背靠背直流输电可以实现不同供区的柔性互联,基于模块化多电平换流器的电池储能系统(modular multi-level converter based battery energy storage system,MMC-BESS)的换流站还可以起到配合新能源接入、对交直流功率进行平抑及缓冲的...背靠背直流输电可以实现不同供区的柔性互联,基于模块化多电平换流器的电池储能系统(modular multi-level converter based battery energy storage system,MMC-BESS)的换流站还可以起到配合新能源接入、对交直流功率进行平抑及缓冲的作用。以厦门同吉开关站新型配电网示范工程为背景,其两端换流站采用MMC-BESS和基于模块化多电平换流器的中压柔性直流输电(MMC based medium voltage direct current,MMC-MVDC),背靠背实现了2条10 kV交流线路的柔性互联。针对该工程运行控制策略进行了分析和仿真研究,验证了控制策略的有效性,以及关键部件的状态在合理的范围内,对实际工程的设计和运行具有一定的指导意义。展开更多
电池储能系统(battery energy storage system,BESS)的应用使电力系统的能量应用形式更加丰富,且具有高度的灵活性和可靠性。模块化多电平电池储能系统(battery energy storage system based on modular multilevel converter,MMC-BESS...电池储能系统(battery energy storage system,BESS)的应用使电力系统的能量应用形式更加丰富,且具有高度的灵活性和可靠性。模块化多电平电池储能系统(battery energy storage system based on modular multilevel converter,MMC-BESS)具有效率高、谐波含量小、故障容错能力强等特点,适用于中高压大容量储能场合。重点研究了电池荷电状态(SOC)对电池储能系统运行功率边界的影响,基于典型的MMC-BESS系统拓扑和数学模型,采用聚合方法,提出了快速MMC-BESS电压与SOC关系的模型。根据SOC范围分析了MMC-BESS的输入输出有功功率和无功功率边界,为电池储能系统的均衡设计和运行提供了理论依据。展开更多
为了研究模块化多电平换流器(modular multilevel converter,MMC)在嵌入储能系统(battery energy storage system,BESS)后内部动态特性的变化规律,对MMC-BESS的运行特性进行了详细分析,并提出了一种桥臂级平均值模型(arm average model,...为了研究模块化多电平换流器(modular multilevel converter,MMC)在嵌入储能系统(battery energy storage system,BESS)后内部动态特性的变化规律,对MMC-BESS的运行特性进行了详细分析,并提出了一种桥臂级平均值模型(arm average model,AAM)进行验证。首先,在假设桥臂中各储能子模块状态一致的前提下,将离散环节连续化,并根据电路特性方程构建了MMC-BESS的AAM电路模型。然后,根据交流端、直流端以及储能端之间的功率关系对MMC-BESS的运行模式进行划分,建立了桥臂电流与电池功率之间的关系,并对电池功率不均衡状态下的桥臂电流进行了分析。最后,利用Matlab/Simulink分别搭建了MMC-BESS的开关模型和AAM模型,并基于AAM验证了多种工况下的桥臂电流响应。仿真结果表明,AAM在显著提高仿真效率的同时可保证较高的准确性,电池功率的大小与均衡状况对桥臂电流的成分有较大影响。展开更多
部分接入电池储能系统的模块化多电平换流器(MMC with partly integrated BESS,MMCPBESS)可以在接入储能的同时节约建造成本,但其控制更加复杂。针对下桥臂接入储能电池的MMC-PBESS拓扑,建立数学模型及等效电路。在此基础上给出电容电...部分接入电池储能系统的模块化多电平换流器(MMC with partly integrated BESS,MMCPBESS)可以在接入储能的同时节约建造成本,但其控制更加复杂。针对下桥臂接入储能电池的MMC-PBESS拓扑,建立数学模型及等效电路。在此基础上给出电容电压均衡策略,提出了上/下桥臂分控的控制策略,并分析了其运行边界。在MATLAB/Simulink平台搭建仿真模型,仿真了不同交直流功率比例的运行工况,所提控制策略可以在维持电容电压平衡的同时实现对电池充电的功能。该策略无需额外的环流计算,上下桥臂控制解耦,简单灵活。展开更多
The series line-commutated converter(LCC)and modular multilevel converter(MMC)hybrid high-voltage direct current(HVDC)system provides a more economical and flexible alternative for ultra-HVDC(UHVDC)transmission,which ...The series line-commutated converter(LCC)and modular multilevel converter(MMC)hybrid high-voltage direct current(HVDC)system provides a more economical and flexible alternative for ultra-HVDC(UHVDC)transmission,which is the so-called Baihetan-Jiangsu HVDC(BJ-HVDC)project of China.In one LCC and two MMCs(1+2)operation mode,the sub-module(SM)capacitors suffer the most rigorous overvoltage induced by three-phase-to-ground fault at grid-side MMC and valve-side single-phase-to-ground fault in internal MMC.In order to suppress such huge overvoltage,this paper demonstrates a novel alternative by employing the MMC-based embedded battery energy storage system(MMC-BESS).Firstly,the inducements of SM overvoltage are analyzed.Then,coordinated with MMC-BESS,new fault ride-through(FRT)strategies are proposed to suppress the overvoltage and improve the FRT capability.Finally,several simulation scenarios are carried out on PSCAD/EMTDC.The overvoltage suppression is verified against auxiliary device used in the BJ-HVDC project in a monopolar BJ-HVDC system.Further,the proposed FRT strategies are validated in the southern Jiangsu power grid of China based on the planning data in the summer of 2025.Simulation results show that the MMC-BESS and proposed FRT strategies could effectively suppress the overvoltage and improve the FRT capability.展开更多
For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead...For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.展开更多
文摘背靠背直流输电可以实现不同供区的柔性互联,基于模块化多电平换流器的电池储能系统(modular multi-level converter based battery energy storage system,MMC-BESS)的换流站还可以起到配合新能源接入、对交直流功率进行平抑及缓冲的作用。以厦门同吉开关站新型配电网示范工程为背景,其两端换流站采用MMC-BESS和基于模块化多电平换流器的中压柔性直流输电(MMC based medium voltage direct current,MMC-MVDC),背靠背实现了2条10 kV交流线路的柔性互联。针对该工程运行控制策略进行了分析和仿真研究,验证了控制策略的有效性,以及关键部件的状态在合理的范围内,对实际工程的设计和运行具有一定的指导意义。
文摘电池储能系统(battery energy storage system,BESS)的应用使电力系统的能量应用形式更加丰富,且具有高度的灵活性和可靠性。模块化多电平电池储能系统(battery energy storage system based on modular multilevel converter,MMC-BESS)具有效率高、谐波含量小、故障容错能力强等特点,适用于中高压大容量储能场合。重点研究了电池荷电状态(SOC)对电池储能系统运行功率边界的影响,基于典型的MMC-BESS系统拓扑和数学模型,采用聚合方法,提出了快速MMC-BESS电压与SOC关系的模型。根据SOC范围分析了MMC-BESS的输入输出有功功率和无功功率边界,为电池储能系统的均衡设计和运行提供了理论依据。
文摘为了研究模块化多电平换流器(modular multilevel converter,MMC)在嵌入储能系统(battery energy storage system,BESS)后内部动态特性的变化规律,对MMC-BESS的运行特性进行了详细分析,并提出了一种桥臂级平均值模型(arm average model,AAM)进行验证。首先,在假设桥臂中各储能子模块状态一致的前提下,将离散环节连续化,并根据电路特性方程构建了MMC-BESS的AAM电路模型。然后,根据交流端、直流端以及储能端之间的功率关系对MMC-BESS的运行模式进行划分,建立了桥臂电流与电池功率之间的关系,并对电池功率不均衡状态下的桥臂电流进行了分析。最后,利用Matlab/Simulink分别搭建了MMC-BESS的开关模型和AAM模型,并基于AAM验证了多种工况下的桥臂电流响应。仿真结果表明,AAM在显著提高仿真效率的同时可保证较高的准确性,电池功率的大小与均衡状况对桥臂电流的成分有较大影响。
文摘部分接入电池储能系统的模块化多电平换流器(MMC with partly integrated BESS,MMCPBESS)可以在接入储能的同时节约建造成本,但其控制更加复杂。针对下桥臂接入储能电池的MMC-PBESS拓扑,建立数学模型及等效电路。在此基础上给出电容电压均衡策略,提出了上/下桥臂分控的控制策略,并分析了其运行边界。在MATLAB/Simulink平台搭建仿真模型,仿真了不同交直流功率比例的运行工况,所提控制策略可以在维持电容电压平衡的同时实现对电池充电的功能。该策略无需额外的环流计算,上下桥臂控制解耦,简单灵活。
文摘模块化多电平变换器(Modular Multilevel Converter,MMC)子模块直流侧加入储能电池即构成储能型MMC换流器,无需额外的功率转换装置即可对交、直流电网提供有功功率支撑。文中分析了储能型MMC换流器的复杂工况,针对性地提出了基于直流功率、交流功率的相间、桥臂间与模块间三级荷电状态(state of charge,SOC)均衡控制策略,并通过仿真和实验验证了所提策略的正确性。
文摘The series line-commutated converter(LCC)and modular multilevel converter(MMC)hybrid high-voltage direct current(HVDC)system provides a more economical and flexible alternative for ultra-HVDC(UHVDC)transmission,which is the so-called Baihetan-Jiangsu HVDC(BJ-HVDC)project of China.In one LCC and two MMCs(1+2)operation mode,the sub-module(SM)capacitors suffer the most rigorous overvoltage induced by three-phase-to-ground fault at grid-side MMC and valve-side single-phase-to-ground fault in internal MMC.In order to suppress such huge overvoltage,this paper demonstrates a novel alternative by employing the MMC-based embedded battery energy storage system(MMC-BESS).Firstly,the inducements of SM overvoltage are analyzed.Then,coordinated with MMC-BESS,new fault ride-through(FRT)strategies are proposed to suppress the overvoltage and improve the FRT capability.Finally,several simulation scenarios are carried out on PSCAD/EMTDC.The overvoltage suppression is verified against auxiliary device used in the BJ-HVDC project in a monopolar BJ-HVDC system.Further,the proposed FRT strategies are validated in the southern Jiangsu power grid of China based on the planning data in the summer of 2025.Simulation results show that the MMC-BESS and proposed FRT strategies could effectively suppress the overvoltage and improve the FRT capability.
基金supported by Key Research and Development Program of Hebei Province under Grant 19214405DNational Natural Science Foundation of China under Grant 51677162.
文摘For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.
