Weak power grid voltage out-of-limit suppression method based on energy storage type intelligent soft switch

Abstract

The invention discloses a novel weak power grid voltage out-of-limit suppression method based on an energy storage type intelligent soft switch, and the method comprises the steps: judging whether a system belongs to a weak system or not, and evaluating a weak node of a whole power distribution network through employing a voltage sensitivity standard deviation index; under a weak network condition, respectively evaluating the sensitivity of active power and reactive power to voltage by adopting active and reactive power sensitivity deviation rate indexes; through evaluation, under the condition of a weak network, the sensitivity of active power to voltage is higher than that of reactive power to voltage, so that the network voltage out-of-limit suppression thought of active power first and reactive power second is adopted, and an energy storage type intelligent soft switch E-SOP is additionally installed; and finally, connecting and penetrating the two nodes by adopting the SOP of the E-SOP device, and analyzing the voltage out-of-limit suppression effect of each node. According to the method, the problem of network voltage out-of-limit of the weak power grid is effectively solved, voltage out-of-limit nodes in the weak power grid are accurately controlled and rapidly adjusted, and stable operation and electric energy quality of a power distribution network are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage over-limit suppression of weak power grids, and in particular to a method for voltage over-limit suppression of weak power grids based on energy storage type intelligent soft switches. Background Art

[0002] With the large-scale access of distributed generators (DG), the power imbalance problem between sources and loads in the distribution network has become increasingly serious, causing the distribution network to become "weak" during certain periods of time, which is prone to voltage limit problems and affects the power supply quality and safe and stable operation of the distribution network. The strength of a weak power grid is measured by the short-circuit ratio SCR, which is the ratio of the short-circuit capacity of the power grid to the active power provided to the load. The larger the short-circuit ratio SCR, the smaller the grid impedance reflected, and the stronger the corresponding distribution network strength; the smaller the short-circuit ratio SCR, the greater the grid impedance reflected, and the weaker the corresponding distribution network strength.

[0003] At present, three methods are commonly used to suppress the problem of over-limit voltage fluctuations in power grids. The first is to use reactive compensation devices to support the voltage and ensure that the voltage of the power grid is maintained within the normal range. Magnetic Control Reactor (MCR) and Static Synchronous Compensator (STATCOM) can achieve continuous reactive and voltage regulation. Although these devices are very effective in regulating voltage, they are limited in their effectiveness in dealing with voltage over-limit problems in weak power grids because they cannot provide active power support. The second method is to improve the power supply capacity of the system to make it "stronger" to resist larger disturbances, which can be achieved by increasing short-circuit capacity, increasing transformer capacity, and reducing system internal impedance. The third method is the grid-type energy storage technology that has emerged in recent years. This technology can be used to support the weak nodes of the system. Under grid-type control, the energy storage device can be regarded as a voltage source, thereby providing the required support for the weak nodes. In addition, considering that the traditional reactive-voltage regulation method has limited effect in dealing with the active and reactive coupling relationship of electric energy in weak power grids, it is necessary to propose a method of first performing active power mutual assistance and then performing reactive power on-site compensation. As an advanced power electronic switch, the intelligent soft switch (Soft open point, SOP) can achieve power mutual assistance between power grids in different regions, effectively improving the consumption of new energy, the operation efficiency of the power grid and the power supply capacity. If only energy storage technology is used to support the grid voltage, it is necessary to configure a sufficiently large energy storage capacity, resulting in a high cost. The grid-type energy storage can be combined with the intelligent soft switch, and the idea of ​​"first active, then reactive" is adopted to study the role of the energy storage type intelligent soft switch E-SOP in supporting the voltage of weak nodes. It not only has the function of power mutual assistance between nodes, but also can achieve the power supply and demand balance of source-load between nodes. The installed energy storage device can further improve the power quality of weak nodes. The governance method proposed in this application greatly reduces the configured energy storage capacity, improves the economic benefits of voltage regulation, and further improves the voltage stability of the power grid. Summary of the invention

[0004] In view of the problems and defects described in the above-mentioned prior art, the present invention proposes a method for suppressing voltage over-limit of a weak power grid based on an energy storage type intelligent soft switch, the method comprising the following steps: Step 1: For a given distribution network system, determine whether the system is a weak system, and evaluate the weak nodes of the entire distribution network system by using the voltage sensitivity standard deviation indicator; Step 2: Under weak grid conditions, the active power and reactive power sensitivity deviation rate indicators are used to evaluate the sensitivity of active power and reactive power to voltage respectively; Step 3: After evaluation, under weak network conditions, the sensitivity of active power to voltage is higher than that of reactive power to voltage. The grid voltage over-limit suppression strategy of "active power first, reactive power later" is adopted, and an energy storage type intelligent soft switch E-SOP is installed; Step 4: Use the SOP connection of the E-SOP device to connect the two nodes and analyze the voltage over-limit suppression effect of each node.

[0005] Furthermore, the determination of whether the system belongs to a weak system specifically includes measuring the strength of the weak power grid by the short circuit ratio SCR of the system, as shown in formula (1), ; In the formula, is the short-circuit capacity of the system, is the active power provided to the load, is the voltage at the load connection point, It is the reactance of the system's Thevenin equivalent circuit viewed from both ends of the load; when 2<SCR<3, the system is called a weak network; when SCR≤2, the system is called an extremely weak network.

[0006] Furthermore, the voltage sensitivity standard deviation index is used to evaluate the weak nodes of the entire distribution network system, specifically including the calculation formula of the voltage sensitivity standard deviation index of each node for 24 hours, as shown in formula (2): ; In the formula, represents the voltage sensitivity of node i, represents the average sensitivity, represents the voltage amplitude of node i, Represents the 24-hour average value of the node voltage, Represents the standard deviation of the node's voltage sensitivity.

[0007] Furthermore, the sensitivity of the active power and reactive power to voltage are shown in equations (3) and (4), respectively. ; ; In the formula, It represents the sensitivity of the voltage Ui at node i to the active power Pj at node j, represents the sensitivity of the voltage Ui of node i to the reactive power Qj of node j, n represents the number of nodes in the network, Un represents the voltage amplitude of node n, Rn represents the resistance value between node n-1 and node n, Xn represents the reactance value between node n-1 and node n, represents the cosine value of the phase difference between node i and node j; however, in the actual operation of the distribution network, the voltage amplitude of each node is kept near the standard unit of 1.0 pu, and Small, that is, .

[0008] After calculating the active and reactive power sensitivity of each node for 24 hours a day, the sensitivities of i and j in the same branch and different branches are summed up to obtain the final active and reactive power sensitivity values ​​of each node for 24 hours a day; the average sensitivity value is further calculated, and the deviation rate of active and reactive power sensitivity is obtained based on the maximum and minimum sensitivity values.

[0009] Furthermore, step 4 is specifically as follows: if only adding SOP cannot prevent the voltage from exceeding the upper limit, the energy storage device E inside the device is started to absorb excess energy and reduce the voltage; if only adding SOP cannot prevent the voltage from exceeding the lower limit, the energy storage device E inside the device is also started to release the energy in the energy storage device and raise the voltage.

[0010] On the other hand, the present invention also proposes a weak grid voltage over-limit suppression system based on energy storage type intelligent soft switch. The first building block: for a given distribution network system, it determines whether the system is a weak system and evaluates the weak nodes of the entire distribution network system by using the voltage sensitivity standard deviation indicator; The second building block is used to evaluate the sensitivity of active power and reactive power to voltage respectively using active power and reactive power sensitivity deviation rate indicators under weak network conditions; Optimization module: It is used to evaluate that under weak network conditions, the sensitivity of active power to voltage is higher than that of reactive power to voltage. The idea of ​​"active power first, reactive power later" for suppressing network voltage over-limit is adopted, and an energy storage type intelligent soft switch E-SOP is installed; Analysis module: used to connect two nodes through the SOP connection of the E-SOP device and analyze the voltage over-limit suppression effect of each node.

[0011] On the other hand, the present invention also proposes an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that when the processor executes the program, a method for suppressing over-limit voltage of a weak power grid based on an energy storage-type intelligent soft switch as described above is implemented.

[0012] On the other hand, the present invention also proposes a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for suppressing voltage over-limit of a weak power grid based on an energy storage-type intelligent soft switch as described above is implemented.

[0013] The present invention has the following beneficial technical effects: The method of suppressing voltage over-limit of weak power grid based on energy storage type intelligent soft switch described in the present invention takes into account the coupling of active and reactive power of weak power grid to voltage regulation, and the poor effect of voltage over-limit management of single reactive-voltage regulation. The energy storage type intelligent soft switch E-SOP that can simultaneously adjust the active and reactive power of the connected area is used to suppress the voltage over-limit of weak power grid. Active power mutual assistance between regions is carried out through SOP, and the power supply capacity of weak nodes is improved, thereby also providing voltage support; if further voltage support is needed, it can be achieved through the energy storage unit inside the device, which is equivalent to adding a voltage source at the weak node. By optimizing the configuration of the energy storage unit capacity, the voltage stability problem caused by power imbalance in the weak power grid can be effectively solved, and at the same time, the deficiency of poor voltage over-limit management effect of traditional single reactive-voltage regulation is overcome. BRIEF DESCRIPTION OF THE DRAWINGS The present invention has the following accompanying drawings: Figure 1 This is a flow chart of the method for suppressing voltage over-limit in weak power grid Figure 2 It is an IEEE33 node system connected to distributed power sources Figure 3 is the day-ahead forecast power of PV, WT and load Figure 4 It is the voltage RMS value per unit of each node in the improved IEEE33 node system. Figure 5 is the standard deviation of the voltage sensitivity of each node Figure 6 The voltage per unit value of node 18 and its curves of change with active and reactive power injection Figure 7 is the active and reactive power sensitivity deviation rate of each node Figure 8 It is the solution to install E-SOP between nodes 18 and 33 Fig. 9 The voltage distribution of each node between 18 and 33 nodes with only SOP solution installed Fig.10 The voltage of each node changes with the battery configuration capacity in E-SOP Fig.11 The voltage distribution of each node after installing the E-SOP solution between nodes 18 and 33 DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0016] The following is combined with Figure 1-11The present invention is described in further detail.

[0017] As attached Figure 1 As shown, a flow chart of a method for suppressing voltage over-limit of a weak power grid based on an energy storage type intelligent soft switch comprises the following steps: Step 1: For a given distribution network system, determine whether the system is a weak system, and evaluate the weak nodes of the entire distribution network system by using the voltage sensitivity standard deviation indicator.

[0018] The access of new energy sources leads to a decrease in the short-circuit ratio of the power grid system, making the power grid appear "weak", which may cause network voltage fluctuations and even over-limit problems. Generally speaking, the strength of a weak power grid is measured by the short-circuit ratio (SCR) of the system, as shown in formula (1).

[0019] ; In the formula, is the short-circuit capacity of the system, is the active power provided to the load, is the voltage at the load connection point, It is the reactance of the Thevenin equivalent circuit of the system as seen from both ends of the load. When 2<SCR<3, the system is called a weak network; when SCR≤2, the system is called an extremely weak network.

[0020] This application takes the IEEE 33-node system as the research object, installs new energy generation units at certain nodes, and analyzes the impact of new energy access on the voltage stability of the distribution network. Distributed photovoltaic power generation (PV1 and PV2) and wind power generation units (WT) are installed on the IEEE 33-node system. Figure 2 As shown. A photovoltaic power generation unit PV1 with a capacity of 400MVA is connected to node 32, a photovoltaic power generation unit PV2 with a capacity of 500MVA is connected to node 7, and a wind power generation unit WT with a capacity of 5MW is connected to node 30. The day-ahead power forecast curves of all PV, WT and 2-33 node loads are shown in Figure 3.

[0021] After simulation analysis, the voltage RMS per unit value of each node in the improved IEEE33 node system can be obtained, as shown in Figure 4. Assuming that the voltage fluctuation allowable range is ±5%, that is, the voltage RMS per unit value interval is [0.95, 1.05] pu; the IEEE33 node system line voltage rated RMS value selected in this application is 12.66kV, then its fluctuation allowable range is [12.03kV, 13.29kV]. Figure 4 It can be seen that the upper limit of nodes 28-33 is higher at 1-4, and the lower limit of nodes 13-18 is higher at 9-12 and 15-19. Figure 4The size relationship of the middle curve, taking the voltage values ​​of each node in the first hour, arranged from large to small, are: 30,31,32,33,29,28,27,26,6,7,8,9,10,11,12,13,14,15,16,17,18,5,4,3,23,24,25,2,19,20,21,22,1 node.

[0022] In order to evaluate the weak nodes of the entire system, this application adopts the voltage sensitivity standard deviation index for determination. The calculation formula of the voltage sensitivity standard deviation index of each node for 24 hours is shown in formula (2).

[0023] ; In the formula, represents the voltage sensitivity of node i, represents the average sensitivity, U i represents the voltage amplitude of node i, Represents the 24-hour average value of the node voltage, Represents the standard deviation of the node's voltage sensitivity.

[0024] According to formula (1), the voltage sensitivity standard deviation index of each node for 24 hours is calculated. The results are shown in the attached figure. Figure 5 shown.

[0025] By the attached Figure 5 It can be seen that the standard deviation of voltage sensitivity at nodes 18 and 33 is the largest, indicating that the voltage fluctuations at the two nodes are large, so they are considered to be the weakest nodes of the entire system.

[0026] The massive access of new energy sources will reduce the voltage support strength of the power system and lower the short-circuit ratio SCR. New energy power generation units are extremely random and volatile. Installing them on the load side will make the voltage fluctuations at each node more intense. Especially during periods when new energy sources are abundant, it is also possible that the node voltage exceeds the upper limit, reducing the voltage stability of the entire system. This application analyzes the equivalent Thevenin equivalent circuit parameter values ​​at the two weakest nodes, and applies formula (1). It is calculated that the system short-circuit capacity SCR at node 18 is 2.1454, and the system short-circuit capacity SCR at node 33 is 2.6698, both of which belong to the category of weak networks.

[0027] Step 2: Under weak grid conditions, the active and reactive power sensitivity deviation rate indicators are used to evaluate the sensitivity of active power and reactive power to voltage respectively.

[0028] From step 1, it can be seen that the system selected in this application belongs to a weak network system. Considering the coupling effect of active and reactive power of the weak network system on voltage regulation, the following Figure 4Taking the node 18 at 18:00, which is the most serious moment of crossing the lower limit, as an example, through simulation calculation, the influence of injecting active power and reactive power on the node voltage is analyzed, as shown in the attached figure. Figure 6 shown.

[0029] By the attached Figure 6 From the voltage increase results of the 18 nodes, it can be seen that when the same power value is injected, the active power P has a greater impact on the node voltage than the reactive power Q. Figure 6 It is only intuitive to observe the influence of active power P on node voltage compared with reactive power Q, and there is no exact indicator to describe the degree of influence of power on voltage. Therefore, this application proposes active and reactive power sensitivity deviation rate indicators. Among them, active and reactive power sensitivity are shown in formulas (3) and (4) respectively.

[0030] ; ; In the formula, Represents the voltage at node i U i Active power to node j P j The sensitivity of Represents the voltage at node i U i Reactive power to node j Q j The sensitivity of n is the number of nodes in the network. U n represents the voltage amplitude at node n, R n represents the resistance value between node n-1 and node n, X n represents the reactance value between node n-1 and node n, represents the cosine value of the phase difference between node i and node j. However, considering that in the actual operation of the distribution network, the voltage amplitude of each node is roughly maintained near the standard unit of 1.0 pu, and Very small, that is, it can be considered .

[0031] After calculating the active and reactive power sensitivity of each node for 24 hours a day, the sensitivities of i and j in the same branch and different branches are summed to obtain the final active and reactive power sensitivity values ​​of each node for 24 hours a day. The average sensitivity value is further calculated, and the deviation rate of active and reactive power sensitivity is calculated based on the maximum and minimum sensitivity values, as shown in the attached figure. Figure 7 shown.

[0032] By the attached Figure 7It can be seen that for each node, the active power sensitivity deviation rate is higher than the reactive power sensitivity deviation rate. This shows that for a weak grid system containing a high proportion of new energy power generation units, the active power P has a greater impact on the node voltage than the reactive power Q.

[0033] Step 3: After evaluation, it was found that under weak network conditions, the sensitivity of active power to voltage is higher than that of reactive power to voltage. Therefore, the idea of ​​"active first, then reactive" is adopted to suppress the over-limit of network voltage, and an energy storage type intelligent soft switch E-SOP is installed.

[0034] Through the evaluation indicators of step 2, it is considered that the E-SOP device compensation idea of ​​"active first, reactive later" is completely feasible. At the same time, it is found that the active and reactive power sensitivity deviation rates of nodes 18 and 33 are the highest in the entire system. Combined with the weakest nodes evaluated in step 1, it is possible to consider directly installing E-SOP devices at these two nodes. Therefore, this application decides to install E-SOP devices at nodes 18 and 33, as shown in the attached Figure 8 shown.

[0035] Step 4: Use the SOP of the E-SOP device to connect the two nodes and analyze the voltage over-limit suppression effect of each node. If only adding SOP cannot suppress the voltage over-limit, start the energy storage device E inside the device to absorb excess energy and reduce the voltage; if only adding SOP cannot suppress the voltage over-limit, also start the energy storage device E inside the device to release the energy in the energy storage device and raise the voltage. First, only the active power mutual assistance of SOP is considered, and the supporting role of energy storage on node voltage is not considered. After connecting nodes 18 and 33, the voltage distribution of each node is shown in the attached figure. Fig. 9 To more clearly describe the attached Fig. 9 The size relationship of the middle curve, taking the voltage values ​​of each node in the first hour, arranged from large to small, are: 30,31,32,29,18,33,17,16,15,28,14,13,12,11,10,27,9,26,8,6,7,5,4,3,23,24,25,2,19,20,21,22,1 node.

[0036] By the attached Fig. 9 It can be seen that the voltage of 28-33 nodes exceeds the upper limit when 1-4, and the voltage of 11-18 nodes exceeds the lower limit when 1-3. It can be seen that after being connected through the SOP device, the problem of voltage exceeding the lower limit is completely improved, and the problem of exceeding the upper limit is suppressed to a certain extent, but a new problem of voltage exceeding the upper limit of some nodes has also appeared.

[0037] In response to the above unresolved and newly emerging voltage exceeding the upper limit problem, this application activates the energy storage unit in the E-SOP to absorb the excess new energy that causes the voltage to exceed the upper limit, that is, at 01:00, the energy storage unit in the E-SOP is used to store the excess new energy. Fig.10 The figure shows the effect of different energy storage capacities (configured capacities are 0, 1640 kWh and 1940 kWh) in suppressing the node voltage from exceeding the upper limit at 01:00. Fig.10 It can be seen that when the battery capacity is configured to 1640kWh, it can be found that the problem of the network voltage exceeding the upper limit of all nodes except node 30 is solved, but the voltage per unit value of node 30 is 1.0534, which is still over the limit. When the battery capacity is configured to 1940kWh, the problem of the network voltage exceeding the upper limit of all nodes is solved.

[0038] Regarding the problem of voltage exceeding the lower limit when E-SOP is not installed, although the problem of grid voltage exceeding the lower limit has been solved after installing SOP, further installation of battery energy storage can make the voltage closer to the per unit value and further reduce voltage fluctuations. Fig. 9 The voltage value of node 11 at 18:00 is the lowest, which is 12.402kV, and the corresponding per-unit value is 0.9796. When E-SOP is configured with 300kWh energy storage, the voltage of node 11 is raised to 12.48kV, and the corresponding per-unit value is 0.9858; if the energy storage configuration capacity is further increased to 1100kWh, the voltage of node 11 is raised to 12.53kV, and the corresponding per-unit value is 0.9897. It can be seen that the energy storage unit in E-SOP realizes further regulation of node voltage. The maximum value of the upper and lower limit configuration capacity of energy storage is taken as the final configuration capacity, that is, 1940kWh is taken as the final configuration capacity.

[0039] Attached Fig.11 The voltage distribution of each node after installing E-SOP. Fig.11 The size relationship of the middle curve, taking the voltage values ​​of each node in the first hour, arranged from large to small, are: 30, 29, 28, 4, 31, 5, 27, 32, 26, 3, 6, 23, 33, 18, 24, 7, 25, 17, 8, 9, 2, 19, 16, 10, 1, 20, 21, 22, 15, 14, 13, 12, 11 nodes.

[0040] By the attached Fig.11 It can be seen that the voltage is controlled within the specified range and the voltage fluctuation is significantly reduced. It can be seen that the E-SOP scheme first performs active mutual assistance between nodes, and then realizes the voltage support function by configuring a limited capacity energy storage device, while solving the problem of voltage exceeding the upper and lower limits. Node power mutual assistance reduces the configured energy storage capacity and also improves the economic benefits of voltage regulation.

[0041] The above embodiments describe the technical solutions of the present invention in detail. Obviously, the present invention is not limited to the described embodiments. Based on the embodiments of the present invention, people familiar with the technical field can also make various changes accordingly, but any changes that are equivalent or similar to the present invention belong to the scope of protection of the present invention.

[0042] The contents not described in detail in this specification belong to the prior art and professional common sense known to professional and technical personnel in this field.

Claims

1. A method for suppressing voltage over-limit in a weak power grid based on an energy storage type intelligent soft switch, characterized in that: The method comprises the following steps: Step 1: For a given distribution network system, determine whether the system is a weak system, and evaluate the weak nodes of the entire distribution network system by using the voltage sensitivity standard deviation indicator; Step 2: Under weak grid conditions, the active power and reactive power sensitivity deviation rate indicators are used to evaluate the sensitivity of active power and reactive power to voltage respectively; Step 3: After evaluation, it was found that under weak grid conditions, active power is more sensitive to voltage than reactive power. The grid voltage over-limit suppression strategy of "active first, reactive later" was adopted, and an energy storage type intelligent soft switch E-SOP was installed; Step 4: Use the SOP connection of the E-SOP device to connect the two nodes and analyze the voltage over-limit suppression effect of each node.

2. A method for suppressing voltage over-limit in a weak power grid based on an energy storage type intelligent soft switch according to claim 1, characterized in that: The determination of whether the system belongs to a weak system specifically includes measuring the strength of the weak power grid by the short circuit ratio SCR of the system, as shown in formula (1): ; In the formula, is the short-circuit capacity of the system, is the active power provided to the load, is the voltage at the load connection point, is the reactance of the Thevenin equivalent circuit of the system looking into the load; When 2<SCR<3, the system is called a weak network; when SCR≤2, the system is called an extremely weak network.

3. A method for suppressing voltage over-limit in a weak power grid based on an energy storage type intelligent soft switch as claimed in claim 2, characterized in that: The voltage sensitivity standard deviation index is used to evaluate the weak nodes of the entire distribution network system, specifically including the calculation formula of the voltage sensitivity standard deviation index of each node for 24 hours, as shown in formula (2): ; In the formula, Representation Node The voltage sensitivity, represents the average sensitivity, Representation Node The voltage amplitude, Represents the 24-hour average value of the node voltage, Represents the standard deviation of the node's voltage sensitivity.

4. A method for suppressing voltage over-limit in a weak power grid based on an energy storage type intelligent soft switch as claimed in claim 3, characterized in that: The sensitivity of the active power and reactive power to voltage are shown in equations (3) and (4), respectively. ; ; In the formula, Representation Node The sensitivity of the voltage Ui to the active power Pj at node j, represents the sensitivity of the voltage Ui of node i to the reactive power Qj of node j, n represents the number of nodes in the network, Un represents the voltage amplitude of node n, Rn represents the resistance value between node n-1 and node n, Xn represents the reactance value between node n-1 and node n, represents the cosine value of the phase difference between node i and node j; however, in the actual operation of the distribution network, the voltage amplitude of each node is kept near the standard unit of 1.0 pu, and Small, that is, ; After calculating the active and reactive power sensitivity of each node for 24 hours a day, the sensitivities of i and j in the same branch and different branches are summed up to obtain the final active and reactive power sensitivity values ​​of each node for 24 hours a day; the average sensitivity value is further calculated, and the deviation rate of active and reactive power sensitivity is obtained based on the maximum and minimum sensitivity values.

5. A method for suppressing voltage over-limit in a weak power grid based on an energy storage type intelligent soft switch as claimed in claim 4, characterized in that: Specifically, step 4 is as follows: if only adding SOP cannot prevent the voltage from exceeding the upper limit, the energy storage device E inside the device is started to absorb excess energy and reduce the voltage; if only adding SOP cannot prevent the voltage from exceeding the lower limit, the energy storage device E inside the device is also started to release the energy in the energy storage device and raise the voltage.

6. A weak grid voltage over-limit suppression system based on energy storage type intelligent soft switch, characterized in that: Said: The first building block: for a given distribution network system, it determines whether the system is a weak system and evaluates the weak nodes of the entire distribution network system by using the voltage sensitivity standard deviation indicator; The second building block is used to evaluate the sensitivity of active power and reactive power to voltage respectively using active power and reactive power sensitivity deviation rate indicators under weak network conditions; Optimization module: It is used for the evaluation that under weak network conditions, the sensitivity of active power to voltage is higher than that of reactive power to voltage. The grid voltage over-limit suppression idea of ​​"active first, reactive later" is adopted, and the energy storage type intelligent soft switch E-SOP is installed; Analysis module: used to connect two nodes through the SOP connection of the E-SOP device and analyze the voltage over-limit suppression effect of each node.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, a method for suppressing voltage exceeding a limit in a weak power grid based on an energy storage type intelligent soft switch is implemented as claimed in any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, a method for suppressing voltage exceeding a limit in a weak power grid based on an energy storage type intelligent soft switch is implemented as claimed in any one of claims 1 to 5.

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