A light source of multi-star simulator capable of background adjustment and magnitude control has been designed.Two integrating spheres are employed as the star-point light source and the background light source respe...A light source of multi-star simulator capable of background adjustment and magnitude control has been designed.Two integrating spheres are employed as the star-point light source and the background light source respectively.A beam splitter prism has been designed to serve as the beam combiner for the star-point and the background light sources,and a mathematical model has been constructed respectively to compute the light flux of the two integrating spheres.A magnitude testing system and a background testing system have been created using low-light illuminometer,luminance meter,and testing instruments to measure the star-point magnitude and the background luminance of the multi-star simulator.The test results suggest that the star-point magnitude is adjustable from0 to+5 m_v,with a simulation precision superior to ±0.026 m_v.The maximum background luminance is 3.8×10~5 cd·m^(-2),and the minimum background luminance is6.4×10^(-2)cd·m^(-2).The designed light source system can meet the requirements for simulating the stellar map with a sky background.展开更多
海上风电交流送出场景下,长距离交流海缆并网使得背景谐波放大问题突出,为此研究了基于静止无功发生器(static var generator,SVG)附加控制的长距离交流海缆送出海上风电场群(offshore wind farms with long-distance ac submarine cabl...海上风电交流送出场景下,长距离交流海缆并网使得背景谐波放大问题突出,为此研究了基于静止无功发生器(static var generator,SVG)附加控制的长距离交流海缆送出海上风电场群(offshore wind farms with long-distance ac submarine cable,OWFs-LACSC)背景谐波抑制策略。首先,分析了OWFs-LACSC背景谐波放大的原理,论述了背景谐波放大与谐振的区别;然后,建立了含SVG和直驱风机的OWFs-LACSC阻抗模型,提出利用Park变换的基频偏移特性可实现单通道抑制两种背景谐波,进而结合这一特性和阻性有源滤波原理,在SVG控制环路中附加控制器,并分析了附加控制的参数可行域;最后,利用国内某OWFs-LACSC模型开展仿真,验证了所提策略的可行性与鲁棒性。展开更多
光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boos...光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boost电路中的占空比、输出负载、电感和电容参数,引入蚁群算法对Boost电路参数进行优化,增强搜索过程的多样性和探索性。采用随机化步长,通过模糊控制器,实现对最大功率点跟踪控制。仿真结果表明,当直流母线电压存在扰动时,所提方法可以迅速作出反应,并将电压恢复到正常水平;当光照强度骤减后,仅需要0.9 s左右的时间就可以稳定在最大功率点附近。展开更多
基金Supported by Jilin Province Key Scientific and Technological Projects(20160204008GX)National Key Laboratory Fund Project(61420020210162002)Changchun University of Science and Technology Innovation Fund(XJJLG-2016-15)
文摘A light source of multi-star simulator capable of background adjustment and magnitude control has been designed.Two integrating spheres are employed as the star-point light source and the background light source respectively.A beam splitter prism has been designed to serve as the beam combiner for the star-point and the background light sources,and a mathematical model has been constructed respectively to compute the light flux of the two integrating spheres.A magnitude testing system and a background testing system have been created using low-light illuminometer,luminance meter,and testing instruments to measure the star-point magnitude and the background luminance of the multi-star simulator.The test results suggest that the star-point magnitude is adjustable from0 to+5 m_v,with a simulation precision superior to ±0.026 m_v.The maximum background luminance is 3.8×10~5 cd·m^(-2),and the minimum background luminance is6.4×10^(-2)cd·m^(-2).The designed light source system can meet the requirements for simulating the stellar map with a sky background.
文摘海上风电交流送出场景下,长距离交流海缆并网使得背景谐波放大问题突出,为此研究了基于静止无功发生器(static var generator,SVG)附加控制的长距离交流海缆送出海上风电场群(offshore wind farms with long-distance ac submarine cable,OWFs-LACSC)背景谐波抑制策略。首先,分析了OWFs-LACSC背景谐波放大的原理,论述了背景谐波放大与谐振的区别;然后,建立了含SVG和直驱风机的OWFs-LACSC阻抗模型,提出利用Park变换的基频偏移特性可实现单通道抑制两种背景谐波,进而结合这一特性和阻性有源滤波原理,在SVG控制环路中附加控制器,并分析了附加控制的参数可行域;最后,利用国内某OWFs-LACSC模型开展仿真,验证了所提策略的可行性与鲁棒性。
文摘光伏新能源发电系统的电能产出受到多种外部条件的影响,包括光照强度、环境温度变化以及局部阴影的遮挡效应,容易导致其MPP(Maximum Power Point,最大功率点)发生漂移,从而难以快速准确地跟踪功率点变化。在低碳背景下,计算发电系统Boost电路中的占空比、输出负载、电感和电容参数,引入蚁群算法对Boost电路参数进行优化,增强搜索过程的多样性和探索性。采用随机化步长,通过模糊控制器,实现对最大功率点跟踪控制。仿真结果表明,当直流母线电压存在扰动时,所提方法可以迅速作出反应,并将电压恢复到正常水平;当光照强度骤减后,仅需要0.9 s左右的时间就可以稳定在最大功率点附近。
