Harmonic traceability method and system, computer equipment and storage medium

Abstract

The invention relates to the technical field of artificial intelligence, and discloses a harmonic traceability method and system, computer equipment and a storage medium, and the method comprises the steps: obtaining a harmonic index, detecting a harmonic current value set of each power utilization end when the harmonic index exceeds a preset value, and calculating the harmonic contribution degree of each power utilization end based on the harmonic current value set. The method has the beneficial effects that the harmonic conditions of the transformer substation and the users connected with the transformer substation are comprehensively monitored and evaluated, so that a reasonable voltage harmonic treatment scheme is formulated, the electric energy quality is improved, and the stability and reliability of a power system are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of harmonic source tracing, and in particular to a harmonic source tracing method, system, computer equipment and storage medium. Background Art

[0002] Promoting the construction of a new power system is an important measure to implement the "dual carbon" strategic goal. In recent years, the capacity and proportion of new energy and energy storage connected to the grid have continued to increase, and the problem of grid harmonics has become more and more obvious. Since the grid connection of new energy covers the main grid and distribution network, and new energy and energy storage use a large number of power electronic devices, which are significant harmonic sources, the grid harmonic sources are widely distributed, and cross-voltage level transmission is becoming more and more common.

[0003] In order to ensure the power quality level of the power grid, guide local power management departments to do a good job in power quality management, consolidate the power quality management responsibilities of all parties, strengthen normalized management, and continuously improve the power quality level of the power system. The existing harmonic responsibility quantification method only considers the same voltage level power supply or multi-source harmonics. Summary of the invention

[0004] Based on this, it is necessary to propose a harmonic source tracing method to address the existing harmonic source tracing problem.

[0005] A harmonic source tracing method, the method comprising:

[0006] Detect the harmonic indicators of the current substation;

[0007] When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level;

[0008] Determine whether the number of power consumption terminals is greater than 1;

[0009] If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets;

[0010] Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0011] According to the harmonic contribution of each power consumption end, the corresponding power consumption end is guided to perform voltage harmonic control.

[0012] Furthermore, after the step of calculating the harmonic contribution of each power consumption end based on the multiple harmonic current sets, the method further includes:

[0013] Determine whether there is a next-level substation in each of the user terminals;

[0014] If there is a next-level substation, the secondary harmonic index of the next-level substation is obtained, and the secondary power consumption terminal connected to the next-level substation is obtained;

[0015] Acquire multiple groups of secondary harmonic current values ​​within a preset time period to obtain multiple groups of secondary harmonic current sets;

[0016] Calculating the harmonic contribution of each of the secondary power consumption terminals based on the plurality of sets of secondary harmonic current sets;

[0017] According to the harmonic contribution of each secondary power consumption terminal, the corresponding secondary power consumption terminal is guided to perform voltage harmonic control.

[0018] Furthermore, after the step of determining whether the number of power consumption terminals is greater than 1, the method further includes:

[0019] If the number of power consumption terminals is equal to 1, the harmonic current of the substation and the harmonic current and the first harmonic voltage of the power consumption terminal are obtained;

[0020] Calculating the second harmonic voltage of the power consumption end based on the harmonic current of the substation and the harmonic current of the power consumption end;

[0021] determining whether the second harmonic voltage is greater than the first harmonic voltage;

[0022] If the second harmonic voltage is greater than the first harmonic voltage, the user end is guided to perform voltage harmonic control; if the second harmonic voltage is less than the first harmonic voltage, the substation is guided to perform harmonic control.

[0023] Furthermore, the step of calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets includes:

[0024] According to the target formula V h-tot =γ1I h-1 +γ2I h-2 +γ3I h-3 +...γ0 sets the system impedance of each power terminal; where γ0 represents a preset parameter, γ1, γ2, γ3, ..., represent the system impedance of the first power terminal, the second power terminal, the third power terminal, ..., respectively, I h-1 ,I h-2 ,I h-3 , ..., respectively represent the harmonic currents of the first power terminal, the second power terminal, the third power terminal, ..., V h-tot Indicates the harmonic current value;

[0025] Substituting the plurality of harmonic current sets into the target formula to obtain the preset parameters and the system impedance of each power consumption end;

[0026] According to the formula Calculate the harmonic contribution of each power consumption end, where I h-i represents the harmonic current value of the i-th power consumption terminal, r i represents the system impedance of the ith power consumption end, H tot-i Indicates the harmonic contribution of the i-th power consumption terminal.

[0027] Furthermore, the step of substituting the plurality of harmonic current sets into the target formula to solve and obtain preset parameters and system impedance of each power consumption end includes:

[0028] Determine whether there is at least one unknown harmonic current at each power consumption end;

[0029] If there is at least one unknown harmonic current of the power consumption end, multiple groups of the harmonic current sets are substituted into the target formula, and the preset parameters and the system impedance of each power consumption end are obtained by fitting through the least square method.

[0030] Furthermore, the step of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal includes:

[0031] Setting a value of harmonic contribution according to the value of the harmonic index exceeding the preset value;

[0032] Selecting a power consumption terminal according to the harmonic contribution of each power consumption terminal from large to small, until the harmonic contribution of the selected power consumption terminal is greater than or equal to the value of the harmonic contribution;

[0033] Provide guidance for selected power users to carry out harmonic control.

[0034] Furthermore, after the step of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal, the method further includes:

[0035] The target harmonic index of the current substation after detection and control;

[0036] Determine whether the target harmonic index is less than or equal to a preset value;

[0037] If it is less than or equal to the preset value, the management is judged to be qualified.

[0038] A harmonic source tracing device, comprising:

[0039] Detection module, used to detect the harmonic indicators of the current substation;

[0040] A first acquisition module is used to acquire the power consumption end connected to the substation when the detected harmonic index exceeds a preset value; wherein the power consumption end is a user or a substation at a next level;

[0041] A judging module, used to judge whether the number of power consumption terminals is greater than 1;

[0042] A second acquisition module is used to acquire a plurality of groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period if the number of the power consumption terminals is greater than 1, so as to obtain a plurality of groups of harmonic current sets;

[0043] A calculation module, used for calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets;

[0044] The control module is used to guide the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal.

[0045] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0046] Detect the harmonic indicators of the current substation;

[0047] When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level;

[0048] Determine whether the number of power consumption terminals is greater than 1;

[0049] If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets;

[0050] Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0051] According to the harmonic contribution of each power consumption terminal, the corresponding power consumption terminal is guided to perform voltage harmonic control. A computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following steps:

[0052] Detect the harmonic indicators of the current substation;

[0053] When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level;

[0054] Determine whether the number of power consumption terminals is greater than 1;

[0055] If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets;

[0056] Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0057] According to the harmonic contribution of each power consumption end, the corresponding power consumption end is guided to perform voltage harmonic control.

[0058] The beneficial effects of the present invention are as follows: by obtaining harmonic indicators, when the harmonic indicators exceed the preset values, the harmonic current value sets of each power consumption end are detected, and the harmonic contribution of each power consumption end is calculated based on the harmonic current value sets, thereby achieving comprehensive monitoring and evaluation of the harmonic conditions of the substation and its connected users, thereby formulating a reasonable voltage harmonic control plan, improving the power quality, and ensuring the stability and reliability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] in:

[0061] Figure 1 is an application environment diagram of a harmonic source tracing method in an embodiment;

[0062] Figure 2 is a flow chart of a harmonic source tracing method in one embodiment;

[0063] Figure 3 A structural block diagram of a harmonic tracing system in one embodiment;

[0064] Figure 4 FIG. 4 is a structural block diagram of a computer device in one embodiment. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Figure 1 FIG. 1 is a diagram of the application environment of harmonic tracing in an embodiment. Figure 1, the harmonic source tracing method is applied to the harmonic source tracing system. The harmonic source tracing system includes a terminal 110 and a server 120. The terminal 110 and the server 120 are connected via a network, the terminal 110 can be a desktop terminal or a mobile terminal, and the mobile terminal can be at least one of a mobile phone, a tablet computer, a laptop computer, etc. The server 120 can be implemented as an independent server or a server cluster composed of multiple servers. The terminal 110 is used to detect harmonic currents, and the server 120 is used to analyze the harmonic contribution of the power consumption end.

[0067] like Figure 2 As shown, in one embodiment, a harmonic source tracing method is provided. The method can be applied to both a terminal and a server. This embodiment is illustrated by applying to a server. The harmonic source tracing method specifically includes the following steps:

[0068] S1: Detect the harmonic index of the current substation;

[0069] S2: When the detected harmonic index exceeds a preset value, obtaining the power consumption end connected to the substation; wherein the power consumption end is a user or a substation at the next level;

[0070] S3: Determine whether the number of power consumption terminals is greater than 1;

[0071] S4: If the number of the power consumption terminals is greater than 1, obtaining multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period to obtain multiple groups of harmonic current sets;

[0072] S5: Calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets;

[0073] S6: According to the harmonic contribution of each power consumption end, guide the corresponding power consumption end to perform voltage harmonic control.

[0074] As described in step S1 above, the harmonic index of the current substation is detected; the harmonic index of the substation is monitored in real time, which is an important parameter for evaluating the power quality of the power system. Harmonics refer to the frequency components in the current or voltage waveform, which are integer multiples of the fundamental frequency (50Hz or 60Hz). Harmonics can cause equipment failure, increase losses and affect the quality of power. Use equipment such as a harmonic analyzer or a data acquisition system to continuously measure the harmonic components of the voltage and current in the substation, and record the total harmonic voltage distortion (THD) and the amplitude of each harmonic.

[0075] As described in the above step S2, when the detected harmonic index exceeds the preset value, the power consumption end connected to the substation is obtained; wherein, the power consumption end is the user or the next-level substation; once it is detected that the harmonic index exceeds the preset threshold, it is necessary to find all power consumption terminals connected to the substation to ensure that subsequent analysis and governance can be carried out in a targeted manner.

[0076] As described in the above steps S3-S4, it is determined whether the number of power consumption terminals is greater than 1. If the number of power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets; when the number of power consumption terminals exceeds 1, harmonic data within a period of time is collected for in-depth analysis. Data is collected from the substation and each power consumption terminal, and the harmonic voltage (collected from the substation) and harmonic current (collected from each power consumption terminal) within a certain period of time are recorded. The collection method can be through a power quality measurement device.

[0077] As described in step S5 above, the harmonic contribution of each power terminal is calculated based on multiple groups of harmonic current sets. The contribution of each power terminal to the overall harmonic level is calculated to identify the main sources of harmonic generation. This helps to formulate targeted governance measures. By analyzing the data, commonly used methods include spectrum analysis, phasor calculation, etc., to evaluate the impact of the harmonic current output by each power terminal on the harmonic voltage of the substation, and calculate the contribution percentage of each power terminal. The specific calculation method will be described in detail later. I will not go into details here.

[0078] As described in the above step S6, the corresponding power user is guided to perform voltage harmonic control according to the harmonic contribution of each power user. According to the calculated harmonic contribution, specific voltage harmonic control measures are formulated to help users improve the quality of electric energy. Specifically, the analysis results are fed back to each power user, and it is recommended that it take corresponding control measures, such as installing harmonic filters, adjusting equipment operation modes, changing electricity usage habits, etc., which can effectively reduce the harmonic content and protect the health of the power grid and power equipment. The harmonic conditions of the substation and its connected users can be fully monitored and evaluated, so as to formulate a reasonable voltage harmonic control plan, improve the quality of electric energy, and ensure the stability and reliability of the power system.

[0079] In one embodiment, after the step S5 of calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets, the method further includes:

[0080] S601: Determine whether there is a substation at the next level in each of the user terminals;

[0081] S602: If there is a next-level substation, obtain a secondary harmonic index of the next-level substation, and obtain a secondary power consumption terminal connected to the next-level substation;

[0082] S603: Acquire multiple groups of secondary harmonic current values ​​within a preset time period to obtain multiple groups of secondary harmonic current sets;

[0083] S604: Calculating the harmonic contribution of each of the secondary power consumption terminals based on the multiple groups of secondary harmonic current sets;

[0084] S605: Instructing the corresponding secondary power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each secondary power consumption terminal.

[0085] As described in the above steps S601-S605, it is determined whether there are further substations in the identified user end. If there is a substation at the next level in the user end, special attention should be paid to their harmonic conditions. Each power end connected to the substation is checked through the system database to determine whether it is a substation at the next level, which can be obtained according to the actual equipment connection information. When the substation at the next level is found, its harmonic index is obtained, and all secondary power ends connected to the substation are identified. The harmonic values ​​of the substation at the next level are asked from the monitoring system, such as secondary harmonic voltage and current, and which power ends are connected to this substation. After identifying all secondary power ends, their harmonic current values ​​within a certain period of time are recorded to provide data support for calculating the contribution. The harmonic current data of the substation at the next level and its connected power ends are continuously recorded using equipment such as a harmonic analyzer or a monitoring system, which is usually collected at intervals of minutes or hours to form multiple data sets. Analyze the data and calculate how each secondary power end affects the overall harmonic level. Through these calculations, it is easy to find the main harmonic sources and take corresponding actions. The collected secondary harmonic current sets are analyzed through complex mathematical models (such as Fourier transform, power spectrum density analysis, etc.), and the contribution ratio of the harmonic current of each power end to the overall harmonics is determined, visualized and summarized. The analysis results are organized into reports or instruction manuals and fed back to the secondary power end, suggesting that they take appropriate measures, such as installing harmonic filters, adjusting equipment layout, optimizing load distribution, etc., in order to reduce harmonic generation and improve power quality. Thus, the hierarchical and graded method is continuously traced downward to find the main source of harmonics. In addition, if the secondary substation is also connected to a lower-level substation, the above steps can be repeated until the harmonic contribution rate of all users has been calculated.

[0086] In one embodiment, after the step S3 of determining whether the number of power consumption terminals is greater than 1, the method further includes:

[0087] S401: If the number of power consumption terminals is equal to 1, obtaining the harmonic current of the substation and the harmonic current and the first harmonic voltage of the power consumption terminal;

[0088] S402: Calculating the second harmonic voltage of the power consumption end based on the harmonic current of the substation and the harmonic current of the power consumption end;

[0089] S403: Determine whether the second harmonic voltage is greater than the first harmonic voltage;

[0090] S404: If the second harmonic voltage is greater than the first harmonic voltage, instruct the user end to perform voltage harmonic governance; if the second harmonic voltage is less than the first harmonic voltage, instruct the substation to perform harmonic governance.

[0091] As described in the above steps S401-S403, assuming that the system side harmonic current is I s-h , the user side harmonic current is I L-h , the admittance of the hth harmonic is Y h , V h is the busbar harmonic voltage. The phase difference between the hth harmonic current on the system side and the user side is δ h Among them, V h ,I s-h ,I L-h , δ h It can be obtained through power quality measurement devices. cos is the cosine function. Since harmonic voltage and current are vectors, vector superposition is applied, such as Figure 2 As shown. After expansion, it satisfies formula (1)

[0092] |I L-h | 2 =|I s-h | 2 -2|I s-h Y h V h |cos(δ h )+|Y h V h | 2 (1)

[0093] When the harmonic currents contributed by the system and the user are equal, |I s-h | 2 Moving to the right, we can observe that the left side of equation (2) is 0.

[0094] |I L-h | 2 -|I s-h | 2 =-2|I s-h Y h V h |cos(δ h )+|Y h V h | 2 (2)

[0095] When the harmonic currents contributed by the system and the user are equal, |I s-h | 2 Moving to the right, we can see that the left side of equation (2) is 0. After rearranging the right side of (2), we get:

[0096]

[0097] If I L-h >I s-h When , similar deduction is obtained:

[0098]

[0099] According to the above relationship, the measured V h With V h,avg For comparison, if V h Greater than V h,avg , then the main harmonic source is the user side; otherwise, it is the grid side.

[0100] In one embodiment, the step S5 of calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets includes:

[0101] S501: According to the target formula V h-tot =γ1I h-1 +γ2I h-2 +γ3I h-3 +...γ0 sets the system impedance of each power terminal; where γ0 represents a preset parameter, γ1, γ2, γ3, ..., represent the system impedance of the first power terminal, the second power terminal, the third power terminal, ..., respectively, I h-1 ,I h-2 ,I h-3 , ..., respectively represent the harmonic currents of the first power terminal, the second power terminal, the third power terminal, ..., V h-tot Indicates the harmonic current value;

[0102] S502: Substituting the plurality of harmonic current sets into the target formula to obtain preset parameters and system impedance of each power consumption end;

[0103] S503: According to the formula Calculate the harmonic contribution of each power consumption end, where I h-i represents the harmonic current value of the i-th power consumption terminal, r i represents the system impedance of the ith power consumption end, H tot-i Indicates the harmonic contribution of the i-th power consumption end.

[0104] As described in the above steps S501-S503, the calculation of the harmonic contribution of each power consumption end is realized, that is, the target formula is set. Since multiple sets of data sets can be obtained, when there are enough data sets, the system impedance in the target formula can be solved. This is because the system impedance is difficult to obtain. Therefore, when the number of data sets is greater than the number of power consumption ends, the formula can be directly solved to obtain the preset parameters and the system impedance of each power consumption end, and then the harmonic contribution is calculated according to the formula.

[0105] In one embodiment, the step S502 of substituting the plurality of harmonic current sets into the target formula to solve and obtain the preset parameters and the system impedance of each power consumption end includes:

[0106] S5021: Determine whether there is at least one power consumption terminal with unknown harmonic current among the power consumption terminals;

[0107] S5022: If there is at least one unknown harmonic current of the power consumption end, multiple groups of the harmonic current sets are substituted into the target formula, and the preset parameters and the system impedance of each power consumption end are obtained by fitting through the least square method.

[0108] As described in the above steps S5021-S5022, since some harmonic currents of the power consumption ends cannot be detected in actual situations, multiple groups of the harmonic current sets can be substituted into the target formula, and the preset parameters and the system impedance of each power consumption end can be obtained by fitting the least squares method. The least squares method is a mathematical optimization technique widely used in data fitting and estimation problems. Its main purpose is to find a model that minimizes the error between the results predicted by the model and the actual data.

[0109] In one embodiment, the step S6 of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal includes:

[0110] S601: Setting a value of harmonic contribution according to the value of the harmonic index exceeding the preset value;

[0111] S602: selecting a power terminal according to the harmonic contribution of each power terminal from large to small, until the harmonic contribution of the selected power terminal is greater than or equal to the value of the harmonic contribution;

[0112] S603: guiding the selected power consumption end to perform harmonic control.

[0113] As described in the above steps S601-S603, in order to carry out effective harmonic governance, it is first necessary to define a threshold value, and the value of the harmonic contribution is set based on this threshold value. Specifically, by analyzing the previously obtained harmonic index, it is determined which power consumption ends have a higher contribution and compared with the preset harmonic level. Once the harmonic index of a certain power consumption end exceeds the preset value, a higher contribution value can be set. In order to effectively screen out power consumption ends with higher contribution, ensure that the governance measures are concentrated in the most needed places. All identified power consumption ends can be sorted and arranged from large to small according to the harmonic contribution values ​​calculated before. Start screening from the power consumption end with the highest contribution, and gradually check whether its harmonic contribution reaches or exceeds the set threshold. Once the power consumption end that meets the conditions is found, stop screening. This can make the governance measures focus on the most serious harmonic sources and optimize the allocation of resources. Once the power consumption end that needs to be harmonic governance is selected, it is necessary to provide guidance and provide specific governance solutions for the selected power consumption end, including but not limited to technical advice, equipment upgrades, installation or replacement of harmonic filters, and operation adjustments. Guidance materials can include technical manuals, online training, on-site guidance, etc., to ensure that users clearly understand the measures to be taken and the expected results. Monitor the governance effect and provide feedback and adjustment plans when necessary to ensure that the governance effect is continuously optimized. The entire voltage harmonic governance process not only makes full use of the information on harmonic contribution, but also ensures the efficient use of resources and the targeted governance. This process-based governance strategy can effectively reduce the harmonic content in the power system, thereby improving the overall power quality and the stability of system operation.

[0114] In one embodiment, after the step S6 of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal, the method further includes:

[0115] S701: Detecting the target harmonic index of the current substation after treatment;

[0116] S702: Determine whether the target harmonic index is less than or equal to a preset value;

[0117] S703: If it is less than or equal to the preset value, it is determined that the treatment is qualified.

[0118] As described in the above steps S701-S703, the effect detection after treatment is realized. After the implementation of harmonic treatment measures, the harmonic indicators of the substation must be re-monitored to evaluate whether the treatment is effective. Use a harmonic analyzer or other monitoring equipment to record the harmonic indicators of the voltage and current of the substation after treatment. Determine the current harmonic indicators, such as the total harmonic distortion (THD) and the amplitude of each harmonic. The effectiveness of the treatment measures is judged by comparing the harmonic indicators after treatment with the established preset values. Compare the detected current harmonic indicators with the preset values ​​set earlier. This preset value usually represents the standard or requirement of the power system and is intended to ensure the quality of electric energy. If the current target harmonic indicator is less than or equal to the preset value, it indicates that the treatment is effective; otherwise, further treatment may be required. If the target harmonic indicator is indeed less than or equal to the preset value, the effectiveness of the treatment measures can be further confirmed and determined to be "qualified for treatment". At this time, the relevant data and results can be recorded for subsequent analysis or reporting, and the relevant users or management departments can be notified at the same time. Through measurement and analysis, we can ensure that the control measures can effectively reduce the impact of harmonics, improve the power quality, and ultimately enhance the overall stability and reliability of the power system. If the control is not up to standard, further adjustments and optimizations may be required. Such a feedback loop is crucial to continuously improve the power quality of the power system.

[0119] In a specific embodiment, there are generally three typical working conditions. The first is that the power grid is directly connected to the user, such as the dedicated transformer load under the 10 / 0.4kV distribution transformer; the second working condition is that there are multiple users in the same level substation, such as multiple 35kV users under the 35kV substation; the third working condition is that the line connects the next level substation and multiple users. If multi-level harmonic source tracing analysis is to be implemented, it is necessary to find a harmonic responsibility division method that is suitable for these three working conditions.

[0120] Method 1: Only one user is connected to the grid:

[0121] Assume the harmonic current on the system side is I s-h , the user side harmonic current is I L-h , the admittance of the hth harmonic is Y h , V h is the busbar harmonic voltage. The phase difference between the hth harmonic current on the system side and the user side is δ h Among them, V h ,I s-h ,I L-h , δ h It can be obtained through power quality measurement devices. Since harmonic voltage and current are vectors, vector superposition is applied. After expansion, it satisfies formula (1):

[0122] |I L-h | 2 =|I s-h |2 -2|I s-h Y h V h |cos(δ h )+|Y h V h | 2 (1)

[0123] When the harmonic currents contributed by the system and the user are equal, |I s-h | 2 Moving to the right, we can observe that the left side of equation (2) is 0.

[0124] |I L-h | 2 -|I s-h | 2 =-2|I s-h Y h V h |cos(δ h )+|Y h V h | 2 (2)

[0125] When the harmonic currents contributed by the system and the user are equal, |I s-h | 2 Moving to the right, we can see that the left side of equation (2) is 0. After rearranging the right side of (2), we get:

[0126]

[0127] If I L-h >I s-h When , similar deduction is obtained:

[0128]

[0129] According to the above relationship, the measured V h With V h,avg For comparison, if V h Greater than V h,avg , then the main harmonic source is the user side; otherwise, it is the grid side.

[0130] Method 2: There are multiple users in the same substation

[0131] When there are multiple users in the same level substation, V h-1 、V h-2 、V h-3 ...correspond to the harmonic voltage values ​​actually generated by the first, second, third, etc. users, and V h-0 is the background harmonic voltage of the power grid system.

[0132] The harmonic voltage and harmonic current satisfy:

[0133] V h-1 =Z h-1 I h-1 (5)

[0134] Since the system impedance is difficult to measure, but the harmonic current of each user can be measured, the relationship can be expressed as:

[0135] V h-tot =γ1I h-1 +γ2I h-2 +γ3I h-3 +...γ0 (6)

[0136] Formula (6) can be solved by looking at multiple variables at once. h-tot ,I h-1 ,I h-2 ,I h-3 ...User harmonics can be measured by power quality monitoring devices. After the n+1 groups of measurement data are brought in, γ0, γ1, γ2, γ3... can be solved. If there are not enough power quality monitoring devices, the least squares method can be used to fit and obtain γ0, γ1, γ2, γ3...

[0137] After solving, if there are i users, the harmonic contribution of the i-th user can be calculated by formula (7).

[0138]

[0139] Method 3: The line connects the next-level substation and multiple users

[0140] Divide the users of the same voltage level at the same station and the next-level stations into a region of the same level, such as Region 1 to Region J in the figure. Calculate the harmonic contribution of each region according to Method 2, and then continue to trace the sub-regions, and cycle down in sequence until there are no users and lower-level stations.

[0141] Combining the above three methods, the main steps of the implementation method of the present invention are as follows:

[0142] Step 1: The harmonic exceeding standard event is measured by the power quality monitoring device, triggering the hierarchical and partitioned harmonic source tracing algorithm;

[0143] Step 2: Find the bus corresponding to the harmonic exceeding event, and based on the grid connection relationship, construct the connecting bus connecting the substation and the user, that is, the grid topology map.

[0144] Step 3: Determine whether the conditions of method 1 are met through the constructed power grid topology diagram. If so, execute the algorithm of method 1 for tracing; if not, execute step 4;

[0145] Step 4: Determine whether the conditions of method 2 are met. If so, execute the algorithm of method 2 for tracing; if not, execute step 5;

[0146] Step 5: Execute method 3 to divide the layers and regions, and use method 2 to complete the hierarchical and partitioned harmonic tracing.

[0147] The present invention also provides a harmonic source tracing device, the device comprising:

[0148] Detection module 10, used to detect the harmonic index of the current substation;

[0149] A first acquisition module 20 is used to acquire the power consumption end connected to the substation when the detected harmonic index exceeds a preset value; wherein the power consumption end is a user or a substation at a next level;

[0150] A determination module 30, used to determine whether the number of power consumption terminals is greater than 1;

[0151] A second acquisition module 40 is used to acquire a plurality of groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period to obtain a plurality of groups of harmonic current sets if the number of the power consumption terminals is greater than 1;

[0152] A calculation module 50, configured to calculate the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0153] The control module 60 is used to guide the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal.

[0154] It should be noted that other embodiments of a harmonic source tracing device of the present invention are the same as an embodiment of a harmonic source tracing method, and will not be described in detail here.

[0155] The beneficial effects of the present invention are as follows: by obtaining harmonic indicators, when the harmonic indicators exceed the preset values, the harmonic current value sets of each power consumption end are detected, and the harmonic contribution of each power consumption end is calculated based on the harmonic current value sets, thereby achieving comprehensive monitoring and evaluation of the harmonic conditions of the substation and its connected users, thereby formulating a reasonable voltage harmonic control plan, improving the power quality, and ensuring the stability and reliability of the power system.

[0156] Figure 4 FIG. 1 shows an internal structure diagram of a computer device in an embodiment. The computer device may be a terminal or a server. Figure 4As shown, the computer device includes a processor, a memory and a network interface connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor may implement the harmonic tracing method. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor may implement the harmonic tracing method. Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0157] In one embodiment, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0158] Detect the harmonic indicators of the current substation;

[0159] When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level;

[0160] Determine whether the number of power consumption terminals is greater than 1;

[0161] If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets;

[0162] Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0163] According to the harmonic contribution of each power consumption end, the corresponding power consumption end is guided to perform voltage harmonic control.

[0164] It realizes comprehensive monitoring and evaluation of the harmonic conditions of substations and their connected users, so as to formulate reasonable voltage harmonic control plans, improve power quality, and ensure the stability and reliability of the power system.

[0165] In one embodiment, a computer-readable storage medium is provided, storing a computer program, wherein when the computer program is executed by a processor, the processor performs the following steps:

[0166] Detect the harmonic indicators of the current substation;

[0167] When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level;

[0168] Determine whether the number of power consumption terminals is greater than 1;

[0169] If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets;

[0170] Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets;

[0171] According to the harmonic contribution of each power consumption end, the corresponding power consumption end is guided to perform voltage harmonic control.

[0172] It realizes comprehensive monitoring and evaluation of the harmonic conditions of substations and their connected users, so as to formulate reasonable voltage harmonic control plans, improve power quality, and ensure the stability and reliability of the power system.

[0173] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate 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).

[0174] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0175] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A harmonic source tracing method, characterized in that: The method comprises: Detect the harmonic indicators of the current substation; When the detected harmonic index exceeds a preset value, an electricity consumption end connected to the substation is obtained; wherein the electricity consumption end is a user or a substation at a next level; Determine whether the number of power consumption terminals is greater than 1; If the number of the power consumption terminals is greater than 1, multiple groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period are obtained to obtain multiple groups of harmonic current sets; Calculating the harmonic contribution of each power consumption terminal based on the plurality of harmonic current sets; According to the harmonic contribution of each power consumption end, the corresponding power consumption end is guided to perform voltage harmonic control.

2. The harmonic source tracing method according to claim 1, characterized in that: After the step of calculating the harmonic contribution of each power consumption end based on the multiple harmonic current sets, the method further includes: Determine whether there is a next-level substation in each of the user terminals; If there is a next-level substation, the secondary harmonic index of the next-level substation is obtained, and the secondary power consumption terminal connected to the next-level substation is obtained; Acquire multiple groups of secondary harmonic current values ​​within a preset time period to obtain multiple groups of secondary harmonic current sets; Calculating the harmonic contribution of each of the secondary power consumption terminals based on the plurality of sets of secondary harmonic current sets; According to the harmonic contribution of each secondary power consumption terminal, the corresponding secondary power consumption terminal is guided to perform voltage harmonic control.

3. The harmonic source tracing method according to claim 1, characterized in that: After the step of determining whether the number of power consumption terminals is greater than 1, the method further includes: If the number of power consumption terminals is equal to 1, the harmonic current of the substation and the harmonic current and the first harmonic voltage of the power consumption terminal are obtained; Calculating the second harmonic voltage of the power consumption end based on the harmonic current of the substation and the harmonic current of the power consumption end; determining whether the second harmonic voltage is greater than the first harmonic voltage; If the second harmonic voltage is greater than the first harmonic voltage, the user end is guided to perform voltage harmonic control; if the second harmonic voltage is less than the first harmonic voltage, the substation is guided to perform harmonic control.

4. The harmonic source tracing method according to claim 1, characterized in that: The step of calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets includes: According to the target formula V h-tot =γ1I h-1 +γ2I h-2 +γ3I h-3 +...γ0 sets the system impedance of each power terminal; where γ0 represents a preset parameter, γ1, γ2, γ3, ..., represent the system impedance of the first power terminal, the second power terminal, the third power terminal, ..., respectively, I h-1 ,I h-2 ,I h-3 , ..., respectively represent the harmonic currents of the first power terminal, the second power terminal, the third power terminal, ..., V h-tot Indicates the harmonic current value; Substituting the plurality of harmonic current sets into the target formula to obtain the preset parameters and the system impedance of each power consumption end; According to the formula Calculate the harmonic contribution of each power consumption end, where I h-i represents the harmonic current value of the i-th power consumption terminal, r i represents the system impedance of the ith power consumption end, H tot-i Indicates the harmonic contribution of the i-th power consumption terminal.

5. The harmonic source tracing method according to claim 4, characterized in that: The step of substituting the plurality of harmonic current sets into the target formula to solve and obtain preset parameters and system impedances of each power consumption end comprises: Determine whether there is at least one unknown harmonic current at each power consumption end; If there is at least one unknown harmonic current of the power consumption end, multiple groups of the harmonic current sets are substituted into the target formula, and the preset parameters and the system impedance of each power consumption end are obtained by fitting through the least square method.

6. The harmonic source tracing method according to claim 1, characterized in that: The step of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal comprises: Setting a value of harmonic contribution according to the value of the harmonic index exceeding the preset value; Selecting a power consumption terminal according to the harmonic contribution of each power consumption terminal from large to small, until the harmonic contribution of the selected power consumption terminal is greater than or equal to the value of the harmonic contribution; Provide guidance for selected power users to carry out harmonic control.

7. The harmonic source tracing method according to claim 1, characterized in that: After the step of guiding the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal, the method further includes: The target harmonic index of the current substation after detection and control; Determine whether the target harmonic index is less than or equal to a preset value; If it is less than or equal to the preset value, the management is judged to be qualified.

8. A harmonic tracing system, characterized in that: The system comprises: Detection module, used to detect the harmonic indicators of the current substation; A first acquisition module is used to acquire the power consumption end connected to the substation when the detected harmonic index exceeds a preset value; wherein the power consumption end is a user or a substation at a next level; A judging module, used to judge whether the number of power consumption terminals is greater than 1; A second acquisition module is used to acquire a plurality of groups of harmonic voltages of the substation and harmonic current values ​​of each power consumption terminal within a preset time period if the number of the power consumption terminals is greater than 1, so as to obtain a plurality of groups of harmonic current sets; A calculation module, used for calculating the harmonic contribution of each power consumption end based on the multiple groups of harmonic current sets; The control module is used to guide the corresponding power consumption terminal to perform voltage harmonic control according to the harmonic contribution of each power consumption terminal.

9. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the processor executes the steps of the harmonic source tracing method according to any one of claims 1 to 7.

10. A computer device, characterized in that: The device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the harmonic source tracing method according to any one of claims 1 to 7.

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