Method and apparatus for determining background harmonic voltage

Abstract

The application provides a background harmonic voltage determination method and device, and relates to the technical field of power systems. The method comprises the following steps: determining the range of interference sources involved in background harmonic analysis according to the position of a target node in a power system; establishing an interference source harmonic analysis model for each type of interference source within the range of interference sources; establishing an equivalent voltage source model for each type of interference source outside the range of interference sources; and performing power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node. The device is used to execute the above method. The background harmonic voltage determination method and device provided by the application provide a method and basis for background harmonic analysis before the access of interference sources.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system, and particularly relates to a method and device for determining background harmonic voltage. BACKGROUND

[0002] Before a power system disturbance source (including a new energy station, a DC converter valve, an electrified railway, a smelting load, a drilling load, etc.) is connected to a system, harmonic problems caused by the disturbance sources already connected to the system need to be researched to master the current harmonic state of the system and provide a reference and basis for evaluating harmonic problems caused by the new disturbance source. However, there is no related technical solution in the prior art. SUMMARY

[0003] In view of the problems in the prior art, the embodiments of the present application provide a method and device for determining background harmonic voltage, which can at least partially solve the problems in the prior art.

[0004] In one aspect, the present application provides a method for determining background harmonic voltage, comprising:

[0005] determining a range of disturbance sources involved in background harmonic analysis according to a position of a target node in a power system;

[0006] establishing a disturbance source harmonic analysis model for each type of disturbance source in the range of disturbance sources;

[0007] establishing an equivalent voltage source model for each type of disturbance source outside the range of disturbance sources;

[0008] performing a power flow calculation according to the disturbance source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node.

[0009] Optionally, the determination of the range of disturbance sources involved in background harmonic analysis according to the position of the target node in the power system comprises:

[0010] determining the range of disturbance sources covered by nodes in the power system within a range of N transformers from the target node as the range of disturbance sources involved in background harmonic analysis, wherein N is a positive integer greater than 1.

[0011] Optionally, the disturbance source harmonic analysis model comprises a power system device model, a power system line model, a disturbance source model, a non-disturbance source load model, and / or a power grid equivalent model.

[0012] Optionally, the power system device model comprises a conventional generator set harmonic impedance model and / or a transformer harmonic impedance model.

[0013] Optionally, the disturbance source model comprises a new energy disturbance source model and / or a non-linear load type disturbance source model.

[0014] Optionally, the power grid equivalent model comprises a system harmonic impedance model and an equivalent voltage source model.

[0015] In another aspect, the present application provides a background harmonic voltage determination device, comprising:

[0016] A first determination module is configured to determine a range of interference sources involved in background harmonic analysis according to a position of a target node in a power system.

[0017] A first establishment module is configured to establish an interference source harmonic analysis model for each type of interference source within the range of interference sources.

[0018] A second establishment module is configured to establish an equivalent voltage source model for each type of interference source outside the range of interference sources.

[0019] A second determination module is configured to determine a background harmonic voltage of the target node by performing a power flow calculation based on the interference source harmonic analysis model and the equivalent voltage source model.

[0020] Optionally, the first determination module is specifically configured to:

[0021] The range of interference sources covered by nodes within N transformer ranges from the target node in the power system is determined as the range of interference sources involved in background harmonic analysis, wherein N is a positive integer greater than 1.

[0022] Optionally, the interference source harmonic analysis model comprises a power system device model, a power system line model, an interference source model, a non-interference source load model, and / or a power grid equivalent model.

[0023] Optionally, the power system device model comprises a conventional generator harmonic impedance model and / or a transformer harmonic impedance model.

[0024] Optionally, the interference source model comprises a new energy interference source model and / or a non-linear load type interference source model.

[0025] Optionally, the power grid equivalent model comprises a system harmonic impedance model and an equivalent voltage source model.

[0026] In yet another aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the background harmonic voltage determination method according to any one of the above embodiments.

[0027] In still another aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the steps of the method for determining background harmonic voltage according to any one of the above embodiments.

[0028] The method and device for determining background harmonic voltage provided by the embodiments of the present application determine the range of interference sources involved in background harmonic analysis according to the position of a target node in a power system; establish an interference source harmonic analysis model for each type of interference source within the range of interference sources; establish an equivalent voltage source model for each type of interference source outside the range of interference sources; and perform power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node. In this way, a method and basis are provided for background harmonic analysis before the connection of interference sources. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort. In the drawings:

[0030] Figure 1 is a method for determining background harmonic voltage provided by an embodiment of the present application.

[0031] Figure 2 is a schematic diagram of a power system provided in an embodiment of the present application.

[0032] Figure 3 is a schematic diagram of a power system provided in an embodiment of the present application. Figure 2 is a schematic diagram of an equivalent voltage source model for interference sources outside the range of interference sources in the power system shown in the above figure.

[0033] Figure 4 is a nominal π circuit model provided by an embodiment of the present application.

[0034] Figure 5 is a new energy interference source model provided by an embodiment of the present application.

[0035] Figure 6 is a distributed power source model provided by an embodiment of the present application.

[0036] Figure 7 is a non-linear load type interference source model provided by an embodiment of the present application.

[0037] Figure 8 is a structure schematic diagram of a device for determining background harmonic voltage provided by another embodiment of the present application.

[0038] Figure 9 is a schematic diagram of the physical structure of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, further detailed descriptions will be made to the embodiments of the present application with reference to the drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not used as limitations to the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in any manner without conflicts.

[0040] The execution subject of the method for determining the background harmonic voltage provided by the embodiments of the present application includes but is not limited to a computer.

[0041] Figure 1 is a method for determining the background harmonic voltage provided by an embodiment of the present application, as shown in Figure 1 The method for determining the background harmonic voltage provided by the embodiments of the present application includes:

[0042] S101, determining the range of interference sources involved in the background harmonic analysis according to the position of a target node in a power system;

[0043] In this step, the target node can be a node to which a new interference source is to be connected. Before the background harmonic analysis, due to the large size of the power system, it is impossible to analyze the influence of each interference source in the power system on the background harmonic of the target node, so it is necessary to first determine the range of interference sources involved in the background harmonic analysis, and accurately evaluate the influence of various interference sources within the range of interference sources on the background harmonic of the target node.

[0044] S102, establishing an interference source harmonic analysis model for various interference sources within the range of interference sources;

[0045] In this step, for various interference sources directly connected within the range, an interference source harmonic analysis model should be established to analyze the influence of various interference sources within the range on the background harmonic of the target node.

[0046] S103, establishing an equivalent voltage source model for various interference sources outside the range of interference sources;

[0047] In this step, various interference sources connected by nodes outside the range do not establish an interference source harmonic analysis model. Instead, an equivalent voltage source model is used to replace the interference source harmonic analysis model according to the power flow distribution, and the equivalent voltage source is connected to the nodes within the range to ensure that the power flow distribution of each node after the equivalence is the same as that before the equivalence. That is, it is considered that the harmonic current emitted by the interference sources outside the range can be ignored, and this equivalence only ensures that the power flow distribution does not change, but does not consider the harmonic current content injected by these nodes.

[0048] In this embodiment of the invention, the execution order of steps S102 and S103 is not limited. Steps S102 and S103 can be executed simultaneously or sequentially.

[0049] S104. Perform power flow calculations based on the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node.

[0050] In this step, after establishing the interference source harmonic analysis model and the equivalent voltage source model, power flow calculations are performed on the power system. If the power flow converges, the background harmonic voltage of the target node is determined based on the calculation results. The interference source harmonic analysis model and the equivalent voltage source model constitute the power system model. Given a defined power system model, performing power flow calculations and determining the background harmonic voltage of the target node based on the power system model is a conventional technique in this field and will not be elaborated further here.

[0051] The method for determining background harmonic voltage provided in this invention involves determining the range of interference sources involved in background harmonic analysis based on the location of the target node in the power system; establishing an interference source harmonic analysis model for various interference sources within the range; establishing an equivalent voltage source model for various interference sources outside the range; and performing power flow calculations based on the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node. This provides a method and basis for background harmonic analysis before interference sources are connected.

[0052] Optionally, determining the range of interference sources involved in the background harmonic analysis based on the location of the target node in the power system includes: determining the range of interference sources covered by nodes in the power system that are within N transformer ranges from the target node as the range of interference sources involved in the background harmonic analysis, where N is a positive integer greater than 1.

[0053] In this embodiment, N can be 2. When N is 2, the range of interference sources involved in the background harmonic analysis is the range of interference sources covering the nodes of both transformers starting from the target node. Figure 2 For example, the range of interference sources involved in background harmonic analysis is as follows:

[0054] If a new interference source is to be connected to the 110kV A-section busbar, and N is 2, then the range of interference sources involved in the background harmonic analysis is as follows: Figure 2 The dashed circle indicates the range of interference sources involved in the busbar. Harmonic analysis models should be established for all types of interference sources directly connected to the busbar within this range.

[0055] The various interference sources accessed by the nodes outside the region are not established interference source harmonic analysis models. Instead, according to the power flow distribution, an equivalent voltage source model is used to replace the interference sources, and the equivalent voltage source is connected to the nodes in the region (as shown in Figure 3 ), to ensure that the power flow distribution of each node after equivalence is the same as before equivalence. It is considered that the harmonic current emitted by the interference source after crossing two substations can be ignored, and this equivalence only ensures that the power flow distribution does not change, and the harmonic current content injected by these nodes is not considered, such as Figure 2 transformer T12, etc.

[0056] Optionally, the interference source harmonic analysis model includes: a power system device model, a power system line model, an interference source model, a non-interference source load model, and / or a power grid equivalence model.

[0057] In this embodiment, the power system device model refers to the harmonic analysis model of various power devices within the interference source range, which can include a conventional generator set harmonic impedance model and / or a transformer harmonic impedance model. For example, for the power system shown in Figure 2 , the power system device model includes a conventional generator set harmonic impedance model and a transformer harmonic impedance model.

[0058] Among them, the conventional generator set mainly refers to a thermal power generator set, and the harmonic impedance ZG(h) thereof is:

[0059]

[0060] The above harmonic impedance formula is the established conventional generator set harmonic impedance model, wherein: Z G1(h) , Z G2(h) , and Z G0(h) are positive sequence, negative sequence, and zero sequence harmonic impedances, respectively; R a is a fundamental armature resistance; X” d is a sub-transient reactance; X2 is a negative sequence reactance; X0 is a zero sequence reactance; and n is a positive integer.

[0061] For a transformer, if the rated capacity of the transformer is S T (MVA) and the rated voltage is U T (line voltage, kV), then the transformer fundamental positive sequence impedance Z T1 is:

[0062]

[0063] If the transformer fundamental positive sequence resistance is R T1 , the fundamental positive sequence reactance is X T1 , and there is:

[0064] Z T1 =R T1 +jXT1 ;

[0065] If the transformer has ground impedance Z Tg , the zero sequence impedance of the transformer Z T0 is:

[0066] Z T0 = Z T1 + 3Z Tg ;

[0067] If the transformer is resistance grounded, i.e. Z Tg = R Tg , there is:

[0068] Z T0 = R T1 + 3R Tg +jX T1 ;

[0069] The harmonic impedance of the transformer (without considering the skin effect of the winding) is:

[0070]

[0071] The harmonic impedance formula of the above transformer is the established harmonic impedance model of the transformer, wherein: Z T1(h) is the positive sequence impedance under hth harmonic; Z T2(h) is the negative sequence impedance under hth harmonic; Z T0(h) is the zero sequence impedance under hth harmonic; and n is a positive integer.

[0072] The power system line model refers to the harmonic analysis model of the transmission line and cable within the range of the interference source. When the length of the transmission line is within 200 km (or the length of the cable is within 50 km), a nominal π circuit model (see Figure 4 ) can be used. When the length of the transmission line exceeds 200 km (or the length of the cable line exceeds 50 km), the use of the nominal π circuit model will affect the accuracy of the calculation, and an equivalent π circuit model can be used.

[0073] (1) Nominal π circuit model of the line

[0074] a) Positive sequence and negative sequence parameters of the line

[0075] The harmonic positive sequence parameters and the negative sequence parameters of the line are consistent in expression, and the determination method of the positive sequence parameters is given as follows:

[0076] The unit length impedance is z L1 = r L1 +jx L1 (Ω / km), wherein r L1 is the unit length resistance, and x L1 is the unit length reactance; and the unit length susceptance is yL1 If the line has a resistance of r (Ω / km) and a reactance of x (Ω / km) and a length of L (km), the fundamental line parameters are:

[0077] Z L1 = z L1 × L = (r L1 + jx L1 ) × L = R L1 + jX L1 ;

[0078] Y L1 = y L1 × L;

[0079] where:

[0080] Z L1 : fundamental positive sequence impedance;

[0081] R L1 : fundamental positive sequence resistance;

[0082] X L1 : fundamental positive sequence reactance;

[0083] Y L1 : fundamental positive sequence susceptance.

[0084] When the skin effect is considered, the parameters at the hth harmonic are:

[0085]

[0086] Y L1(h) = hY L1 (h = 3n ± 1);

[0087] where n is a positive integer.

[0088] The nominal π parameters of the line are:

[0089] Z p1(h) = Z L1(h) ;

[0090]

[0091] b) Line zero sequence parameters

[0092] The fundamental zero sequence resistance R L0 and the fundamental zero sequence reactance X L0 can be expressed as:

[0093] R L0 = (r L1 + 3r g )L

[0094] X L0 = kx L1 L

[0095] wherein:

[0096] r g : unit length ground resistance, about 0.05 Ω / km;

[0097] k: proportional coefficient, refer to Table 1 below.

[0098] Table 1 Proportional coefficient

[0099]

[0100] Unit length line fundamental wave zero sequence capacitance c L0 (F / km) is:

[0101] wherein:

[0102] r is the conductor radius;

[0103] H sm : geometric mean distance between three-phase conductor and its mirror image;

[0104] H mm : geometric mean distance between three-phase conductor and different phase conductor mirror image;

[0105] D m : geometric mean distance between three-phase conductors.

[0106] Length L line capacitance C L0 is:

[0107] C L0 = c L0 L

[0108] Susceptance Y is:

[0109] Y L0 = 2πfC L0

[0110] When considering the skin effect of the line, the parameters under the hth harmonic are:

[0111]

[0112] Y L0(h) = hY L0 (h = 3n);

[0113] wherein, Z L0 is the zero sequence impedance; R L0 is the zero sequence resistance; X L0 is the zero sequence reactance; Y L0 is the zero sequence susceptance; and n is a positive integer.

[0114] The nominal π parameters of the line are:

[0115] Z p0(h) = Z L0(h) ;

[0116]

[0117] (2) Line equivalent π circuit model

[0118] For the equivalent π circuit model parameters, there are:

[0119]

[0120]

[0121] In the formula:

[0122]

[0123] The interference source model refers to the harmonic analysis model of various interference sources within the interference source range, which can include a new energy interference source model and / or a nonlinear load type interference source model. For example, for the power system shown in Figure 2 , the interference source model includes a new energy interference source model and a nonlinear load type interference source model.

[0124] (1) New energy interference source

[0125] New energy interference sources include wind farms, photovoltaic power stations, and distributed power sources. The centralized access wind farm and photovoltaic power station model is as shown in Figure 5 Such power sources require a certain support capability for system voltage levels, and an AC voltage source and harmonic current source model are used in parallel form. For the AC voltage source model, it can be processed according to the PV node.

[0126] The distributed power source model is as shown in Figure 6 Unlike the centralized access wind farm and photovoltaic power station model, distributed power sources do not involve reactive power support for the system, and are processed according to the PQ node, using a PQ node and harmonic current source model in parallel form.

[0127] (2) Nonlinear load type interference source

[0128] Nonlinear load type interference sources include electrified railways, electric heating loads, rolling mills, motor speed regulation systems, charging piles, etc. Such interference source models are in the form of load nodes and harmonic current sources in parallel, and are processed according to the PQ node, as shown in Figure 7 .

[0129] Non-disturbing source loads include residential areas, lighting loads, schools, office sites, etc. Such loads are considered to not provide harmonic current to the system. The non-disturbing source load model is processed according to a PQ node. If the fundamental load power is P + jQ, the load rated voltage is U L , and the load fundamental impedance is:

[0130] In the formula, R L is the equivalent resistance of the load, and X L is the equivalent reactance of the load.

[0131] The following is obtained:

[0132]

[0133]

[0134] The load harmonic impedance is:

[0135]

[0136] In the formula, Z 0(h) is the zero-sequence harmonic impedance, which is infinite; most residential electric loads have no zero-sequence current path, and the zero-sequence impedance can be considered to be infinite; and n is a positive integer.

[0137] The power grid equivalent model includes a system harmonic impedance model and an equivalent voltage source model. The power grid equivalent model mainly obtains the system harmonic impedance, as shown in FIG. 5. Figure 2 The system equivalent should know the three-phase short-circuit capacity and the single-phase short-circuit capacity

[0138] The system fundamental positive-sequence impedance is:

[0139]

[0140] In the formula, R s1 represents the fundamental positive-sequence resistance; X s1 represents the fundamental positive-sequence reactance; and U sN represents the nominal voltage.

[0141] The system fundamental zero-sequence impedance is:

[0142]

[0143] In the formula, R s0 represents the fundamental zero-sequence resistance; and X s0 represents the fundamental zero-sequence reactance.

[0144] The system harmonic impedance is:

[0145]

[0146] In the formula, n is a positive integer.

[0147] The method for determining background harmonic voltage provided by the embodiment of the present application has at least the following beneficial effects:

[0148] (1) The system network frame range to be considered for background harmonic analysis of a certain node of the system is determined.

[0149] (2) A method for establishing models of various typical interference sources of the system is provided.

[0150] (3) A method for establishing harmonic impedance models of equivalent systems, generators, transformers, lines and loads is provided.

[0151] (4) The calculation process of the background harmonic is determined.

[0152] The content of the harmonic voltage of a certain node of the power system under the existing conditions (including the existing network frame structure and the capacity of the interference sources already connected) is evaluated, thereby providing a reference and basis for evaluating the harmonic problem caused by the newly connected interference sources.

[0153] Figure 8 is a structural schematic diagram of the background harmonic voltage determination device provided by an embodiment of the present application, as shown in Figure 8 The background harmonic voltage determination device provided by the embodiment of the present application comprises: a first determination module 21, configured to determine the interference source range involved in background harmonic analysis according to the position of a target node in the power system; a first establishment module 22, configured to establish an interference source harmonic analysis model for each type of interference source within the interference source range; a second establishment module 23, configured to establish an equivalent voltage source model for each type of interference source outside the interference source range; and a second determination module 24, configured to perform power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model, and determine the background harmonic voltage of the target node.

[0154] The background harmonic voltage determination device provided by the embodiment of the present application determines the interference source range involved in background harmonic analysis according to the position of a target node in the power system, establishes an interference source harmonic analysis model for each type of interference source within the interference source range, establishes an equivalent voltage source model for each type of interference source outside the interference source range, and performs power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model, thereby determining the background harmonic voltage of the target node. In this way, a method and basis are provided for background harmonic analysis before the connection of interference sources.

[0155] Optionally, the first determination module is specifically configured to:

[0156] The range of interference sources covered by nodes within N transformers away from the target node in the power system is defined as the range of interference sources involved in the background harmonic analysis, where N is a positive integer greater than 1.

[0157] Optionally, the interference source harmonic analysis model includes: a power system equipment model, a power system line model, an interference source model, a non-interference source load model, and / or a power grid equivalent model.

[0158] Optionally, the power system equipment model includes a conventional generator set harmonic impedance model and / or a transformer harmonic impedance model.

[0159] Optionally, the interference source model includes a new energy interference source model and / or a nonlinear load-type interference source model.

[0160] Optionally, the equivalent power grid model includes a system harmonic impedance model and an equivalent voltage source model.

[0161] The embodiments of the device provided in this invention can be used to execute the processing flow of the above method embodiments. Its functions will not be repeated here, but can be referred to the detailed description of the above method embodiments.

[0162] Figure 9 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, as shown below. Figure 9 As shown, the electronic device may include a processor 301, a communication interface 302, a memory 303, and a communication bus 304, wherein the processor 301, the communication interface 302, and the memory 303 communicate with each other via the communication bus 304. The processor 301 can call logical instructions in the memory 303 to execute the method described in any of the above embodiments, such as: determining the range of interference sources involved in the background harmonic analysis based on the location of the target node in the power system; establishing an interference source harmonic analysis model for various interference sources within the interference source range; establishing an equivalent voltage source model for various interference sources outside the interference source range; and performing power flow calculations based on the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node.

[0163] In addition, the logic instructions in the memory 303 described above can be realized in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0164] The embodiment discloses a computer program product, which comprises a computer program stored on a non-transitory computer readable storage medium, and the computer program comprises program instructions, when the program instructions are executed by a computer, the computer can execute the method provided by the above-mentioned method embodiments, for example, comprising: determining the range of interference sources involved in background harmonic analysis according to the position of the target node in the power system; for each type of interference source within the range of interference sources, establishing an interference source harmonic analysis model; for each type of interference source outside the range of interference sources, establishing an equivalent voltage source model; performing power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node.

[0165] The embodiment provides a computer readable storage medium, which stores a computer program, and the computer program causes the computer to execute the method provided by the above-mentioned method embodiments, for example, comprising: determining the range of interference sources involved in background harmonic analysis according to the position of the target node in the power system; for each type of interference source within the range of interference sources, establishing an interference source harmonic analysis model; for each type of interference source outside the range of interference sources, establishing an equivalent voltage source model; performing power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node.

[0166] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0167] The present application is described in reference to the flow diagrams and / or block diagrams of the methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flow diagrams and / or block diagrams, and combinations of blocks in the flow diagrams and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 Figure 1

[0168] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 Figure 1

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow diagrams and / or block diagrams block or blocks. Figure 1 Figure 1

[0170] In this description, references to "one embodiment", "an embodiment", "some embodiments", "example", "exemplary", "specific example", or "some examples", etc., mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present application. These phrases can not necessarily refer to the same embodiment or example. Furthermore, these phrases can refer to one or more embodiments or examples. In the following description, numerous specific details are disclosed, merely for providing a thorough understanding of embodiments of the application. The specific

[0171] ​​​​​​The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are merely examples of the present application and are not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of determining a background harmonic voltage, characterized by, The method comprises the following steps: determining the range of interference sources involved in the background harmonic analysis according to the position of the target node in the power system; establishing an interference source harmonic analysis model for each type of interference source within the range of interference sources; establishing an equivalent voltage source model for each type of interference source outside the range of interference sources; performing power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node. The step of determining the range of interference sources involved in the background harmonic analysis according to the position of the target node in the power system comprises: determining the range of interference sources covered by the nodes within N transformer ranges from the target node in the power system as the range of interference sources involved in the background harmonic analysis, wherein N is a positive integer greater than 1.

2. The method of claim 1, wherein, The interference source harmonic analysis model comprises a power system device model, a power system line model, an interference source model, a non-interference source load model, and / or a power grid equivalent model.

3. The method of claim 2, wherein, The power system device model comprises a conventional generator set harmonic impedance model and / or a transformer harmonic impedance model.

4. The method of claim 2, wherein, The interference source model comprises a new energy interference source model and / or a non-linear load type interference source model.

5. The method of claim 2, wherein, The power grid equivalent model comprises a system harmonic impedance model and an equivalent voltage source model.

6. A device for determining a background harmonic voltage, characterized by The method comprises the following steps: a first determining module configured to determine the range of interference sources involved in the background harmonic analysis according to the position of the target node in the power system; a first establishing module configured to establish an interference source harmonic analysis model for each type of interference source within the range of interference sources; a second establishing module configured to establish an equivalent voltage source model for each type of interference source outside the range of interference sources; a second determining module configured to perform power flow calculation according to the interference source harmonic analysis model and the equivalent voltage source model to determine the background harmonic voltage of the target node. The first determining module is specifically configured to: determine the range of interference sources covered by the nodes within N transformer ranges from the target node in the power system as the range of interference sources involved in the background harmonic analysis, wherein N is a positive integer greater than 1.

7. The apparatus of claim 6, wherein, The interference source harmonic analysis model comprises a power system device model, a power system line model, an interference source model, a non-interference source load model, and / or a power grid equivalent model.

8. The apparatus of claim 7, wherein, The power system device model comprises a conventional generator set harmonic impedance model and / or a transformer harmonic impedance model.

9. The apparatus of claim 7, wherein, The interference source model comprises a new energy interference source model and / or a non-linear load type interference source model.

10. The apparatus of claim 7, wherein, The power grid equivalent model comprises a system harmonic impedance model and an equivalent voltage source model.

11. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the method of any one of claims 1 to 5.

12. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 5.

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