中压直挂光伏发电系统不需要工频升压变压器和无功补偿装置,无夜间损耗,近年来受到广泛关注。大量光伏组串经隔离型直流变换器输出串联汇集,再通过模块化多电平变换器(modular multilevel converter,MMC)换流器并网送出功率,形成两级式...中压直挂光伏发电系统不需要工频升压变压器和无功补偿装置,无夜间损耗,近年来受到广泛关注。大量光伏组串经隔离型直流变换器输出串联汇集,再通过模块化多电平变换器(modular multilevel converter,MMC)换流器并网送出功率,形成两级式中压直挂光伏发电拓扑。该拓扑运行效率高,但各光伏组串最大功率点追踪(maximum power point tracking,MPPT)控制较为困难。把隔离型直流变换器输入侧并联,并在光伏组串与隔离型直流变换器间插入MPPT变换器,有利于MPPT控制,但增加系统损耗。面向两级功率变换式中压直挂光伏发电系统,提出隔离变换器的模块间电压-功率自主跟踪控制方法,使变换器在实现各光伏组串最大功率点追踪控制的同时,不经过通信和闭环控制就可以实现各功率模块输出电压自动分配,从而可以减少功率变换层级,提高运行效率和鲁棒性。仿真分析和小功率实验结果验证所提模块间功率控制策略的有效性。展开更多
In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Si...In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Since, payload is a critical parameter of the FLM whose variation greatly influences the controller performance. The proposed controller guarantees stability under change in payload by attenuating the non-modeled higher order dynamics using a new nonlinear autoregressive moving average with exogenous-input(NARMAX) model of the FLM. The parameters of the FLM are identified on-line using recursive least square(RLS) algorithm and using minimum variance control(MVC) laws the control parameters are updated in real-time. This proposed NSPID controller has been implemented in real-time on an experimental set-up. The joint tracking and link deflection performances of the proposed adaptive controller are compared with that of a popular direct adaptive controller(DAC). From the obtained results, it is confirmed that the proposed controller exhibits improved performance over the DAC both in terms of accurate position tracking and quick damping of link deflections when subjected to variable payloads.展开更多
文章提出了一种自底向上的虚拟电厂(virtual power plant, VPP)自组织聚合运行调度方法,旨在通过分布式能源(distributed energy resources, DER)间的动态自组织聚合,降低调度过程中的调控量。首先,针对分布式能源的出力特性,以跟踪系...文章提出了一种自底向上的虚拟电厂(virtual power plant, VPP)自组织聚合运行调度方法,旨在通过分布式能源(distributed energy resources, DER)间的动态自组织聚合,降低调度过程中的调控量。首先,针对分布式能源的出力特性,以跟踪系数量化评估其与负荷的一致性水平,并给出相关优化调控模型,同时考虑DER具备的基础智能,作为自组织聚合的基础。其次,引入联盟博弈的框架,给出了聚合效用函数及其对应的利益分配机制,并以其作为依据确立了DER的自组织聚合条件。最后,基于Pareto规则提出"聚合-分裂"机制,促进虚拟电厂的有序进化,形成虚拟电厂自组织聚合运行策略。算例表明,所提方法可根据DER出力特性动态组合,其总体调控量与集中优化时相当,相比各DER独立优化则显著下降;其计算量和计算时间,与各DER独立优化时相当,较集中优化显著下降。展开更多
文摘中压直挂光伏发电系统不需要工频升压变压器和无功补偿装置,无夜间损耗,近年来受到广泛关注。大量光伏组串经隔离型直流变换器输出串联汇集,再通过模块化多电平变换器(modular multilevel converter,MMC)换流器并网送出功率,形成两级式中压直挂光伏发电拓扑。该拓扑运行效率高,但各光伏组串最大功率点追踪(maximum power point tracking,MPPT)控制较为困难。把隔离型直流变换器输入侧并联,并在光伏组串与隔离型直流变换器间插入MPPT变换器,有利于MPPT控制,但增加系统损耗。面向两级功率变换式中压直挂光伏发电系统,提出隔离变换器的模块间电压-功率自主跟踪控制方法,使变换器在实现各光伏组串最大功率点追踪控制的同时,不经过通信和闭环控制就可以实现各功率模块输出电压自动分配,从而可以减少功率变换层级,提高运行效率和鲁棒性。仿真分析和小功率实验结果验证所提模块间功率控制策略的有效性。
文摘In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Since, payload is a critical parameter of the FLM whose variation greatly influences the controller performance. The proposed controller guarantees stability under change in payload by attenuating the non-modeled higher order dynamics using a new nonlinear autoregressive moving average with exogenous-input(NARMAX) model of the FLM. The parameters of the FLM are identified on-line using recursive least square(RLS) algorithm and using minimum variance control(MVC) laws the control parameters are updated in real-time. This proposed NSPID controller has been implemented in real-time on an experimental set-up. The joint tracking and link deflection performances of the proposed adaptive controller are compared with that of a popular direct adaptive controller(DAC). From the obtained results, it is confirmed that the proposed controller exhibits improved performance over the DAC both in terms of accurate position tracking and quick damping of link deflections when subjected to variable payloads.
文摘文章提出了一种自底向上的虚拟电厂(virtual power plant, VPP)自组织聚合运行调度方法,旨在通过分布式能源(distributed energy resources, DER)间的动态自组织聚合,降低调度过程中的调控量。首先,针对分布式能源的出力特性,以跟踪系数量化评估其与负荷的一致性水平,并给出相关优化调控模型,同时考虑DER具备的基础智能,作为自组织聚合的基础。其次,引入联盟博弈的框架,给出了聚合效用函数及其对应的利益分配机制,并以其作为依据确立了DER的自组织聚合条件。最后,基于Pareto规则提出"聚合-分裂"机制,促进虚拟电厂的有序进化,形成虚拟电厂自组织聚合运行策略。算例表明,所提方法可根据DER出力特性动态组合,其总体调控量与集中优化时相当,相比各DER独立优化则显著下降;其计算量和计算时间,与各DER独立优化时相当,较集中优化显著下降。
