CN115085177A - SOC equalization method and system of energy storage system with common DC bus - Google Patents
SOC equalization method and system of energy storage system with common DC bus Download PDFInfo
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- H—ELECTRICITY
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Abstract
Description
技术领域technical field
本发明涉及储能系统技术领域,尤其是涉及一种共直流母线的储能系统SOC均衡方法及系统。The invention relates to the technical field of energy storage systems, in particular to a method and system for SOC equalization of energy storage systems with a common DC bus.
背景技术Background technique
当前储能系统的电柜充电电流采取EMS(Energy Management System,能量管理系统)对PCS(Power Conversion System,储能变流器)下发总电流,电柜自由分配充放电电流的方式。At present, the charging current of the electric cabinet of the energy storage system adopts the way that the EMS (Energy Management System, energy management system) sends the total current to the PCS (Power Conversion System, energy storage converter), and the electric cabinet freely distributes the charging and discharging current.
但电柜的内部阻抗不一致会造成电柜间实际电流出现偏差,以造成电柜间荷电状态SOC差异大,而电柜间SOC差异大会造成电柜间环流问题,导致有些电柜充电不满及各电柜放电不均等,增加电量损耗。However, the inconsistency of the internal impedance of the electrical cabinets will cause the actual current to deviate between the electrical cabinets, resulting in a large difference in the SOC between the electrical cabinets. The discharge of each electric cabinet is uneven, which increases the power consumption.
发明内容SUMMARY OF THE INVENTION
本发明所要解决的技术问题是:提供一种共直流母线的储能系统SOC均衡方法及系统,解决储能系统电柜间电量不均流的问题。The technical problem to be solved by the present invention is to provide a SOC equalization method and system of an energy storage system with a common DC bus, so as to solve the problem of uneven current flow among the electrical cabinets of the energy storage system.
为了解决上述技术问题,本发明采用的技术方案为:In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:
一种共直流母线的储能系统SOC均衡方法,包括步骤:A method for balancing the SOC of an energy storage system with a common DC bus, comprising the steps of:
S1、主机EMS根据储能变流器PCS的工作状态、电柜的工作状态和SOC控制DC/DC变换器的工作模式;S1. The host EMS controls the working mode of the DC/DC converter according to the working state of the energy storage converter PCS, the working state of the electrical cabinet and the SOC;
其中所述PCS、所述电柜和所述DC/DC变换器在储能系统的各子系统中均配置有一个,且每个所述子系统中,所述PCS、所述DC/DC变换器和所述电柜依次连接,每个所述PCS未与所述DC/DC变换器连接的一端并联接至电网,每个所述PCS与所述DC/DC变换器的连接处通过一直流母线并联。Wherein, one of the PCS, the electrical cabinet and the DC/DC converter is configured in each subsystem of the energy storage system, and in each of the subsystems, the PCS, the DC/DC converter are The converter and the electrical cabinet are connected in sequence, the end of each PCS that is not connected to the DC/DC converter is connected to the power grid in parallel, and the connection between each PCS and the DC/DC converter is connected by a direct current The busbars are connected in parallel.
为了解决上述技术问题,本发明采用的另一个技术方案为:In order to solve the above-mentioned technical problems, another technical scheme adopted by the present invention is:
一种共直流母线的储能系统SOC均衡系统,包括主机EMS,所述主机EMS包括第一存储器、第一处理器以及存储在第一存储器上并可在第一处理器上运行的第一计算机程序,An energy storage system SOC equalization system with a common DC bus, comprising a host EMS, the host EMS comprising a first memory, a first processor, and a first computer stored on the first memory and running on the first processor program,
所述第一处理器在执行所述第一计算机程序时实现以下步骤:The first processor implements the following steps when executing the first computer program:
S1、根据储能变流器PCS的工作状态、电柜的工作状态和SOC控制DC/DC变换器的工作模式;S1. Control the working mode of the DC/DC converter according to the working state of the energy storage converter PCS, the working state of the electrical cabinet and the SOC;
其中所述PCS、所述电柜和所述DC/DC变换器在储能系统的各子系统中均配置有一个,且每个所述子系统中,所述PCS、所述DC/DC变换器和所述电柜依次连接,每个所述PCS未与所述DC/DC变换器连接的一端并联接至电网,每个所述PCS与所述DC/DC变换器的连接处通过一直流母线并联。Wherein, one of the PCS, the electrical cabinet and the DC/DC converter is configured in each subsystem of the energy storage system, and in each of the subsystems, the PCS, the DC/DC converter are The converter and the electrical cabinet are connected in sequence, the end of each PCS that is not connected to the DC/DC converter is connected to the power grid in parallel, and the connection between each PCS and the DC/DC converter is connected by a direct current The busbars are connected in parallel.
本发明的有益效果在于:本发明提供一种共直流母线的储能系统SOC均衡方法及系统,通过为储能系统的多个子系统均配置一PCS,以实现对各子系统的单独调控,并使得各子系统的DC/DC变换器共用一条直流母线,默认条件下设置各子系统的DC/DC变换器采用恒压模式,当各电柜的SOC出现不均衡时,主机EMS能根据PCS和电柜的工作状态和各电柜的SOC来及时调控DC/DC变换器的工作模式,并在直流母线下进行电柜间的电量流转以均衡各子系统充放电流一致,解决储能系统电柜间电量不均流的问题。The beneficial effects of the present invention are as follows: the present invention provides a method and system for SOC equalization of an energy storage system with a common DC bus, by configuring a PCS for each of the multiple subsystems of the energy storage system, so as to realize the independent regulation of each subsystem, and Make the DC/DC converters of each subsystem share a DC bus. By default, the DC/DC converters of each subsystem are set to use constant voltage mode. When the SOC of each cabinet is unbalanced, the host EMS can be based on PCS and The working state of the electrical cabinet and the SOC of each electrical cabinet can adjust the working mode of the DC/DC converter in time, and the power flow between the electrical cabinets is carried out under the DC bus to balance the charging and discharging current of each subsystem, and solve the problem of the energy storage system. The problem of uneven power flow between cabinets.
附图说明Description of drawings
图1为现有储能系统的拓扑结构图;Fig. 1 is the topology structure diagram of the existing energy storage system;
图2为本发明实施例的一种共直流母线的储能系统的拓扑结构图;2 is a topological structure diagram of an energy storage system with a common DC bus according to an embodiment of the present invention;
图3为本发明实施例的一种共直流母线的储能系统SOC均衡方法的流程图;3 is a flowchart of a method for balancing SOC of an energy storage system with a common DC bus according to an embodiment of the present invention;
图4为本发明实施例的一种共直流母线的储能系统SOC均衡系统的结构示意图。FIG. 4 is a schematic structural diagram of an SOC equalization system of an energy storage system with a common DC bus according to an embodiment of the present invention.
标号说明:Label description:
10、一种共直流母线的储能系统SOC均衡系统;10. An energy storage system SOC equalization system with a common DC bus;
20、主机EMS;21、第一存储器;22、第一处理器;20. Host EMS; 21. First memory; 22. First processor;
30、从机EMS;31、第二存储器;32、第二处理器。30. Slave EMS; 31. Second memory; 32. Second processor.
具体实施方式Detailed ways
为详细说明本发明的技术内容、所实现目的及效果,以下结合实施方式并配合附图予以说明。In order to describe in detail the technical content, achieved objects and effects of the present invention, the following descriptions are given with reference to the embodiments and the accompanying drawings.
请参照图2至图3,一种共直流母线的储能系统SOC均衡方法,包括步骤:Please refer to FIG. 2 to FIG. 3 , a method for SOC equalization of an energy storage system with a common DC bus, including steps:
S1、主机EMS根据储能变流器PCS的工作状态、电柜的工作状态和SOC控制DC/DC变换器的工作模式;S1. The host EMS controls the working mode of the DC/DC converter according to the working state of the energy storage converter PCS, the working state of the electrical cabinet and the SOC;
其中所述PCS、所述电柜和所述DC/DC变换器在储能系统的各子系统中均配置有一个,且每个所述子系统中,所述PCS、所述DC/DC变换器和所述电柜依次连接,每个所述PCS未与所述DC/DC变换器连接的一端并联接至电网,每个所述PCS与所述DC/DC变换器的连接处通过一直流母线并联。Wherein, one of the PCS, the electrical cabinet and the DC/DC converter is configured in each subsystem of the energy storage system, and in each of the subsystems, the PCS, the DC/DC converter are The converter and the electrical cabinet are connected in sequence, the end of each PCS that is not connected to the DC/DC converter is connected to the power grid in parallel, and the connection between each PCS and the DC/DC converter is connected by a direct current The busbars are connected in parallel.
由上述描述可知,本发明的有益效果在于:通过为储能系统的多个子系统均配置一PCS,以实现对各子系统的单独调控,并使得各子系统的DC/DC变换器共用一条直流母线,默认条件下设置各子系统的DC/DC变换器采用恒压模式,当各电柜的SOC出现不均衡时,主机EMS能根据PCS和电柜的工作状态和各电柜的SOC来及时调控DC/DC变换器的工作模式,并在直流母线下进行电柜间的电量流转以均衡各子系统充放电流一致,解决储能系统电柜间电量不均流的问题。It can be seen from the above description that the beneficial effect of the present invention is: by configuring a PCS for each of the multiple subsystems of the energy storage system, to realize the independent regulation of each subsystem, and to make the DC/DC converters of each subsystem share a direct current Bus, by default, the DC/DC converters of each subsystem are set to use constant voltage mode. When the SOC of each cabinet is unbalanced, the host EMS can timely check according to the working status of the PCS and the cabinet and the SOC of each cabinet. The working mode of the DC/DC converter is regulated, and the power flow between the cabinets is carried out under the DC bus to balance the charging and discharging currents of each subsystem, and solve the problem of uneven power flow between the cabinets of the energy storage system.
进一步地,所述步骤S1之前还包括步骤:Further, before the step S1, it also includes the steps:
S0、每个所述子系统的从机EMS实时检测和采集各自所述子系统下的所述PCS的工作状态、所述电柜的工作状态和所述电柜的SOC,并发送至所述主机EMS;S0. The slave EMS of each of the subsystems detects and collects the working state of the PCS, the working state of the electrical cabinet and the SOC of the electrical cabinet in real time under the respective subsystems, and sends them to the host EMS;
其中,所述PCS的工作状态包括运行状态和停止状态,所述运行状态下所述PCS将电网侧的交流电转换为直流电或者将直流电转换为交流电并入电网侧,所述停止状态下所述PCS停止电能转换;Wherein, the working state of the PCS includes a running state and a stopped state. In the running state, the PCS converts the alternating current on the grid side to direct current or converts the direct current into alternating current and merges it into the grid side. In the stopped state, the PCS stop power conversion;
所述电柜的工作状态包括充电状态和放电状态。The working state of the electrical cabinet includes a charging state and a discharging state.
由上述描述可知,为每个子系统也各配置一个从机EMS,用于实时检测各子系统中PCS和电柜的工作状态和实时采集各电柜的SOC,及时发送给主机EMS以进行分析和功率值下发,即从机EMS负责传递信息,主机EMS负责控制直流下达,分工明确,互不干扰,便于后序各子系统DC/DC变换器的工作模式的调控。It can be seen from the above description that each subsystem is also equipped with a slave EMS, which is used to detect the working status of PCS and electrical cabinets in each subsystem in real time, collect the SOC of each electrical cabinet in real time, and send it to the host EMS in time for analysis and analysis. Power value distribution, that is, the slave EMS is responsible for transmitting information, and the host EMS is responsible for controlling the DC distribution. The division of labor is clear and does not interfere with each other, which is convenient for the regulation of the working mode of the DC/DC converters of the subsequent subsystems.
进一步地,所述步骤S1具体为:Further, the step S1 is specifically:
所述主机EMS接收并分析所述从机EMS发送的每个所述PCS的工作状态,当每个所述PCS的工作状态均为所述停止状态时,执行步骤S11,当每个所述PCS的工作状态均为所述运行状态时,执行步骤S12,否则进行故障告警;The host EMS receives and analyzes the working state of each PCS sent by the slave EMS. When the working state of each PCS is the stopped state, step S11 is executed, and when each PCS is in the stopped state, step S11 is executed. When the working states of all are the running states, step S12 is performed, otherwise, a fault alarm is performed;
S11、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的SOC:S11. The host EMS receives and analyzes the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第一电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第一电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一电柜的电量输出均分至其余所述子系统中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the first electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the first electrical cabinet is located is controlled to be 10% of the rated power. The output power equally divides the power output of the first electrical cabinet into the remaining subsystems, and controls the DC/DC converters in the remaining subsystems to maintain a constant voltage mode;
若存在第二电柜的SOC低出其他电柜中最高SOC的20%,则控制除所述第二电柜之外的其他电柜所在的所述子系统中的所述DC/DC变换器以额定功率的2%的输出功率将各自所述子系统中的所述电柜的电量输出至所述第二电柜所在的所述子系统中,并控制所述第二电柜所在的所述子系统中的所述DC/DC变换器保持恒压模式;If there is a second electrical cabinet whose SOC is lower than 20% of the highest SOC among other electrical cabinets, control the DC/DC converters in the subsystems where other electrical cabinets except the second electrical cabinet are located Output the power of the electrical cabinets in the respective subsystems to the subsystem where the second electrical cabinet is located at an output power of 2% of the rated power, and control all the electrical cabinets where the second electrical cabinet is located. the DC/DC converter in the subsystem maintains a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第一最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一最高电柜的电量输出、控制具有最低SOC的第一最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输入功率接收所述第一最高电柜输出的电量为所述第一最低电柜充电,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the first highest electrical cabinet with the highest SOC is located. The DC/DC converter outputs the electricity of the first highest electrical cabinet at an output power of 10% of the rated power, and controls the DC/DC in the subsystem where the first lowest electrical cabinet with the lowest SOC is located. The DC converter receives the power output from the first highest electrical cabinet with an input power of 10% of the rated power to charge the first lowest electrical cabinet, and controls the DC/DC converters in the rest of the subsystems to maintain constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式;Otherwise, the DC/DC converters in each of the subsystems maintain a constant voltage mode;
S12、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的工作状态和SOC,并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式。S12. The host EMS receives and analyzes the working state and SOC of each electric cabinet sent by the slave EMS, and controls the working mode of the DC/DC converter according to the working state and SOC of the electric cabinet .
由上述描述可知,当PCS处在停止状态,即PCS停止电能转换时,电网侧输入储能系统的交流电不被转换为直流电输送到子系统的电柜中进行储能或直流负载中进行供电,但此时若是各子系统中的电柜之间SOC存在不均衡,出现单个过高、单个过低或者一高一低时,即可根据各个子系统中电柜的SOC状态控制DC/DC变换器将电柜的电量经由共直流母线的作用下或输出、或输入给其他子系统,以确保各子系统电柜间SOC的均衡、一致。It can be seen from the above description that when the PCS is in a stopped state, that is, when the PCS stops power conversion, the AC power input to the energy storage system on the grid side is not converted into DC power and sent to the electrical cabinet of the subsystem for energy storage or DC load for power supply. However, at this time, if there is an imbalance in the SOC among the cabinets in each subsystem, and a single high, a single low, or one high and one low occurs, the DC/DC conversion can be controlled according to the SOC status of the cabinets in each subsystem. Under the action of the common DC bus, the controller outputs or inputs the power of the cabinet to other subsystems to ensure the balance and consistency of the SOC among the cabinets of each subsystem.
进一步地,所述步骤S12中并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式,具体为:Further, in the step S12, the working mode of the DC/DC converter is controlled according to the working state and SOC of the electrical cabinet, specifically:
当每个所述电柜的工作状态均为所述充电状态时,执行步骤S13,当每个所述电柜的工作状态均为所述放电状态时,执行步骤S14,否则进行故障告警;When the working state of each of the electrical cabinets is the charging state, step S13 is performed; when the working state of each of the electrical cabinets is the discharging state, step S14 is performed, otherwise, a fault alarm is performed;
S13、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的SOC:S13. The host EMS receives and analyzes the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第三电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第三电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the third electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the third electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the third electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若存在第四电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第四电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第四电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the fourth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the fourth electrical cabinet is located is controlled to be 120% of the rated power. The charging power is stored in the fourth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第二最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最高电柜中、控制具有最低SOC的第二最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the second highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 80% of the rated power into the second highest electrical cabinet, where the second lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the second lowest electrical cabinet at a charging power of 120% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式;Otherwise, the DC/DC converters in each of the subsystems maintain a constant voltage mode;
S24、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的SOC:若存在第五电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第五电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第五电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;S24. The master EMS receives and analyzes the SOC of each of the electrical cabinets sent by the slave EMS: if there is a fifth electrical cabinet whose SOC is 20% higher than the lowest SOC among other electrical cabinets, control the SOC of the fifth electrical cabinet. The DC/DC converter in the subsystem where the fifth electrical cabinet is located stores the DC power converted from the grid side through the PCS into the fifth electrical cabinet with a charging power of 120% of the rated power, and controls the DC/DC converters in the remaining subsystems maintain a constant voltage mode;
若存在第六电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第六电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第六电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the sixth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the sixth electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the sixth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第三最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最高电柜中、控制具有最低SOC的第三最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the third highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 120% of the rated power into the third highest electrical cabinet, where the third lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the third lowest electrical cabinet at a charging power of 80% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式。Otherwise, the DC/DC converters in each of the subsystems maintain the constant voltage mode.
由上述描述可知,当PCS处在运行状态时,即此时PCS会将电网侧的交流电转换为直流电输出为各子系统的电柜进行充能或为直流负载进行供电,而此时的电柜则可能存在被电网侧经PCS转换的直流电进行充电的状态或与电网侧经PCS转换的直流电一起共同为直流负载供电的状态,则无论电柜是在充电还是放电状态下,当电柜的SOC中出现单个过高、单个过低或者一高一低时,也可根据各个子系统中电柜的SOC状态控制DC/DC变换器调整各自所在子系统下的电柜的充电或放电功率,以确保各子系统电柜间充放电的均衡,进一步确保各子系统电柜间SOC的均衡、一致。It can be seen from the above description that when the PCS is in the running state, that is, at this time, the PCS will convert the AC power on the grid side into DC power and output it to charge the electrical cabinets of each subsystem or supply power for the DC load, and the electrical cabinets at this time. Then there may be a state of being charged by the DC power converted by the PCS on the grid side or a state of powering the DC load together with the DC power converted by the PCS on the grid side. When there is a single high, a single low or one high and one low, the DC/DC converter can also be controlled according to the SOC state of the electrical cabinet in each subsystem to adjust the charging or discharging power of the electrical cabinet under the respective subsystem, so that the Ensure the balance of charge and discharge between the cabinets of each subsystem, and further ensure the balance and consistency of the SOC between the cabinets of each subsystem.
进一步地,所述步骤S11中若存在第一电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:Further, if the SOC of the first electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets in the step S11, the step further includes:
实时分析所述第一电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第一电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the first electrical cabinet and the lowest SOC in the remaining electrical cabinets in real time, and control the DC/DC conversion in the subsystem where the first electrical cabinet is located when the difference is less than 3% The output power of the device is 0;
所述步骤S11中若存在第二电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S11, if the SOC of the second electrical cabinet is lower than 20% of the highest SOC in the other electrical cabinets, the step further includes:
实时分析所述第二电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the second electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S11中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S11, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第一最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和第一最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0;Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the first highest electrical cabinet is located with the first The input power of the DC/DC converters in the subsystem where the lowest electrical cabinet is located is adjusted to 0;
所述步骤S13中若存在第三电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:In the step S13, if the SOC of the third electrical cabinet is 20% higher than the lowest SOC of the other electrical cabinets, the step further includes:
实时分析所述第三电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第三电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Real-time analysis of the difference between the SOC of the third electrical cabinet and the lowest SOC in the remaining electrical cabinets, and when the difference is less than 3%, control the DC/DC conversion in the subsystem where the third electrical cabinet is located The output power of the device is 0;
所述步骤S13中若存在第四电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S13, if the SOC of the fourth electrical cabinet is lower than 20% of the highest SOC in the other electrical cabinets, the step further includes:
实时分析所述第四电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the fourth electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S13中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S13, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第二最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第二最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0;Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the second highest electrical cabinet is located with the The input powers of the DC/DC converters in the subsystem where the second lowest electrical cabinet is located are all adjusted to 0;
所述步骤S14中若存在第五电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:In the step S14, if the SOC of the fifth electrical cabinet is 20% higher than the lowest SOC of the other electrical cabinets, the step further includes:
实时分析所第五电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第五电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Real-time analysis of the difference between the SOC of the fifth electrical cabinet and the lowest SOC in the remaining electrical cabinets, when the difference is less than 3%, control the DC/DC converter in the subsystem where the fifth electrical cabinet is located The output power is 0;
所述步骤S14中若存在第六电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S14, if the SOC of the sixth electric cabinet is lower than 20% of the highest SOC in the other electric cabinets, the step further includes:
实时分析所述第六电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the sixth electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S14中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S14, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第三最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第三最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0。Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the third highest electrical cabinet is located with the The input powers of the DC/DC converters in the subsystem where the third lowest electrical cabinet is located are all adjusted to 0.
由上述描述可知,当控制各子系统中DC/DC变换器执行相应的输入输出功率后,还需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续输入或输出自身所处子系统的电柜的电量至其他子系统中,而又造成相较之前的反向SOC不均衡;同理,当控制各子系统中DC/DC变换器执行相应的充放电功率后,也需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续以较高或较低的充放电功率工作导致自身所处子系统的电柜的电量过充或过放导致电柜间SOC相较之前又变为反向的不均衡。It can be seen from the above description that after controlling the DC/DC converters in each subsystem to perform the corresponding input and output power, it is also necessary to monitor the SOC status between the electrical cabinets of each subsystem in real time, so as to stop the device in time when the SOC status is close to the same. Determine the working mode of the DC/DC converter, restore each DC/DC converter to the constant voltage mode, and avoid the DC/DC converter in the subsystem with higher or lower SOC to continuously input or output the voltage of the subsystem where it is located. The power of the electric cabinet is transferred to other subsystems, which causes the reverse SOC to be unbalanced compared to the previous one. Similarly, after controlling the DC/DC converters in each subsystem to perform the corresponding charging and discharging power, it is also necessary to monitor each subsystem in real time. The state of the SOC between the cabinets of the subsystem, so that when the SOC state is close to the same, the set working mode of the DC/DC converter can be stopped in time, and the DC/DC converters can be restored to the constant voltage mode again to avoid higher or higher voltage. The DC/DC converter in the subsystem with low SOC continues to work with higher or lower charging and discharging power, resulting in overcharge or overdischarge of the power of the cabinet in the subsystem where it is located, resulting in the SOC between the cabinets becoming higher than before. Reverse imbalance.
请参照图4,一种共直流母线的储能系统SOC均衡系统,包括主机EMS,所述主机EMS包括第一存储器、第一处理器以及存储在第一存储器上并可在第一处理器上运行的第一计算机程序,Please refer to FIG. 4 , an energy storage system SOC equalization system with a common DC bus includes a host EMS, the host EMS includes a first memory, a first processor, and is stored on the first memory and can be stored on the first processor. a first computer program to run,
所述第一处理器在执行所述第一计算机程序时实现以下步骤:The first processor implements the following steps when executing the first computer program:
S1、根据储能变流器PCS的工作状态、电柜的工作状态和SOC控制DC/DC变换器的工作模式;S1. Control the working mode of the DC/DC converter according to the working state of the energy storage converter PCS, the working state of the electrical cabinet and the SOC;
其中所述PCS、所述电柜和所述DC/DC变换器在储能系统的各子系统中均配置有一个,且每个所述子系统中,所述PCS、所述DC/DC变换器和所述电柜依次连接,每个所述PCS未与所述DC/DC变换器连接的一端并联接至电网,每个所述PCS与所述DC/DC变换器的连接处通过一直流母线并联。Wherein, one of the PCS, the electrical cabinet and the DC/DC converter is configured in each subsystem of the energy storage system, and in each of the subsystems, the PCS, the DC/DC converter are The converter and the electrical cabinet are connected in sequence, the end of each PCS that is not connected to the DC/DC converter is connected to the power grid in parallel, and the connection between each PCS and the DC/DC converter is connected by a direct current The busbars are connected in parallel.
由上述描述可知,本发明的有益效果在于:基于同一技术构思,配合上述的一种共直流母线的储能系统SOC均衡方法,提供一种共直流母线的储能系统SOC均衡系统,通过为储能系统的多个子系统均配置一PCS,以实现对各子系统的单独调控,并使得各子系统的DC/DC变换器共用一条直流母线,默认条件下设置各子系统的DC/DC变换器采用恒压模式,当各电柜的SOC出现不均衡时,主机EMS能根据PCS和电柜的工作状态和各电柜的SOC来及时调控DC/DC变换器的工作模式,并在直流母线下进行电柜间的电量流转以均衡各子系统充放电流一致,解决储能系统电柜间电量不均流的问题。It can be seen from the above description that the beneficial effects of the present invention are: based on the same technical concept, in conjunction with the above-mentioned method for SOC balancing of energy storage systems with a common DC bus, a SOC balancing system for energy storage systems with a common DC bus is provided. Multiple subsystems of the energy system are equipped with a PCS to realize independent control of each subsystem, and make the DC/DC converters of each subsystem share a DC bus, and the DC/DC converters of each subsystem are set by default. Using the constant voltage mode, when the SOC of each electrical cabinet is unbalanced, the host EMS can adjust the working mode of the DC/DC converter in time according to the working state of the PCS and the electrical cabinet and the SOC of each electrical cabinet, and under the DC bus The electric power flow between the electric cabinets is carried out to balance the charging and discharging current of each subsystem, and the problem of uneven electric current between electric cabinets of the energy storage system is solved.
进一步地,还包括从机EMS,所述从机EMS包括第二存储器、第二处理器以及存储在第二存储器上并可在第二处理器上运行的第二计算机程序;Further, a slave EMS is also included, the slave EMS includes a second memory, a second processor, and a second computer program stored on the second memory and executable on the second processor;
所述第二处理器在执行所述第二计算机程序时实现以下步骤:The second processor implements the following steps when executing the second computer program:
S0、实时检测和采集各自所述子系统下的所述PCS的工作状态、所述电柜的工作状态和所述电柜的SOC,并发送至所述主机EMS;S0, real-time detection and collection of the working state of the PCS, the working state of the electrical cabinet and the SOC of the electrical cabinet under the respective subsystems, and sending them to the host EMS;
其中,所述PCS的工作状态包括运行状态和停止状态,所述运行状态下所述PCS将电网侧的交流电转换为直流电或者将直流电转换为交流电并入电网侧,所述停止状态下所述PCS停止电能转换;Wherein, the working state of the PCS includes a running state and a stopped state. In the running state, the PCS converts the alternating current on the grid side to direct current or converts the direct current into alternating current and merges it into the grid side. In the stopped state, the PCS stop power conversion;
所述电柜的工作状态包括充电状态和放电状态。The working state of the electrical cabinet includes a charging state and a discharging state.
由上述描述可知,为每个子系统也各配置一个从机EMS,用于实时检测各子系统中PCS和电柜的工作状态和实时采集各电柜的SOC,及时发送给主机EMS以进行分析和功率值下发,即从机EMS负责传递信息,主机EMS负责控制直流下达,分工明确,互不干扰,便于后序各子系统DC/DC变换器的工作模式的调控。It can be seen from the above description that each subsystem is also equipped with a slave EMS, which is used to detect the working status of PCS and electrical cabinets in each subsystem in real time, collect the SOC of each electrical cabinet in real time, and send it to the host EMS in time for analysis and analysis. Power value distribution, that is, the slave EMS is responsible for transmitting information, and the host EMS is responsible for controlling the DC distribution. The division of labor is clear and does not interfere with each other, which is convenient for the regulation of the working mode of the DC/DC converters of the subsequent subsystems.
进一步地,所述步骤S1具体为:Further, the step S1 is specifically:
接收并分析所述从机EMS发送的每个所述PCS的工作状态,当每个所述PCS的工作状态均为所述停止状态时,执行步骤S11,当每个所述PCS的工作状态均为所述运行状态时,执行步骤S12,否则进行故障告警;Receive and analyze the working state of each PCS sent by the slave EMS, when the working state of each PCS is the stopped state, execute step S11, when the working state of each PCS is When it is in the running state, step S12 is performed, otherwise, a fault alarm is performed;
S11、接收并分析所述从机EMS发送的每个所述电柜的SOC:S11. Receive and analyze the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第一电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第一电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一电柜的电量输出均分至其余所述子系统中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the first electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the first electrical cabinet is located is controlled to be 10% of the rated power. The output power equally divides the power output of the first electrical cabinet into the remaining subsystems, and controls the DC/DC converters in the remaining subsystems to maintain a constant voltage mode;
若存在第二电柜的SOC低出其他电柜中最高SOC的20%,则控制除所述第二电柜之外的其他电柜所在的所述子系统中的所述DC/DC变换器以额定功率的2%的输出功率将各自所述子系统中的所述电柜的电量输出至所述第二电柜所在的所述子系统中,并控制所述第二电柜所在的所述子系统中的所述DC/DC变换器保持恒压模式;If there is a second electrical cabinet whose SOC is lower than 20% of the highest SOC among other electrical cabinets, control the DC/DC converters in the subsystems where other electrical cabinets except the second electrical cabinet are located Output the power of the electrical cabinets in the respective subsystems to the subsystem where the second electrical cabinet is located at an output power of 2% of the rated power, and control all the electrical cabinets where the second electrical cabinet is located. the DC/DC converter in the subsystem maintains a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第一最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一最高电柜的电量输出、控制具有最低SOC的第一最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输入功率接收所述第一最高电柜输出的电量为所述第一最低电柜充电,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the first highest electrical cabinet with the highest SOC is located. The DC/DC converter outputs the electricity of the first highest electrical cabinet at an output power of 10% of the rated power, and controls the DC/DC in the subsystem where the first lowest electrical cabinet with the lowest SOC is located. The DC converter receives the power output from the first highest electrical cabinet with an input power of 10% of the rated power to charge the first lowest electrical cabinet, and controls the DC/DC converters in the rest of the subsystems to maintain constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式;Otherwise, the DC/DC converters in each of the subsystems maintain a constant voltage mode;
S12、接收并分析所述从机EMS发送的每个所述电柜的工作状态和SOC,并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式。S12. Receive and analyze the working state and SOC of each of the electrical cabinets sent by the slave EMS, and control the working mode of the DC/DC converter according to the working state and SOC of the electrical cabinet.
由上述描述可知,当PCS处在停止状态,即PCS停止电能转换时,电网侧输入储能系统的交流电不被转换为直流电输送到子系统的电柜中进行储能或直流负载中进行供电,但此时若是各子系统中的电柜之间SOC存在不均衡,出现单个过高、单个过低或者一高一低时,即可根据各个子系统中电柜的SOC状态控制DC/DC变换器将电柜的电量经由共直流母线的作用下或输出、或输入给其他子系统,以确保各子系统电柜间SOC的均衡、一致。It can be seen from the above description that when the PCS is in a stopped state, that is, when the PCS stops power conversion, the AC power input to the energy storage system on the grid side is not converted into DC power and sent to the electrical cabinet of the subsystem for energy storage or DC load for power supply. However, at this time, if there is an imbalance in the SOC among the cabinets in each subsystem, and a single high, a single low, or one high and one low occurs, the DC/DC conversion can be controlled according to the SOC status of the cabinets in each subsystem. Under the action of the common DC bus, the controller outputs or inputs the power of the cabinet to other subsystems to ensure the balance and consistency of the SOC among the cabinets of each subsystem.
进一步地,所述步骤S12中并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式,具体为:Further, in the step S12, the working mode of the DC/DC converter is controlled according to the working state and SOC of the electrical cabinet, specifically:
当每个所述电柜的工作状态均为所述充电状态时,执行步骤S13,当每个所述电柜的工作状态均为所述放电状态时,执行步骤S14,否则进行故障告警;When the working state of each of the electrical cabinets is the charging state, step S13 is performed; when the working state of each of the electrical cabinets is the discharging state, step S14 is performed, otherwise, a fault alarm is performed;
S13、接收并分析所述从机EMS发送的每个所述电柜的SOC:S13. Receive and analyze the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第三电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第三电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the third electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the third electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the third electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若存在第四电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第四电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第四电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the fourth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the fourth electrical cabinet is located is controlled to be 120% of the rated power. The charging power is stored in the fourth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第二最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最高电柜中、控制具有最低SOC的第二最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the second highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 80% of the rated power into the second highest electrical cabinet, where the second lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the second lowest electrical cabinet at a charging power of 120% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式;Otherwise, the DC/DC converters in each of the subsystems maintain a constant voltage mode;
S24、接收并分析所述从机EMS发送的每个所述电柜的SOC:若存在第五电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第五电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第五电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;S24. Receive and analyze the SOC of each of the electrical cabinets sent by the slave EMS: if there is a fifth electrical cabinet whose SOC is 20% higher than the lowest SOC among other electrical cabinets, control where the fifth electrical cabinet is located. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the fifth electrical cabinet with a charging power of 120% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
若存在第六电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第六电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第六电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the sixth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the sixth electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the sixth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第三最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最高电柜中、控制具有最低SOC的第三最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the third highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 120% of the rated power into the third highest electrical cabinet, where the third lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the third lowest electrical cabinet at a charging power of 80% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
否则各所述子系统中的所述DC/DC变换器均保持恒压模式。Otherwise, the DC/DC converters in each of the subsystems maintain the constant voltage mode.
由上述描述可知,当PCS处在运行状态时,即此时PCS会将电网侧的交流电转换为直流电输出为各子系统的电柜进行充能或为直流负载进行供电,而此时的电柜则可能存在被电网侧经PCS转换的直流电进行充电的状态或与电网侧经PCS转换的直流电一起共同为直流负载供电的状态,则无论电柜是在充电还是放电状态下,当电柜的SOC中出现单个过高、单个过低或者一高一低时,也可根据各个子系统中电柜的SOC状态控制DC/DC变换器调整各自所在子系统下的电柜的充电或放电功率,以确保各子系统电柜间充放电的均衡,进一步确保各子系统电柜间SOC的均衡、一致。It can be seen from the above description that when the PCS is in the running state, that is, at this time, the PCS will convert the AC power on the grid side into DC power and output it to charge the electrical cabinets of each subsystem or supply power for the DC load, and the electrical cabinets at this time. Then there may be a state of being charged by the DC power converted by the PCS on the grid side or a state of powering the DC load together with the DC power converted by the PCS on the grid side. When there is a single high, a single low or one high and one low, the DC/DC converter can also be controlled according to the SOC state of the electrical cabinet in each subsystem to adjust the charging or discharging power of the electrical cabinet under the respective subsystem, so that the Ensure the balance of charge and discharge between the cabinets of each subsystem, and further ensure the balance and consistency of the SOC between the cabinets of each subsystem.
进一步地,所述步骤S11中若存在第一电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:Further, if the SOC of the first electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets in the step S11, the step further includes:
实时分析所述第一电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第一电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the first electrical cabinet and the lowest SOC in the remaining electrical cabinets in real time, and control the DC/DC conversion in the subsystem where the first electrical cabinet is located when the difference is less than 3% The output power of the device is 0;
所述步骤S11中若存在第二电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S11, if the SOC of the second electrical cabinet is lower than 20% of the highest SOC in the other electrical cabinets, the step further includes:
实时分析所述第二电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the second electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S11中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S11, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第一最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和第一最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0;Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the first highest electrical cabinet is located with the first The input power of the DC/DC converters in the subsystem where the lowest electrical cabinet is located is adjusted to 0;
所述步骤S13中若存在第三电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:In the step S13, if the SOC of the third electrical cabinet is 20% higher than the lowest SOC of the other electrical cabinets, the step further includes:
实时分析所述第三电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第三电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Real-time analysis of the difference between the SOC of the third electrical cabinet and the lowest SOC in the remaining electrical cabinets, and when the difference is less than 3%, control the DC/DC conversion in the subsystem where the third electrical cabinet is located The output power of the device is 0;
所述步骤S13中若存在第四电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S13, if the SOC of the fourth electrical cabinet is lower than 20% of the highest SOC in the other electrical cabinets, the step further includes:
实时分析所述第四电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the fourth electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S13中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S13, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第二最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第二最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0;Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the second highest electrical cabinet is located with the The input powers of the DC/DC converters in the subsystem where the second lowest electrical cabinet is located are all adjusted to 0;
所述步骤S14中若存在第五电柜的SOC高出其他电柜中最低SOC的20%,还包括步骤:In the step S14, if the SOC of the fifth electrical cabinet is 20% higher than the lowest SOC of the other electrical cabinets, the step further includes:
实时分析所第五电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第五电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Real-time analysis of the difference between the SOC of the fifth electrical cabinet and the lowest SOC in the remaining electrical cabinets, when the difference is less than 3%, control the DC/DC converter in the subsystem where the fifth electrical cabinet is located The output power is 0;
所述步骤S14中若存在第六电柜的SOC低出其他电柜中最高SOC的20%,还包括步骤:In the step S14, if the SOC of the sixth electric cabinet is lower than 20% of the highest SOC in the other electric cabinets, the step further includes:
实时分析所述第六电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0;Analyze the difference between the SOC of the sixth electrical cabinet and the highest SOC in the remaining electrical cabinets in real time, and control the output of the DC/DC converter in the subsystem where the remaining electrical cabinets are located when the difference is less than 3% power is 0;
所述步骤S14中若所述电柜的SOC中存在最高SOC比最低SOC高出20%、最低SOC比次低SOC低出10%,还包括步骤:In the step S14, if the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, the step further includes:
实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第三最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第三最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0。Analyze the difference between the highest SOC and the lowest SOC in real time, and when the difference is less than 3%, compare the output power of the DC/DC converter in the subsystem where the third highest electrical cabinet is located with the The input powers of the DC/DC converters in the subsystem where the third lowest electrical cabinet is located are all adjusted to 0.
由上述描述可知,当控制各子系统中DC/DC变换器执行相应的输入输出功率后,还需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续输入或输出自身所处子系统的电柜的电量至其他子系统中,而又造成相较之前的反向SOC不均衡;同理,当控制各子系统中DC/DC变换器执行相应的充放电功率后,也需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续以较高或较低的充放电功率工作导致自身所处子系统的电柜的电量过充或过放导致电柜间SOC相较之前又变为反向的不均衡。It can be seen from the above description that after controlling the DC/DC converters in each subsystem to perform the corresponding input and output power, it is also necessary to monitor the SOC status between the electrical cabinets of each subsystem in real time, so as to stop the device in time when the SOC status is close to the same. Determine the working mode of the DC/DC converter, restore each DC/DC converter to the constant voltage mode, and avoid the DC/DC converter in the subsystem with higher or lower SOC to continuously input or output the voltage of the subsystem where it is located. The power of the electric cabinet is transferred to other subsystems, which causes the reverse SOC to be unbalanced compared to the previous one. Similarly, after controlling the DC/DC converters in each subsystem to perform the corresponding charging and discharging power, it is also necessary to monitor each subsystem in real time. The state of the SOC between the cabinets of the subsystem, so that when the SOC state is close to the same, the set working mode of the DC/DC converter can be stopped in time, and the DC/DC converters can be restored to the constant voltage mode again to avoid higher or higher voltage. The DC/DC converter in the subsystem with low SOC continues to work with higher or lower charging and discharging power, resulting in overcharge or overdischarge of the power of the cabinet in the subsystem where it is located, resulting in the SOC between the cabinets becoming higher than before. Reverse imbalance.
本发明提供的一种共直流母线的储能系统SOC均衡方法及系统,适用于又多个子系统构成的储能系统中、同时可继续添加或减少子系统的场景,以下结合实施例具体说明。The SOC equalization method and system of an energy storage system with a common DC bus provided by the present invention is suitable for the scenario of an energy storage system composed of multiple subsystems, and the subsystems can be continuously added or removed at the same time.
请参照图1至图3,本发明的实施例一为:Please refer to FIG. 1 to FIG. 3 , the first embodiment of the present invention is:
一种共直流母线的储能系统SOC均衡方法,在现有如图1所示的由多个子系统构成的储能系统拓扑结构上,在本实施例中,如图2所示,为每个子系统均增加一PCS储能变流器连接电网侧和电柜侧,其中,各子系统PCS的一端并联入电网,另一端各自依次连接一DC/DC变换器和一电柜,且每个子系统的PCS与DC/DC变换器的连接处又通过一条直流母线并联在一起,直流母线的作用可在各子系统间进行电流的互相流向。A method for balancing the SOC of an energy storage system with a common DC bus. On the existing topology of an energy storage system composed of multiple subsystems as shown in FIG. 1 , in this embodiment, as shown in FIG. 2 , for each subsystem A PCS energy storage converter is added to connect the grid side and the electric cabinet side. One end of each subsystem PCS is connected to the grid in parallel, and the other end is connected to a DC/DC converter and an electric cabinet in turn, and each subsystem is connected to the power grid. The connection between the PCS and the DC/DC converter is connected in parallel through a DC bus, and the function of the DC bus can carry out the mutual flow of current between the subsystems.
在本实施例中,PCS储能变流器采用双向AC/DC变换器,当PCS作为AC/DC整流器工作时,可将电网侧的交流电整流为直流电,再经DC/DC变换器进行功率调节后输入电柜进行充电,或是为直流负载供电。值得说明的是,电网侧的交流电也可以不经过PCS逆变为直流电,而是直接为交流负载供电,即如图1所示;同时若PCS作为DC/AC逆变器时,也可以实现将电柜侧经DC/DC变换器进行功率调节输出后的直流电又逆变为交流电给交流负载供电。In this embodiment, the PCS energy storage converter adopts a bidirectional AC/DC converter. When the PCS works as an AC/DC rectifier, it can rectify the alternating current on the grid side into direct current, and then adjust the power through the DC/DC converter. Then input it into the electric cabinet for charging, or supply power to the DC load. It is worth noting that the AC power on the grid side can also be converted into DC power without going through the PCS, but directly supply power to the AC load, as shown in Figure 1; at the same time, if the PCS is used as a DC/AC inverter, it can also be realized. On the cabinet side, the DC power after power regulation and output by the DC/DC converter is converted into AC power to supply power to the AC load.
如图3所示,在本实施例中,包括步骤:As shown in Figure 3, in this embodiment, the steps include:
S0、每个子系统的从机EMS实时检测和采集各自子系统下的PCS的工作状态、电柜的工作状态和电柜的SOC,并发送至主机EMS;S0. The slave EMS of each subsystem detects and collects the working status of the PCS, the working status of the electrical cabinet and the SOC of the electrical cabinet in real time under the respective subsystems, and sends them to the host EMS;
其中,PCS的工作状态包括运行状态和停止状态,运行状态下PCS将电网侧的交流电转换为直流电或者将直流电转换为交流电并入电网侧,停止状态下PCS停止电能转换;Among them, the working state of the PCS includes a running state and a stopped state. In the running state, the PCS converts the alternating current on the grid side into direct current or converts the direct current into alternating current and merges it into the grid side, and in the stopped state, the PCS stops the power conversion;
电柜的工作状态包括充电状态和放电状态。The working state of the electric cabinet includes the charging state and the discharging state.
S1、主机EMS根据储能变流器PCS的工作状态、电柜的工作状态和SOC控制DC/DC变换器的工作模式。S1. The host EMS controls the working mode of the DC/DC converter according to the working state of the energy storage converter PCS, the working state of the electrical cabinet and the SOC.
即在本实施例中,通过为储能系统的多个子系统均配置一PCS,以实现对各子系统的单独调控,并使得各子系统的DC/DC变换器共用一条直流母线,由从机EMS实时检测各子系统中PCS和电柜的工作状态和实时采集各电柜的SOC,并发送至主机EMS,默认条件下设置各子系统的DC/DC变换器采用恒压模式,当各电柜的SOC出现不均衡时,主机EMS能根据PCS和电柜的工作状态和各电柜的SOC来及时调控DC/DC变换器的工作模式,并在直流母线下进行电柜间的电量流转以均衡各子系统充放电流一致,解决储能系统电柜间电量不均流的问题。That is, in this embodiment, a PCS is configured for multiple subsystems of the energy storage system, so as to realize the independent regulation of each subsystem, and make the DC/DC converters of each subsystem share a DC bus, and the slave The EMS detects the working status of PCS and electrical cabinets in each subsystem in real time, collects the SOC of each electrical cabinet in real time, and sends it to the host EMS. By default, the DC/DC converter of each subsystem is set to use constant voltage mode. When the SOC of the cabinet is unbalanced, the host EMS can adjust the working mode of the DC/DC converter in time according to the working status of the PCS and the electric cabinet and the SOC of each electric cabinet, and carry out the power flow between the electric cabinets under the DC bus. Balance the charge and discharge currents of each subsystem to be consistent, and solve the problem of uneven current between the cabinets of the energy storage system.
另外,步骤S0中为每个子系统也各配置一个从机EMS,用于实时检测各子系统中PCS和电柜的工作状态和实时采集各电柜的SOC,及时发送给主机EMS以进行分析和功率值下发,即从机EMS负责传递信息,主机EMS负责控制直流下达,分工明确,互不干扰,也便于后序各子系统DC/DC变换器的工作模式的调控。In addition, in step S0, each subsystem is also equipped with a slave EMS for real-time detection of the working status of the PCS and electrical cabinets in each subsystem and real-time acquisition of the SOC of each electrical cabinet, and timely sent to the host EMS for analysis and analysis. Power value distribution, that is, the slave EMS is responsible for transmitting information, and the host EMS is responsible for controlling the DC distribution. The division of labor is clear and does not interfere with each other, which is also convenient for the regulation of the working mode of the DC/DC converters of the subsequent subsystems.
本发明的实施例二为:The second embodiment of the present invention is:
一种共直流母线的储能系统SOC均衡方法,在上述实施例一的基础上,在本实施例中,所述步骤S1具体为:A method for balancing the SOC of an energy storage system with a common DC bus, on the basis of the above-mentioned first embodiment, in this embodiment, the step S1 is specifically:
所述主机EMS接收并分析所述从机EMS发送的每个所述PCS的工作状态,当每个所述PCS的工作状态均为所述停止状态时,执行步骤S11,当每个所述PCS的工作状态均为所述运行状态时,执行步骤S12,否则进行故障告警。The host EMS receives and analyzes the working state of each PCS sent by the slave EMS. When the working state of each PCS is the stopped state, step S11 is executed, and when each PCS is in the stopped state, step S11 is executed. When the working states of the devices are all the running states, step S12 is performed; otherwise, a fault alarm is performed.
S11、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的SOC:S11. The host EMS receives and analyzes the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第一电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第一电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一电柜的电量输出均分至其余所述子系统中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the first electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the first electrical cabinet is located is controlled to be 10% of the rated power. The output power equally divides the power output of the first electrical cabinet into the remaining subsystems, and controls the DC/DC converters in the remaining subsystems to maintain a constant voltage mode;
实时分析所述第一电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第一电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。Analyze the difference between the SOC of the first electrical cabinet and the lowest SOC in the remaining electrical cabinets in real time, and control the DC/DC conversion in the subsystem where the first electrical cabinet is located when the difference is less than 3% The output power of the device is 0.
若存在第二电柜的SOC低出其他电柜中最高SOC的20%,则控制除所述第二电柜之外的其他电柜所在的所述子系统中的所述DC/DC变换器以额定功率的2%的输出功率将各自所述子系统中的所述电柜的电量输出至所述第二电柜所在的所述子系统中,并控制所述第二电柜所在的所述子系统中的DC/DC变换器保持恒压模式;If there is a second electrical cabinet whose SOC is lower than 20% of the highest SOC among other electrical cabinets, control the DC/DC converters in the subsystems where other electrical cabinets except the second electrical cabinet are located Output the power of the electrical cabinets in the respective subsystems to the subsystem where the second electrical cabinet is located at an output power of 2% of the rated power, and control all the electrical cabinets where the second electrical cabinet is located. The DC/DC converter in the subsystem described above maintains the constant voltage mode;
同时,实时分析所述第二电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。At the same time, the difference between the SOC of the second electrical cabinet and the highest SOC in the remaining electrical cabinets is analyzed in real time, and when the difference is less than 3%, the DC/DC converter in the subsystem where the remaining electrical cabinets are located is controlled. The output power is 0.
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第一最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输出功率将所述第一最高电柜的电量输出、控制具有最低SOC的第一最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的10%的输入功率接收所述第一最高电柜输出的电量为所述第一最低电柜充电,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the first highest electrical cabinet with the highest SOC is located. The DC/DC converter outputs the electricity of the first highest electrical cabinet at an output power of 10% of the rated power, and controls the DC/DC in the subsystem where the first lowest electrical cabinet with the lowest SOC is located. The DC converter receives the power output from the first highest electrical cabinet with an input power of 10% of the rated power to charge the first lowest electrical cabinet, and controls the DC/DC converters in the rest of the subsystems to maintain constant voltage mode;
同时,实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第一最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和第一最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0。At the same time, the difference between the highest SOC and the lowest SOC is analyzed in real time, and when the difference is less than 3%, the output power of the DC/DC converter in the subsystem where the first highest electrical cabinet is located and the The input powers of the DC/DC converters in the subsystem where the first lowest electrical cabinet is located are all adjusted to 0.
否则各所述子系统中的所述DC/DC变换器均保持恒压模式。Otherwise, the DC/DC converters in each of the subsystems maintain the constant voltage mode.
S12、所述主机EMS接收并分析所述从机EMS发送的每个所述电柜的工作状态和SOC,并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式。S12. The host EMS receives and analyzes the working state and SOC of each electric cabinet sent by the slave EMS, and controls the working mode of the DC/DC converter according to the working state and SOC of the electric cabinet .
其中,在本实施例中,所述步骤S12中并根据所述电柜的工作状态和SOC控制所述DC/DC变换器的工作模式,具体为:Wherein, in this embodiment, in the step S12, the working mode of the DC/DC converter is controlled according to the working state and SOC of the electric cabinet, specifically:
当每个所述电柜的工作状态均为所述充电状态时,执行步骤S13,当每个所述电柜的工作状态均为所述放电状态时,执行步骤S14,否则进行故障告警。When the working state of each of the electrical cabinets is the charging state, step S13 is performed; when the working state of each of the electrical cabinets is the discharging state, step S14 is performed; otherwise, a fault alarm is performed.
S13、接收并分析所述从机EMS发送的每个所述电柜的SOC:S13. Receive and analyze the SOC of each of the electrical cabinets sent by the slave EMS:
若存在第三电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第三电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the third electrical cabinet is 20% higher than the lowest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the third electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the third electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
同时,实时分析所述第三电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第三电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。At the same time, the difference between the SOC of the third electrical cabinet and the lowest SOC in the remaining electrical cabinets is analyzed in real time, and when the difference is less than 3%, the DC/DC in the subsystem where the third electrical cabinet is located is controlled. The output power of the DC converter is zero.
若存在第四电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第四电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第四电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the fourth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the fourth electrical cabinet is located is controlled to be 120% of the rated power. The charging power is stored in the fourth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
同时,实时分析所述第四电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。At the same time, the difference between the SOC of the fourth electrical cabinet and the highest SOC in the remaining electrical cabinets is analyzed in real time, and when the difference is less than 3%, the DC/DC converter in the subsystem where the remaining electrical cabinets are located is controlled. The output power is 0.
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第二最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最高电柜中、控制具有最低SOC的第二最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第二最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the second highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 80% of the rated power into the second highest electrical cabinet, where the second lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the second lowest electrical cabinet at a charging power of 120% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
同时,实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第二最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第二最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0。At the same time, the difference between the highest SOC and the lowest SOC is analyzed in real time, and when the difference is less than 3%, the output power and The input powers of the DC/DC converters in the subsystem where the second lowest electrical cabinet is located are all adjusted to 0.
否则各所述子系统中的所述DC/DC变换器均保持恒压模式。Otherwise, the DC/DC converters in each of the subsystems maintain the constant voltage mode.
S24、接收并分析所述从机EMS发送的每个所述电柜的SOC:若存在第五电柜的SOC高出其他电柜中最低SOC的20%,则控制所述第五电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第五电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;S24. Receive and analyze the SOC of each of the electrical cabinets sent by the slave EMS: if there is a fifth electrical cabinet whose SOC is 20% higher than the lowest SOC among other electrical cabinets, control where the fifth electrical cabinet is located. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the fifth electrical cabinet with a charging power of 120% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
同时,实时分析所第五电柜的SOC与其余电柜中最低SOC的差值,当差值小于3%时,控制所述第五电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。At the same time, the difference between the SOC of the fifth electrical cabinet and the lowest SOC in the remaining electrical cabinets is analyzed in real time, and when the difference is less than 3%, the DC/DC in the subsystem where the fifth electrical cabinet is located is controlled. The output power of the converter is 0.
若存在第六电柜的SOC低出其他电柜中最高SOC的20%,则控制所述第六电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第六电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the SOC of the sixth electrical cabinet is lower than 20% of the highest SOC in other electrical cabinets, the DC/DC converter in the subsystem where the sixth electrical cabinet is located is controlled to be 80% of the rated power. The charging power is stored in the sixth electrical cabinet from the DC power converted by the PCS from the grid side, and the DC/DC converters in the remaining subsystems are controlled to maintain a constant voltage mode;
同时,实时分析所述第六电柜的SOC与其余电柜中最高SOC的差值,当差值小于3%时,控制其余电柜所在的所述子系统中的所述DC/DC变换器的输出功率为0。At the same time, the difference between the SOC of the sixth electrical cabinet and the highest SOC in the remaining electrical cabinets is analyzed in real time, and when the difference is less than 3%, the DC/DC converter in the subsystem where the remaining electrical cabinets are located is controlled. The output power is 0.
若所述电柜的SOC中存在最高SOC比最低SOC高出20%,且最低SOC比次低SOC低出10%,则控制具有最高SOC的第三最高电柜所在的所述子系统中的所述DC/DC变换器以额定功率的120%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最高电柜中、控制具有最低SOC的第三最低电柜所在的所述子系统中的所述DC/DC变换器以额定功率的80%的充电功率将从电网侧经所述PCS转换的直流电存储至所述第三最低电柜中,并控制其余所述子系统中的所述DC/DC变换器保持恒压模式;If the highest SOC is 20% higher than the lowest SOC and the lowest SOC is 10% lower than the next lowest SOC in the SOC of the electrical cabinet, control the SOC in the subsystem where the third highest electrical cabinet with the highest SOC is located. The DC/DC converter stores the DC power converted from the grid side via the PCS at a charging power of 120% of the rated power into the third highest electrical cabinet, where the third lowest electrical cabinet with the lowest SOC is controlled. The DC/DC converter in the subsystem stores the DC power converted by the PCS from the grid side into the third lowest electrical cabinet at a charging power of 80% of the rated power, and controls the rest of the sub-systems. the DC/DC converter in the system remains in constant voltage mode;
同时,实时分析最高SOC与最低SOC之间的差值,当差值小于3%时,将所述第三最高电柜所在的所述子系统中的所述DC/DC变换器的输出功率和所述第三最低电柜所在的所述子系统中的所述DC/DC变换器的输入功率均调节为0。At the same time, the difference between the highest SOC and the lowest SOC is analyzed in real time, and when the difference is less than 3%, the output power of the DC/DC converter in the subsystem where the third highest electrical cabinet is located and the The input powers of the DC/DC converters in the subsystem where the third lowest electrical cabinet is located are all adjusted to 0.
否则各所述子系统中的所述DC/DC变换器均保持恒压模式。Otherwise, the DC/DC converters in each of the subsystems maintain the constant voltage mode.
即在本实施例中,当PCS处在停止状态,即PCS停止电能转换时,电网侧输入储能系统的交流电不被转换为直流电输送到子系统的电柜中进行储能或直流负载中进行供电,但此时若是各子系统中的电柜之间SOC存在不均衡,出现单个过高、单个过低或者一高一低时,即可根据各个子系统中电柜的SOC状态控制DC/DC变换器将电柜的电量经由共直流母线的作用下或输出、或输入给其他子系统,以确保各子系统电柜间SOC的均衡、一致。That is, in this embodiment, when the PCS is in a stopped state, that is, when the PCS stops power conversion, the AC power input to the energy storage system on the grid side is not converted into DC power and sent to the electrical cabinet of the subsystem for energy storage or DC load. At this time, if the SOC of the cabinets in each subsystem is unbalanced, and there is a single high, a single too low, or one high and one low, the DC/DC can be controlled according to the SOC status of the cabinets in each subsystem. The DC converter outputs or inputs the power of the electrical cabinet to other subsystems through the common DC bus, so as to ensure the balance and consistency of the SOC among the electrical cabinets of each subsystem.
当控制各子系统中DC/DC变换器执行相应的输入输出功率后,还需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续输入或输出自身所处子系统的电柜的电量至其他子系统中,而又造成相较之前的反向SOC不均衡。After controlling the DC/DC converters in each subsystem to perform the corresponding input and output power, it is also necessary to monitor the SOC status between the electrical cabinets of each subsystem in real time, so as to stop the set DC/DC in time when the SOC status is close to the same The working mode of the converter, restore each DC/DC converter to the constant voltage mode, and prevent the DC/DC converter in the subsystem with higher or lower SOC from continuously inputting or outputting the power of the cabinet of the subsystem where it is located. In other subsystems, it also causes the reverse SOC to be unbalanced compared to the previous one.
同理,当PCS处在运行状态时,即此时PCS会将电网侧的交流电转换为直流电输出为各子系统的电柜进行充能或为直流负载进行供电,而此时的电柜则可能存在被电网侧经PCS转换的直流电进行充电的状态或与电网侧经PCS转换的直流电一起共同为直流负载供电的状态,则无论电柜是在充电还是放电状态下,当电柜的SOC中出现单个过高、单个过低或者一高一低时,也可根据各个子系统中电柜的SOC状态控制DC/DC变换器调整各自所在子系统下的电柜的充电或放电功率,以确保各子系统电柜间充放电的均衡,进一步确保各子系统电柜间SOC的均衡、一致。In the same way, when the PCS is in the running state, that is, at this time, the PCS will convert the AC power on the grid side into DC power and output it to charge the electrical cabinets of each subsystem or supply power for the DC load, while the electrical cabinets at this time may be. There is a state of being charged by the DC power converted by the PCS on the grid side or the state of powering the DC load together with the DC power converted by the PCS on the grid side. When a single is too high, a single is too low or one is high and one is low, the DC/DC converter can also be controlled according to the SOC state of the electrical cabinet in each subsystem to adjust the charging or discharging power of the electrical cabinet under the respective subsystem to ensure that each The balance of charge and discharge between the subsystems and cabinets further ensures the balance and consistency of the SOC between the subsystems and cabinets.
当控制各子系统中DC/DC变换器执行相应的充放电功率后,也需要实时监测各子系统的电柜间SOC的状态,以便在SOC状态接近一致的时候及时停止设定的DC/DC变换器的工作模式,重新恢复各DC/DC变换器为恒压模式,避免较高或较低SOC的子系统中的DC/DC变换器持续以较高或较低的充放电功率工作导致自身所处子系统的电柜的电量过充或过放导致电柜间SOC相较之前又变为反向的不均衡。After controlling the DC/DC converters in each subsystem to perform the corresponding charging and discharging power, it is also necessary to monitor the SOC status between the cabinets of each subsystem in real time, so as to stop the set DC/DC in time when the SOC status is close to the same The working mode of the converter, restore each DC/DC converter to the constant voltage mode, to avoid the DC/DC converter in the subsystem with higher or lower SOC continuously working with higher or lower charging and discharging power, causing itself The overcharge or overdischarge of the power cabinets of the subsystems where the power is located causes the SOC between the cabinets to become reversed and unbalanced compared to the previous ones.
另外,值得说明的是,在本实施例中,各子系统的PCS、电柜的工作状态应当一致,即步骤S1中的主机EMS需要分析每个所述PCS的工作状态是否均为所述停止状态或所述运行状态,以及步骤12中主机EMS还需要分析每个所述电柜的工作状态是否均为所述充电状态或所述放电状态,否则会故障告警。因为本发明所提供的一种共直流母线的储能系统的SOC均衡方法,本身就是建立在储能系统的各子系统再同一运行工况下以解决其产生的电柜间SOC不均衡、充放电电流不均流的问题,因此其前提必然是各子系统的PCS和电柜的工作状态应当是一致相同的。In addition, it is worth noting that, in this embodiment, the working states of the PCS and the electrical cabinet of each subsystem should be consistent, that is, the host EMS in step S1 needs to analyze whether the working state of each PCS is the stop state or the running state, and the host EMS in step 12 also needs to analyze whether the working state of each of the electrical cabinets is the charging state or the discharging state, otherwise a fault alarm will be issued. Because the SOC equalization method of the energy storage system with a common DC bus provided by the present invention is itself established under the same operating condition of each subsystem of the energy storage system to solve the SOC imbalance between the electrical cabinets and the charging The problem of uneven discharge current flow, so the premise must be that the working states of the PCS and the electric cabinet of each subsystem should be consistent and the same.
请参照图4,本发明的实施例三为:Please refer to FIG. 4 , the third embodiment of the present invention is:
一种共直流母线的储能系统SOC均衡系统10,包括主机EMS20和从机EMS30,所述主机EMS20包括第一存储器21、第一处理器22以及存储在第一存储器21上并可在第一处理器22上运行的第一计算机程序,所述从机EMS30包括第二存储器31、第二处理器32以及存储在第二存储器31上并可在第二处理器32上运行的第二计算机程序。An energy storage system
所述第一处理器22在执行所述第一计算机程序时实现如上述实施例一或实施例二中的步骤S1,所述第二处理器32在执行所述第二计算机程序时实现如上述实施例一或实施例二中的步骤S0。When executing the first computer program, the
综上所述,本发明提供的一种共直流母线的储能系统SOC均衡方法及系统,具有以下有益效果:To sum up, the SOC equalization method and system of an energy storage system with a common DC bus provided by the present invention have the following beneficial effects:
1、灵活扩容和缩减子系统,安装方便;1. Flexible expansion and reduction of subsystems, easy installation;
2、解决各子系统电柜间SOC不均衡的问题。2. Solve the problem of unbalanced SOC among the cabinets of various subsystems.
以上所述仅为本发明的实施例,并非因此限制本发明的专利范围,凡是利用本发明说明书及附图内容所作的等同变换,或直接或间接运用在相关的技术领域,均同理包括在本发明的专利保护范围内。The above descriptions are only examples of the present invention, and are not intended to limit the scope of the present invention. Any equivalent transformations made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in related technical fields, are similarly included in the within the scope of patent protection of the present invention.
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