基于扩展等面积准则理论的大容量机组投运对电网暂态稳定性的影响研究

针对电网网架薄弱地区大容量机组的投运可能会造成系统暂态稳定水平降低,导致电网接带负荷能力下降的问题,结合某电网的实际情况,运用等面积准则和扩展等面积准则对该电网HY电厂新增机组后出现的暂态稳定问题进行计算分析,指出在电网规划和设计中应该充分考虑送端电源系统结构、机组出力大小以及该地区短路容量等因素,以避免因送端系统“大机大负荷小网”的结构特点而造成电网暂态稳定水平下降。通过仿真分析,提出可以通过扩建主变压器、控制机组出力、快速切除故障、改善发电机及其励磁调节系统特性、提高领前群机组机端电压和无功出力及切机等措施来提高地区电网的暂态稳定性和接带负荷能力。     

考虑安全稳定约束的电网新能源承载能力分析

基于某电网2022年规划数据,分析并确定了在不同方式安排下考虑电压稳定、功角稳定、频率稳定及热稳定等安全稳定约束的电网新能源承载能力,研究影响承载能力的关键因素及制约因素。分析表明：电网的新能源承载能力与常规机组开机水平、旋转备用容量、负荷水平及联络线功率等关键因素呈现强相关性;随常规机组开机容量变化,影响新能源承载能力的制约因素的表现形式也在发生变化;该电网光伏发电接入点较为分散,受电压安全影响,优先考虑光伏发电的风光组合发电方式,能够提升全网新能源总的承载能力,其结果可服务于电网的规划和调度运行。     

Ultraviolet photodetector based on Au doped TiO2 nanowires array with low dark current

Au nanoparticles doped TiO2 nanowires (NWs) arrays with an average diameter of 100 nm were synthesized through a facile solvothermal method. Thereafter, metal/semiconductor/metal (MSM) structured detectors with Ag electrodes were fabricated on these NWs. The ultraviolet (UV) sensing characteristics of pure TiO2 and Au-doped ones (Au-TiO2) were investigated. Compared with pure TiO2, the Au-TiO2 NWs based device shows a much lower dark current of 1.5 nA at 3 V bias. The low dark current mechanism might be due to the promoted directional transmission of carriers induced by Au doping. The photoresponse is nearly one order of magnitude under 360 nm monochromatic illumination. The Au-TiO2 NWs detector with simple fabrication process, low noise and good overall performance provides a broad way in fabricating UV imaging arrays.