Y型模块化多电平换流器(modular multilevel converter in Y configuration,Y-MMC)的Y形结构,使其预充电及并网过程更为复杂,基于环流控制的一般启动策略不再适用。针对上述问题,设计基于模型预测控制的渐进预充电方法及无扰动并网方法...Y型模块化多电平换流器(modular multilevel converter in Y configuration,Y-MMC)的Y形结构,使其预充电及并网过程更为复杂,基于环流控制的一般启动策略不再适用。针对上述问题,设计基于模型预测控制的渐进预充电方法及无扰动并网方法,提出一种模型预测渐进启动控制策略。首先,建立桥臂电流和电容电压预测模型,通过模型预测控制改变充电电流回路、幅值和相角,实现可控充电最大有功输入,对各个桥臂渐进充电。其次,根据电流误差灵活投切子模块,逐渐平衡充电回路电势差,辅助模型预测控制抑制冲击电流。然后,协调外环比例积分控制与内环模型预测控制,通过切换外环功率和电压控制模式,实现基于Y-MMC的柔性低频输电系统无扰动并网过程。最后,通过Matlab/Simulink对双端柔性低频输电系统进行仿真分析,所提控制策略保障了启动过程较低的电流冲击和较高的充电速度,使系统平稳快速进入稳定运行状态。展开更多
Three parallel lab-scale expanded granular sludge bed(EGSB) reactors were employed to evaluate the start-up process of bio-hydrogen production from molasses wastewater.With other start-up parameters controlled the sam...Three parallel lab-scale expanded granular sludge bed(EGSB) reactors were employed to evaluate the start-up process of bio-hydrogen production from molasses wastewater.With other start-up parameters controlled the same,the effect of inoculating sludge pre-treatments was studied.Two methods of pre-treatments(pre-heating and pre-aeration) were conducted for the inoculating sludge in two reactors compared with a non-pre-treatment reactor(control reactor).The results showed that the reactors with pre-treatment performed better in the start-up process than the control one.The hydrogen-producing bacteria were efficiently enriched at the start-up period,shortening the start-up process.At the end of the start-up stage,the acidification rate of the pre-treatment reactors was 10%—30% more than the control one,and hydrogen production increased by 1.69—1.82 times.Considering cost and feasibility,the authors suggest applying the pre-aeration method to treat the inoculating sludge to get more efficient start-up in the industrial scale bio-hydrogen production plant.展开更多
文摘Y型模块化多电平换流器(modular multilevel converter in Y configuration,Y-MMC)的Y形结构,使其预充电及并网过程更为复杂,基于环流控制的一般启动策略不再适用。针对上述问题,设计基于模型预测控制的渐进预充电方法及无扰动并网方法,提出一种模型预测渐进启动控制策略。首先,建立桥臂电流和电容电压预测模型,通过模型预测控制改变充电电流回路、幅值和相角,实现可控充电最大有功输入,对各个桥臂渐进充电。其次,根据电流误差灵活投切子模块,逐渐平衡充电回路电势差,辅助模型预测控制抑制冲击电流。然后,协调外环比例积分控制与内环模型预测控制,通过切换外环功率和电压控制模式,实现基于Y-MMC的柔性低频输电系统无扰动并网过程。最后,通过Matlab/Simulink对双端柔性低频输电系统进行仿真分析,所提控制策略保障了启动过程较低的电流冲击和较高的充电速度,使系统平稳快速进入稳定运行状态。
文摘Three parallel lab-scale expanded granular sludge bed(EGSB) reactors were employed to evaluate the start-up process of bio-hydrogen production from molasses wastewater.With other start-up parameters controlled the same,the effect of inoculating sludge pre-treatments was studied.Two methods of pre-treatments(pre-heating and pre-aeration) were conducted for the inoculating sludge in two reactors compared with a non-pre-treatment reactor(control reactor).The results showed that the reactors with pre-treatment performed better in the start-up process than the control one.The hydrogen-producing bacteria were efficiently enriched at the start-up period,shortening the start-up process.At the end of the start-up stage,the acidification rate of the pre-treatment reactors was 10%—30% more than the control one,and hydrogen production increased by 1.69—1.82 times.Considering cost and feasibility,the authors suggest applying the pre-aeration method to treat the inoculating sludge to get more efficient start-up in the industrial scale bio-hydrogen production plant.
