Nothing Special   »   [go: up one dir, main page]

CN113985210A - Voltage sag domain calculation method considering voltage sag amplitude and duration - Google Patents

Voltage sag domain calculation method considering voltage sag amplitude and duration Download PDF

Info

Publication number
CN113985210A
CN113985210A CN202111282851.6A CN202111282851A CN113985210A CN 113985210 A CN113985210 A CN 113985210A CN 202111282851 A CN202111282851 A CN 202111282851A CN 113985210 A CN113985210 A CN 113985210A
Authority
CN
China
Prior art keywords
sag
voltage
line
fault
duration
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202111282851.6A
Other languages
Chinese (zh)
Other versions
CN113985210B (en
Inventor
刘海涛
张匡翼
马丙泰
张埕瑜
黄铖
陆恒
耿宗璞
袁华骏
王宇昊
张效诚
仲聪
朱康凯
马佳伊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing Institute of Technology
Original Assignee
Nanjing Institute of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing Institute of Technology filed Critical Nanjing Institute of Technology
Priority to CN202111282851.6A priority Critical patent/CN113985210B/en
Publication of CN113985210A publication Critical patent/CN113985210A/en
Application granted granted Critical
Publication of CN113985210B publication Critical patent/CN113985210B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Locating Faults (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention relates to a voltage sag domain calculation method considering voltage sag amplitude and duration, which comprises the following steps: determining a sensitive load voltage sag threshold and a duration threshold according to a sensitive load voltage tolerance curve; calculating the residual voltage amplitude of a bus connected to a sensitive load when the head end and the tail end of a certain line in the system have faults, and comparing the residual voltage amplitude with a voltage sag threshold value to obtain a voltage judgment quantity; acquiring line fault clearing time according to the system protection information, and comparing the line fault clearing time with a duration threshold value to obtain duration judgment quantity; and preliminarily judging whether the line is positioned in a sag domain according to the voltage judgment quantity and the duration judgment quantity: solving the critical point by adopting a quadratic interpolation method and a secant iteration method; and traversing all lines in the system to obtain a final sag domain of the sensitive load. Compared with the prior art, the voltage sag amplitude and the duration are considered at the same time, so that the voltage sag domain range of the sensitive load can be determined more accurately.

Description

一种考虑电压暂降幅值与持续时间的电压暂降域计算方法A Voltage Sag Domain Calculation Method Considering Voltage Sag Amplitude and Duration

技术领域technical field

本发明属于配电网电压暂降域评估领域，具体涉及一种考虑电压暂降幅值与持续时间的电压暂降域计算方法。The invention belongs to the field of voltage sag domain evaluation of a distribution network, and particularly relates to a voltage sag domain calculation method considering the voltage sag amplitude and duration.

背景技术Background technique

随着现代工业的发展，电力系统中接入的敏感负荷越来越多，电压暂降作为主要的电能质量问题给用户带来的经济损失越来越大。系统中短路故障、大型电机启动、雷击等均会造成母线电压暂降，其中短路故障是引起电压暂降的主要原因。因此对电网故障时敏感负荷接入点的电压暂降问题进行精确评估具有十分重要的意义。With the development of modern industry, more and more sensitive loads are connected to the power system, and voltage sag, as the main power quality problem, brings more and more economic losses to users. In the system, short-circuit fault, large-scale motor starting, lightning strike, etc. will cause the bus voltage sag, among which the short-circuit fault is the main cause of the voltage sag. Therefore, it is of great significance to accurately evaluate the voltage sag problem of the sensitive load access point when the power grid is faulty.

电压暂降域是指该区域内的故障会导致所关心的敏感负荷点不能正常工作，电压暂降域分析是综合评估电压暂降的前提与基础。目前，常用的暂降域识别方法主要有故障点法、临界距离法和解析法等。现有方法均存在一定的缺陷，如，临界距离法对于辐射型网络简单适用，但不适用于环网；故障点法若要较高的精确度则必须设置较多的故障点，计算量很大，该方法在大规模电力系统中的效率较低。而且目前的暂降域分析方法往往只考虑电压暂降幅值的影响，没有结合实际敏感负荷电压耐受曲线。The voltage sag domain means that the fault in this area will cause the concerned sensitive load points to fail to work normally. The analysis of the voltage sag domain is the premise and basis for comprehensive evaluation of the voltage sag. At present, the commonly used sag domain identification methods mainly include fault point method, critical distance method and analytical method. The existing methods all have certain defects. For example, the critical distance method is simple and applicable to the radial network, but not suitable for the ring network; if the fault point method needs higher accuracy, more fault points must be set, and the amount of calculation is very large. large, the method is less efficient in large-scale power systems. Moreover, the current sag domain analysis methods often only consider the influence of the voltage sag amplitude, and do not combine the actual sensitive load voltage withstand curve.

发明内容SUMMARY OF THE INVENTION

本发明针对现有技术中的不足，提供一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，采用以下技术方案：Aiming at the deficiencies in the prior art, the present invention provides a voltage sag domain calculation method considering the voltage sag amplitude and duration, and adopts the following technical solutions:

一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，包括以下步骤：A voltage sag domain calculation method considering the voltage sag amplitude and duration includes the following steps:

步骤1：根据敏感负荷电压耐受曲线，确定敏感负荷电压暂降阈值Uth和持续时间阈值Tth；Step 1: According to the voltage tolerance curve of the sensitive load, determine the voltage sag threshold U th and the duration threshold T th of the sensitive load;

步骤2：计算系统中某线路首端和末端发生故障时，接入敏感负荷的母线S的残余电压幅值

Figure BDA0003331770980000011
和
Figure BDA0003331770980000012
并将其与电压暂降阈值Uth比较，得到电压判定量sagU，Step 2: Calculate the residual voltage amplitude of the bus S connected to the sensitive load when a fault occurs at the head and end of a line in the system
Figure BDA0003331770980000011
and
Figure BDA0003331770980000012
And compare it with the voltage sag threshold U th to obtain the voltage judgment quantity sag U ,

Figure BDA0003331770980000013
Figure BDA0003331770980000013

步骤3：根据系统保护信息获取线路故障切除时间t，并将其与持续时间阈值Tth比较，得到持续时间判定量sagT，Step 3: Obtain the line fault removal time t according to the system protection information, and compare it with the duration threshold T th to obtain the duration determination amount sag T ,

Figure BDA0003331770980000021
Figure BDA0003331770980000021

步骤4：由电压判定量sagU和持续时间判定量sagT初步判断该线路是否位于暂降域内：Step 4: Preliminarily judge whether the line is located in the sag domain by the voltage judgment quantity sag U and the duration judgment quantity sag T :

若sagU＝0或sagT＝0，则该线路完全位于暂降域外；If sag U = 0 or sag T = 0, the line is completely outside the sag area;

若sagU＝1且sagT＝1，则该线路部分位于暂降域内且只存在一个临界点；If sag U = 1 and sag T = 1, the line part is located in the sag domain and there is only one critical point;

若sagU＝2且sagT＝1，则采用黄金分割搜索法计算母线S的残余电压最大值

Figure BDA0003331770980000022
若
Figure BDA0003331770980000023
则该线路部分位于暂降域内且存在两个临界点，否则该线路完全位于暂降域内；If sag U = 2 and sag T = 1, use the golden section search method to calculate the maximum residual voltage of bus S
Figure BDA0003331770980000022
like
Figure BDA0003331770980000023
Then the line is partially in the sag domain and there are two critical points, otherwise the line is completely in the sag domain;

步骤5：采用二次插值法和割线迭代法对临界点进行求解；Step 5: Use quadratic interpolation method and secant iteration method to solve the critical point;

步骤6：遍历系统中的所有线路，按照上述步骤得到敏感负荷最终的暂降域。Step 6: Traverse all the lines in the system, and obtain the final sag domain of the sensitive load according to the above steps.

进一步地，步骤2中，所述残余电压幅值

Figure BDA0003331770980000024
和
Figure BDA0003331770980000025
为某线路首端和末端发生故障时母线S的A相残余电压，Further, in step 2, the residual voltage amplitude
Figure BDA0003331770980000024
and
Figure BDA0003331770980000025
is the A-phase residual voltage of the bus S when the head and end of a line are faulty,

Figure BDA0003331770980000026
Figure BDA0003331770980000026

其中，

Figure BDA0003331770980000027
和
Figure BDA0003331770980000028
分别为线路首端和末端发生故障前母线S的A相电压，ΔUA为发生故障时A相电压的变化值，in,
Figure BDA0003331770980000027
and
Figure BDA0003331770980000028
are the A-phase voltage of the bus S before the fault occurs at the head end and the end of the line respectively, ΔU A is the change value of the A-phase voltage when the fault occurs,

若故障为单相接地短路故障，

Figure BDA0003331770980000029
If the fault is a single-phase-to-ground short-circuit fault,
Figure BDA0003331770980000029

若故障为两相短路故障，

Figure BDA00033317709800000210
If the fault is a two-phase short-circuit fault,
Figure BDA00033317709800000210

若故障为两相接地短路故障，

Figure BDA00033317709800000211
If the fault is a two-phase-to-ground short-circuit fault,
Figure BDA00033317709800000211

若故障为三相短路故障，

Figure BDA00033317709800000212
If the fault is a three-phase short-circuit fault,
Figure BDA00033317709800000212

其中，

Figure BDA00033317709800000213
为故障点F发生故障前的电压幅值，且
Figure BDA00033317709800000214
分别为故障发生前该线路首端母线m、末端母线n的电压幅值，λ为该线路故障位置信息量且λ＝lmF/lmn，lmF为故障点F与该线路首端的距离，lmn为该线路长度；in,
Figure BDA00033317709800000213
is the voltage amplitude before the fault occurs at the fault point F, and
Figure BDA00033317709800000214
are the voltage amplitudes of the busbar m at the head end and the busbar n at the end of the line before the fault occurs, λ is the information amount of the fault location of the line and λ=l mF /l mn , lmF is the distance between the fault point F and the head end of the line, l mn is the length of the line;

Figure BDA0003331770980000031
为故障点F与母线S间的各序阻抗，且
Figure BDA0003331770980000032
Figure BDA0003331770980000033
为该线路首端母线m与母线S间的各序互阻抗，
Figure BDA0003331770980000034
为该线路末端母线n与母线S间的各序互阻抗；
Figure BDA0003331770980000031
is the sequence impedance between the fault point F and the bus S, and
Figure BDA0003331770980000032
Figure BDA0003331770980000033
is the sequence mutual impedance between the busbar m and busbar S at the head end of the line,
Figure BDA0003331770980000034
is the sequence mutual impedance between bus n and bus S at the end of the line;

Figure BDA0003331770980000035
为故障点F的各序自阻抗，且
Figure BDA0003331770980000035
is the self-impedance of each sequence at fault point F, and

Figure BDA0003331770980000036
Figure BDA0003331770980000036

Figure BDA0003331770980000037
为该线路首端母线m的各序自阻抗，
Figure BDA0003331770980000038
为该线路末端母线n的各序自阻抗，
Figure BDA0003331770980000039
为该线路首端母线m与末端母线n间的各序互阻抗，
Figure BDA00033317709800000310
为该线路的各序阻抗。
Figure BDA0003331770980000037
is the self-impedance of each sequence of the bus m at the head end of the line,
Figure BDA0003331770980000038
is the self-impedance of each sequence of bus n at the end of the line,
Figure BDA0003331770980000039
is the mutual impedance of each sequence between the busbar m at the head end and the busbar n at the end of the line,
Figure BDA00033317709800000310
is the sequence impedance of the line.

进一步地，步骤4中，采用黄金分割搜索法计算母线S的残余电压最大值

Figure BDA00033317709800000311
的具体步骤为：Further, in step 4, use the golden section search method to calculate the maximum residual voltage of the bus S
Figure BDA00033317709800000311
The specific steps are:

S4.1、定义两个初值点λ1和λ2，令S4.1. Define two initial value points λ 1 and λ 2 , let

Figure BDA00033317709800000312
λa＝0，λb＝1；
Figure BDA00033317709800000312
λ a = 0, λ b = 1;

S4.2、计算|f(λ1)|和f(λ2)|，S4.2. Calculate |f(λ 1 )| and f(λ 2 )|,

若|f(λ1)|≥|f(λ2)|，令λb＝λ2，λ2＝λ1，

Figure BDA00033317709800000313
If |f(λ 1 )|≥|f(λ 2 )|, let λ b =λ 2 , λ 2 =λ 1 ,
Figure BDA00033317709800000313

若|f(λ1)|＜|f(λ2)|，令λa＝λ1，λ1＝λ2，

Figure BDA00033317709800000314
If |f(λ 1 )|<|f(λ 2 )|, let λ a =λ 1 , λ 1 =λ 2 ,
Figure BDA00033317709800000314

S4.3、若|λb-λa|＜ε则λmax＝(λb+λa)/2，否则返回S4.2直至|λb-λa|＜ε，ε为迭代精度；S4.3. If |λ b -λ a |<ε, then λ max =(λ b +λ a )/2, otherwise return to S4.2 until |λ b -λ a |<ε, where ε is the iteration accuracy;

S4.4、将母线S的残余电压最大值

Figure BDA00033317709800000315
表示为：S4.4. Set the maximum value of the residual voltage of bus S
Figure BDA00033317709800000315
Expressed as:

Figure BDA00033317709800000316
Figure BDA00033317709800000316

其中，

Figure BDA00033317709800000317
为故障前母线S的A相电压，
Figure BDA00033317709800000318
Figure BDA00033317709800000319
in,
Figure BDA00033317709800000317
is the A-phase voltage of bus S before the fault,
Figure BDA00033317709800000318
Figure BDA00033317709800000319

进一步地，所述步骤5包括以下步骤：Further, the step 5 includes the following steps:

S5.1、选取λ1＝0、λ2＝0.5、λ2＝1三个点作为插值点进行二次插值，得到插值方程S5.1. Select three points of λ 1 =0, λ 2 =0.5, and λ 2 =1 as the interpolation points to perform quadratic interpolation to obtain the interpolation equation

Uth＝a0+a1λ+a2λ2，U th =a 0 +a 1 λ+a 2 λ 2 ,

其中，a0＝|f(0)|，a1＝-3|f(0)|+4|f(0.5)|-|f(1)|，a2＝2|f(0)|-4|f(0.5)|+2|f(1)|；where a 0 =|f(0)|, a 1 =-3|f(0)|+4|f(0.5)|-|f(1)|, a 2 =2|f(0)|- 4|f(0.5)|+2|f(1)|;

S5.2、求解插值方程在[0,1]上的根，根的个数为临界点个数；S5.2. Solve the roots of the interpolation equation on [0,1], the number of roots is the number of critical points;

S5.3、对于根λroot，将其作为临界点的近似值并通过割线迭代法获取临界点的精确值：S5.3. For the root λ root , take it as the approximate value of the critical point and obtain the exact value of the critical point through the secant iteration method:

确定割线法的迭代区间为[λroot,λroot+0.01]和[λroot-0.01,λroot]，分别在迭代区间内依次进行以下迭代：Determine the iterative interval of the secant method as [λ root ,λ root +0.01] and [λ root -0.01,λ root ], and perform the following iterations in the iteration interval respectively:

Figure BDA0003331770980000041
λfrom＝λend，λend＝λnew，
Figure BDA0003331770980000041
λ from =λ end , λ end =λ new ,

直至满足迭代结束条件||f(λnew)|-Uth|＜ε，则此时的λnew为根λroot对应的临界点的精确值，λfrom与λend分别为迭代区间的左端点值和右端点值，若某迭代区间内无法满足迭代条件则转换到另一迭代区间。Until the iteration end condition ||f(λ new )|-U th |<ε is satisfied, then λ new is the exact value of the critical point corresponding to the root λ root , λ from and λ end are the left endpoints of the iteration interval respectively value and the right endpoint value, if the iteration condition cannot be satisfied in an iteration interval, it will switch to another iteration interval.

进一步地，所述迭代精度ε＝0.001。Further, the iteration precision ε=0.001.

相比于现有技术，本发明同时考虑了电压暂降幅值和持续时间，从而可以更加精确地确定敏感负荷的电压暂降域范围。Compared with the prior art, the present invention considers the voltage sag amplitude and duration at the same time, so that the voltage sag domain range of the sensitive load can be determined more accurately.

附图说明Description of drawings

图1为本发明方法的流程图；Fig. 1 is the flow chart of the inventive method;

图2为本发明中线路故障示意图；Fig. 2 is the schematic diagram of line fault in the present invention;

图3为本发明中黄金分割法的流程图。FIG. 3 is a flow chart of the golden section method in the present invention.

具体实施方式Detailed ways

现在结合附图对本发明作进一步详细的说明。The present invention will now be described in further detail with reference to the accompanying drawings.

如图1所示，本发明主要包括以下步骤：As shown in Figure 1, the present invention mainly comprises the following steps:

步骤1：根据敏感负荷电压耐受曲线，确定敏感负荷电压暂降阈值Uth和持续时间阈值Tth。Step 1: According to the voltage tolerance curve of the sensitive load, determine the voltage sag threshold U th and the duration threshold T th of the sensitive load.

步骤2：计算系统中某线路首端和末端发生故障时，接入敏感负荷的母线S的残余电压幅值

Figure BDA0003331770980000042
和
Figure BDA0003331770980000043
并将其与电压暂降阈值Uth比较，得到电压判定量sagU，Step 2: Calculate the residual voltage amplitude of the bus S connected to the sensitive load when a fault occurs at the head and end of a line in the system
Figure BDA0003331770980000042
and
Figure BDA0003331770980000043
And compare it with the voltage sag threshold U th to obtain the voltage judgment quantity sag U ,

Figure BDA0003331770980000044
Figure BDA0003331770980000044

残余电压幅值

Figure BDA0003331770980000045
和
Figure BDA0003331770980000046
为某线路首端和末端发生故障时母线S的A相残余电压，且Residual voltage amplitude
Figure BDA0003331770980000045
and
Figure BDA0003331770980000046
is the A-phase residual voltage of the bus S when the head and end of a line are faulty, and

Figure BDA0003331770980000051
Figure BDA0003331770980000051

其中，

Figure BDA0003331770980000052
和
Figure BDA0003331770980000053
分别为线路首端和末端发生故障前母线S的A相电压，ΔUA为发生故障时A相电压的变化值，in,
Figure BDA0003331770980000052
and
Figure BDA0003331770980000053
are the A-phase voltage of the bus S before the fault occurs at the head end and the end of the line respectively, ΔU A is the change value of the A-phase voltage when the fault occurs,

若故障为单相接地短路故障，

Figure BDA0003331770980000054
If the fault is a single-phase-to-ground short-circuit fault,
Figure BDA0003331770980000054

若故障为两相短路故障，

Figure BDA0003331770980000055
If the fault is a two-phase short-circuit fault,
Figure BDA0003331770980000055

若故障为两相接地短路故障，

Figure BDA0003331770980000056
If the fault is a two-phase-to-ground short-circuit fault,
Figure BDA0003331770980000056

若故障为三相短路故障，

Figure BDA0003331770980000057
If the fault is a three-phase short-circuit fault,
Figure BDA0003331770980000057

其中，

Figure BDA0003331770980000058
为故障点F发生故障前的电压幅值，且
Figure BDA0003331770980000059
分别为故障发生前该线路首端母线m、末端母线n的电压幅值，λ为该线路故障位置信息量且λ＝lmF/lmn，lmF为故障点F与该线路首端的距离，lmn为该线路长度，故障线路示意如图2；in,
Figure BDA0003331770980000058
is the voltage amplitude before the fault occurs at the fault point F, and
Figure BDA0003331770980000059
are the voltage amplitudes of the busbar m at the head end and the busbar n at the end of the line before the fault occurs, λ is the information amount of the fault location of the line and λ=l mF /l mn , lmF is the distance between the fault point F and the head end of the line, l mn is the length of the line, and the fault line is shown in Figure 2;

Figure BDA00033317709800000510
为故障点F与母线S间的各序阻抗，且
Figure BDA00033317709800000511
Figure BDA00033317709800000512
为该线路首端母线m与母线S间的各序互阻抗，
Figure BDA00033317709800000513
为该线路末端母线n与母线S间的各序互阻抗；
Figure BDA00033317709800000510
is the sequence impedance between the fault point F and the bus S, and
Figure BDA00033317709800000511
Figure BDA00033317709800000512
is the sequence mutual impedance between the busbar m and busbar S at the head end of the line,
Figure BDA00033317709800000513
is the sequence mutual impedance between bus n and bus S at the end of the line;

Figure BDA00033317709800000514
为故障点F的各序自阻抗，且
Figure BDA00033317709800000514
is the self-impedance of each sequence at fault point F, and

Figure BDA00033317709800000515
Figure BDA00033317709800000515

Figure BDA00033317709800000516
为该线路首端母线m的各序自阻抗，
Figure BDA00033317709800000517
为该线路末端母线n的各序自阻抗，
Figure BDA00033317709800000518
为该线路首端母线m与末端母线n间的各序互阻抗，
Figure BDA00033317709800000519
为该线路的各序阻抗。
Figure BDA00033317709800000516
is the self-impedance of each sequence of the bus m at the head end of the line,
Figure BDA00033317709800000517
is the self-impedance of each sequence of bus n at the end of the line,
Figure BDA00033317709800000518
is the mutual impedance of each sequence between the busbar m at the head end and the busbar n at the end of the line,
Figure BDA00033317709800000519
is the sequence impedance of the line.

步骤3：根据系统保护信息获取线路故障切除时间t，并将其与持续时间阈值Tth比较，得到持续时间判定量sagT，

Figure BDA00033317709800000520
Step 3: Obtain the line fault removal time t according to the system protection information, and compare it with the duration threshold T th to obtain the duration determination amount sag T ,
Figure BDA00033317709800000520

步骤4：由电压判定量sagU和持续时间判定量sagT初步判断该线路是否位于暂降域内：Step 4: Preliminarily judge whether the line is located in the sag domain by the voltage judgment quantity sag U and the duration judgment quantity sag T :

若sagU＝0或sagT＝0，则该线路完全位于暂降域外；If sag U = 0 or sag T = 0, the line is completely outside the sag area;

若sagU＝1且sagT＝1，则该线路部分位于暂降域内且只存在一个临界点；If sag U = 1 and sag T = 1, the line part is located in the sag domain and there is only one critical point;

若sagU＝2且sagT＝1，则采用黄金分割搜索法计算母线S的残余电压最大值

Figure BDA0003331770980000061
若
Figure BDA0003331770980000062
则该线路部分位于暂降域内且存在两个临界点，否则该线路完全位于暂降域内。If sag U = 2 and sag T = 1, use the golden section search method to calculate the maximum residual voltage of bus S
Figure BDA0003331770980000061
like
Figure BDA0003331770980000062
Then the line is partially in the sag domain and there are two critical points, otherwise the line is completely in the sag domain.

如图3所示，采用黄金分割搜索法计算母线S的残余电压最大值

Figure BDA0003331770980000063
的具体步骤为：As shown in Figure 3, using the golden section search method to calculate the maximum residual voltage of the bus S
Figure BDA0003331770980000063
The specific steps are:

S4.1、定义两个初值点λ1和λ2，令S4.1. Define two initial value points λ 1 and λ 2 , let

Figure BDA0003331770980000064
λa＝0，λb＝1；
Figure BDA0003331770980000064
λ a = 0, λ b = 1;

S4.2、计算|f(λ1)|和|f(λ2)|，S4.2. Calculate |f(λ 1 )| and |f(λ 2 )|,

若|f(λ1)|≥|f(λ2)|，令λb＝λ2，λ2＝λ1，

Figure BDA0003331770980000065
If |f(λ 1 )|≥|f(λ 2 )|, let λ b =λ 2 , λ 2 =λ 1 ,
Figure BDA0003331770980000065

若|f(λ1)|＜|f(λ2)|，令λa＝λ1，λ1＝λ2，

Figure BDA0003331770980000066
If |f(λ 1 )|<|f(λ 2 )|, let λ a =λ 1 , λ 1 =λ 2 ,
Figure BDA0003331770980000066

S4.3、若|λb-λa|＜ε则λmax＝(λb+λa)/2，否则返回S4.2直至|λb-λa|＜ε，ε为迭代精度；S4.3. If |λ b -λ a |<ε, then λ max =(λ b +λ a )/2, otherwise return to S4.2 until |λ b -λ a |<ε, where ε is the iteration accuracy;

S4.4、将母线S的残余电压最大值

Figure BDA00033317709800000611
表示为：S4.4. Set the maximum value of the residual voltage of bus S
Figure BDA00033317709800000611
Expressed as:

Figure BDA0003331770980000067
Figure BDA0003331770980000067

其中，

Figure BDA0003331770980000068
为故障前母线S的A相电压，
Figure BDA0003331770980000069
Figure BDA00033317709800000610
in,
Figure BDA0003331770980000068
is the A-phase voltage of bus S before the fault,
Figure BDA0003331770980000069
Figure BDA00033317709800000610

步骤5：采用二次插值法和割线迭代法对临界点进行求解，具体为：Step 5: Use the quadratic interpolation method and the secant iteration method to solve the critical point, specifically:

S5.1、选取λ1＝0、λ2＝0.5、λ2＝1三个点作为插值点进行二次插值，得到插值方程S5.1. Select three points of λ 1 =0, λ 2 =0.5, and λ 2 =1 as the interpolation points to perform quadratic interpolation to obtain the interpolation equation

Uth＝a0+a1λ+a2λ2，U th =a 0 +a 1 λ+a 2 λ 2 ,

其中，a0＝|f(0)|，a1＝-3|f(0)|+4|f(0.5)|-|f(1)|，a2＝2|f(0)|-4|f(0.5)|+2|f(1)|；where a 0 =|f(0)|, a 1 =-3|f(0)|+4|f(0.5)|-|f(1)|, a 2 =2|f(0)|- 4|f(0.5)|+2|f(1)|;

S5.2、求解插值方程在[0,1]上的根，根的个数为临界点个数；S5.2. Solve the roots of the interpolation equation on [0,1], the number of roots is the number of critical points;

S5.3、对于根λroot，将其作为临界点的近似值并通过割线迭代法获取临界点的精确值：S5.3. For the root λ root , take it as the approximate value of the critical point and obtain the exact value of the critical point through the secant iteration method:

确定割线法的迭代区间为[λroot,λroot+0.01]和[λroot-0.01,λroot]，分别在迭代区间内依次进行以下迭代：Determine the iterative interval of the secant method as [λ root ,λ root +0.01] and [λ root -0.01,λ root ], and perform the following iterations in the iteration interval respectively:

Figure BDA0003331770980000071
Figure BDA0003331770980000071

直至满足迭代结束条件||f(λnew)|-Uth|＜ε，ε一般取值为0.001，则此时的λnew为根λroot对应的临界点的精确值，λfrom与λend分别为迭代区间的左端点值和右端点值，若某迭代区间内无法满足迭代条件则转换到另一迭代区间。Until the iterative end condition ||f(λ new )|-U th |<ε, ε generally takes the value 0.001, then λ new is the exact value of the critical point corresponding to the root λ root , λ from and λ end are the left endpoint value and right endpoint value of the iteration interval, respectively. If the iteration condition cannot be satisfied in an iteration interval, it will switch to another iteration interval.

步骤6：遍历系统中的所有线路，按照上述步骤得到敏感负荷最终的暂降域。Step 6: Traverse all the lines in the system, and obtain the final sag domain of the sensitive load according to the above steps.

以上仅是本发明的优选实施方式，本发明的保护范围并不仅局限于上述实施例，凡属于本发明思路下的技术方案均属于本发明的保护范围。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理前提下的若干改进和润饰，应视为本发明的保护范围。The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions that belong to the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (5)

1.一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，其特征在于，包括以下步骤：1. a voltage sag domain calculation method considering voltage sag amplitude and duration, is characterized in that, comprises the following steps: 步骤1：根据敏感负荷电压耐受曲线，确定敏感负荷电压暂降阈值Uth和持续时间阈值Tth；Step 1: According to the voltage tolerance curve of the sensitive load, determine the voltage sag threshold U th and the duration threshold T th of the sensitive load; 步骤2：计算系统中某线路首端和末端发生故障时，接入敏感负荷的母线S的残余电压幅值
Figure FDA0003331770970000011
和
Figure FDA0003331770970000012
并将其与电压暂降阈值Uth比较，得到电压判定量sagU，Step 2: Calculate the residual voltage amplitude of the bus S connected to the sensitive load when a fault occurs at the head and end of a line in the system
Figure FDA0003331770970000011
and
Figure FDA0003331770970000012
And compare it with the voltage sag threshold U th to obtain the voltage judgment quantity sag U ,
Figure FDA0003331770970000013
Figure FDA0003331770970000013
 步骤3：根据系统保护信息获取线路故障切除时间t，并将其与持续时间阈值Tth比较，得到持续时间判定量sagT，Step 3: Obtain the line fault removal time t according to the system protection information, and compare it with the duration threshold T th to obtain the duration determination amount sag T ,
Figure FDA0003331770970000014
Figure FDA0003331770970000014
 步骤4：由电压判定量sagU和持续时间判定量sagT初步判断该线路是否位于暂降域内：Step 4: Preliminarily judge whether the line is located in the sag domain by the voltage judgment quantity sag U and the duration judgment quantity sag T : 若sagU＝0或sagT＝0，则该线路完全位于暂降域外；If sag U = 0 or sag T = 0, the line is completely outside the sag area; 若sagU＝1且sagT＝1，则该线路部分位于暂降域内且只存在一个临界点；If sag U = 1 and sag T = 1, the line part is located in the sag domain and there is only one critical point; 若sagU＝2且sagT＝1，则采用黄金分割搜索法计算母线S的残余电压最大值
Figure FDA0003331770970000015
若
Figure FDA0003331770970000016
则该线路部分位于暂降域内且存在两个临界点，否则该线路完全位于暂降域内；If sag U = 2 and sag T = 1, use the golden section search method to calculate the maximum residual voltage of bus S
Figure FDA0003331770970000015
like
Figure FDA0003331770970000016
Then the line is partially in the sag domain and there are two critical points, otherwise the line is completely in the sag domain; 步骤5：采用二次插值法和割线迭代法对临界点进行求解；Step 5: Use quadratic interpolation method and secant iteration method to solve the critical point; 步骤6：遍历系统中的所有线路，按照上述步骤得到敏感负荷最终的暂降域。Step 6: Traverse all the lines in the system, and obtain the final sag domain of the sensitive load according to the above steps. 2.如权利要求1所述的一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，其特征在于，步骤2中，所述残余电压幅值
Figure FDA0003331770970000017
和
Figure FDA0003331770970000018
为某线路首端和末端发生故障时母线S的A相残余电压，2. A voltage sag domain calculation method considering voltage sag amplitude and duration according to claim 1, wherein in step 2, the residual voltage amplitude
Figure FDA0003331770970000017
and
Figure FDA0003331770970000018
is the A-phase residual voltage of the bus S when the head and end of a line are faulty,
Figure FDA0003331770970000019
Figure FDA0003331770970000019
 其中，
Figure FDA00033317709700000110
和
Figure FDA00033317709700000111
分别为线路首端和末端发生故障前母线S的A相电压，ΔUA为发生故障时A相电压的变化值，in,
Figure FDA00033317709700000110
and
Figure FDA00033317709700000111
are the A-phase voltage of the bus S before the fault occurs at the head end and the end of the line respectively, ΔU A is the change value of the A-phase voltage when the fault occurs, 若故障为单相接地短路故障，
Figure FDA0003331770970000021
If the fault is a single-phase-to-ground short-circuit fault,
Figure FDA0003331770970000021
 若故障为两相短路故障，
Figure FDA0003331770970000022
If the fault is a two-phase short-circuit fault,
Figure FDA0003331770970000022
 若故障为两相接地短路故障，
Figure FDA0003331770970000023
If the fault is a two-phase-to-ground short-circuit fault,
Figure FDA0003331770970000023
 若故障为三相短路故障，
Figure FDA0003331770970000024
If the fault is a three-phase short-circuit fault,
Figure FDA0003331770970000024
 其中，
Figure FDA0003331770970000025
为故障点F发生故障前的电压幅值，且
Figure FDA0003331770970000026
Figure FDA0003331770970000027
分别为故障发生前该线路首端母线m、末端母线n的电压幅值，λ为该线路故障位置信息量且λ＝lmF/lmn，lmF为故障点F与该线路首端的距离，lmn为该线路长度；in,
Figure FDA0003331770970000025
is the voltage amplitude before the fault occurs at the fault point F, and
Figure FDA0003331770970000026
Figure FDA0003331770970000027
are the voltage amplitudes of the busbar m at the head end and the busbar n at the end of the line before the fault occurs, λ is the information amount of the fault location of the line and λ=l mF /l mn , lmF is the distance between the fault point F and the head end of the line, l mn is the length of the line;
Figure FDA0003331770970000028
为故障点F与母线S间的各序阻抗，且
Figure FDA0003331770970000029
Figure FDA00033317709700000210
为该线路首端母线m与母线S间的各序互阻抗，
Figure FDA00033317709700000211
为该线路末端母线n与母线S间的各序互阻抗；
Figure FDA0003331770970000028
is the sequence impedance between the fault point F and the bus S, and
Figure FDA0003331770970000029
Figure FDA00033317709700000210
is the sequence mutual impedance between the busbar m and busbar S at the head end of the line,
Figure FDA00033317709700000211
is the sequence mutual impedance between bus n and bus S at the end of the line;
Figure FDA00033317709700000212
为故障点F的各序自阻抗，且
Figure FDA00033317709700000212
is the self-impedance of each sequence at fault point F, and
Figure FDA00033317709700000213
Figure FDA00033317709700000213
Figure FDA00033317709700000214
为该线路首端母线m的各序自阻抗，
Figure FDA00033317709700000215
为该线路末端母线n的各序自阻抗，
Figure FDA00033317709700000216
为该线路首端母线m与末端母线n间的各序互阻抗，
Figure FDA00033317709700000217
为该线路的各序阻抗。
Figure FDA00033317709700000214
is the self-impedance of each sequence of the bus m at the head end of the line,
Figure FDA00033317709700000215
is the self-impedance of each sequence of bus n at the end of the line,
Figure FDA00033317709700000216
is the mutual impedance of each sequence between the busbar m at the head end and the busbar n at the end of the line,
Figure FDA00033317709700000217
is the sequence impedance of the line. 3.如权利要求2所述的一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，其特征在于，步骤4中，采用黄金分割搜索法计算母线S的残余电压最大值
Figure FDA00033317709700000218
的具体步骤为：3. a kind of voltage sag domain calculation method considering voltage sag amplitude and duration as claimed in claim 2, is characterized in that, in step 4, adopts golden section search method to calculate the residual voltage maximum value of bus S
Figure FDA00033317709700000218
The specific steps are: S4.1、定义两个初值点λ1和λ2，令S4.1. Define two initial value points λ 1 and λ 2 , let
Figure FDA00033317709700000219
Figure FDA00033317709700000219
 S4.2、计算|f(λ1)|和|f(λ2)|，S4.2. Calculate |f(λ 1 )| and |f(λ 2 )|, 若|f(λ1)|≥|f(λ2)|，令λb＝λ2，λ2＝λ1，
Figure FDA00033317709700000220
If |f(λ 1 )|≥|f(λ 2 )|, let λ b =λ 2 , λ 2 =λ 1 ,
Figure FDA00033317709700000220
 若|f(λ1)|＜|f(λ2)|，令λa＝λ1，λ1＝λ2，
Figure FDA0003331770970000031
If |f(λ 1 )|<|f(λ 2 )|, let λ a =λ 1 , λ 1 =λ 2 ,
Figure FDA0003331770970000031
 S4.3、若|λb-λa|＜ε则λmax＝(λb+λa)/2，否则返回S4.2直至|λb-λa|＜ε，ε为迭代精度；S4.3. If |λ b -λ a |<ε, then λ max =(λ b +λ a )/2, otherwise return to S4.2 until |λ b -λ a |<ε, where ε is the iteration accuracy; S4.4、将母线S的残余电压最大值
Figure FDA0003331770970000032
表示为：S4.4. Set the maximum value of the residual voltage of bus S
Figure FDA0003331770970000032
Expressed as:
Figure FDA0003331770970000033
Figure FDA0003331770970000033
 其中，
Figure FDA0003331770970000034
为故障前母线S的A相电压，
Figure FDA0003331770970000035
Figure FDA0003331770970000036
in,
Figure FDA0003331770970000034
is the A-phase voltage of bus S before the fault,
Figure FDA0003331770970000035
Figure FDA0003331770970000036
 4.如权利要求3所述的一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，其特征在于，所述步骤5包括以下步骤：4. A voltage sag domain calculation method considering voltage sag amplitude and duration as claimed in claim 3, wherein step 5 comprises the following steps: S5.1、选取λ1＝0、λ2＝0.5、λ2＝1三个点作为插值点进行二次插值，得到插值方程S5.1. Select three points of λ 1 =0, λ 2 =0.5, and λ 2 =1 as the interpolation points to perform quadratic interpolation to obtain the interpolation equation Uth＝a0+a1λ+a2λ2，U th =a 0 +a 1 λ+a 2 λ 2 , 其中，a0＝|f(0)|，a1＝-3|f(0)|+4|f(0.5)|-|f(1)|，a2＝2|f(0)|-4|f(0.5)|+2|f(1)|；where a 0 =|f(0)|, a 1 =-3|f(0)|+4|f(0.5)|-|f(1)|, a 2 =2|f(0)|- 4|f(0.5)|+2|f(1)|; S5.2、求解插值方程在[0,1]上的根，根的个数为临界点个数；S5.2. Solve the roots of the interpolation equation on [0,1], the number of roots is the number of critical points; S5.3、对于根λroot，将其作为临界点的近似值并通过割线迭代法获取临界点的精确值：S5.3. For the root λ root , take it as the approximate value of the critical point and obtain the exact value of the critical point by the secant iteration method: 确定割线法的迭代区间为[λroot,λroot+0.01]和[λroot-0.01,λroot]，分别在迭代区间内依次进行以下迭代：Determine the iterative interval of the secant method as [λ root ,λ root +0.01] and [λ root -0.01,λ root ], and perform the following iterations in the iteration interval respectively:
Figure FDA0003331770970000037
λfrom＝λend，λend＝λnew，
Figure FDA0003331770970000037
λ from =λ end , λ end =λ new , 直至满足迭代结束条件||f(λnew)|-Uth|＜ε，则此时的λnew为根λroot对应的临界点的精确值，λfrom与λend分别为迭代区间的左端点值和右端点值，若某迭代区间内无法满足迭代条件则转换到另一迭代区间。Until the iteration end condition ||f(λ new )|-U th |<ε is satisfied, then λ new is the exact value of the critical point corresponding to the root λ root , λ from and λ end are the left endpoints of the iteration interval respectively value and the right endpoint value, if the iteration condition cannot be satisfied in an iteration interval, it will switch to another iteration interval. 5.如权利要求3所述的一种考虑电压暂降幅值与持续时间的电压暂降域计算方法，其特征在于，所述迭代精度ε＝0.001。5 . The voltage sag domain calculation method considering the voltage sag amplitude and duration according to claim 3 , wherein the iteration accuracy ε=0.001. 6 .
CN202111282851.6A 2021-11-01 2021-11-01 A voltage sag domain calculation method that considers voltage sag amplitude and duration Active CN113985210B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111282851.6A CN113985210B (en) 2021-11-01 2021-11-01 A voltage sag domain calculation method that considers voltage sag amplitude and duration

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111282851.6A CN113985210B (en) 2021-11-01 2021-11-01 A voltage sag domain calculation method that considers voltage sag amplitude and duration

Publications (2)

Publication Number Publication Date
CN113985210A true CN113985210A (en) 2022-01-28
CN113985210B CN113985210B (en) 2023-12-05

Family

ID=79745349

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111282851.6A Active CN113985210B (en) 2021-11-01 2021-11-01 A voltage sag domain calculation method that considers voltage sag amplitude and duration

Country Status (1)

Country Link
CN (1) CN113985210B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116613716A (en) * 2023-07-20 2023-08-18 国网江西省电力有限公司电力科学研究院 A method and system for preventing and controlling voltage sags based on fault domains
CN117630565A (en) * 2023-11-27 2024-03-01 广东电网有限责任公司 A method for obtaining voltage sag domain

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130054162A1 (en) * 2011-08-31 2013-02-28 Tollgrade Communications, Inc. Methods and apparatus for determining conditions of power lines
WO2013047928A1 (en) * 2011-09-29 2013-04-04 한국전력공사 System and method for detecting an abnormal waveform in a power distribution system
CN110082643A (en) * 2019-05-22 2019-08-02 广东电网有限责任公司 A kind of probabilistic temporary drop area recognition method of consideration load sensitivity
CN111007357A (en) * 2019-12-18 2020-04-14 广东电网有限责任公司 Sag domain identification method considering load voltage sag tolerance capacity curve
CN112415329A (en) * 2020-10-27 2021-02-26 广东电网有限责任公司广州供电局 Voltage sag identification method and device, computer equipment and storage medium

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130054162A1 (en) * 2011-08-31 2013-02-28 Tollgrade Communications, Inc. Methods and apparatus for determining conditions of power lines
WO2013047928A1 (en) * 2011-09-29 2013-04-04 한국전력공사 System and method for detecting an abnormal waveform in a power distribution system
CN110082643A (en) * 2019-05-22 2019-08-02 广东电网有限责任公司 A kind of probabilistic temporary drop area recognition method of consideration load sensitivity
CN111007357A (en) * 2019-12-18 2020-04-14 广东电网有限责任公司 Sag domain identification method considering load voltage sag tolerance capacity curve
CN112415329A (en) * 2020-10-27 2021-02-26 广东电网有限责任公司广州供电局 Voltage sag identification method and device, computer equipment and storage medium

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
刘海涛: "基于最优组合赋权改进S变换的电压暂降检测方法", 电测与仪表, vol. 57, no. 15 *
孙维蒙: "基于智能学习算法的电压暂降影响评估与定位研究", 《中国优秀硕士学位论文全文数据库工程科技II辑》, no. 5 *
马明: "一种基于临界点法的电压暂降域混合识别方法", 供用电, vol. 36, no. 4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116613716A (en) * 2023-07-20 2023-08-18 国网江西省电力有限公司电力科学研究院 A method and system for preventing and controlling voltage sags based on fault domains
CN116613716B (en) * 2023-07-20 2023-12-05 国网江西省电力有限公司电力科学研究院 Voltage sag control method and system based on fault domain
CN117630565A (en) * 2023-11-27 2024-03-01 广东电网有限责任公司 A method for obtaining voltage sag domain

Also Published As

Publication number Publication date
CN113985210B (en) 2023-12-05

Similar Documents

Publication Publication Date Title
CN107102236B (en) A single-phase-to-ground fault line selection method based on post-fault waveform correlation analysis
CN105699855B (en) Based on the single-ended traveling wave fault location calculation method not influenced by traveling wave speed and distance measuring method
CN102175922A (en) Phasor measurement unit (PMU) measurement data-based power line parameter identification and estimation method
CN113985210A (en) Voltage sag domain calculation method considering voltage sag amplitude and duration
CN104330696B (en) A kind of recognition methods of line fault subregion
CN111142048A (en) On-line detection method of transformer winding short-circuit fault based on spatial three-dimensional curve analysis
CN103439624B (en) Supertension line fault phase selection method based on voltage fault component
CN110045232A (en) A kind of system with non effectively earth ed neutral ground fault phase discrimination method
CN107462810B (en) A fault section location method suitable for active distribution network
CN106385014A (en) Relay protection distance setting value check method based on measured impedance
CN106990327B (en) Detection method of short-circuit fault point of high-voltage single-core cable
CN111426912A (en) Line double-end fault positioning method and system based on golden section search
CN118226199B (en) Cable fault detection system for power transmission
CN114465211A (en) Flexible line protection method and system based on first wave time of smoothing inductor voltage
CN108808634B (en) Longitudinal Protection Method for HVDC Transmission Lines Based on Smoothing Reactor Voltage
CN112731053B (en) A high-resistance grounding fault location method for resonant grounded distribution network
CN107677870A (en) A kind of quick measuring circuit of power distribution network zero-sequence current
CN111537832A (en) Line fault positioning method, terminal and system for multi-terminal flexible direct current transmission system
CN111913078A (en) An operation-based fault identification method for transmission lines
CN112083280A (en) Method for identifying fault interval of hybrid multi-terminal direct-current power transmission system
CN117421546A (en) High-voltage current transformer error approximation evaluation method and system based on initial error
CN112731068B (en) A simultaneous ground fault detection method for two feeders with the same phase in a small resistance grounding system
CN117330898A (en) A method and system for locating fault sections of distribution network cables based on sheath signal characteristic identification
CN113075498B (en) Power distribution network traveling wave fault positioning method and system based on residual error clustering
CN112505472B (en) Fault location method for three-phase hybrid power supply network based on traveling waves

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant