESLLC, the dynamic performances for different perturbations (line, load and component variations) are obtained for PIC plus FLC and compared with PIC plus PIC. The study of two cases is performed at various operating regions by developing the MATLAB/Simulink model.
