WO2024040670A1

WO2024040670A1 - Method, apparatus, and device for calculating dc component of short-circuit current

Info

Publication number: WO2024040670A1
Application number: PCT/CN2022/120777
Authority: WO
Inventors: 苏寅生; 毛振宇; 徐光虎; 赵利刚; 姚海成; 涂思嘉
Original assignee: 中国南方电网有限责任公司
Priority date: 2022-08-25
Filing date: 2022-09-23
Publication date: 2024-02-29
Also published as: CN115308473A

Abstract

A method, apparatus, and device for calculating a DC component of a short-circuit current. The method comprises: using a fault point when an asymmetric short-circuit fault occurs in a radial network as a split point; acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnet at the fault point; calculating input impedance and equivalent impedance of each subnet according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each subnet; and calculating a DC component of a short-circuit current on the basis of the input impedance and the equivalent impedance of each subnet. Hence, according to the present application, a DC component of a short-circuit current when an asymmetric short-circuit fault occurs in a radial network can be calculated. In addition, according to the present application, the effect of each subnet on the DC component of the short-circuit current can be considered, and compared with calculation of the direct-current component of the short-circuit current only based on the whole radial network, the DC component of the short-circuit current is calculated more accurately.

Description

短路电流直流分量计算方法、装置及设备Short-circuit current DC component calculation method, device and equipment

本申请要求于2022年08月25日提交中国专利局、申请号为202211024945.8、发明名称为“短路电流直流分量计算方法、装置及设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims priority to the Chinese patent application submitted to the China Patent Office on August 25, 2022, with the application number 202211024945.8 and the invention title "Short-circuit current DC component calculation method, device and equipment", the entire content of which is incorporated by reference. in this application.

技术领域Technical field

本申请涉及电网技术领域，更具体地说，涉及一种短路电流直流分量计算方法、装置及设备。The present application relates to the field of power grid technology, and more specifically, to a method, device and equipment for calculating the DC component of short-circuit current.

背景技术Background technique

电网中为了降低输电损耗，发电机、变压器的容量逐步增大，电网中直流线路及交流线路的电阻逐步减小。但发电机及变压器容量的增大及输电线路电阻的减小，导致电网发生短路故障时，短路故障点等效***的电抗电阻比越来越大，短路电流直流分量随之增大，基于此，短路电流直流分量对电网的影响日益突出。In order to reduce transmission losses in the power grid, the capacity of generators and transformers is gradually increased, and the resistance of DC lines and AC lines in the power grid is gradually reduced. However, as the capacity of generators and transformers increases and the resistance of transmission lines decreases, when a short-circuit fault occurs in the power grid, the reactance-to-resistance ratio of the equivalent system at the short-circuit fault point becomes larger and larger, and the DC component of the short-circuit current increases accordingly. Based on this , the DC component of short-circuit current has an increasingly prominent impact on the power grid.

现有技术中仅提出了电网发生对称短路时，短路电流直流分量的计算方法，并未提出电网发生不对称短路时，短路电流直流分量的计算方法。The existing technology only proposes a method for calculating the DC component of the short-circuit current when a symmetrical short-circuit occurs in the power grid, but does not propose a method for calculating the DC component of the short-circuit current when an asymmetric short-circuit occurs in the power grid.

发明内容Contents of the invention

有鉴于此，本申请提供了一种短路电流直流分量计算方法、装置及设备，用于计算电网发生不对称短路时的短路电流直流分量。In view of this, this application provides a short-circuit current DC component calculation method, device and equipment for calculating the short-circuit current DC component when an asymmetric short circuit occurs in the power grid.

为了实现上述目的，现提出的方案如下：In order to achieve the above objectives, the following solutions are proposed:

一种短路电流直流分量计算方法，包括：A method for calculating the DC component of short-circuit current, including:

以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网；Taking the fault point when an asymmetric short-circuit fault occurs in the radial network as the split point, split the radial network into multiple subnets;

获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗；Obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point;

根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗；Calculate each sub-network according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point. The input impedance and equivalent impedance of the network;

基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。The DC component of the short-circuit current is calculated based on the input impedance and equivalent impedance of each of the subnets.

可选的，所述获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，包括：Optionally, obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point. ,include:

确定发生所述不对称短路故障的故障时间，及所述不对称短路故障发生后的目标时间，所述目标时间为不对称短路故障持续过程中的任意时刻；Determine the fault time when the asymmetric short-circuit fault occurs, and the target time after the asymmetric short-circuit fault occurs, where the target time is any time during the duration of the asymmetric short-circuit fault;

计算所述目标时间与所述故障时间之间的目标时间差；Calculating a target time difference between the target time and the failure time;

基于所述目标时间差，确定与所述目标时间对应的等效频率；Based on the target time difference, determine an equivalent frequency corresponding to the target time;

根据所述目标时间对应的等效频率，计算与所述目标时间对应的各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗。According to the equivalent frequency corresponding to the target time, calculate the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork corresponding to the target time at the fault point.

可选的，所述根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗，包括：Optionally, the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point , calculate the input impedance and equivalent impedance of each subnet, including:

确定所述不对称短路故障的故障类型，所述故障类型为单相短路故障、两相短路故障或两相短路接地故障；Determine the fault type of the asymmetric short-circuit fault, where the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit to ground fault;

调用预置的与所述故障类型对应的输入阻抗解析式及等效阻抗解析式；Call the preset input impedance analytical formula and equivalent impedance analytical formula corresponding to the fault type;

利用每一子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗，及与所述故障类型对应的输入阻抗解析式，计算得到每一子网的输入阻抗；Calculate the input impedance of each subnetwork using the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each subnetwork at the fault point, and the input impedance analytical formula corresponding to the fault type;

利用每一子网在所述故障点的正序等效阻抗、负序等效阻抗、零序等效阻抗，及与所述故障类型对应的等效阻抗解析式，计算得到每一子网的等效阻抗。Using the positive sequence equivalent impedance, negative sequence equivalent impedance, zero sequence equivalent impedance of each subnet at the fault point, and the equivalent impedance analytical formula corresponding to the fault type, the value of each subnet is calculated. Equivalent impedance.

可选的，基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量，包括：Optionally, calculate the DC component of the short-circuit current based on the input impedance and equivalent impedance of each subnet, including:

计算并联阻抗，所述并联阻抗等于1与各个所述子网的输入阻抗的倒数之和之间的比值；Calculate a parallel impedance equal to the ratio between 1 and the sum of the reciprocals of the input impedances of each of the subnetworks;

获取故障点等效电压源；Obtain the equivalent voltage source of the fault point;

将所述故障点等效电压源及所述并联阻抗之间的比值作为短路电流初始值；The ratio between the equivalent voltage source at the fault point and the parallel impedance is used as the initial value of the short-circuit current;

利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量。The DC component of the short-circuit current is calculated using the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the initial value of the short-circuit current.

可选的，利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量，包括：Optionally, the DC component of the short-circuit current is calculated using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current, including:

将所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，代入预置的短路电流直流分量的解析式，计算得到所述短路电流直流分量。Substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into the preset analytical formula of the DC component of the short-circuit current, the short-circuit current is calculated DC component.

可选的，所述短路电流直流分量的解析式为：Optionally, the analytical formula of the DC component of the short-circuit current is:

其中，I _dc为短路电流直流分量，N为各个所述子网的总数量，I _k"为短路电流初始值，Z _equ为并联阻抗，x为子网的编号，Z _xequ为编号为x的子网的输入阻抗，T _xa为编号为x的子网的短路电流直流分量衰减时间常数，t为当前时间与故障时间的时间差。 Among them, I _dc is the DC component of the short-circuit current, N is the total number of each sub-network, I _k " is the initial value of the short-circuit current, Z _equ is the parallel impedance, x is the number of the sub-network, Z _xequ is the number of The input impedance of the subnet, _Txa is the attenuation time constant of the short-circuit current DC component of the subnet numbered x, and t is the time difference between the current time and the fault time.

可选的，所述编号为x的子网的短路电流直流分量衰减时间常数的解析式为：Optionally, the analytical formula of the attenuation time constant of the short-circuit current DC component of the subnetwork numbered x is:

其中，Z _xCequ为编号为x的子网的等效阻抗，f _c为t对应的该编号为x的子网的等效频率。 Among them, Z _xCequ is the equivalent impedance of the subnet numbered x, and f _c is the equivalent frequency of the subnet numbered x corresponding to t.

可选的，所述以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网，包括：Optionally, the fault point when an asymmetric short circuit fault occurs in the radial network is used as the split point, and the radial network is split into multiple subnets, including:

判断所述故障点是否处于所述辐射形网络的线路上；Determine whether the fault point is on the line of the radial network;

若所述故障点处于所述辐射形网络的线路上，则以辐射形网络短路故障时的故障点为拆分点，将所述辐射形网络拆分为两个子网；If the fault point is on the line of the radial network, then the fault point when the radial network is short-circuited is used as the split point, and the radial network is split into two subnets;

若所述故障点并未处于所述辐射形网络的线路上，则所述故障点为所述辐射形网络的节点，以发生所述不对称短路故障的节点为拆分点，对所述辐射形网络进行拆分，其中，所述子网的数量等于汇入该节点的支路数，每一子网中包含有一个汇入该节点的支路，各子网中所包含的汇入该节点的支路并不相同。If the fault point is not on the line of the radial network, the fault point is a node of the radial network, and the node where the asymmetric short circuit fault occurs is the split point, and the radial The network is split, where the number of the subnets is equal to the number of branches that flow into the node, each subnet contains a branch that flows into the node, and each subnet contains a branch that flows into the node. The branches of nodes are not the same.

一种短路电流直流分量计算装置，包括：A short-circuit current DC component calculation device, including:

拆分单元，用于以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网；A splitting unit configured to use the fault point when an asymmetric short-circuit fault occurs in the radial network as the splitting point to split the radial network into multiple subnets;

获取单元，用于获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗；An acquisition unit, used to acquire the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point;

计算单元，根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗；The calculation unit calculates each subnetwork based on the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point. The input impedance and equivalent impedance of the subnetwork;

利用单元，用于基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。A utilization unit is used to calculate the DC component of the short-circuit current based on the input impedance and equivalent impedance of each of the subnetworks.

一种短路电流直流分量计算设备，包括存储器和处理器；A short-circuit current DC component calculation device, including a memory and a processor;

所述存储器，用于存储程序；The memory is used to store programs;

所述处理器，用于执行所述程序，实现上述的短路电流直流分量计算方法的各个步骤。The processor is used to execute the program and implement each step of the above-mentioned method for calculating the DC component of the short-circuit current.

一种可读存储介质，其上存储有计算机程序，所述计算机程序被处理器执行时，实现如上述的短路电流直流分量计算方法的各个步骤。A readable storage medium on which a computer program is stored. When the computer program is executed by a processor, each step of the above-mentioned short-circuit current DC component calculation method is implemented.

从上述的技术方案可以看出，本申请提供的短路电流直流分量计算方法，首先可以将辐射形网络发生不对称短路故障时的故障点作为拆分点，将所述辐射形网络拆分为多个子网，如此，本申请仅在电网发生不对称短路时，且电网为辐射形网络时执行；随后，可以获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗、零序等效阻抗；根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗，最后，可以基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。可见，本申请可以计算辐射形网络发生不对称短路故障时的短路电流直流分量。It can be seen from the above technical solution that the short-circuit current DC component calculation method provided by this application can first use the fault point when an asymmetric short-circuit fault occurs in the radial network as the split point, and split the radial network into multiple subnet, in this way, this application is only executed when an asymmetric short circuit occurs in the power grid and the power grid is a radial network; subsequently, the positive sequence input impedance, negative sequence input impedance, and Zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance, zero sequence equivalent impedance; according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each subnet at the fault point, Positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance are used to calculate the input impedance and equivalent impedance of each of the subnets. Finally, based on the input impedance and equivalent impedance of each of the subnets, the calculation The DC component of the short-circuit current. It can be seen that this application can calculate the DC component of the short-circuit current when an asymmetric short-circuit fault occurs in the radial network.

此外，本申请中可以基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量，如此，可以逐一考虑每一子网对短路电流直流分量的影响，相比于仅仅基于整个辐射形网络计算短路电流直流分量，能够更准确地计算得出短路电流直流分量。In addition, in this application, the DC component of the short-circuit current can be calculated based on the input impedance and equivalent impedance of each sub-network. In this way, the impact of each sub-network on the DC component of the short-circuit current can be considered one by one. Compared with simply based on The entire radial network calculates the DC component of the short-circuit current and can calculate the DC component of the short-circuit current more accurately.

附图说明Description of drawings

为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据提供的附图获得其他的附图。In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only This is an embodiment of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

图1为本申请公开的一种短路电流直流分量计算方法流程图；Figure 1 is a flow chart of a method for calculating the DC component of short-circuit current disclosed in this application;

图2为本申请公开的一种短路电流直流分量计算装置结构框图；Figure 2 is a structural block diagram of a short-circuit current DC component calculation device disclosed in this application;

图3为本申请公开的一种短路电流直流分量计算设备的硬件结构框图。Figure 3 is a hardware structure block diagram of a short-circuit current DC component calculation device disclosed in this application.

具体实施方式Detailed ways

下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

本申请提供的短路电流直流分量计算方法，可以应用于辐射形网络中，属于电网技术领域，本申请可以计算辐射形网络发生不对称短路故障时的短路电流的直流分量。The method for calculating the DC component of short-circuit current provided by this application can be applied to radial networks and belongs to the field of power grid technology. This application can calculate the DC component of short-circuit current when an asymmetric short-circuit fault occurs in a radial network.

接下来结合图1对本申请的短路电流直流分量计算方法进行详细介绍，包括如下步骤：Next, the calculation method of the short-circuit current DC component of this application will be introduced in detail in conjunction with Figure 1, including the following steps:

步骤S1、以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网。Step S1: Use the fault point when an asymmetric short-circuit fault occurs in the radial network as the split point, and split the radial network into multiple subnets.

具体地，可对发生不对称短路故障的辐射形网络进行拆分，在拆分过程中，可将发生故障的故障点作为拆分点，并基于拆分点与该辐射形网络中所处的位置，确定拆分的方式，拆分后得到多个子网。各个所述子网组合可以得到完整的辐射形网络。Specifically, a radial network in which an asymmetric short-circuit fault occurs can be split. During the splitting process, the fault point where the fault occurs can be used as the split point, and based on the split point and the location in the radial network, Location, determine the splitting method, and obtain multiple subnets after splitting. Each combination of the subnets can result in a complete radial network.

步骤S2、获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗。Step S2: Obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point.

具体地，可以根据辐射形网络构建各个所述子网的正序节点导纳矩阵、负序节点导纳矩阵及零序节点导纳矩阵。各节点导纳矩阵的表现形式如下：Specifically, the positive sequence node admittance matrix, the negative sequence node admittance matrix, and the zero sequence node admittance matrix of each subnetwork can be constructed according to the radial network. The expression of the admittance matrix of each node is as follows:

其中，正序节点导纳矩阵、负序节点导纳矩阵及零序节点导纳矩阵中的对角线元素Y _ii称为节点i的自导纳，其值等于接于节点i的所有支路导纳之和；非对角线元素Y _ij称为节点i及节点j间的导纳，其值等于接于节点i及节点j间的支路导纳的负值，若节点i及节点j间不存在直接支路则Y _ij＝0。因此，任何电网拓扑连接关系都可用节点导纳矩阵描述。 Among them, the diagonal element Y _ii in the positive sequence node admittance matrix, negative sequence node admittance matrix and zero sequence node admittance matrix is called the self-admittance of node i, and its value is equal to all branches connected to node i The sum of admittances; the off-diagonal element Y _ij is called the admittance between node i and node j, and its value is equal to the negative value of the branch admittance connected between node i and node j. If node i and node j If there is no direct branch between them, Y _ij =0. Therefore, any power grid topological connection relationship can be described by the node admittance matrix.

具体地，导纳解析式为：Specifically, the analytical formula of admittance is:

其中，Z _ij为节点i及节点j间的支路阻抗，R _ij为节点i及节点j间的支路电阻，X _ij为节点i及节点j间的支路电抗，为避免符号冲突用J表示虚部单位，w是辐射形网络运转的角速度，L _ij是节点i及节点j间的线圈电感。 Among them, Z _ij is the branch impedance between node i and node j, R _ij is the branch resistance between node i and node j, X _ij is the branch reactance between node i and node j, and J is used to avoid symbol conflict. represents the imaginary unit, w is the angular velocity of the radial network operation, and L _ij is the coil inductance between node i and node j.

可采用等效频率法对各个子网的正序节点导纳矩阵进行修正，得到等效频率下的各个子网的正序节点等效导纳矩阵；采用等效频率法对各个子网的负序节点导纳矩阵进行修正，得到等效频率下的各个子网的负序节点等效导纳矩阵；采用等效频率法对各个子网的零序节点等效导纳矩阵进行修正，得到等效频率下的各个子网的零序节点导纳矩阵。The equivalent frequency method can be used to correct the positive-sequence node admittance matrix of each subnet, and the positive-sequence node equivalent admittance matrix of each subnet at the equivalent frequency can be obtained; the equivalent frequency method can be used to correct the negative-sequence node admittance matrix of each subnet. The sequence node admittance matrix is corrected to obtain the negative sequence node equivalent admittance matrix of each subnet at the equivalent frequency; the equivalent frequency method is used to correct the zero sequence node equivalent admittance matrix of each subnet, and the equivalent admittance matrix of each subnet is obtained. The zero-sequence node admittance matrix of each subnetwork at the effective frequency.

具体地，等效频率下的导纳解析式为：Specifically, the analytical formula of admittance at equivalent frequency is:

其中，Y _Cij为等效频率下的导纳，Z _Cij为节点i及节点j间的等效频率下的支路阻抗，R _Cij为节点i及节点j间等效频率下的支路电阻，X _Cij为节点i及节点j间等效频率下的支路电抗，为避免符号冲突用J表示虚部单位，w _c是辐射形网络运转的角速度。 Among them, Y _Cij is the admittance at the equivalent frequency, Z _Cij is the branch impedance at the equivalent frequency between node i and node j, R _Cij is the branch resistance at the equivalent frequency between node i and node j, X _Cij is the branch reactance at the equivalent frequency between node i and node j. To avoid symbol conflict, J is used to represent the imaginary unit, and w _c is the angular velocity of the radial network operation.

当确定等效频率后，可以根据上述等效频率下的导纳解析式计算各个子网对应的零序节点等效导纳矩阵、正序节点等效导纳矩阵及负序节点等效导纳矩阵中的各个等效导纳，其中等效导纳为等效频率下的导纳。After the equivalent frequency is determined, the zero-sequence node equivalent admittance matrix, the positive-sequence node equivalent admittance matrix, and the negative-sequence node equivalent admittance corresponding to each subnet can be calculated based on the admittance analytical formula at the above equivalent frequency. Each equivalent admittance in the matrix, where the equivalent admittance is the admittance at the equivalent frequency.

各个子网的零序节点导纳矩阵、正序节点导纳矩阵、负序节点导纳矩阵、零序节点等效导纳矩阵、正序节点等效导纳矩阵及负序节点等效导纳矩阵组成辐射形网络节点导纳矩阵集合，可对辐射形网络节点导纳矩阵集合中的每一导纳矩阵进行处理，得到各个子网的零序节点阻抗矩阵、正序节点阻抗矩阵、负序节点阻抗矩阵、零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵。Zero sequence node admittance matrix, positive sequence node admittance matrix, negative sequence node admittance matrix, zero sequence node equivalent admittance matrix, positive sequence node equivalent admittance matrix and negative sequence node equivalent admittance of each subnet The matrix forms a radial network node admittance matrix set. Each admittance matrix in the radial network node admittance matrix set can be processed to obtain the zero-sequence node impedance matrix, positive-sequence node impedance matrix, and negative-sequence node impedance matrix of each subnetwork. Node impedance matrix, zero sequence node equivalent impedance matrix, positive sequence node equivalent impedance matrix and negative sequence node equivalent impedance matrix.

其中，处理的过程中，可以对每一导纳矩阵进行三角分解，得到各因子矩阵，即Y＝LDU，Y为导纳矩阵，U及L互为转置，L为单位下三角矩阵，D为对角矩阵，U为单位上三角矩阵。Among them, during the processing, each admittance matrix can be triangulated to obtain each factor matrix, that is, Y = LDU, Y is the admittance matrix, U and L are the transposes of each other, L is the unit lower triangular matrix, D is a diagonal matrix, and U is a unit upper triangular matrix.

U、D及L中的各个元素的计算解析式如下所示：The analytical formulas for calculating each element in U, D and L are as follows:

d _ii为D矩阵中第i行第i列的元素；u _ij为U矩阵中第i行第j列的元素；l _ij为L矩阵中第i行第j列的元素。 d _ii is the element in row i and column i in D matrix; u _ij is the element in row i and column j in matrix U; l _ij is the element in row i and column j in matrix L.

由U、D及L中的各个元素组成因子表如下所示：The factor table composed of each element in U, D and L is as follows:

通过上述方式得到每一导纳矩阵对应的因子表后，可以通过下述解析式计算每一导纳矩阵对应的阻抗矩阵的第j列的各个元素：After obtaining the factor table corresponding to each admittance matrix through the above method, each element of the j-th column of the impedance matrix corresponding to each admittance matrix can be calculated through the following analytical formula:

基于此，计算得到每一子网对应的零序节点阻抗矩阵、正序节点阻抗矩阵、负序节点阻抗矩阵、零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵。Based on this, the zero-sequence node impedance matrix, positive-sequence node impedance matrix, negative-sequence node impedance matrix, zero-sequence node equivalent impedance matrix, positive-sequence node equivalent impedance matrix and negative-sequence node equivalent corresponding to each subnet are calculated. impedance matrix.

根据故障点在辐射形网络中的位置，确定每一个子网对应的零序节点阻抗矩阵、正序节点阻抗矩阵、负序节点阻抗矩阵、零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵中与故障点对应的阻抗，得到故障点与每一子网对应的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗及零序等效阻抗。According to the location of the fault point in the radial network, determine the zero-sequence node impedance matrix, positive-sequence node impedance matrix, negative-sequence node impedance matrix, zero-sequence node equivalent impedance matrix, and positive-sequence node equivalent impedance corresponding to each subnet. The impedance corresponding to the fault point in the matrix and the negative sequence node equivalent impedance matrix is used to obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, and negative sequence corresponding to the fault point and each subnet. Equivalent impedance and zero sequence equivalent impedance.

步骤S3、根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗。Step S3: Calculate each sub-network according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance at the fault point. The input impedance and equivalent impedance of the subnet.

具体地，可以通过对每一子网与故障点对应的正序输入阻抗、负序输入阻抗及零序输入阻抗进行处理，得到该子网的输入阻抗。Specifically, the input impedance of the subnet can be obtained by processing the positive sequence input impedance, negative sequence input impedance and zero sequence input impedance corresponding to each subnet and the fault point.

通过对每一子网与故障点对应的正序等效阻抗、负序等效阻抗和零序等效阻抗进行处理，得到该子网的等效阻抗。By processing the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnet and the fault point, the equivalent impedance of the subnet is obtained.

步骤S4、基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。Step S4: Calculate the DC component of the short-circuit current based on the input impedance and equivalent impedance of each sub-network.

具体地，通过对各个子网的输入阻抗及等效阻抗进行处理，得到每个子网对短路电流直流分量的贡献值，将各个子网对应的贡献值相加，相加后得到的结果为短路电流直流分量。Specifically, by processing the input impedance and equivalent impedance of each subnet, the contribution value of each subnet to the DC component of the short-circuit current is obtained. The corresponding contribution values of each subnet are added up. The result obtained after the addition is short circuit. DC component of current.

从上述的技术方案可以看出，本申请实施例提供的短路电流直流分量计算方法，首先可以将辐射形网络发生不对称短路故障时的故障点作为拆分点，将所述辐射形网络拆分为多个子网，如此，本申请仅在电网发生不对称短路时，且电网为辐射形网络时执行；随后，可以获取各个子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗、零序等效阻抗；根据各个子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗，最后，可以基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。可见，本申请可以计算辐射形网络发生不对称短路故障时的短路电流直流分量。It can be seen from the above technical solution that the short-circuit current DC component calculation method provided by the embodiment of the present application can first use the fault point when an asymmetric short-circuit fault occurs in the radial network as the split point, and split the radial network. There are multiple subnets, so this application is only executed when an asymmetric short circuit occurs in the power grid and the power grid is a radial network; subsequently, the positive sequence input impedance, negative sequence input impedance, and negative sequence input impedance of each subnet at the fault point can be obtained. Zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance, zero sequence equivalent impedance; according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence of each subnet at the fault point Equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance are used to calculate the input impedance and equivalent impedance of each subnet. Finally, the input impedance and equivalent impedance of each subnet can be calculated based on the input impedance and equivalent impedance of each subnet. DC component of short circuit current. It can be seen that this application can calculate the DC component of the short-circuit current when an asymmetric short-circuit fault occurs in the radial network.

在本申请的一些实施例中，对步骤S1，以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网的过程进行详细说明，具体步骤如下：In some embodiments of the present application, step S1 is described in detail, taking the fault point when an asymmetric short-circuit fault occurs in the radial network as the splitting point, and splitting the radial network into multiple subnets. Specifically, Proceed as follows:

S10、判断所述故障点是否处于所述辐射形网络的线路上，若是，则执行步骤S11，若否，则执行步骤S12。S10. Determine whether the fault point is on the line of the radial network. If so, perform step S11. If not, perform step S12.

具体地，对于发生不对称故障的辐射形网络而言，故障点可能处于辐射形网络的线路上，也可能为辐射形网络的节点。当故障点处于不同的位置时，拆分辐射形网络的方式也会不同。Specifically, for a radial network where an asymmetric fault occurs, the fault point may be on a line of the radial network or a node of the radial network. When the fault points are in different locations, the way of splitting the spoke network will be different.

S11、以辐射形网络故障时的故障点为拆分点，将所述辐射形网络拆分为两个子网。S11. Taking the fault point when the radial network fails as the split point, split the radial network into two subnets.

当所述故障点为所述辐射形网络的线路，则可以直接在故障点处对辐射形网络进行分割，将辐射形网络分割为两个子网。When the fault point is a line of the radial network, the radial network can be divided directly at the fault point to divide the radial network into two subnets.

两个子网在故障点处拼接后，可以得到完整的辐射形网络。After the two subnets are spliced at the fault point, a complete radial network can be obtained.

S12、以发生所述不对称短路故障的节点为拆分点，对所述辐射形网络进行拆分，其中，所述子网的数量等于汇入该节点的支路数，每一子网中包含有一个汇入该节点的支路，各子网中所包含的汇入该节点的支路并不相同。S12. Use the node where the asymmetric short-circuit fault occurs as a split point to split the radial network. The number of subnets is equal to the number of branches flowing into the node. In each subnet, There is a branch that flows into the node. The branches that flow into the node are different in each subnet.

具体地，当所述故障点为所述辐射形网络的节点时，则可以直接在故障点处对辐射形网络进行分割，将辐射形网络分割为与故障点支路数相同数量的子网。Specifically, when the fault point is a node of the radial network, the radial network can be divided directly at the fault point, and the radial network can be divided into subnets with the same number of branches as the fault point.

由上述的技术方案可以看出，相比于上一个实施例，本实施例提供了一种分割辐射形网络为多个子网的可选的方式，通过上述的方式，可以针对故障点所处的位置，对辐射形网络进行拆分，从而更好地计算得到短路电流直流分量。It can be seen from the above technical solution that compared with the previous embodiment, this embodiment provides an optional method of dividing the radial network into multiple subnets. Through the above method, it is possible to target the location of the fault point. Position, split the radial network to better calculate the DC component of the short-circuit current.

在本申请的一些实施例中，对步骤S2中获取各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗的过程进行详细说明，步骤如下：In some embodiments of the present application, the process of obtaining the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point in step S2 is described in detail. The steps are as follows :

S20、确定发生所述不对称短路故障的故障时间，及所述不对称短路故障发生后的目标时间，所述目标时间为不对称短路故障持续过程中的任意时刻。S20. Determine the fault time when the asymmetric short-circuit fault occurs and the target time after the asymmetric short-circuit fault occurs. The target time is any time during the duration of the asymmetric short-circuit fault.

具体地，在发生不对称短路故障后，可以计算任意时刻对应的短路电流直流分量。因而，可以确定需要得到短路电流直流分量的时刻，将该时刻作为目标时间。Specifically, after an asymmetric short-circuit fault occurs, the corresponding DC component of the short-circuit current at any time can be calculated. Therefore, the time at which the DC component of the short-circuit current needs to be obtained can be determined and used as the target time.

S21、计算所述目标时间与所述故障时间之间的目标时间差。S21. Calculate the target time difference between the target time and the failure time.

具体地，可以计算目标时间与故障时间之间的差值，并将该差值作为目标时间差，该目标时间差表明故障时间至目标时间所经过的时间长度。Specifically, the difference between the target time and the failure time can be calculated and used as the target time difference. The target time difference indicates the length of time that elapses from the failure time to the target time.

S22、基于所述目标时间差，确定与所述目标时间对应的等效频率。S22. Based on the target time difference, determine the equivalent frequency corresponding to the target time.

具体地，乘积与比值之间存在对应关系，乘积为目标时间和故障时间的时间差，比值为等效频率和辐射形网络的额定频率之间的比值。Specifically, there is a correspondence between the product and the ratio, where the product is the time difference between the target time and the failure time, and the ratio is the ratio between the equivalent frequency and the rated frequency of the radial network.

表1中记录了乘积与比值之间存在对应关系。t为目标时间与故障时间的时间差，f _c为等效频率，f为额定频率。 Table 1 records the corresponding relationship between the product and the ratio. t is the time difference between the target time and the fault time, f _c is the equivalent frequency, and f is the rated frequency.

表1Table 1

f·tf·t	[0，1)[0,1)	[0，2.5)[0,2.5)	[2.5，5)[2.5,5)	[5，∞)[5,∞)
f _c/f f _c /f	0.270.27	0.150.15	0.0920.092	0.0550.055

因而，确定目标时间差后，可以计算目标时间差与辐射形网络的额定频率之间的乘积，确定该乘积的范围，并确定该范围对应的等效频率与额定频率之间的比值，将额定频率与该比值相乘，得到的结果即为等效频率。Therefore, after determining the target time difference, you can calculate the product between the target time difference and the rated frequency of the radial network, determine the range of the product, and determine the ratio between the equivalent frequency corresponding to the range and the rated frequency, and compare the rated frequency and The ratios are multiplied and the result is the equivalent frequency.

S23、根据所述目标时间对应的等效频率，计算与所述目标时间对应的各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗。S23. According to the equivalent frequency corresponding to the target time, calculate the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork corresponding to the target time at the fault point.

具体地，在确定了等效频率后，可以通过上述的等效频率下的导纳解析式，确定目标时间对应的各个子网的零序节点等效导纳矩阵、正序节点等效导纳矩阵及负序节点等效导纳矩阵中的各个等效导纳。Specifically, after the equivalent frequency is determined, the zero-sequence node equivalent admittance matrix and positive-sequence node equivalent admittance of each subnetwork corresponding to the target time can be determined through the above-mentioned admittance analytical formula at the equivalent frequency. Each equivalent admittance in the matrix and negative sequence node equivalent admittance matrix.

基于上述对辐射形网络节点导纳矩阵集合中的每一导纳矩阵进行处理，得到各个子网的零序节点阻抗矩阵、正序节点阻抗矩阵、负序节点阻抗矩阵、零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵的方法，得到目标时间对应的零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵。Based on the above, each admittance matrix in the radial network node admittance matrix set is processed to obtain the zero-sequence node impedance matrix, positive-sequence node impedance matrix, negative-sequence node impedance matrix, and zero-sequence node equivalent impedance of each subnetwork. The method of matrix, positive sequence node equivalent impedance matrix and negative sequence node equivalent impedance matrix is used to obtain the zero sequence node equivalent impedance matrix, positive sequence node equivalent impedance matrix and negative sequence node equivalent impedance matrix corresponding to the target time.

从目标时间对应的零序节点等效阻抗矩阵、正序节点等效阻抗矩阵及负序节点等效阻抗矩阵中，选取与故障点对应的等效阻抗，得到目标时间对应的各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗、零序等效阻抗。From the equivalent impedance matrix of zero-sequence nodes, the equivalent impedance matrix of positive-sequence nodes, and the equivalent impedance matrix of negative-sequence nodes corresponding to the target time, select the equivalent impedance corresponding to the fault point to obtain each of the subnetworks corresponding to the target time. Positive sequence equivalent impedance, negative sequence equivalent impedance, and zero sequence equivalent impedance at the fault point.

从上述技术方案可以看出，相比于上述实施例，本实施例提供了一种确定各个子网在故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗的可选的方式。通过上述实施例可以对故障发生后的时间进行分段，每段时间中所对应的等效频率并不相同，等效频率的不同，每一子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗也会改变，正序等效阻抗、负序等效阻抗和零序等效阻抗的不同，各个子网的等效阻抗亦会不同，等效阻抗不同最终会导致不同时间段下的短路电流直流分量的不同。基于此，在不同时间段下，短路电流直流分量不同。其中，分段是基于额定频率确定的，更为可靠。因而，本实施例提供的方式提高了计算短路电流直流分量的可靠性。通过求取不同时间段下的等效阻抗及输入阻抗，能够减少各支路阻抗比L/R相差较大时的误差，进一步提高本申请计算得到的短路电流直流分量的准确性。It can be seen from the above technical solution that compared with the above embodiment, this embodiment provides an optional method of determining the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point. The way. Through the above embodiment, the time after the fault occurs can be divided into segments. The corresponding equivalent frequencies in each period are different. Depending on the equivalent frequency, the positive sequence equivalent impedance of each subnet at the fault point is , the negative sequence equivalent impedance and the zero sequence equivalent impedance will also change. The difference between the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance will also cause the equivalent impedance of each subnet to be different. The equivalent impedance The difference will ultimately lead to differences in the DC component of the short-circuit current in different time periods. Based on this, the DC component of the short-circuit current is different in different time periods. Among them, the segmentation is determined based on the rated frequency, which is more reliable. Therefore, the method provided by this embodiment improves the reliability of calculating the DC component of the short-circuit current. By calculating the equivalent impedance and input impedance in different time periods, the error when the impedance ratio L/R of each branch is greatly different can be reduced, and the accuracy of the DC component of the short-circuit current calculated in this application can be further improved.

在本申请的一些实施例中，对步骤S3，根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗的过程进行详细说明，步骤如下：In some embodiments of the present application, for step S3, according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, and negative sequence equivalent of each subnetwork at the fault point Impedance and zero-sequence equivalent impedance, the process of calculating the input impedance and equivalent impedance of each of the subnetworks will be described in detail. The steps are as follows:

S30、确定所述不对称短路故障的故障类型，所述故障类型为单相短路故障、两相短路故障或两相短路接地故障。S30. Determine the fault type of the asymmetric short-circuit fault. The fault type is a single-phase short-circuit fault, a two-phase short-circuit fault, or a two-phase short-circuit to ground fault.

具体地，不对称短路故障的故障类型有单相短路故障、两相短路故障或两相短路接地故障这三种。Specifically, there are three types of asymmetric short-circuit faults: single-phase short-circuit fault, two-phase short-circuit fault or two-phase short-circuit to ground fault.

基于发生不对称短路故障的故障点的各支路连接方式，确定故障类型为单相短路故障、两相短路故障或两相短路接地故障。Based on the connection mode of each branch at the fault point where an asymmetric short-circuit fault occurs, the fault type is determined to be a single-phase short-circuit fault, a two-phase short-circuit fault, or a two-phase short-circuit to ground fault.

S31、调用预置的与所述故障类型对应的输入阻抗解析式及等效阻抗解析式。S31. Call the preset input impedance analytical formula and equivalent impedance analytical formula corresponding to the fault type.

具体地，针对不同的故障类型存在不同的计算阻抗的方式，通过解析式可以计算得到各个子网对应的输入阻抗及等效阻抗。Specifically, there are different methods of calculating impedance for different fault types. The input impedance and equivalent impedance corresponding to each subnet can be calculated through analytical formulas.

其中，输入阻抗解析式为：Among them, the input impedance analytical formula is:

其中，Z _xequ为编号x的子网的输入阻抗，

为编号x的子网在故障点的正序输入阻抗，

为编号x的子网在故障点的负序输入阻抗，

为编号x的子网在故障点的零序输入阻抗。 Among them, Z _xequ is the input impedance of the subnet numbered x,

is the positive sequence input impedance of the subnet numbered x at the fault point,

is the negative sequence input impedance of the subnet numbered x at the fault point,

is the zero-sequence input impedance of the subnetwork numbered x at the fault point.

等效阻抗解析式为：The equivalent impedance analytical formula is:

其中，Z _xCequ为编号x的子网的输入阻抗，

为编号x的子网在故障点的正序输入阻抗，

为编号x的子网在故障点的负序输入阻抗，

为编号x的子网在故障点的零序输入阻抗。 Among them, Z _xCequ is the input impedance of the subnet numbered x,

S32、利用每一子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗，及与所述故障类型对应的输入阻抗解析式，计算得到每一子网的输入阻抗。S32. Calculate the input impedance of each subnet using the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each subnet at the fault point, and the input impedance analytical formula corresponding to the fault type. .

具体地，将每一子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗代入至与故障类型对应的解析式中，得到每一子网的输入阻抗。Specifically, the positive sequence input impedance, negative sequence input impedance, and zero sequence input impedance of each subnetwork at the fault point are substituted into the analytical expression corresponding to the fault type to obtain the input impedance of each subnetwork.

同一辐射形网络中同一故障点所对应的各个子网的故障类型是一致的。The fault types of each subnet corresponding to the same fault point in the same radial network are consistent.

S33、利用每一子网在所述故障点的正序等效阻抗、负序等效阻抗、零序等效阻抗，及与所述故障类型对应的等效阻抗解析式，计算得到每一子网的等效阻抗。S33. Use the positive sequence equivalent impedance, negative sequence equivalent impedance, zero sequence equivalent impedance of each subnet at the fault point, and the equivalent impedance analytical formula corresponding to the fault type to calculate each subnet. The equivalent impedance of the network.

具体地，将每一子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗代入至与故障类型对应的解析式中，得到每一子网的输入阻抗。Specifically, the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnet at the fault point are substituted into the analytical expression corresponding to the fault type to obtain the input impedance of each subnet. .

从上述技术方案可以看出，本实施例提供了一种计算每一子网输入阻抗及等效阻抗的可选的方式。通过上述的方式，可以针对不同的故障类型，采用不同的计算方式。基于此，计算得到的短路电流直流分量与故障类型相关，更能提高短路电流直流分量的准确程度。It can be seen from the above technical solution that this embodiment provides an optional way to calculate the input impedance and equivalent impedance of each subnet. Through the above method, different calculation methods can be used for different fault types. Based on this, the calculated DC component of the short-circuit current is related to the fault type, which can improve the accuracy of the DC component of the short-circuit current.

在本申请的一些实施例中，对步骤S4，基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量的过程进行详细说明，步骤如下：In some embodiments of the present application, step S4, the process of calculating the DC component of the short-circuit current based on the input impedance and equivalent impedance of each of the subnetworks is described in detail. The steps are as follows:

S40、计算并联阻抗，所述并联阻抗等于1与各个所述子网的输入阻抗的倒数之和之间的比值。S40. Calculate the parallel impedance, which is equal to the ratio between 1 and the sum of the reciprocals of the input impedances of each of the subnetworks.

具体地，可以通过并联阻抗解析式计算辐射形网络的并联阻抗。Specifically, the parallel impedance of the radial network can be calculated through the parallel impedance analytical formula.

并联阻抗解析式如下所示：The analytical formula of parallel impedance is as follows:

其中，Z _equ为并联阻抗，N为各个子网的总数量。 Among them, Z _equ is the parallel impedance, and N is the total number of each subnet.

S41、获取故障点等效电压源。S41. Obtain the equivalent voltage source of the fault point.

具体地，可采用等效电压源法，计算故障点等效电压源。将辐射形网络中各电源置零，并在故障点加入理想电压源作为唯一的有源电压V _f，其计算公式为： Specifically, the equivalent voltage source method can be used to calculate the equivalent voltage source at the fault point. Set each power supply in the radial network to zero, and add an ideal voltage source as the only active voltage V _f at the fault point. The calculation formula is:

其中，U _n为辐射形网络的标称电压，c为电压系数，c的取值范围如表2所示： Among them, U _n is the nominal voltage of the radial network, c is the voltage coefficient, and the value range of c is as shown in Table 2:

表2Table 2

S42、将所述故障点等效电压源及所述并联阻抗之间的比值作为短路电流初始值。S42. Use the ratio between the equivalent voltage source at the fault point and the parallel impedance as the initial value of the short-circuit current.

具体地，短路电流初始值的解析式为：Specifically, the analytical formula for the initial value of the short-circuit current is:

其中，V _f为故障点等效电压源，Z _equ为并联阻抗，I _k"为短路电流初始值。 Among them, V _f is the equivalent voltage source at the fault point, Z _equ is the parallel impedance, and I _k " is the initial value of the short-circuit current.

S43、利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量。S43. Calculate the DC component of the short-circuit current using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current.

具体地，可以利用并联阻抗、每一子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算每一子网对短路电流直流分量的贡献值，将各个子网对应的贡献值相加，相加后的值即为短路电流直流分量。Specifically, the parallel impedance, the input impedance of each subnet, the equivalent impedance of each subnet and the initial value of the short-circuit current can be used to calculate the contribution value of each subnet to the DC component of the short-circuit current, and divide each subnet into The corresponding contribution values of the network are added, and the added value is the DC component of the short-circuit current.

从上述技术方案可以看出，本实施例提供了一种于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量的可选的方式。通过上述的方式，可以计算得到短路电流初始值，而在故障持续过程中，短路电流直流分量基于短路电流初始值不断衰减，因而，通过计算短路电流初始值可以提高计算的短路电流直流分量的可靠性。It can be seen from the above technical solution that this embodiment provides an optional method of calculating the DC component of the short-circuit current based on the input impedance and equivalent impedance of each sub-network. Through the above method, the initial value of the short-circuit current can be calculated. During the duration of the fault, the DC component of the short-circuit current continues to attenuate based on the initial value of the short-circuit current. Therefore, calculating the initial value of the short-circuit current can improve the reliability of the calculated DC component of the short-circuit current. sex.

在本申请的一些实施例中，对步骤S43，利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量的过程进行详细说明，步骤如下：In some embodiments of the present application, for step S43, the short circuit is calculated using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current. The process of the DC component of the current is explained in detail. The steps are as follows:

S430、将所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，代入预置的短路电流直流分量的解析式，计算得到所述短路电流直流分量。S430. Substitute the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into the preset analytical formula of the DC component of the short-circuit current, and calculate the DC component of short circuit current.

具体地，可以预置有计算短路电流直流分量的解析式，将上述实施例中所得到的并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值代入至解析式中，以计算得到短路电流直流分量。Specifically, an analytical formula for calculating the DC component of the short-circuit current may be preset, and the parallel impedance obtained in the above embodiment, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the short-circuit current are The initial value is substituted into the analytical formula to calculate the DC component of the short-circuit current.

从上述技术方案可以看出，本实施例提供了一种计算短路电流直流分量的可选的方式。通过上述的方式，可以在计算得到并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值后，直接调用解析式得到短路电流指令分量，更为简单快捷，提高计算短路电流直流分量的速度。It can be seen from the above technical solution that this embodiment provides an optional way to calculate the DC component of the short-circuit current. Through the above method, after calculating the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current, the analytical formula can be directly called to obtain the short-circuit current command component, and more For simplicity and speed, the speed of calculating the DC component of short-circuit current is increased.

在本申请的一些实施例中，短路电流直流分量的解析式为：In some embodiments of the present application, the analytical formula of the DC component of the short-circuit current is:

其中，I _dc为短路电流直流分量，N为各个子网的总数量，I _k"为短路电流初始值，Z _equ为并联阻抗，x为子网的编号，Z _xequ为编号为x的子网的输入阻抗，T _xa为编号为x的子网的短路电流直流分量衰减时间常数，t为当前时间与故障时间的时间差。 Among them, I _dc is the DC component of the short-circuit current, N is the total number of each sub-network, I _k " is the initial value of the short-circuit current, Z _equ is the parallel impedance, x is the number of the sub-network, Z _xequ is the sub-network numbered x The input impedance _of

具体地，随着时间的变化，短路电流直流分量在短路电流初始值的基础上衰减，因而，计算各个时间下的短路电流直流分量时，需要考虑短路电流初始值及短路电流直流分量衰减时间常数，为了进一步提高创造性，本申请还考虑到了组成辐射形网络的各个子网。Specifically, as time changes, the DC component of the short-circuit current decays based on the initial value of the short-circuit current. Therefore, when calculating the DC component of the short-circuit current at each time, it is necessary to consider the initial value of the short-circuit current and the decay time constant of the DC component of the short-circuit current. , In order to further improve the creativity, this application also takes into consideration the various subnetworks that make up the radial network.

从上述技术方案可以看出，本实施例在计算短路电流直流分量时考虑到了各个子网，若仅仅考虑完整的辐射形网络在满足工程需求的情况下，需要忽略部分误差，以至于误差难以避免，而本申请在考虑到各个子网的短路电流的直流分量的情况下，能够有效地减少误差。It can be seen from the above technical solution that this embodiment takes each subnet into account when calculating the DC component of the short-circuit current. If only the complete radial network is considered to meet the engineering requirements, some errors need to be ignored, so that the error is difficult to avoid. , and this application can effectively reduce errors by taking into account the DC component of the short-circuit current of each subnet.

在本申请的一些实施例中，编号为x的子网的短路电流直流分量衰减时间常数的解析式为：In some embodiments of the present application, the analytical formula of the attenuation time constant of the short-circuit current DC component of the subnetwork numbered x is:

具体地，上述的解析式表明，在计算短路电流直流分量衰减时间常数时，采用了等效频率法，等效频率会随时间段的改变而改变。因而，应用了等效频率法可在不同时间段选用不同衰减时间常数T，基于此，可以减小负误差，进一步提高本申请计算短路电流直流分量的准确性及可靠性。Specifically, the above analytical formula shows that when calculating the attenuation time constant of the DC component of the short-circuit current, the equivalent frequency method is used, and the equivalent frequency will change with the change of the time period. Therefore, the equivalent frequency method can be used to select different attenuation time constants T in different time periods. Based on this, the negative error can be reduced and the accuracy and reliability of the calculation of the DC component of the short-circuit current in this application can be further improved.

此外，在计算得到更为准确地短路电流直流分量后，可以更准确地计算得到发生不对称短路故障时的短路冲击电流。而断路器的性能是基于短路冲击电流制备的，基于此，可以利用更为准确的短路冲击电流制备更经济环保且及时开断的断路器。In addition, after calculating the DC component of the short-circuit current more accurately, the short-circuit impulse current when an asymmetric short-circuit fault occurs can be calculated more accurately. The performance of the circuit breaker is based on the short-circuit impulse current. Based on this, more accurate short-circuit impulse current can be used to prepare a more economical, environmentally friendly and timely breaking circuit breaker.

下面对本申请实施例提供的短路电流直流分量计算装置进行描述，下文描述的短路电流直流分量计算装置与上文描述的短路电流直流分量计算方法可相互对应参照。The short-circuit current DC component calculation device provided by the embodiment of the present application will be described below. The short-circuit current DC component calculation device described below and the short-circuit current DC component calculation method described above may correspond to each other.

如图2所示，其公开了一种短路电流直流分量计算装置的结构示意图，该短路电流直流分量计算装置可以包括：As shown in Figure 2, it discloses a schematic structural diagram of a short-circuit current DC component calculation device. The short-circuit current DC component calculation device may include:

拆分单元1，用于以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网；Splitting unit 1 is used to use the fault point when an asymmetric short-circuit fault occurs in the radial network as the splitting point, and split the radial network into multiple subnets;

获取单元2，用于获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗；Obtaining unit 2 is used to obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point. ;

计算单元3，根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗；The calculation unit 3 calculates based on the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point. The input impedance and equivalent impedance of each of the subnetworks;

利用单元4，用于基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。Utilizing unit 4 is used to calculate the DC component of the short-circuit current based on the input impedance and equivalent impedance of each of the subnetworks.

进一步地，所述获取单元，可以包括：Further, the acquisition unit may include:

第一获取单元，用于确定发生所述不对称短路故障的故障时间，及所述不对称短路故障发生后的目标时间，所述目标时间为不对称短路故障持续过程中的任意时刻；The first acquisition unit is used to determine the fault time when the asymmetric short-circuit fault occurs, and the target time after the asymmetric short-circuit fault occurs, and the target time is any time during the duration of the asymmetric short-circuit fault;

第二获取单元，用于计算所述目标时间与所述故障时间之间的目标时间差；a second acquisition unit configured to calculate the target time difference between the target time and the failure time;

第三获取单元，用于基于所述目标时间差，确定与所述目标时间对应的等效频率；A third acquisition unit configured to determine the equivalent frequency corresponding to the target time based on the target time difference;

第四获取单元，用于根据所述目标时间对应的等效频率，计算与所述目标时间对应的各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗。The fourth acquisition unit is used to calculate the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork corresponding to the target time at the fault point according to the equivalent frequency corresponding to the target time. sequence equivalent impedance.

进一步地，计算单元，可以包括：Further, the computing unit may include:

第一计算单元，用于确定所述不对称短路故障的故障类型，所述故障类型为单相短路故障、两相短路故障或两相短路接地故障；A first calculation unit configured to determine the fault type of the asymmetric short-circuit fault, where the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault, or a two-phase short-circuit to ground fault;

第二计算单元，用于调用预置的与所述故障类型对应的输入阻抗解析式及等效阻抗解析式；The second calculation unit is used to call the preset input impedance analytical formula and equivalent impedance analytical formula corresponding to the fault type;

第三计算单元，用于利用每一子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗，及与所述故障类型对应的输入阻抗解析式，计算得到每一子网的输入阻抗；The third calculation unit is used to use the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each subnetwork at the fault point, and the input impedance analytical formula corresponding to the fault type to calculate each The input impedance of the subnet;

第四计算单元，用于利用每一子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗，及与所述故障类型对应的等效阻抗解析式，计算得到每一子网的等效阻抗。The fourth calculation unit is used to utilize the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point, and the equivalent impedance analytical formula corresponding to the fault type, Calculate the equivalent impedance of each subnet.

进一步地，利用单元，可以包括：Further, the utilization unit may include:

并联阻抗计算单元，用于计算并联阻抗，所述并联阻抗等于1与各个所述子网的输入阻抗的倒数之和之间的比值；A parallel impedance calculation unit, used to calculate parallel impedance, which is equal to the ratio between 1 and the sum of the reciprocals of the input impedances of each of the subnetworks;

等效电压源获取单元，用于获取故障点等效电压源；The equivalent voltage source acquisition unit is used to obtain the equivalent voltage source of the fault point;

比值计算单元，用于将所述故障点等效电压源及所述并联阻抗之间的比值作为短路电流初始值；A ratio calculation unit, used to use the ratio between the equivalent voltage source at the fault point and the parallel impedance as the initial value of the short-circuit current;

阻抗利用单元，用于利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量。An impedance utilization unit is used to calculate the DC component of the short-circuit current using the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the initial value of the short-circuit current.

进一步地，阻抗利用单元，可以包括：Further, the impedance utilization unit may include:

直流分量计算单元，用于将所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，代入预置的短路电流直流分量的解析式，计算得到所述短路电流直流分量。A DC component calculation unit is used to substitute the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the initial value of the short-circuit current into the preset analytical formula of the DC component of the short-circuit current. , calculate the DC component of the short-circuit current.

进一步地，直流分量计算单元，可以包括：Further, the DC component calculation unit may include:

直流分量解析式存储单元，用于存储下述解析式：DC component analytical formula storage unit, used to store the following analytical formula:

衰减常数存储单元，用于存储下述解析式：The attenuation constant storage unit is used to store the following analytical formula:

本申请实施例提供的短路电流直流分量计算装置可应用于短路电流直流分量计算设备，如服务器、PC终端及计算器等。可选的，图3示出了短路电流直流分量计算设备的硬件结构框图，参照图3，短路电流直流分量计算设备的硬件结构可以包括：至少一个处理器1，至少一个通信接口2，至少一个存储器3和至少一个通信总线4；The short-circuit current DC component calculation device provided by the embodiment of the present application can be applied to short-circuit current DC component calculation equipment, such as servers, PC terminals, and calculators. Optionally, Figure 3 shows a hardware structure block diagram of the short-circuit current DC component calculation device. Referring to Figure 3, the hardware structure of the short-circuit current DC component calculation device may include: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4;

在本申请实施例中，处理器1、通信接口2、存储器3、通信总线4的数量为至少一个，且处理器1、通信接口2、存储器3通过通信总线4完成相互间的通信；In the embodiment of the present application, the number of processor 1, communication interface 2, memory 3, and communication bus 4 is at least one, and processor 1, communication interface 2, and memory 3 complete communication with each other through communication bus 4;

处理器1可能是一个中央处理器CPU，或者是特定集成电路ASIC(Application Specific Integrated Circuit)，或者是被配置成实施本发明实施例的一个或多个集成电路等；The processor 1 may be a central processing unit CPU, or an application specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention, etc.;

存储器3可能包含高速RAM存储器，也可能还包括非易失性存储器(non-volatile memory)等，例如至少一个磁盘存储器； Memory 3 may include high-speed RAM memory, and may also include non-volatile memory (non-volatile memory), such as at least one disk memory;

其中，存储器存储有程序，处理器可调用存储器存储的程序，所述程序用于：The memory stores a program, and the processor can call the program stored in the memory. The program is used for:

可选的，所述程序的细化功能和扩展功能可参照上文描述。Optionally, the detailed functions and extended functions of the program may refer to the above description.

本申请实施例还提供一种存储介质，该存储介质可存储有适于处理器执行的程序，所述程序用于：Embodiments of the present application also provide a storage medium, which can store a program suitable for execution by a processor, where the program is used for:

可选地，所述程序的细化功能和扩展功能可参照上文描述。Optionally, the detailed functions and extended functions of the program may refer to the above description.

最后，还需要说明的是，在本文中，诸如第一和第二等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or any such actual relationship or sequence between operations. Furthermore, the terms "comprises," "comprises," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on its differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other.

对所公开的实施例的上述说明，使本领域专业技术人员能够实现或使用本申请。对这些实施例的多种修改对本领域的专业技术人员来说将是显而易见的，本文中所定义的一般原理可以在不脱离本申请的精神或范围的情况下，在其它实施例中实现。本申请的各个实施例之间可以相互结合。因此，本申请将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be practiced in other embodiments without departing from the spirit or scope of the application. Various embodiments of the present application can be combined with each other. Therefore, the present application is not to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

一种短路电流直流分量计算方法，其特征在于，包括：A method for calculating the DC component of short-circuit current, which is characterized by including:

以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网；Taking the fault point when an asymmetric short-circuit fault occurs in the radial network as the split point, split the radial network into multiple subnets;

获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗；Obtain the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point;

根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗；Calculate each sub-network according to the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point. The input impedance and equivalent impedance of the network;

基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。The DC component of the short-circuit current is calculated based on the input impedance and equivalent impedance of each of the subnets.
根据权利要求1所述的短路电流直流分量计算方法，其特征在于，所述获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，包括：The short-circuit current DC component calculation method according to claim 1, characterized in that: obtaining the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence, etc. of each of the subnetworks at the fault point Effective impedance, negative sequence equivalent impedance and zero sequence equivalent impedance, including:

确定发生所述不对称短路故障的故障时间，及所述不对称短路故障发生后的目标时间，所述目标时间为不对称短路故障持续过程中的任意时刻；Determine the fault time when the asymmetric short-circuit fault occurs, and the target time after the asymmetric short-circuit fault occurs, where the target time is any time during the duration of the asymmetric short-circuit fault;

计算所述目标时间与所述故障时间之间的目标时间差；Calculating a target time difference between the target time and the failure time;

基于所述目标时间差，确定与所述目标时间对应的等效频率；Based on the target time difference, determine an equivalent frequency corresponding to the target time;

根据所述目标时间对应的等效频率，计算与所述目标时间对应的各个所述子网在所述故障点的正序等效阻抗、负序等效阻抗和零序等效阻抗。According to the equivalent frequency corresponding to the target time, calculate the positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork corresponding to the target time at the fault point.
根据权利要求1所述的所述的短路电流直流分量计算方法，其特征在于，所述根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗，包括：The short-circuit current DC component calculation method according to claim 1, characterized in that the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each sub-network at the fault point, Positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance, calculate the input impedance and equivalent impedance of each subnet, including:

确定所述不对称短路故障的故障类型，所述故障类型为单相短路故障、两相短路故障或两相短路接地故障；Determine the fault type of the asymmetric short-circuit fault, where the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit to ground fault;

调用预置的与所述故障类型对应的输入阻抗解析式及等效阻抗解析式；Call the preset input impedance analytical formula and equivalent impedance analytical formula corresponding to the fault type;

利用每一子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗，及与所述故障类型对应的输入阻抗解析式，计算得到每一子网的输入阻抗；The input impedance of each subnetwork is calculated using the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance of each subnetwork at the fault point, and the input impedance analytical formula corresponding to the fault type;

利用每一子网在所述故障点的正序等效阻抗、负序等效阻抗、零序等效阻抗，及与所述故障类型对应的等效阻抗解析式，计算得到每一子网的等效阻抗。Using the positive sequence equivalent impedance, negative sequence equivalent impedance, zero sequence equivalent impedance of each subnet at the fault point, and the equivalent impedance analytical formula corresponding to the fault type, the value of each subnet is calculated. Equivalent impedance.
根据权利要求1所述的短路电流直流分量计算方法，其特征在于，所述基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量，包括：The short-circuit current DC component calculation method according to claim 1, characterized in that the calculation of the short-circuit current DC component based on the input impedance and equivalent impedance of each of the sub-networks includes:

计算并联阻抗，所述并联阻抗等于1与各个所述子网的输入阻抗的倒数之和之间的比值；Calculate a parallel impedance equal to the ratio between 1 and the sum of the reciprocals of the input impedances of each of the subnetworks;

获取故障点等效电压源；Obtain the equivalent voltage source of the fault point;

将所述故障点等效电压源及所述并联阻抗之间的比值作为短路电流初始值；The ratio between the equivalent voltage source at the fault point and the parallel impedance is used as the initial value of the short-circuit current;

利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量。The DC component of the short-circuit current is calculated using the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the initial value of the short-circuit current.
根据权利要求4所述的短路电流直流分量计算方法，其特征在于，所述利用所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，计算得到所述短路电流直流分量，包括：The short-circuit current DC component calculation method according to claim 4, characterized in that the method uses the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks and the initial short-circuit current. value, the DC component of the short-circuit current is calculated, including:

将所述并联阻抗、各个所述子网的输入阻抗、各个所述子网的等效阻抗及所述短路电流初始值，代入预置的短路电流直流分量的解析式，计算得到所述短路电流直流分量。Substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into the preset analytical formula of the DC component of the short-circuit current, the short-circuit current is calculated DC component.
根据权利要求5所述的短路电流直流分量计算方法，其特征在于，所述短路电流直流分量的解析式为：The short-circuit current DC component calculation method according to claim 5, characterized in that the analytical formula of the short-circuit current DC component is:

其中，I _dc为短路电流直流分量，N为各个子网的总数量，I" _k为短路电流初始值，Z _equ为并联阻抗，x为子网的编号，Z _xequ为编号为x的子网的输入阻抗，T _xa为编号为x的子网的短路电流直流分量衰减时间常数，t为当前时间与故障时间的时间差。 Among them, I _dc is the DC component of the short-circuit current, N is the total number of each sub-network, I" _k is the initial value of the short-circuit current, Z _equ is the parallel impedance, x is the number of the sub-network, Z _xequ is the sub-network numbered x The input impedance _of
根据权利要求6所述的短路电流直流分量计算方法，其特征在于，所述编号为x的子网的短路电流直流分量衰减时间常数的解析式为：The short-circuit current DC component calculation method according to claim 6, characterized in that the analytical formula of the attenuation time constant of the short-circuit current DC component of the subnetwork numbered x is:

其中，Z _xCequ为编号为x的子网的等效阻抗，f _c为t对应的该编号为x的子网的等效频率。 Among them, Z _xCequ is the equivalent impedance of the subnet numbered x, and f _c is the equivalent frequency of the subnet numbered x corresponding to t.
根据权利要求1所述的短路电流直流分量计算方法，其特征在于，所述以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网，包括：The short-circuit current DC component calculation method according to claim 1, characterized in that the fault point when an asymmetric short-circuit fault occurs in the radial network is the split point, and the radial network is split into multiple sub-networks. ,include:

判断所述故障点是否处于所述辐射形网络的线路上；Determine whether the fault point is on the line of the radial network;

若所述故障点处于所述辐射形网络的线路上，则以辐射形网络故障时的故障点为拆分点，将所述辐射形网络拆分为两个子网；If the fault point is on the line of the radial network, the fault point when the radial network fails is used as the split point, and the radial network is split into two subnets;

若所述故障点并未处于所述辐射形网络的线路上，则所述故障点为所述辐射形网络的节点，以发生所述不对称短路故障的节点为拆分点，对所述辐射形网络进行拆分，其中，所述子网的数量等于汇入该节点的支路数，每一子网中包含有一个汇入该节点的支路，各子网中所包含的汇入该节点的支路并不相同。If the fault point is not on the line of the radial network, the fault point is a node of the radial network, and the node where the asymmetric short circuit fault occurs is the split point, and the radial The network is split, where the number of the subnets is equal to the number of branches that flow into the node, each subnet contains a branch that flows into the node, and each subnet contains a branch that flows into the node. The branches of nodes are not the same.
一种短路电流直流分量计算装置，其特征在于，包括：A short-circuit current DC component calculation device, which is characterized in that it includes:

拆分单元，用于以辐射形网络发生不对称短路故障时的故障点为拆分点，将所述辐射形网络拆分为多个子网；A splitting unit configured to use the fault point when an asymmetric short-circuit fault occurs in the radial network as the splitting point to split the radial network into multiple subnets;

获取单元，用于获取各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗；An acquisition unit, used to acquire the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each of the subnetworks at the fault point;

计算单元，根据各个所述子网在所述故障点的正序输入阻抗、负序输入阻抗、零序输入阻抗、正序等效阻抗、负序等效阻抗和零序等效阻抗，计算各个所述子网的输入阻抗及等效阻抗；The calculation unit calculates each subnetwork based on the positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each subnetwork at the fault point. The input impedance and equivalent impedance of the subnetwork;

利用单元，用于基于各个所述子网的输入阻抗及等效阻抗，计算所述短路电流直流分量。A utilization unit is used to calculate the DC component of the short-circuit current based on the input impedance and equivalent impedance of each of the subnets.
一种短路电流直流分量计算设备，其特征在于，包括存储器和处理器；A short-circuit current DC component calculation device, characterized by including a memory and a processor;

所述存储器，用于存储程序；The memory is used to store programs;

所述处理器，用于执行所述程序，实现如权利要求1-8中任一项所述的短路电流直流分量计算方法的各个步骤。The processor is configured to execute the program to implement each step of the short-circuit current DC component calculation method according to any one of claims 1 to 8.