CN115764824A - A current protection setting method for distribution network considering inverter power control strategy - Google Patents

A current protection setting method for distribution network considering inverter power control strategy Download PDF

Info

Publication number
CN115764824A
CN115764824A CN202211539240.XA CN202211539240A CN115764824A CN 115764824 A CN115764824 A CN 115764824A CN 202211539240 A CN202211539240 A CN 202211539240A CN 115764824 A CN115764824 A CN 115764824A
Authority
CN
China
Prior art keywords
iidg
current
fault
phase
voltage
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.)
Pending
Application number
CN202211539240.XA
Other languages
Chinese (zh)
Inventor
邓超平
陈锦山
孙鑫
祁琦
唐志军
林国栋
林少真
王新澜
林金东
李兆祥
郭健生
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.)
Electric Power Research Institute of State Grid Fujian Electric Power Co Ltd
State Grid Fujian Electric Power Co Ltd
Original Assignee
Electric Power Research Institute of State Grid Fujian Electric Power Co Ltd
State Grid Fujian Electric Power Co Ltd
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 Electric Power Research Institute of State Grid Fujian Electric Power Co Ltd, State Grid Fujian Electric Power Co Ltd filed Critical Electric Power Research Institute of State Grid Fujian Electric Power Co Ltd
Priority to CN202211539240.XA priority Critical patent/CN115764824A/en
Publication of CN115764824A publication Critical patent/CN115764824A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Control Of Electrical Variables (AREA)

Abstract

本发明涉及一种考虑逆变电源控制策略的配电网电流保护整定方法，包括以下步骤：确定故障类型；确定IIDG控制策略；根据所述故障类型和所述IIDG控制策略确定低电压穿越控制策略；根据配电网网络拓扑结构参数计算保护末端线路故障时IIDG接入点的电压，确定IIDG的运行点，得到IIDG在故障时的输出最大电流；确定保护安装位置，根据保护安装位置进行整定。本发明在整定计算的过程中充分考虑了实际工程中逆变电源的控制策略，将逆变电源分为跟网型和构网型，不同控制策略逆变电源在故障期间的故障穿越策略不同，因此提供故障电流的计算方法也不同。

Figure 202211539240

The present invention relates to a current protection setting method for distribution network considering the control strategy of inverter power supply, comprising the following steps: determining the fault type; determining the IIDG control strategy; determining the low voltage ride-through control strategy according to the fault type and the IIDG control strategy ; According to the network topology parameters of the distribution network, calculate the voltage of the IIDG access point when the protection end line fails, determine the operating point of the IIDG, and obtain the maximum output current of the IIDG when the fault occurs; determine the protection installation position, and adjust according to the protection installation position. In the process of setting calculation, the present invention fully considers the control strategy of the inverter power supply in the actual project, and divides the inverter power supply into a follow-up network type and a network-building type. Different control strategies have different fault ride-through strategies for the inverter power supply during a fault. Therefore, the calculation method of providing fault current is also different.

Figure 202211539240

Description

一种考虑逆变电源控制策略的配电网电流保护整定方法A current protection setting method for distribution network considering inverter power control strategy

技术领域technical field

本发明涉及一种考虑逆变电源控制策略的配电网电流保护整定方法，属于配电网继电保护技术领域。The invention relates to a current protection setting method of a distribution network considering a control strategy of an inverter power supply, and belongs to the technical field of relay protection of a distribution network.

背景技术Background technique

随着传统化石能源的逐渐衰竭，各国电力行业开始将目光转向了清洁、高效和灵活的发电方式——分布式发电(Distributed Generation，DG)。然而，大规模的新能源逆变型分布式电源(Inverter Interfaced Distributed Generation，IIDG)接入配电网，使传统配电网的故障特性发生了改变。同时，逆变型分布式电源的输出特性较传统电源更为复杂，输出电流由控制器的控制策略决定。在传统三段式电流保护整定计算中，短路电流的大小与线路的长度成反比，用的是躲开线路末端最大短路电流的方法。但在含有IIDG的配电线路中，由于IIDG的存在导致短路电流的大小与线路的长度不再成反比，短路电流的大小与IIDG的输入功率，短路点位置都相关联，并且是非线性关系，所以IIDG接入配网后，传统的电流保护容易误动、拒动。由于逆变电源接入后配电网线路主保护依然按照原有配置和整定方法进行配置和整定，这将会导致发生故障时，线路主保护可能发生误动、拒动，严重情况下导致整个主线路上所有的负荷失电，扩大了停电范围。现有技术中大多数是针对基于锁相环控制的跟网型逆变电源，不能适用于构网型控制策略的逆变电源。With the gradual depletion of traditional fossil energy, the power industries of various countries have begun to turn their attention to a clean, efficient and flexible power generation method - distributed generation (Distributed Generation, DG). However, the large-scale new energy inverter distributed generation (Inverter Interfaced Distributed Generation, IIDG) connected to the distribution network has changed the fault characteristics of the traditional distribution network. At the same time, the output characteristics of the inverter distributed power supply are more complex than the traditional power supply, and the output current is determined by the control strategy of the controller. In the traditional three-stage current protection setting calculation, the magnitude of the short-circuit current is inversely proportional to the length of the line, and the method of avoiding the maximum short-circuit current at the end of the line is used. However, in the distribution line containing IIDG, due to the existence of IIDG, the magnitude of the short-circuit current is no longer inversely proportional to the length of the line. The magnitude of the short-circuit current is related to the input power of the IIDG and the location of the short-circuit point, and it is a nonlinear relationship. Therefore, after the IIDG is connected to the distribution network, the traditional current protection is easy to malfunction or refuse to operate. Since the main protection of the distribution network line is still configured and set according to the original configuration and setting method after the inverter power supply is connected, this will cause the main protection of the line to malfunction or refuse to operate when a fault occurs. All loads on the main line lost power, expanding the scope of the outage. Most of the existing technologies are aimed at grid-following inverters based on phase-locked loop control, and cannot be applied to inverters with grid-based control strategies.

发明内容Contents of the invention

为了克服上述问题，本发明提供一种考虑逆变电源控制策略的配电网电流保护整定方法，该方法在整定计算的过程中充分考虑了实际工程中逆变电源的控制策略，将逆变电源分为跟网型和构网型，不同控制策略逆变电源在故障期间的故障穿越策略不同，因此提供故障电流的计算方法也不同。In order to overcome the above problems, the present invention provides a distribution network current protection setting method that considers the control strategy of the inverter power supply. It is divided into follow-up network type and structured network type. Different control strategies have different fault ride-through strategies for inverter power during a fault, so the calculation methods for providing fault current are also different.

本发明的技术方案如下：Technical scheme of the present invention is as follows:

一种考虑逆变电源控制策略的配电网电流保护整定方法，包括以下步骤：A method for setting current protection of a distribution network considering an inverter power control strategy, comprising the following steps:

确定故障类型；determine the type of failure;

确定IIDG控制策略；Determine the IIDG control strategy;

根据所述故障类型和所述IIDG控制策略确定穿越控制策略；determining a ride-through control strategy according to the fault type and the IIDG control strategy;

根据配电网网络拓扑结构参数计算保护末端线路故障时IIDG接入点的电压，确定IIDG的运行点，得到IIDG在故障时的输出最大电流；Calculate the voltage of the IIDG access point when the protection terminal line fails according to the network topology parameters of the distribution network, determine the operating point of the IIDG, and obtain the maximum output current of the IIDG when the fault occurs;

确定保护安装位置，根据保护安装位置进行整定。Determine the installation position of the protection, and adjust according to the installation position of the protection.

进一步的，所述故障类型包括三相短路故障和两相短路故障。Further, the fault types include three-phase short-circuit faults and two-phase short-circuit faults.

进一步的，所述IIDG控制策略包括跟网型IIDG和构网型IIDG，其中，所述跟网型IIDG包括有双环控制跟网型IIDG和无双环控制跟网型IIDG，所述构网型IIDG包括有双环控制构网型IIDG和无双环控制构网型IIDG。Further, the IIDG control strategy includes a network-following type IIDG and a network-building type IIDG, wherein the network-following type IIDG includes a double-loop control network-following type IIDG and a non-double-loop control network-following type IIDG, and the network-building type IIDG It includes IIDG with double-loop control network and IIDG without double-loop control network.

进一步的，故障类型为三相短路故障时，根据有双环控制跟网型IIDG的低电压穿越控制策略，所述IIDG输出故障电流特性为：Further, when the fault type is a three-phase short-circuit fault, according to the low-voltage ride-through control strategy of the double-loop control and network-following IIDG, the fault current characteristics of the IIDG output are:

Figure BDA0003976435860000021
Figure BDA0003976435860000021

Figure BDA0003976435860000022
Figure BDA0003976435860000022

其中，IIIDG-3为三相短路故障时IIDG输出的故障电流,Id为IIDG在dq旋转坐标系下的d轴电流，Iq为IIDG在dq旋转坐标系下的q轴电流，IIDG输出故障电流在旋转坐标系下K1、K2为电压支撑系数，Imax为逆变电源提供的最大电流，Vs表示IIDG接入点电压的标幺值，VPCC为IIDG接入点的电压。Among them, I IIDG-3 is the fault current output by IIDG when a three-phase short-circuit fault occurs, I d is the d-axis current of IIDG in the dq rotating coordinate system, I q is the q-axis current of IIDG in the dq rotating coordinate system, and the IIDG output Fault current in the rotating coordinate system K 1 and K 2 are the voltage support coefficients, I max is the maximum current provided by the inverter power supply, V s is the per unit value of the IIDG access point voltage, and V PCC is the voltage of the IIDG access point .

进一步的，故障类型为三相短路故障时，所述有双环控制构网型IIDG的低电压穿越控制策略为：Further, when the fault type is a three-phase short-circuit fault, the low-voltage ride-through control strategy of the double-loop control network type IIDG is:

利用有双环控制构网型IIDG的自身特性为系统提供无功，采用电流限幅控制，在故障时电流饱和切换为矢量电流控制进行限流，限幅环节和退出的逻辑为：Utilize the characteristics of the IIDG with double-loop control network structure to provide reactive power for the system, adopt current limit control, and switch to vector current control for current limit when the current is saturated when a fault occurs. The logic of the limit link and exit is as follows:

Figure BDA0003976435860000023
Figure BDA0003976435860000023

其中，Id,ref、Iq,ref分别为双环控制中电压内环输出的d轴、q轴电流参考值；

Figure BDA0003976435860000024
分别为电流限幅环节输出的d轴、q轴电流参考值，Imax为逆变电源提供的最大电流。Among them, I d,ref and I q,ref are respectively the d-axis and q-axis current reference values output by the voltage inner loop in the double-loop control;
Figure BDA0003976435860000024
are the d-axis and q-axis current reference values output by the current limiting link, and I max is the maximum current provided by the inverter power supply.

进一步的，故障类型为三相短路故障时，由于构网型IIDG可以利用自身的无功-下垂特性为电网提供支撑，所述无双环控制构网型IIDG的故障穿越控制策略为：Further, when the fault type is a three-phase short-circuit fault, since the grid-structured IIDG can use its own reactive power-sag characteristics to provide support for the power grid, the fault ride-through control strategy of the grid-structured IIDG without double-loop control is:

通过添加虚拟阻抗与调节逆变器输出电压限制IIDG的输出电流，并且，虚拟阻抗在稳态时不起作用；Limit the output current of IIDG by adding virtual impedance and adjusting the output voltage of the inverter, and the virtual impedance does not work in steady state;

此时逆变电源提供的最大电流Imax为：At this time, the maximum current I max provided by the inverter power supply is:

Figure BDA0003976435860000031
Figure BDA0003976435860000031

其中，Ef为输出电压指令值，VPCC为IIDG接入点的电压，θvsg和θf分别为IIDG输出电压相位和IIDG接入点处的电压相位，R和L分别为接入配电网输电线路的电阻和电感，γ和ω分别为阻抗角和角频率。Among them, E f is the output voltage command value, V PCC is the voltage of the IIDG access point, θ vsg and θ f are the phases of the IIDG output voltage and the voltage phase at the IIDG access point, respectively, R and L are the access power distribution The resistance and inductance of the grid transmission line, γ and ω are impedance angle and angular frequency, respectively.

进一步的，故障类型为两相短路故障时，所述构网型IIDG的低电压穿越控制策略为：Further, when the fault type is a two-phase short-circuit fault, the low voltage ride-through control strategy of the networked IIDG is:

采用正负序独立控制对二次谐波进行消除，经过正负序独立控制对二次谐波进行消除，经过正负序独立控制后的跟网型IIDG故障电流的输出特性为：The positive and negative sequence independent control is used to eliminate the second harmonic, and the positive and negative sequence independent control is used to eliminate the second harmonic. After the positive and negative sequence independent control, the output characteristics of the grid-following IIDG fault current are:

Figure BDA0003976435860000032
Figure BDA0003976435860000032

Figure BDA0003976435860000033
Figure BDA0003976435860000033

其中，IIIDG-3为两相短路故障时IIDG输出的故障电流,Iq +、Id +分别为IIDG的d、q轴输出电流正序分量，K1、K2为电压支撑系数，Imax为逆变电源允许提供的最大电流，IN为IIDG输出的额定电流,VPCC+为IIDG接入点的正序电压，Vs+表示IIDG接入点正序电压的标幺值。Among them, I IIDG-3 is the fault current output by IIDG when two-phase short-circuit fault occurs, I q + , I d + are the positive sequence components of the d-axis and q-axis output current of IIDG respectively, K 1 , K 2 are voltage support coefficients, I max is the maximum current allowed by the inverter power supply, I N is the rated current output by IIDG, V PCC+ is the positive sequence voltage of the IIDG access point, and V s+ is the per unit value of the positive sequence voltage of the IIDG access point.

进一步的，故障类型为两相短路故障时，无双环控制构网型IIDG的低电压穿越控制策略还包括：Furthermore, when the fault type is a two-phase short-circuit fault, the low voltage ride-through control strategy of the non-double-loop control network type IIDG also includes:

以AB两相短路故障为例，通过在故障相投入虚拟阻抗和更改故障指令集消除不平衡故障电流，具体为：Taking the AB two-phase short-circuit fault as an example, the unbalanced fault current is eliminated by putting virtual impedance in the fault phase and changing the fault instruction set, specifically:

Figure BDA0003976435860000041
Figure BDA0003976435860000041

Figure BDA0003976435860000042
Figure BDA0003976435860000042

Imax＝max{Imax-a，Imax-b}；I max = max{I max-a , I max-b };

其中，Imax为逆变电源提供的最大电流，Imax-a、Imax-b分别代表IIDG提供的a相最大电流和b相最大电流，Efa、Efb分别代表IIDG的a相输出电压和b相输出电压，VPCCa和VPCCb分别为并网点的a相电压和b相电压，θvsga和θvsgb分别为IIDG输出电压a相和b相的初始相位，θfa和θfb分别为IIDG接入点处的a相和b相的电压初始相位，R和L分别为接入配电网输电线路的电阻和电感，γ和ω分别为阻抗角和角频率。Among them, I max is the maximum current provided by the inverter power supply, I max-a and I max-b respectively represent the maximum current of phase a and phase b provided by IIDG, and E fa and E fb represent the output voltage of phase a of IIDG respectively and b-phase output voltage, V PCCa and V PCCb are the a-phase voltage and b-phase voltage of the grid-connected point respectively, θ vsga and θ vsgb are the initial phases of IIDG output voltage a-phase and b-phase respectively, θ fa and θ fb are respectively The initial voltage phases of phase a and phase b at the IIDG access point, R and L are the resistance and inductance of the transmission line connected to the distribution network, respectively, and γ and ω are the impedance angle and angular frequency, respectively.

进一步的，所述确定保护安装位置，根据保护安装位置进行整定，具体为：Further, the determination of the protection installation position is performed according to the protection installation position, specifically:

S1、判断保护位置是否安装在IIDG上游，若是则执行步骤S2，否则执行步骤S3；S1. Determine whether the protection position is installed upstream of the IIDG, if so, execute step S2, otherwise execute step S3;

S2、判断是否为I段保护，若是，则不考虑IIDG的影响对电流保护进行整定计算，并结束整定，否则执行步骤S4；S2. Determine whether it is stage I protection, if so, perform setting calculation on the current protection regardless of the influence of IIDG, and end the setting, otherwise execute step S4;

S3、确定保护整定类型，所述保护整定类型包括I段保护和II段保护，若保护整定类型为I段保护，则执行步骤S5；S3. Determine the protection setting type, the protection setting type includes I-section protection and II-section protection, if the protection setting type is I-section protection, then perform step S5;

S4、按照如下该公式进行整定：S4, adjust according to the following formula:

Figure BDA0003976435860000043
Figure BDA0003976435860000043

其中，Iact-II、Iact-I为分别电流保护II段和I段的整定值、Krel-II为II段保护的可靠性系数、Kb为分支系数；Among them, I act-II and I act-I are the setting values of section II and section I of the current protection respectively, K rel-II is the reliability coefficient of section II protection, and K b is the branch coefficient;

三相短路故障时的分支系数Kb-3为：The branching coefficient K b-3 of three-phase short-circuit fault is:

Figure BDA0003976435860000044
Figure BDA0003976435860000044

其中，E为配电网的电源电压，Z为电源的阻抗，ZAB为线路AB的阻抗，线路AB为IIDG接入点上游线路，ZBC为线路BC的阻抗，线路BC为IIDG接入点下游线路，VPCC为IIDG接入点的电压；Among them, E is the power supply voltage of the distribution network, Z is the impedance of the power supply, ZAB is the impedance of the line AB, the line AB is the upstream line of the IIDG access point, Z BC is the impedance of the line BC, and the line BC is the IIDG access point Downstream line, V PCC is the voltage of IIDG access point;

两相短路故障时的分支系数Kb-2为：The branching coefficient K b-2 of two-phase short-circuit fault is:

Figure BDA0003976435860000051
Figure BDA0003976435860000051

Figure BDA0003976435860000052
Figure BDA0003976435860000052

其中，IIIDG-A为IIDG的a相输出电流的正序分量，VPCCa+为IIDG接入点的a相正序电压，ZAB+和ZAB-分别为线路AB的正序阻抗和负序阻抗，ZBC+和ZBC-分别为线路BC的正序阻抗和负序阻抗，Z+为电源的正序阻抗；Among them, IIIDG-A is the positive sequence component of the a-phase output current of IIDG, V PCCa+ is the positive-sequence voltage of a-phase at the IIDG access point, Z AB+ and Z AB- are the positive-sequence impedance and negative-sequence impedance of line AB, respectively , Z BC+ and Z BC- are positive sequence impedance and negative sequence impedance of line BC respectively, Z + is positive sequence impedance of power supply;

S5、按照如下该公式进行整定：S5, adjust according to the following formula:

Figure BDA0003976435860000053
Figure BDA0003976435860000053

其中，Krel-I为保护I段的可靠性系数。Among them, K rel-I is the reliability coefficient of the protection section I.

本发明具有如下有益效果：The present invention has following beneficial effect:

本发明在整定计算的过程中充分考虑了实际工程中逆变电源的控制策略，将逆变电源分为跟网型和构网型，不同控制策略逆变电源在故障期间的故障穿越策略不同，因此提供故障电流的计算方法也不同，相比于现有技术能够适用于构网型IIDG，有利于工程实现。In the process of setting calculation, the present invention fully considers the control strategy of the inverter power supply in the actual project, and divides the inverter power supply into a follow-up network type and a network-building type. Different control strategies have different fault ride-through strategies for the inverter power supply during a fault. Therefore, the calculation method for providing the fault current is also different. Compared with the prior art, it can be applied to the grid-type IIDG, which is beneficial to engineering realization.

附图说明Description of drawings

图1为本发明的方法流程。Fig. 1 is the method flow chart of the present invention.

具体实施方式Detailed ways

下面结合附图和具体实施例来对本发明进行详细的说明。The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

参考图1，一种考虑逆变电源控制策略的配电网电流保护整定方法，包括以下步骤：Referring to Fig. 1, a current protection setting method for distribution network considering inverter control strategy includes the following steps:

确定故障类型；determine the type of failure;

确定IIDG控制策略；Determine the IIDG control strategy;

根据所述故障类型和所述IIDG控制策略确定穿越控制策略；determining a ride-through control strategy according to the fault type and the IIDG control strategy;

根据配电网网络拓扑结构参数计算保护末端线路故障时IIDG接入点的电压，确定IIDG的运行点，得到IIDG在故障时的输出最大电流；Calculate the voltage of the IIDG access point when the protection terminal line fails according to the network topology parameters of the distribution network, determine the operating point of the IIDG, and obtain the maximum output current of the IIDG when the fault occurs;

确定保护安装位置，根据保护安装位置进行整定。Determine the installation position of the protection, and adjust according to the installation position of the protection.

在本发明的具体实施方式中，所述故障类型包括三相短路故障和两相短路故障。In a specific embodiment of the present invention, the fault types include three-phase short-circuit faults and two-phase short-circuit faults.

在本发明的具体实施方式中，所述IIDG控制策略包括跟网型IIDG和构网型IIDG，其中，所述跟网型IIDG包括有双环控制跟网型IIDG和无双环控制跟网型IIDG，所述构网型IIDG包括有双环控制构网型IIDG和无双环控制构网型IIDG。In a specific embodiment of the present invention, the IIDG control strategy includes a network-following type IIDG and a network-building type IIDG, wherein the network-following type IIDG includes a double-loop control network-following type IIDG and a non-double-loop control network-following type IIDG, The networked IIDG includes a double-loop control networked IIDG and a double-loop controlled networked IIDG.

在本发明的一种实施方式中，故障类型为三相短路故障时，根据有双环控制跟网型IIDG的低电压穿越控制策略，所述IIDG输出故障电流特性为：In one embodiment of the present invention, when the fault type is a three-phase short-circuit fault, according to the low voltage ride-through control strategy of the double-loop control follow-up type IIDG, the output fault current characteristics of the IIDG are:

Figure BDA0003976435860000061
Figure BDA0003976435860000061

Figure BDA0003976435860000062
Figure BDA0003976435860000062

其中，IIIDG-3为三相短路故障时IIDG输出的故障电流,Id为IIDG在dq旋转坐标系下的d轴电流，Iq为IIDG在dq旋转坐标系下的q轴电流，IIDG输出故障电流在旋转坐标系下K1、K2为电压支撑系数，Imax为逆变电源提供的最大电流，Vs表示IIDG接入点电压的标幺值，VPCC为IIDG接入点的电压。Among them, I IIDG-3 is the fault current output by IIDG when a three-phase short-circuit fault occurs, I d is the d-axis current of IIDG in the dq rotating coordinate system, I q is the q-axis current of IIDG in the dq rotating coordinate system, and the IIDG output Fault current in the rotating coordinate system K 1 and K 2 are the voltage support coefficients, I max is the maximum current provided by the inverter power supply, V s is the per unit value of the IIDG access point voltage, and V PCC is the voltage of the IIDG access point .

在本发明的一种实施方式中，故障类型为三相短路故障时，所述有双环控制构网型IIDG的低电压穿越控制策略为：In an embodiment of the present invention, when the fault type is a three-phase short-circuit fault, the low voltage ride-through control strategy of the double-loop control network type IIDG is:

利用有双环控制构网型IIDG的自身特性为系统提供无功，采用电流限幅控制，在故障时电流饱和切换为矢量电流控制进行限流，限幅环节和退出的逻辑为：Utilize the characteristics of the IIDG with double-loop control network structure to provide reactive power for the system, adopt current limit control, and switch to vector current control for current limit when the current is saturated when a fault occurs. The logic of the limit link and exit is as follows:

Figure BDA0003976435860000063
Figure BDA0003976435860000063

其中，Id,ref、Iq,ref分别为双环控制中电压内环输出的d轴、q轴电流参考值；

Figure BDA0003976435860000064
分别为电流限幅环节输出的d轴、q轴电流参考值，Imax为逆变电源提供的最大电流。Among them, I d,ref and I q,ref are respectively the d-axis and q-axis current reference values output by the voltage inner loop in the double-loop control;
Figure BDA0003976435860000064
are the d-axis and q-axis current reference values output by the current limiting link, and I max is the maximum current provided by the inverter power supply.

在本发明的一种实施方式中，故障类型为三相短路故障时，由于构网型IIDG可以利用自身的无功-下垂特性为电网提供支撑，所述无双环控制构网型IIDG的故障穿越控制策略为：In one embodiment of the present invention, when the fault type is a three-phase short-circuit fault, since the grid-structured IIDG can use its own reactive power-droop characteristics to provide support for the power grid, the fault ride-through of the grid-structured IIDG without double-loop control The control strategy is:

通过添加虚拟阻抗与调节逆变器输出电压限制IIDG的输出电流，并且，虚拟阻抗在稳态时不起作用；Limit the output current of IIDG by adding virtual impedance and adjusting the output voltage of the inverter, and the virtual impedance does not work in steady state;

此时逆变电源提供的最大电流Imax为：At this time, the maximum current I max provided by the inverter power supply is:

Figure BDA0003976435860000071
Figure BDA0003976435860000071

其中，Ef为输出电压指令值，VPCC为IIDG接入点的电压，θvsg和θf分别为IIDG输出电压相位和IIDG接入点处的电压相位，R和L分别为接入配电网输电线路的电阻和电感，γ和ω分别为阻抗角和角频率。Among them, E f is the output voltage command value, V PCC is the voltage of the IIDG access point, θ vsg and θ f are the phases of the IIDG output voltage and the voltage phase at the IIDG access point, respectively, R and L are the access power distribution The resistance and inductance of the grid transmission line, γ and ω are impedance angle and angular frequency, respectively.

在本发明的一种实施方式中，故障类型为两相短路故障时，所述构网型IIDG的低电压穿越控制策略为：In one embodiment of the present invention, when the fault type is a two-phase short-circuit fault, the low voltage ride-through control strategy of the networked IIDG is:

采用正负序独立控制对二次谐波进行消除，经过正负序独立控制对二次谐波进行消除，经过正负序独立控制后的跟网型IIDG故障电流的输出特性为：The positive and negative sequence independent control is used to eliminate the second harmonic, and the positive and negative sequence independent control is used to eliminate the second harmonic. After the positive and negative sequence independent control, the output characteristics of the grid-following IIDG fault current are:

Figure BDA0003976435860000072
Figure BDA0003976435860000072

Figure BDA0003976435860000073
Figure BDA0003976435860000073

其中，IIIDG-3为两相短路故障时IIDG输出的故障电流,Iq +、Id +分别为IIDG的d、q轴输出电流正序分量，K1、K2为电压支撑系数，Imax为逆变电源允许提供的最大电流，IN为IIDG输出的额定电流,VPCC+为IIDG接入点的正序电压，Vs+表示IIDG接入点正序电压的标幺值。Among them, I IIDG-3 is the fault current output by IIDG when two-phase short-circuit fault occurs, I q + , I d + are the positive sequence components of the d-axis and q-axis output current of IIDG respectively, K 1 , K 2 are voltage support coefficients, I max is the maximum current allowed by the inverter power supply, I N is the rated current output by IIDG, V PCC+ is the positive sequence voltage of the IIDG access point, and V s+ represents the per unit value of the positive sequence voltage of the IIDG access point.

在本发明的一种实施方式中，故障类型为两相短路故障时，无双环控制构网型IIDG的低电压穿越控制策略还包括：In an embodiment of the present invention, when the fault type is a two-phase short-circuit fault, the low voltage ride-through control strategy of the non-double-loop control network type IIDG further includes:

以AB两相短路故障为例，通过在故障相投入虚拟阻抗和更改故障指令集消除不平衡故障电流，具体为：Taking the AB two-phase short-circuit fault as an example, the unbalanced fault current is eliminated by putting virtual impedance in the fault phase and changing the fault instruction set, specifically:

Figure BDA0003976435860000081
Figure BDA0003976435860000081

Figure BDA0003976435860000082
Figure BDA0003976435860000082

Imax＝max{Imax-a，Imax-b}；I max = max{I max-a , I max-b };

其中，Imax为逆变电源提供的最大电流，Imax-a、Imax-b分别代表IIDG提供的a相最大电流和b相最大电流，Efa、Efb分别代表IIDG的a相输出电压和b相输出电压，VPCCa和VPCCb分别为并网点的a相电压和b相电压，θvsga和θvsgb分别为IIDG输出电压a相和b相的初始相位，θfa和θfb分别为IIDG接入点处的a相和b相的电压初始相位，R和L分别为接入配电网输电线路的电阻和电感，γ和ω分别为阻抗角和角频率。Among them, I max is the maximum current provided by the inverter power supply, I max-a and I max-b respectively represent the maximum current of phase a and phase b provided by IIDG, and E fa and E fb represent the output voltage of phase a of IIDG respectively and b-phase output voltage, V PCCa and V PCCb are the a-phase voltage and b-phase voltage of the grid-connected point respectively, θ vsga and θ vsgb are the initial phases of IIDG output voltage a-phase and b-phase respectively, θ fa and θ fb are respectively The initial voltage phases of phase a and phase b at the IIDG access point, R and L are the resistance and inductance of the transmission line connected to the distribution network, respectively, and γ and ω are the impedance angle and angular frequency, respectively.

在本发明的一种实施方式中，所述确定保护安装位置，根据保护安装位置进行整定，具体为：In one embodiment of the present invention, the determination of the protection installation position is set according to the protection installation position, specifically:

S1、判断保护位置是否安装在IIDG上游，若是则执行步骤S2，否则执行步骤S3；S1. Determine whether the protection position is installed upstream of the IIDG, if so, execute step S2, otherwise execute step S3;

S2、判断是否为I段保护，若是，则不考虑IIDG的影响对电流保护进行整定计算，并结束整定，否则执行步骤S4；S2. Determine whether it is stage I protection, if so, perform setting calculation on the current protection regardless of the influence of IIDG, and end the setting, otherwise execute step S4;

S3、确定保护整定类型，所述保护整定类型包括I段保护和II段保护，若保护整定类型为I段保护，则执行步骤S5；S3. Determine the protection setting type, the protection setting type includes I-section protection and II-section protection, if the protection setting type is I-section protection, then perform step S5;

S4、按照如下该公式进行整定：S4, adjust according to the following formula:

Figure BDA0003976435860000083
Figure BDA0003976435860000083

其中，Iact-II、Iact-I为分别电流保护II段和I段的整定值、Krel-II为II段保护的可靠性系数、Kb为分支系数；Among them, I act-II and I act-I are the setting values of section II and section I of the current protection respectively, K rel-II is the reliability coefficient of section II protection, and K b is the branch coefficient;

三相短路故障时的分支系数Kb-3为：The branching coefficient K b-3 of three-phase short-circuit fault is:

Figure BDA0003976435860000084
Figure BDA0003976435860000084

其中，E为配电网的电源电压，Z为电源的阻抗，ZAB为线路AB的阻抗，线路AB为IIDG接入点上游线路，ZBC为线路BC的阻抗，线路BC为IIDG接入点下游线路，VPCC为IIDG接入点的电压；Among them, E is the power supply voltage of the distribution network, Z is the impedance of the power supply, ZAB is the impedance of the line AB, the line AB is the upstream line of the IIDG access point, Z BC is the impedance of the line BC, and the line BC is the IIDG access point Downstream line, V PCC is the voltage of IIDG access point;

两相短路故障时的分支系数Kb-2为：The branching coefficient K b-2 of two-phase short-circuit fault is:

Figure BDA0003976435860000091
Figure BDA0003976435860000091

Figure BDA0003976435860000092
Figure BDA0003976435860000092

其中，IIIDG-A为IIDG的a相输出电流的正序分量，VPCCa+为IIDG接入点的a相正序电压，ZAB+和ZAB-分别为线路AB的正序阻抗和负序阻抗，ZBC+和ZBC-分别为线路BC的正序阻抗和负序阻抗，Z+为电源的正序阻抗；Among them, IIIDG-A is the positive sequence component of the a-phase output current of IIDG, V PCCa+ is the positive-sequence voltage of a-phase at the IIDG access point, Z AB+ and Z AB- are the positive-sequence impedance and negative-sequence impedance of line AB, respectively , Z BC+ and Z BC- are positive sequence impedance and negative sequence impedance of line BC respectively, Z + is positive sequence impedance of power supply;

S5、按照如下该公式进行整定：S5, adjust according to the following formula:

Figure BDA0003976435860000093
Figure BDA0003976435860000093

其中，Krel-I为保护I段的可靠性系数。Among them, K rel-I is the reliability coefficient of the protection section I.

以上所述仅为本发明的实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书及附图内容所作的等效结构，或直接或间接运用在其他相关的技术领域，均同理包括在本发明的专利保护范围内。The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structures made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields, are all the same. included in the scope of patent protection of the present invention.

Claims (9)

1. A power distribution network current protection setting method considering an inverter power supply control strategy is characterized by comprising the following steps:
determining a fault type;
determining an IIDG control strategy;
determining a traversing control strategy according to the fault type and the IIDG control strategy;
calculating the voltage of an IIDG access point when a line at the tail end of the protection is in fault according to the topological structure parameters of the power distribution network, determining the operating point of the IIDG, and obtaining the output maximum current of the IIDG when the line is in fault;
and determining a protection installation position, and setting according to the protection installation position.
2. The method for power distribution network current protection setting considering the inverter power control strategy according to claim 1, wherein the fault types include a three-phase short-circuit fault and a two-phase short-circuit fault.
3. The method for power distribution network current protection setting considering the inverter power control strategy according to claim 2, wherein the IIDG control strategy comprises a network following type IIDG and a network configuration type IIDG, wherein the network following type IIDG comprises a double-ring control network following type IIDG and a double-ring-free control network following type IIDG, and the network configuration type IIDG comprises a double-ring control network configuration type IIDG and a double-ring-free control network configuration type IIDG.
4. The method for protecting and setting the power distribution network current considering the control strategy of the inverter power supply according to claim 3, wherein when the fault type is a three-phase short-circuit fault, according to a low-voltage ride-through control strategy of an IIDG with a double-loop control grid-connected type, the IIDG outputs fault current characteristics as follows:
Figure FDA0003976435850000011
wherein, I IIDG-3 Fault current, I, output by IIDG for three-phase short-circuit fault d Is d-axis current, I, of IIDG in dq rotation coordinate system q For the q-axis current of the IIDG under the dq rotation coordinate system, the IIDG outputs the fault current K under the rotation coordinate system 1 、K 2 Is the voltage support coefficient, I max Maximum current, V, supplied to the inverter s Per unit value, V, representing the voltage at the IIDG access point PCC Is the voltage of the IIDG access point.
5. The method for power distribution network current protection setting considering the inverter power control strategy of claim 4, wherein when the fault type is a three-phase short-circuit fault, the low voltage ride through control strategy with the double-loop control network type IIDG is as follows:
the method is characterized in that the self characteristic of the IIDG with the double-loop control network structure is utilized to provide reactive power for a system, current limiting control is adopted, current saturation is switched to vector current control to limit current during fault, and the logic of the limiting link and the exiting logic is as follows:
Figure FDA0003976435850000021
wherein, I d,ref 、I q,ref D-axis and q-axis current reference values output by the voltage inner ring in double-ring control respectively;
Figure FDA0003976435850000022
d-axis and q-axis current reference values I output by the current amplitude limiting link respectively max The maximum current provided by the inverter.
6. The method for power distribution network current protection setting considering the inverter power control strategy of claim 3, wherein when the fault type is a three-phase short-circuit fault, because the network type IIDG can provide support for the power grid by utilizing the reactive-droop characteristic of the network type IIDG, the fault ride-through control strategy of the non-double-ring control network type IIDG is as follows:
limiting the output current of the IIDG by adding a virtual impedance and adjusting the output voltage of the inverter, wherein the virtual impedance does not play a role in a steady state;
at the moment, the inverter supplies the maximum current I max Comprises the following steps:
Figure FDA0003976435850000023
wherein E is f To output a voltage command value, V PCC Voltage of IIDG access point, [ theta ] vsg And theta f The phase positions are respectively the IIDG output voltage phase and the voltage phase at the IIDG access point, R and L are respectively the resistance and the inductance of the power transmission line accessed to the power distribution network, and gamma and omega are respectively an impedance angle and angular frequency.
7. The method for power distribution network current protection setting considering the inverter power control strategy of claim 3, wherein when the fault type is a two-phase short-circuit fault, the low voltage ride through control strategy of the network type IIDG is as follows:
the positive and negative sequence independent control is adopted to eliminate the second harmonic, and the output characteristic of the net-following type IIDG fault current after the positive and negative sequence independent control is as follows:
Figure FDA0003976435850000024
wherein, I IIDG-3 Fault current, I, output by IIDG in case of two-phase short-circuit fault q + 、I d + D and q axis output current positive sequence components, K, of IIDG 1 、K 2 Is the voltage support coefficient, I max Maximum current, I, allowed to be supplied by the inverter N Rated current, V, for IIDG output PCC+ Is the positive sequence voltage of the IIDG access point,
Figure FDA0003976435850000034
represents the per unit value of the positive sequence voltage of the IIDG access point.
8. The method for power distribution network current protection setting considering the inverter power control strategy of claim 3, wherein when the fault type is a two-phase short-circuit fault, the low voltage ride through control strategy of the double-loop-free control network type IIDG further comprises:
taking an AB two-phase short circuit fault as an example, the unbalanced fault current is eliminated by throwing virtual impedance and changing a fault instruction set in the fault phase, specifically:
Figure FDA0003976435850000031
Figure FDA0003976435850000032
I max ＝max{I max-a ，I max-b }
wherein, I max Maximum current, I, supplied to the inverter max-a 、I max-b Respectively representing the a-phase maximum current and the b-phase maximum current, E, supplied by IIDG fa 、E fb Respectively representing phase a and phase b output voltages, V, of IIDG PCCa And V PCCb A-phase voltage and b-phase voltage of grid connection point, theta vsga And theta vsgb Initial phase, θ, of phase a and phase b of the IIDG output voltage, respectively fa And theta fb The initial phase of the voltage of the phase a and the phase b at the IIDG access point are respectively, R and L are respectively a resistor and an inductor which are accessed to a power transmission line of a power distribution network, and gamma and omega are respectively an impedance angle and angular frequency.
9. The method for setting power distribution network current protection in consideration of the inverter power control strategy according to claim 3, wherein the determination of the protection installation position is performed, and the setting is performed according to the protection installation position, specifically:
s1, judging whether a protection position is installed at the upstream of an IIDG, if so, executing a step S2, and otherwise, executing a step S3;
s2, judging whether the protection is I-section protection, if so, performing setting calculation on the current protection without considering the influence of the IIDG, and finishing the setting, otherwise, executing the step S4;
s3, determining a protection setting type, wherein the protection setting type comprises a section I protection and a section II protection, and if the protection setting type is the section I protection, executing the step S5;
s4, setting according to the following formula:
Figure FDA0003976435850000033
wherein, I act-II 、I act-I For respectively protecting setting value and K of section II and section I rel-II Reliability factor, K, for segment II protection b Is the branching coefficient;
branch coefficient K at three-phase short-circuit fault b-3 Comprises the following steps:
Figure FDA0003976435850000041
wherein E is the power supply voltage of the distribution network, Z is the impedance of the power supply, Z AB Is the impedance of line AB, which is the line upstream of the IIDG access point, Z BC Is the impedance of line BC, which is the downstream line of IIDG access point, V PCC A voltage of the IIDG access point;
branching coefficient K at two-phase short-circuit fault b-2 Comprises the following steps:
Figure FDA0003976435850000042
wherein, I IIDG-A Is a positive sequence component, V, of the a-phase output current of IIDG PCCa+ A phase positive sequence voltage, Z, for IIDG access point AB+ And Z AB- Positive and negative sequence impedances, Z, respectively, of the line AB BC+ And Z BC- Positive and negative sequence impedances, Z, respectively, of the line BC + Positive sequence impedance for the power supply;
s5, setting according to the following formula:
Figure FDA0003976435850000043
wherein, K rel-I To protect the reliability factor of the I section.
CN202211539240.XA 2022-12-01 2022-12-01 A current protection setting method for distribution network considering inverter power control strategy Pending CN115764824A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211539240.XA CN115764824A (en) 2022-12-01 2022-12-01 A current protection setting method for distribution network considering inverter power control strategy

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211539240.XA CN115764824A (en) 2022-12-01 2022-12-01 A current protection setting method for distribution network considering inverter power control strategy

Publications (1)

Publication Number Publication Date
CN115764824A true CN115764824A (en) 2023-03-07

Family

ID=85342705

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211539240.XA Pending CN115764824A (en) 2022-12-01 2022-12-01 A current protection setting method for distribution network considering inverter power control strategy

Country Status (1)

Country Link
CN (1) CN115764824A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117269838A (en) * 2023-11-22 2023-12-22 中国电力科学研究院有限公司 Method and system for determining short-circuit current of network-structured power electronic equipment
CN117895555A (en) * 2024-03-12 2024-04-16 南方电网数字电网研究院股份有限公司 Electric automobile fills electric pile that possesses trouble electric wire netting and supports and emergent power supply function

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117269838A (en) * 2023-11-22 2023-12-22 中国电力科学研究院有限公司 Method and system for determining short-circuit current of network-structured power electronic equipment
CN117269838B (en) * 2023-11-22 2024-01-30 中国电力科学研究院有限公司 Method and system for determining short-circuit current of network-structured power electronic equipment
CN117895555A (en) * 2024-03-12 2024-04-16 南方电网数字电网研究院股份有限公司 Electric automobile fills electric pile that possesses trouble electric wire netting and supports and emergent power supply function

Similar Documents

Publication Publication Date Title
CN109067193B (en) Cascade power electronic transformer and unbalance compensation control method thereof
CN106505595B (en) Transmission line of electricity three-phase imbalance governing system and method based on MMC-UPFC
CN109038658B (en) Open sea wind power flexible direct current sending-out system and onshore alternating current single-phase earth fault ride-through method
CN112821391B (en) Method and system for providing short-circuit current of grid-connected converter
CN115764824A (en) A current protection setting method for distribution network considering inverter power control strategy
CN108183486A (en) A kind of flexibility multimode switch and its control method
CN104485684A (en) Fault current calculation method for electric power system comprising double-feed wind power generator set
CN109950916B (en) UPFC Fault Transition Method Based on Hybrid Impedance
CN108233401A (en) Flexible direct-current transmission converter power regulating method
Xu et al. Study on fault characteristics and distance protection applicability of VSC-HVDC connected offshore wind power plants
CN108808710A (en) A kind of UPFC three-phase imbalance optimization methods based on nonlinear Control
CN106501667A (en) A kind of fault-line selecting method of single-phase wire break containing distributed power distribution network
CN112583050A (en) Control method and system for multi-VSG inverter loop current suppression and fault handling
CN108365624A (en) Fault ride-through and converter energy coordination method on AC side of flexible HVDC transmission
CN105515023A (en) Novel cascade STATCOM converter unit fault-tolerant method
CN107332454A (en) The outer tube open fault fault tolerant control method and system of parallel connection type three-level current transformer
CN112865060A (en) Novel four-leg topological power distribution network integrated arc extinction device and method
CN118117592A (en) A method and system for controlling asymmetric fault ride-through of grid-type converter equipment
Wang et al. Voltage stability analysis of power systems with a large number of non-synchronous machine sources connected
CN106972759A (en) A power supply for simulating grid disturbance
CN106786562A (en) The self-excitation activation system and method for a kind of SSSC
CN105099154B (en) Open-circuit fault tolerance method for permanent magnet direct-drive wind power generation system converter
CN113241748A (en) Transient overvoltage suppression method and system for power electronic converter connected to weak power grid
CN116722581A (en) Double-fed fan fault ride-through method and system based on transformer voltage support
CN115021319A (en) Networking and island operation control method and system of modular multilevel converter

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