Decreasing costs and favorable policies have resulted in increased penetration of solar photovoltaic(PV)power generation in distribution networks.As the PV systems penetration is likely to increase in the future,utili...Decreasing costs and favorable policies have resulted in increased penetration of solar photovoltaic(PV)power generation in distribution networks.As the PV systems penetration is likely to increase in the future,utilizing the reactive power capability of PV inverters to mitigate voltage deviations is being promoted.In recent years,droop control of inverter-based distributed energy resources has emerged as an essential tool for use in this study.The participation of PV systems in voltage regulation and its coordination with existing controllers,such as on-load tap changers,is paramount for controlling the voltage within specified limits.In this work,control strategies are presented that can be coordinated with the existing controls in a distributed manner.The effectiveness of the proposed method was demonstrated through simulation results on a distribution system.展开更多
柔性交流输电系统(flexible alternative current transmission systems,FACTS)装置如混合式统一潮流控制器(hybrid unified power flow controller,HUPFC)可调节线路潮流,有效提升输电网络的传输容量。为解决传统HUPFC中使用机械式有...柔性交流输电系统(flexible alternative current transmission systems,FACTS)装置如混合式统一潮流控制器(hybrid unified power flow controller,HUPFC)可调节线路潮流,有效提升输电网络的传输容量。为解决传统HUPFC中使用机械式有载分接开关调压带来的诸多问题,文中提出基于全电力电子有载分接开关的快速电磁式HUPFC。首先,针对其工作特性进行研究,并提出抑制开关切换过程中产生过压的方法。然后,根据不对称级电压Sen变压器的工作点合成方式存在自由度,实现一种开关切换次数最少的抽头选择策略,并给出从潮流指令改变到开关切换调压的详细步骤。最后,在Simulink中搭建220 kV双回线路仿真模型,对比快速电磁式HUPFC与传统HUPFC的潮流调节过程及结果。结果表明,全电力电子开关在响应速度和降低调节过程中的功率波动等方面更具优势,验证了快速电磁式HUPFC的可行性。展开更多
光伏(photovoltaic,PV)的接入改变了配电网的结构,给传统的调压方式带来了很大影响。为此提出PV高渗透配电网分层调压控制策略,该策略利用有载调压变压器(on-load tap changer,OLTC)与逆变器对网络电压进行分层调节,实现了时间和空间上...光伏(photovoltaic,PV)的接入改变了配电网的结构,给传统的调压方式带来了很大影响。为此提出PV高渗透配电网分层调压控制策略,该策略利用有载调压变压器(on-load tap changer,OLTC)与逆变器对网络电压进行分层调节,实现了时间和空间上的解耦。在日前进行集中控制,采用基于OLTC的最优分接头控制(optimal tap control,OTC)方法,在控制周期内进行时段划分,降低分接头动作频率;在实时进行本地控制,利用逆变器剩余的无功调节能力来修正日前预测造成的误差。以IEEE33节点系统为例进行了仿真,结果表明,所提策略可保证电压不越限的同时有效地提升PV的渗透率。展开更多
基金by a project under the scheme entitled“Developing Policies&Adaptation Strategies to Climate Change in the Baltic Sea Region”(ASTRA),Project No.ASTRA6-4(2014-2020.4.01.16-0032).
文摘Decreasing costs and favorable policies have resulted in increased penetration of solar photovoltaic(PV)power generation in distribution networks.As the PV systems penetration is likely to increase in the future,utilizing the reactive power capability of PV inverters to mitigate voltage deviations is being promoted.In recent years,droop control of inverter-based distributed energy resources has emerged as an essential tool for use in this study.The participation of PV systems in voltage regulation and its coordination with existing controllers,such as on-load tap changers,is paramount for controlling the voltage within specified limits.In this work,control strategies are presented that can be coordinated with the existing controls in a distributed manner.The effectiveness of the proposed method was demonstrated through simulation results on a distribution system.
文摘柔性交流输电系统(flexible alternative current transmission systems,FACTS)装置如混合式统一潮流控制器(hybrid unified power flow controller,HUPFC)可调节线路潮流,有效提升输电网络的传输容量。为解决传统HUPFC中使用机械式有载分接开关调压带来的诸多问题,文中提出基于全电力电子有载分接开关的快速电磁式HUPFC。首先,针对其工作特性进行研究,并提出抑制开关切换过程中产生过压的方法。然后,根据不对称级电压Sen变压器的工作点合成方式存在自由度,实现一种开关切换次数最少的抽头选择策略,并给出从潮流指令改变到开关切换调压的详细步骤。最后,在Simulink中搭建220 kV双回线路仿真模型,对比快速电磁式HUPFC与传统HUPFC的潮流调节过程及结果。结果表明,全电力电子开关在响应速度和降低调节过程中的功率波动等方面更具优势,验证了快速电磁式HUPFC的可行性。
文摘光伏(photovoltaic,PV)的接入改变了配电网的结构,给传统的调压方式带来了很大影响。为此提出PV高渗透配电网分层调压控制策略,该策略利用有载调压变压器(on-load tap changer,OLTC)与逆变器对网络电压进行分层调节,实现了时间和空间上的解耦。在日前进行集中控制,采用基于OLTC的最优分接头控制(optimal tap control,OTC)方法,在控制周期内进行时段划分,降低分接头动作频率;在实时进行本地控制,利用逆变器剩余的无功调节能力来修正日前预测造成的误差。以IEEE33节点系统为例进行了仿真,结果表明,所提策略可保证电压不越限的同时有效地提升PV的渗透率。
