针对永磁风电机组低电压穿越(low voltage ride-through,LVRT)采用改变背靠背变流器控制策略的方法时,存在未考虑因转子转速越限导致机组发生超速脱网的问题,提出了基于变流器控制的LVRT控制策略。基于转子运动方程,推导了能够抑制机组...针对永磁风电机组低电压穿越(low voltage ride-through,LVRT)采用改变背靠背变流器控制策略的方法时,存在未考虑因转子转速越限导致机组发生超速脱网的问题,提出了基于变流器控制的LVRT控制策略。基于转子运动方程,推导了能够抑制机组转子转速越限的机侧变流器有功功率整定计算公式,设计了可降低卸荷电阻使用率的卸荷电阻投切方法,仿真结果验证了该策略的有效性。展开更多
To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Sa...To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae （CAS） was investigated.The CAS beads were characterized by Scanning electron microscope （SEM） and Fourier transformed infrared spectroscopy （FTTR）.The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu（Ⅱ） and Pb（Ⅱ） uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu（Ⅱ） and Pb（Ⅱ） ions in single-component systems with much satisfaction.The experimental adsorption data of Cu（Ⅱ） and Pb（Ⅱ） ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu（lⅡ） ions was more significantly influenced by the presence of the coexistent Pb（Ⅱ） species,while the Pb（Ⅱ） removal was affected slightly by varying the initial concentration of Cu（Ⅱ）.The CAS was successfully regenerated using 1 mol/L HNO3 solution.展开更多
文摘针对永磁风电机组低电压穿越(low voltage ride-through,LVRT)采用改变背靠背变流器控制策略的方法时,存在未考虑因转子转速越限导致机组发生超速脱网的问题,提出了基于变流器控制的LVRT控制策略。基于转子运动方程,推导了能够抑制机组转子转速越限的机侧变流器有功功率整定计算公式,设计了可降低卸荷电阻使用率的卸荷电阻投切方法,仿真结果验证了该策略的有效性。
基金Project(11JJ2031)supported by the Key Project of Natural Science Foundation of Hunan Province,China
文摘To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae （CAS） was investigated.The CAS beads were characterized by Scanning electron microscope （SEM） and Fourier transformed infrared spectroscopy （FTTR）.The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu（Ⅱ） and Pb（Ⅱ） uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu（Ⅱ） and Pb（Ⅱ） ions in single-component systems with much satisfaction.The experimental adsorption data of Cu（Ⅱ） and Pb（Ⅱ） ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu（lⅡ） ions was more significantly influenced by the presence of the coexistent Pb（Ⅱ） species,while the Pb（Ⅱ） removal was affected slightly by varying the initial concentration of Cu（Ⅱ）.The CAS was successfully regenerated using 1 mol/L HNO3 solution.
