Direct-current feed-in receiving-end power grid reactive power distribution method, electronic equipment and medium

Abstract

The invention discloses a direct current feed-in receiving end power grid reactive power distribution method, electronic equipment and a medium. The method comprises the following steps: acquiring an electrical distance between a substation node in a direct current preset range and a direct current; sorting the plurality of transformer substation nodes according to the sequence of the electrical distances from small to large, and constructing a reactive configuration node set of the reactive configuration to be evaluated; calculating and obtaining a reactive power optimization distribution vector based on the reactive power configuration node set; and reactive power optimization distribution is carried out based on the reactive power gap value and the reactive power optimization distribution vector under the DC feed-in fault. According to the method, a specific reactive power optimization distribution scheme is formulated by combining the reactive power configuration node set and the reactive power optimization distribution vector, so that each node can be ensured to quickly adjust reactive power output according to the requirements of the optimization distribution vector under the condition of a fault, a reactive power gap is filled, and the reactive power distribution efficiency is improved. The reactive power balance capability and the voltage stability of the system under a direct current feed-in fault are improved, and safe and stable operation of a power system is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of reactive power optimization in power systems, and particularly relates to a reactive power distribution method, an electronic device, and a medium for a receiving-end power grid with DC feeding. Background Art

[0002] In a power system, a receiving-end power grid refers to a power grid that receives power energy input from an energy base. An active power gap refers to a DC fault that occurs in the receiving-end power grid when the power generation power in the power system is insufficient to meet the load demand. For the reactive power balance in the vicinity of DC, when a DC blocking fault or a commutation failure fault occurs in the receiving-end power grid, it also causes a sharp increase in reactive power demand, affecting the stable operation of the system.

[0003] With the increase in the types of reactive power devices available in the power system, when configuring reactive power devices, it is necessary to consider the cost investment and regulation effect of different types of reactive power devices. For example, as a replacement for traditional units, a synchronous condenser can quickly respond to voltage dips and provide a large amount of dynamic reactive power support. Some power electronic devices can flexibly adjust reactive power output, but their capacity is limited, or they can quickly compensate for reactive power gaps during AC faults and suppress voltage fluctuations. In addition, an energy storage power station has the ability to quickly adjust active or reactive power. The reactive power support provided by it can quickly respond during a fault, and at the same time, the active power injection can relieve the power deficit and reduce the recovery time after commutation failure. The decentralized configuration characteristics of energy storage are also suitable for multi-point layout in a multi-infeed system.

[0004] In related technologies, traditional reactive power optimization methods are mostly static optimizations and are difficult to adapt to the dynamic changes of the power grid. In a multi-infeed DC system, with the increase in the types of reactive power devices available, it is necessary to consider the cost performance of dynamic reactive power configuration to improve the effectiveness and efficiency of the optimization results. Summary of the Invention

[0005] The purpose of the present invention is to be able to optimize the types and capacity selection of reactive power devices in the vicinity of DC, and jointly play the role of reactive power devices in quickly responding and meeting reactive power demands.

[0006] To achieve the above purpose, the present invention proposes a reactive power distribution method for a receiving-end power grid with DC feeding, including: obtaining the electrical distance between a substation node within a preset DC range and the DC, where the substation node is the substation with the highest AC voltage level within the preset range; sorting multiple substation nodes in ascending order of the electrical distance to construct a reactive power configuration node set for evaluating reactive power configuration; calculating and obtaining a reactive power optimization distribution vector based on the reactive power configuration node set; and performing reactive power optimization distribution based on the reactive power gap value under a DC feeding fault and the reactive power optimization distribution vector.

[0007] In an alternative embodiment, reactive power optimization allocation is performed based on the reactive power gap value under DC feed-in fault and the reactive power optimization allocation vector, which specifically includes: obtaining the length of the reactive power optimization allocation vector based on the reactive power optimization allocation vector; obtaining the reactive power equipment capacity based on the length of the reactive power optimization allocation vector, where the reactive power equipment capacity includes dynamic reactive power equipment capacity, static reactive power equipment capacity, and / or total reactive power equipment capacity, and the total reactive power equipment capacity is the sum of the dynamic reactive power equipment capacity and the static reactive power equipment capacity; obtaining the reactive power gap value under DC feed-in fault; and inputting dynamic reactive power equipment, static reactive power equipment, or stopping reactive power allocation based on the reactive power gap value and the reactive power equipment capacity.

[0008] In an alternative embodiment, obtaining the reactive power equipment capacity based on the length of the reactive power optimization allocation vector specifically includes: sorting multiple substation nodes from small to large based on the length of the reactive power optimization allocation vector to obtain a sorted set of the lengths of the reactive power optimization allocation vectors; and calculating the reactive power equipment capacity based on the sorted set of the lengths of the reactive power optimization allocation vectors.

[0009] In an alternative embodiment, inputting dynamic reactive power equipment, static reactive power equipment, or stopping reactive power allocation based on the reactive power gap value and the reactive power equipment capacity specifically includes: calculating a reactive power compensation redundancy ratio based on the reactive power gap value and the reactive power equipment capacity, and the calculation formula is as follows: If the length of the reactive power optimization allocation vector satisfies 0 < length of the reactive power optimization allocation vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop reactive power allocation; otherwise, input node dynamic reactive power equipment or node static reactive power equipment in sequence according to the ascending order of the lengths of the reactive power optimization allocation vectors in the set of the lengths of the reactive power optimization allocation vectors; if the length of the reactive power optimization allocation vector satisfies < length of the reactive power optimization allocation vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop reactive power allocation; otherwise, input node dynamic reactive power equipment or node static reactive power equipment in sequence according to the ascending order of the lengths of the reactive power optimization allocation vectors in the set of the lengths of the reactive power optimization allocation vectors.

[0010] In an alternative embodiment, if the length of the reactive power optimization allocation vector satisfies 0 < length of the reactive power optimization allocation vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop reactive power allocation; otherwise, input node dynamic reactive power equipment or node static reactive power equipment in sequence according to the ascending order of the lengths of the reactive power optimization allocation vectors in the set of the lengths of the reactive power optimization allocation vectors, which specifically includes: if the length of the reactive power optimization allocation vector satisfies where A is the number of nodes. For the node ranked a-th in terms of the length of the reactive power optimization distribution vector, if the cumulative sum of the dynamic reactive power device capacities of the first to a-th substation nodes satisfies then stop the reactive power distribution; otherwise, continue to sequentially put into operation the dynamic reactive power devices of the (a + 1)-th to A-th substation nodes; if it satisfies then stop the reactive power distribution; otherwise, sequentially put into operation the static reactive power device capacities of the nodes in ascending order of the length of the reactive power optimization distribution vector in the set; for the node ranked b-th in terms of the length of the reactive power optimization distribution vector, if the cumulative sum of the static reactive power device capacities of the first to b-th substation nodes where a ≤ A, b ≤ A; if it satisfies then stop the reactive power distribution; otherwise, continue to put into operation the dynamic reactive power devices of the (b + 1)-th to A-th nodes; if it satisfies then stop the reactive power distribution; where the redundancy threshold is 0.05, and define the dynamic reactive power device capacity Q of the node ranked m-th mV and the static reactive power device capacity Q mS .

[0011] In an alternative embodiment, if the length of the reactive power optimization distribution vector satisfies <the length of the reactive power optimization distribution vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop the reactive power distribution; otherwise, in ascending order of the length of the reactive power optimization distribution vector in the set of reactive power optimization distribution vectors, sequentially put into operation the dynamic reactive power devices or static reactive power devices of the nodes, specifically including: if the length of the reactive power optimization distribution vector satisfies where A is the number of nodes. For the node ranked c-th in terms of the length of the reactive power optimization distribution vector, if the cumulative sum of the dynamic reactive power device capacities of the (A + 1)-th to c-th substation nodes satisfies then stop the reactive power distribution; otherwise, continue to sequentially put into operation the dynamic reactive power devices of the (c + 1)-th to c-th substation nodes; if it satisfies then stop the reactive power distribution; otherwise, sequentially put into operation the static reactive power device capacities of the nodes in ascending order of the length of the reactive power optimization distribution vector in the set; for the node ranked d-th in terms of the length of the reactive power optimization distribution vector, if the cumulative sum of the static reactive power device capacities of the (A + 1)-th to d-th substation nodes where c ≤ n, d ≤ n; if it satisfies then stop the reactive power distribution; otherwise, continue to put into operation the static reactive power devices of the (d + 1)-th to n-th nodes; if it satisfies then stop the reactive power distribution; otherwise, configure a reactive power device with a capacity of ΔQ i in the DC i substation, ΔQ iMeet

[0012] In an alternative embodiment, obtaining the length of the reactive power optimization allocation vector based on the reactive power optimization allocation vector specifically includes: defining the reactive power optimization allocation vector of the k-th node as: M k =(S ik , C k ); obtaining the short-circuit capacity of the k-th node in the reactive power configuration node set; calculating the length of the reactive power optimization allocation vector based on the short-circuit capacity and the electrical distance corresponding to the k-th node, and the calculation formula is as follows: In the formula, L k is the length of the reactive power optimization allocation vector, S ik is the electrical distance corresponding to the k-th node, and C k is the short-circuit capacity of the k-th node.

[0013] In an alternative embodiment, the reactive power allocation method for the receiving-end power grid with DC feeding further includes:

[0014] Performing normalization processing on the electrical distance or the short-circuit capacity, and the calculation formula is as follows:

[0015] In the formula, x is the S ik or C k value of the k-th node, x min is the minimum value of the electrical distance or short-circuit capacity of n nodes, x max is the maximum value of the electrical distance or short-circuit capacity of n nodes, and x' is the S ik or C k value of the k-th node after normalization processing.

[0016] In an alternative embodiment, obtaining the electrical distance between the substation node within the DC preset range and the DC specifically includes: obtaining the equivalent reactance from the DC to the substation node of the receiving-end power grid; calculating the electrical distance based on the equivalent reactance, and the calculation formula is as follows: S ij =|X ij |, where j = 1,..., n, X ij is the equivalent reactance, |X ij | is the modulus value of X ij , and S ij is the electrical distance from the i-th DC to the j-th substation node of the receiving-end power grid.

[0017] The present invention also provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute any one of the reactive power distribution methods for the receiving-end power grid with DC feeding.

[0018] The present invention also provides a computer storage medium storing a computer program, which when executed by a processor, implements any one of the reactive power distribution methods for the receiving-end power grid with DC feeding.

[0019] The beneficial effects of the present invention are as follows: By combining the reactive power configuration node set and the reactive power optimal distribution vector to formulate a specific reactive power optimal distribution scheme, the present invention can ensure that in the event of a fault, each node can quickly adjust the reactive power output according to the requirements of the optimal distribution vector to fill the reactive power gap, so as to improve the reactive power balance ability and voltage stability of the system under DC feeding faults and ensure the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flowchart of a reactive power distribution method for a receiving-end power grid with DC feeding provided for an embodiment of the present invention;

[0021] Figure 2 is a block diagram of an electronic device provided for an embodiment of the present invention.

[0022] Description of reference numerals: 110, processor; 120, memory. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0024] In the related art, relevant simulations can show that the advantages of installing a synchronous condenser lie in inertia support and short-term overload capacity, which are suitable for coping with transient reactive power demands. Power electronic devices, such as SVC / STATCOM, have a fast response speed (millisecond level) and can flexibly adjust reactive power output, but their capacity is limited. SVC / STATCOM can quickly compensate for reactive power gaps and suppress voltage fluctuations during AC faults. In addition, the characteristics of the dispersed configuration of energy storage in energy storage power stations are also suitable for multi-point layout in multi-infeed systems.

[0025] In addition, in the selection of reactive power configuration nodes, if the dynamic reactive power support of the receiving-end power grid is insufficient, the ability of the converter station to absorb a large amount of reactive power from the AC system during a fault will be limited due to the long electrical distance, thus exacerbating voltage instability. At the same time, the smaller the short-circuit capacity of the node, the weaker the anti-disturbance ability of the system and the worse the voltage stability, and more reactive power compensation devices need to be configured.

[0026] As Figure 1 shown, according to an embodiment of the present invention, on the one hand, a method for reactive power distribution in a receiving-end power grid with DC feeding is provided, including the following steps:

[0027] Step S101: Obtain the electrical distance between the substation nodes within the preset range of the DC and the DC. The substation nodes are the substations with the highest AC voltage level within the preset range;

[0028] Step S103: Sort multiple substation nodes in ascending order of electrical distance, and construct a set of reactive power configuration nodes to be evaluated for reactive power configuration.

[0029] Step S105: Calculate and obtain a reactive power optimal distribution vector based on the set of reactive power configuration nodes.

[0030] Step S107: Perform reactive power optimal distribution based on the reactive power gap value under DC feeding fault and the reactive power optimal distribution vector.

[0031] In this embodiment, the preset range of the DC includes AC substations near the DC converter station, AC grid nodes directly connected to the DC transmission line, and AC grid regions with strong electrical coupling with the DC system. Within the preset range, substations in the AC grid can be found through the grid geographic information system or the grid connection diagram, and the substations with the highest AC voltage level can be identified and marked as substation nodes. The electrical distance can be calculated through the grid topology structure and line parameters, reflecting the tightness of the electrical connection between the substation node and the DC system. The smaller the electrical distance, the greater the impact of the substation on the DC system.

[0032] According to the electrical distance calculated in step S101, all substation nodes are sorted in ascending order. Substation nodes with smaller electrical distances are considered first because they have a more significant impact on the DC system in reactive power configuration.

[0033] From the sorted substation nodes, a certain number of nodes are selected as the set of nodes to be evaluated for reactive power configuration. These nodes will be the key objects for subsequent reactive power optimal distribution. The number of selected nodes can be determined according to actual needs and system scale, usually including several nodes with the smallest electrical distance.

[0034] Perform reactive power demand analysis on each node in the set of nodes to be evaluated for reactive power configuration. Consider the reactive power requirements of each node under normal operation and fault conditions, including load requirements, equipment losses, and other factors. Combining the results of reactive power demand analysis, calculate the reactive power distribution value for each node. These distribution values constitute the reactive power optimal distribution vector, indicating the reactive power that should be distributed to each node under different operating states to achieve system reactive power balance and voltage stability.

[0035] For the DC power transmission system feeding faults, such as DC blocking, power mutation, etc., the system has a reactive power gap at the moment of fault occurrence and in the subsequent process. The reactive power gap value is the difference between the actual demand of reactive power in the power system and the reactive power that the existing reactive power sources can provide. Through simulation or actual monitoring data, the magnitude and distribution of the reactive power gap can be determined. The existence of the reactive power gap will cause the system voltage to drop, affecting the power quality and system stability. By analyzing the reactive power gap value, it can be determined which nodes need reactive power compensation and the magnitude of the compensation, thereby providing input data for the calculation of the reactive power optimal distribution vector.

[0036] According to the reactive power optimal distribution vector calculated in step S105 and combined with the reactive power gap value under the DC feeding fault, a specific reactive power optimal distribution plan is formulated. This plan should ensure that in the event of a fault, each node can quickly adjust its reactive power output according to the requirements of the optimal distribution vector to fill the reactive power gap, so as to improve the reactive power balance ability and voltage stability of the system under the DC feeding fault and ensure the safe and stable operation of the power system.

[0037] Furthermore, based on step S101: Obtain the electrical distance between the substation nodes and the DC within the DC preset range, which specifically includes the following steps:

[0038] Step S1011: Obtain the equivalent reactance from the DC to the substation nodes of the receiving-end power grid;

[0039] Step S1013: Based on the equivalent reactance, calculate the electrical distance. The calculation formula is as follows:

[0040] S ij =|X ij |, where j = 1,......, n, X ij is the equivalent reactance, |X ij | is the modulus of X ij , and S ij is the electrical distance from the i-th DC to the j-th substation node of the receiving-end power grid.

[0041] The electrical distance is an abstract concept used to describe the "distance" between two power grid nodes. This distance is not the physical distance but the distance calculated based on the reactance value, reflecting the electrical connection strength between the two nodes. The equivalent reactance is the sum of the reactions of inductance and capacitance in an AC circuit. The method of obtaining the equivalent reactance can be carried out in several different ways. For example, it can be obtained by using electrical calculation software. The equivalent parameters of an AC circuit can be measured by the three-meter method. This method calculates the equivalent resistance and equivalent reactance of the load to be measured by separately measuring the voltage, current, and power consumed by the load, thereby determining the equivalent impedance parameters of the load to be measured. Other methods will not be elaborated here.

[0042] Further, in step S107, reactive power optimal allocation is performed based on the reactive power gap value and the reactive power optimal allocation vector under DC feed-in fault, which specifically includes the following steps:

[0043] Step S1071: Obtain the length of the reactive power optimal allocation vector based on the reactive power optimal allocation vector.

[0044] Step S1073: Obtain the reactive power equipment capacity based on the length of the reactive power optimal allocation vector. The reactive power equipment capacity includes the dynamic reactive power equipment capacity, the static reactive power equipment capacity, and / or the total reactive power equipment capacity. The total reactive power equipment capacity is the sum of the dynamic reactive power equipment capacity and the static reactive power equipment capacity.

[0045] Step S1075: Obtain the reactive power gap value under DC feed-in fault.

[0046] Step S1077: Based on the reactive power gap value and the reactive power equipment capacity, put into operation the dynamic reactive power equipment, the static reactive power equipment, or stop reactive power allocation.

[0047] In this embodiment, the reactive power optimal allocation vector is a vector containing the reactive power allocation values of each node, which is used to guide the operation state of the reactive power equipment. The length of the reactive power optimal allocation vector is the number of reactive power allocation values contained in the vector.

[0048] The reactive power equipment capacity includes the dynamic reactive power equipment capacity, the static reactive power equipment capacity, and the total reactive power equipment capacity. The dynamic reactive power equipment capacity refers to the equipment capacity that can quickly adjust the reactive power. The static reactive power equipment capacity refers to the equipment capacity that adjusts the reactive power by switching capacitor or reactor banks. The total reactive power equipment capacity is the sum of the dynamic reactive power equipment capacity and the static reactive power equipment capacity.

[0049] In step 1077, according to the reactive power gap value and the reactive power equipment capacity, put into operation the dynamic reactive power equipment, the static reactive power equipment, or stop reactive power allocation.

[0050] Among them, if the reactive power gap value is large, give priority to putting into operation the dynamic reactive power equipment because they can quickly respond to the changes in reactive power demand.

[0051] If the dynamic reactive power equipment capacity is not enough to meet the reactive power gap, then consider putting into operation the static reactive power equipment.

[0052] If the reactive power gap value is small or the reactive power equipment capacity is sufficient, the input of reactive power equipment can be appropriately reduced to avoid overcompensation.

[0053] Through the above steps, based on the reactive power gap value and the reactive power optimal allocation vector under DC feed-in fault, the dynamic reactive power equipment and the static reactive power equipment can be reasonably put into operation, realizing the optimal allocation of reactive power, and improving the voltage stability and operation efficiency of the power system.

[0054] Based on the characteristics of DC feed-in faults and the key factors of reactive power demand caused thereby, by calculating and analyzing the electrical distances between each node in the system and the DC to be analyzed, and the short-circuit capacity of the nodes, a set of nodes for reactive power configuration to be evaluated and a vector for optimal allocation of node reactive power are constructed. Then, the vector for optimal allocation of node reactive power is used to optimize the configuration process of various types of reactive power devices at the nodes, which can optimize the selection of the types and capacities of reactive power devices in the vicinity of the DC, and jointly play the roles of the fast response of reactive power devices and meeting the reactive power demand.

[0055] Further, in step S1071, obtaining the length of the vector for optimal allocation of reactive power based on the vector for optimal allocation of reactive power specifically includes the following steps:

[0056] Step S10711: Define the vector for optimal allocation of reactive power of the k-th node as: M k =(S ik , C k ).

[0057] Step S10713: Obtain the short-circuit capacity of the k-th node in the set of nodes for reactive power configuration.

[0058] Step S10715: Based on the short-circuit capacity and the electrical distance corresponding to the k-th node, calculate the length of the vector for optimal allocation of reactive power, and the calculation formula is as follows:

[0059]

[0060] In the formula, L k is the length of the vector for optimal allocation of reactive power, S ik is the electrical distance corresponding to the k-th node, and C k is the short-circuit capacity of the k-th node.

[0061] The short-circuit capacity refers to the maximum current value that the system can withstand when a short-circuit fault occurs. This formula combines the influences of the electrical distance and the short-circuit capacity, and can form an index reflecting the importance of the node in reactive power distribution. By calculating this length, the distribution of reactive power in the system can be better understood and optimized.

[0062] Through the above steps, the distribution of reactive power can be optimized, thereby improving the stability and efficiency of the system. By accurately calculating the length of the vector for optimal allocation of reactive power for each node, reactive power equipment can be more reasonably allocated, system losses can be reduced, and power supply quality can be improved.

[0063] Further, the method for reactive power distribution in the receiving-end power grid of DC feed-in further includes the following steps:

[0064] Step S109: Perform normalization processing on the electrical distance or the short-circuit capacity, and the calculation formula is as follows:

[0065]

[0066] wherein, x is the S value of the k-th node ik or C k value, x min is the minimum value of the electrical distance or short-circuit capacity of n nodes, x max is the maximum value of the electrical distance or short-circuit capacity of n nodes, and x' is the S ik or C k value after normalization processing of the k-th node.

[0067] Normalization processing helps to eliminate the influence of different dimensions and orders of magnitude, making the data comparable, so as to facilitate

[0068] further analysis and processing. Define the substation electrical distance of the k-th node in the set of nodes with reactive power configuration to be evaluated as S ik and the short-circuit capacity as C k , where C k is obtained by using electrical calculation software.

[0069] The range of the normalized value x' is between 0 and 1, where 0 indicates that the electrical characteristics of this node are the weakest among all nodes, that is, the minimum value, and 1 indicates the strongest, that is, the maximum value. In this way, all nodes can be compared on the same scale.

[0070] The electrical distance or short-circuit capacity involved in subsequent calculations can all be data after normalization processing.

[0071] Furthermore, in step S1073, obtaining the reactive power equipment capacity based on the length of the reactive power optimization distribution vector specifically includes the following steps:

[0072] Step S10731: Sort multiple substation nodes from small to large based on the length of the reactive power optimization distribution vector to obtain a sorted set of the lengths of the reactive power optimization distribution vectors.

[0073] Step S10731: Calculate the reactive power equipment capacity based on the set of the lengths of the reactive power optimization distribution vectors.

[0074] The sorted set of the lengths of the reactive power optimization distribution vectors sorts n substation nodes from small to large according to the electrical distance to obtain the set of nodes with reactive power configuration to be evaluated {1, 2,..., k,..., n}. Where k is the node whose electrical distance ranks k-th among n nodes after sorting by electrical distance.

[0075] Through the above steps, the lengths of the reactive power optimization distribution vectors of the sorted substation nodes are arranged in sequence to form an ordered set. According to the sorted set of the lengths of the reactive power optimization distribution vectors, combined with the reactive power requirements and equipment characteristics of each node, the dynamic reactive power equipment capacity and the static reactive power equipment capacity are calculated, and the dynamic reactive power equipment capacity is reasonably obtained.

[0076] From the perspective of the embodiments of the present invention, according to the content of step S101, an electrical calculation software is used to obtain the equivalent reactance values of the direct current A to the 12 highest alternating current voltage levels in a certain power system partition, that is, the 500 kV voltage level, of the substations, which are the electrical distance values from the direct current to each substation node. These 12 500 kV substation nodes are re-sorted from largest to smallest according to the electrical distance values, and the node ranked first is the node with the first-ranked electrical distance among the 12 nodes.

[0077] Furthermore, step S1077, based on the reactive power gap value and the reactive power equipment capacity, inputs dynamic reactive power equipment, static reactive power equipment or stops reactive power distribution, specifically including the following steps:

[0078] Step S10771: Calculate the reactive power compensation redundancy ratio based on the reactive power gap value and the reactive power equipment capacity, and the calculation formula is as follows:

[0079] Step S10773: If the length of the reactive power optimization distribution vector satisfies 0 < the length of the reactive power optimization distribution vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop reactive power distribution; otherwise, in the order of the lengths of the reactive power optimization distribution vectors in the set of the lengths of the reactive power optimization distribution vectors from smallest to largest, input the node dynamic reactive power equipment or the node static reactive power equipment in sequence.

[0080] Step S10775: If the length of the reactive power optimization distribution vector satisfies < the length of the reactive power optimization distribution vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop reactive power distribution; otherwise, in the order of the lengths of the reactive power optimization distribution vectors in the set of the lengths of the reactive power optimization distribution vectors from smallest to largest, input the node dynamic reactive power equipment or the node static reactive power equipment in sequence.

[0081] In this embodiment, calculating the redundancy ratio of reactive power compensation based on the reactive power gap value and the reactive power equipment capacity can ensure that when reactive power distribution is carried out, the system can have sufficient redundancy to cope with possible load changes or equipment failures. Inputting the node dynamic reactive power equipment or the node static reactive power equipment in sequence in the order of the lengths of the reactive power optimization distribution vectors in the set of the lengths of the reactive power optimization distribution vectors from smallest to largest can optimize the use of resources as much as possible while meeting the reactive power requirements of the system.

[0082] Through these steps, it can be ensured that when reactive power is distributed, the system can not only meet the current reactive power demand but also maintain a certain redundancy to cope with possible changes or faults. At the same time, by optimizing the use of resources, the operating efficiency and stability of the system can be improved.

[0083] Define the dynamic reactive power equipment capacity Q of the m-th node mV and the static reactive power equipment capacity Q mS . Q mV and Q mS can be obtained from the node equipment ledger information. Define the reactive power capacity Q to be allocated at the m-th node m as Qm = Q mV + Q mS , then the sum of the reactive power equipment capacities accumulated to the m-th node is satisfying where m = 1, 2,..., n.

[0084] From the embodiments of the present invention, according to step S105, calculate the reactive power optimal allocation vectors of 12 nodes in this partition. The reactive power optimal allocation vector of each node consists of two parameters: electrical distance and short-circuit capacity. Considering that both of these parameters are normalized, according to the calculated length of the reactive power optimal allocation vector, re-rank the 12 substation nodes from smallest to largest according to the length of the reactive power optimal allocation vector to obtain a set of reactive power optimal allocation vector lengths. Take the nodes 1, 2, and 3 that were originally ranked in the top three in the set of nodes to be evaluated for reactive power configuration as an example: The length of the reactive power optimal allocation vector of node 1 is 0.054, ranking 4th among the lengths of the reactive power optimal allocation vectors of 12 nodes. Then in the set of reactive power optimal allocation vector lengths, the original node 1 ranks 4th, and the corresponding reactive power optimal allocation vector length is L4, and the node number is changed to node 4. The length of the reactive power optimal allocation vector of node 2 is 0.063, ranking 8th among the lengths of the reactive power optimal allocation vectors of 12 nodes. Then in the set of reactive power optimal allocation vector lengths, the original node 2 ranks 8th, and the corresponding reactive power optimal allocation vector length is L8, and the node number is changed to node 8. The length of the reactive power optimal allocation vector of node 3 is 0.031, ranking 1st among the lengths of the reactive power optimal allocation vectors of 12 nodes. Then in the set of reactive power optimal allocation vector lengths, the original node 3 ranks 1st, and the corresponding reactive power optimal allocation vector length is L1, and the node number is changed to node 1.

[0085] In addition, take node 8 corresponding in the set of reactive power optimal allocation vector lengths as an example. The dynamic reactive power equipment capacity Q of this node 8V is 60 Mvar and the static reactive power equipment capacity Q 8S is 600 Mvar, and Q8 is 660 Mvar. The sum of the reactive power equipment capacities accumulated to the 8th node is 3300 Mvar.

[0086] Further, based on step S10773, if the length of the reactive power optimization distribution vector satisfies 0 < the length of the reactive power optimization distribution vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop the reactive power distribution; otherwise, in the order of the lengths of the reactive power optimization distribution vectors in the set of reactive power optimization distribution vectors from small to large, successively put into the node dynamic reactive power equipment or the node static reactive power equipment, which specifically includes the following steps:

[0087] Step S107731: If the length of the reactive power optimization distribution vector satisfies 0 < LA ≤ where A is the number of nodes. For the node with the reactive power optimization distribution vector length ranked at the a-th position, if the cumulative sum of the dynamic reactive power equipment capacities of the first to the a-th substation nodes satisfies then stop the reactive power distribution; otherwise, continue to successively put into the dynamic reactive power equipment of the (a + 1)-th to the A-th substation nodes;

[0088] Step S107733: If it satisfies then stop the reactive power distribution; otherwise, successively put into the static reactive power equipment capacities of the nodes in the order of the lengths of the reactive power optimization distribution vectors in the set from small to large;

[0089] For the node with the reactive power optimization distribution vector length ranked at the b-th position, if the cumulative sum of the static reactive power equipment capacities of the first to the b-th substation nodes where a ≤ A and b ≤ A;

[0090] Step S107735: If it satisfies then stop the reactive power distribution; otherwise, continue to put into the dynamic reactive power equipment of the (b + 1)-th to the A-th nodes;

[0091] Step S107737: If it satisfies then stop the reactive power distribution;

[0092] where the redundancy threshold is 0.05, and define the dynamic reactive power equipment capacity Q of the node ranked at the m-th position mV and the static reactive power equipment capacity Q mS .

[0093] Further, based on step S107735, if the length of the reactive power optimization distribution vector satisfies < the length of the reactive power optimization distribution vector ≤ and the reactive power compensation redundancy ratio is less than or equal to the redundancy threshold, then stop the reactive power distribution; otherwise, in the order of the lengths of the reactive power optimization distribution vectors in the set of reactive power optimization distribution vectors from small to large, successively put into the node dynamic reactive power equipment or the node static reactive power equipment, which specifically includes the following steps:

[0094] Step S1077351: If the length of the reactive power optimization distribution vector satisfies where A is the number of nodes. For the node with the c-th largest length of the reactive power optimization distribution vector, if the cumulative sum of the dynamic reactive power device capacities of the (A + 1)-th to the c-th substation nodes satisfies then stop the reactive power distribution; otherwise, continue to sequentially turn on the dynamic reactive power devices of the (c + 1)-th to the c-th substation nodes;

[0095] Step S1077353: If it satisfies then stop the reactive power distribution; otherwise, sequentially turn on the static reactive power device capacities of the nodes in ascending order of the length of the reactive power optimization distribution vector in the set;

[0096] For the node with the d-th largest length of the reactive power optimization distribution vector, if the cumulative sum of the static reactive power device capacities of the (A + 1)-th to the d-th substation nodes where c ≤ n, d ≤ n;

[0097] Step S1077355: If it satisfies then stop the reactive power distribution; otherwise, continue to turn on the static reactive power devices of the (d + 1)-th to the n-th nodes;

[0098] Step S1077357: If it satisfies then stop the reactive power distribution; otherwise, configure a reactive power device with a capacity of ΔQ in the DC i substation, and ΔQ i satisfies i satisfies

[0099] From the embodiments of the present invention, according to the content of Step S107, first use electrical calculation software to obtain that the reactive power gap of DC A is 2100 Mvar. After judging the set of the lengths of the reactive power optimization distribution vectors, the lengths corresponding to the nodes that satisfy are the nodes ranked in the top four in the set of the lengths of the reactive power optimization distribution vectors. When sequentially turning on the dynamic reactive power device capacity of the 4th substation node, the cumulative sum of the dynamic reactive power device capacities of the 1st to the 4th substation nodes is 240 Mvar. After judgment, it still does not satisfy Therefore, then sequentially turn on the static reactive power device capacities. When turning on the static reactive power device capacity of the 3rd substation node, the cumulative sum of the static reactive power device capacities of the 1st to the 3rd substation nodes is 1800 Mvar. Judge that it satisfies then stop the reactive power distribution.

[0100] By constructing a set of nodes to be evaluated for reactive power configuration and a vector for optimal reactive power distribution among nodes, the present invention optimizes the configuration process of various types of reactive power devices at nodes, can optimize the type and capacity selection of reactive power devices in the vicinity of DC, and jointly plays the roles of rapid response of reactive power devices and meeting reactive power demands.

[0101] On the other hand, the present invention also provides an electronic device, including: at least one processor 110; a memory 120 communicatively connected to the at least one processor; wherein, the memory 120 stores instructions executable by the at least one processor 110, and when the instructions are executed by the at least one processor 110, the at least one processor 110 is enabled to execute the reactive power distribution method for the receiving-end power grid with DC feeding in any one of the embodiments.

[0102] On the other hand, the present invention also proposes a computer storage medium storing a computer program, and when the computer program is executed by a processor, the reactive power distribution method for the receiving-end power grid with DC feeding in any one of the embodiments is implemented.

[0103] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc. Each embodiment in this specification is described in a progressive manner, and the same or similar parts among the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the device, equipment, and non-volatile computer storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0104] The above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for reactive power distribution in a receiving-end power grid fed with direct current, characterized in that: include: Acquire the electrical distance between a substation node within a preset range of a direct current and the direct current, wherein the substation node is a substation with the highest alternating current voltage level within the preset range; Sorting the plurality of substation nodes in the order of the electrical distance from small to large, and constructing a reactive configuration node set of the reactive configuration to be evaluated; Calculate and obtain a reactive power optimization allocation vector based on the reactive power configuration node set; Reactive power optimization allocation is performed based on the reactive power gap value under the DC feed-in fault and the reactive power optimization allocation vector.

2. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 1, characterized in that: Reactive power optimization allocation is performed based on the reactive power gap value under the DC feed-in fault and the reactive power optimization allocation vector, specifically including: Acquiring a reactive power optimization allocation vector length based on the reactive power optimization allocation vector; Acquire reactive equipment capacity based on the reactive power optimization allocation vector length, wherein the reactive equipment capacity includes dynamic reactive equipment capacity, static reactive equipment capacity and / or total reactive equipment capacity, and the total reactive equipment capacity is the sum of the dynamic reactive equipment capacity and the static reactive equipment capacity; Obtain reactive power gap value under DC feed-in fault; Based on the reactive power gap value and the reactive power equipment capacity, dynamic reactive power equipment, static reactive power equipment or reactive power distribution is put into operation.

3. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 2, characterized in that: Acquiring reactive equipment capacity based on the reactive power optimization allocation vector length specifically includes: Based on the reactive power optimization allocation vector length, sorting the plurality of substation nodes from small to large to obtain a sorted reactive power optimization allocation vector length set; The reactive equipment capacity is calculated based on the reactive power optimization allocation vector length set.

4. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 3, characterized in that: Based on the reactive power gap value and the reactive power equipment capacity, dynamic reactive power equipment, static reactive power equipment or reactive power distribution is put into use, specifically including: The reactive compensation redundancy ratio is calculated based on the reactive gap value and the reactive equipment capacity, and the calculation formula is as follows: If the reactive power optimization allocation vector length satisfies If the reactive compensation redundancy ratio is less than or equal to the redundancy threshold, the reactive power distribution is stopped; otherwise, the node dynamic reactive power equipment or the node static reactive power equipment is put into operation in sequence according to the order of the reactive power optimization allocation vector length in the reactive power optimization allocation vector length set from small to large; If the reactive power optimization allocation vector length satisfies If the reactive compensation redundancy ratio is less than or equal to the redundancy threshold, reactive power distribution is stopped; otherwise, node dynamic reactive devices or node static reactive devices are put into operation in sequence according to the order of reactive power optimization allocation vector lengths in the reactive power optimization allocation vector length set from small to large.

5. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 4, characterized in that: If the reactive power optimization allocation vector length satisfies If the reactive compensation redundancy ratio is less than or equal to the redundancy threshold, the reactive power distribution is stopped; otherwise, the node dynamic reactive equipment or the node static reactive equipment is put into operation in sequence according to the order of the reactive power optimization allocation vector length in the reactive power optimization allocation vector length set from small to large, specifically including: If the reactive power optimization allocation vector length satisfies Where A is the number of nodes. For the node whose reactive power optimization allocation vector length ranks ath, if the cumulative sum of the dynamic reactive power equipment capacity of the 1st to ath substation nodes is satisfy Then the reactive power distribution is stopped; otherwise, the dynamic reactive power equipment of the a+1th to Ath substation nodes are put into operation in sequence; If satisfied Then the reactive power distribution is stopped; otherwise, the static reactive power equipment capacity of the node is put into operation in the order of the length of the reactive power optimization distribution vector in the set from small to large; For the node with the length of the reactive power optimization allocation vector ranked b, if the cumulative sum of the static reactive power equipment capacity of the 1st to the bth substation nodes is Among them, a≤A, b≤A; If satisfied Then the reactive power distribution is stopped; otherwise, the dynamic reactive power equipment of nodes b+1 to A is put into operation; If satisfied Then stop reactive power distribution; Among them, the redundancy threshold is 0.05, and the dynamic reactive equipment capacity Q of the mth node is defined as mV and static reactive power equipment capacity Q mS .

6. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 4, characterized in that: If the reactive power optimization allocation vector length satisfies If the reactive compensation redundancy ratio is less than or equal to the redundancy threshold, the reactive power distribution is stopped; otherwise, the node dynamic reactive equipment or the node static reactive equipment is put into operation in sequence according to the order of the reactive power optimization allocation vector length in the reactive power optimization allocation vector length set from small to large, specifically including: If the reactive power optimization allocation vector length satisfies Where A is the number of nodes. For the node with the length of the reactive power optimization allocation vector ranked c, if the cumulative sum of the dynamic reactive power equipment capacity of the A+1th to cth substation nodes is satisfy Then the reactive power distribution is stopped; otherwise, the dynamic reactive power equipment of the substation nodes from c+1 to c continues to be put into operation in sequence; If satisfied Then the reactive power distribution is stopped; otherwise, the static reactive power equipment capacity of the node is put into operation in the order of the length of the reactive power optimization distribution vector in the set from small to large; For the node with the length of the reactive power optimization allocation vector ranked dth, if the cumulative sum of the static reactive power equipment capacity of the A+1th to dth substation nodes is Among them, c≤n, d≤n; if it satisfies Then the reactive power distribution is stopped; otherwise, the static reactive power equipment of the d+1th to nth nodes is put into operation; If satisfied Then the reactive power distribution is stopped; otherwise, the capacity is configured as ΔQ in the DC station i. i Reactive device, ΔQ i satisfy 7. The reactive power distribution method for a DC-fed receiving-end power grid according to any one of claims 2 to 6, characterized in that: The method of obtaining a reactive power optimization allocation vector length based on the reactive power optimization allocation vector specifically includes: The reactive power optimization allocation vector of the kth node is defined as: M k =(S ik ,C k ); Obtaining the short-circuit capacity of the kth node in the reactive configuration node set; Based on the short-circuit capacity and the electrical distance corresponding to the kth node, the reactive power optimization allocation vector length is calculated, and the calculation formula is as follows: Where, L k Assign vector length for reactive power optimization, S ik is the electrical distance corresponding to the kth node, C k is the short-circuit capacity of the kth node.

8. The method for reactive power distribution in a receiving-end power grid fed by direct current according to claim 7, characterized in that: Also includes: The electrical distance or the short-circuit capacity is normalized, and the calculation formula is as follows: Where x is the S of the kth node ik or C k Value, x min is the minimum electrical distance or short-circuit capacity of n nodes, x max is the maximum electrical distance or short-circuit capacity of n nodes, and x′ is the normalized S of the kth node. ik or C k value.

9. The method for reactive power distribution in a DC-fed receiving-end power grid according to any one of claims 1 to 6, characterized in that: Obtaining the electrical distance between the substation node and the DC within a preset range of the DC specifically includes: Obtain the equivalent reactance of the DC to the receiving grid substation node; Based on the equivalent reactance, the electrical distance is calculated using the following formula: S ij =|X ij |, where j = 1, ..., n, X ij is the equivalent reactance, |X ij | for X ij The modulus value, S ij is the electrical distance from the i-th DC to the j-th substation node of the receiving grid.

10. A computer storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, a reactive power distribution method for a receiving-end power grid fed by direct current is implemented as claimed in any one of claims 1 to 9.

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