Power distribution network transformer power quality comprehensive treatment system and method

Abstract

The invention discloses a power distribution network transformer electric energy quality comprehensive treatment system and method, and belongs to the field of electric energy quality treatment, and the system comprises a data collection module, a load distribution module, an electric energy quality optimization module, and a production area load time sequence optimization module. The data acquisition module, the load distribution module, the electric energy quality optimization module and the production area load time sequence optimization module are in communication connection in sequence; according to the comprehensive treatment system and method for the power quality of the power distribution network transformer, by reasonably distributing loads in a park, reducing the range of preset voltage deviation, harmonic pollution and three-phase imbalance data, calculating transformer loss to compensate adjustment parameters and reasonably planning the load problem of a production area, the purposes of guaranteeing power stability and improving the power quality can be achieved. The power transmission efficiency is optimized, the energy loss is reduced, and the comprehensive quality of electric energy is improved, so that powerful technical support is provided for safe, efficient and sustainable operation of a power distribution network.

Description

Technical Field

[0001] The present invention belongs to the field of power quality management, and specifically relates to a system and method for comprehensive management of power quality of a distribution network transformer. Background Art

[0002] In modern industry and life, the stable operation of the distribution network is of vital importance. With the rapid development of the economy, the electricity demand in the production area, office area and public area of ​​the park is increasing and the power-consuming equipment is diversified, which puts higher requirements on the quality of power.

[0003] At present, there is a lack of effective planning for the power load in different areas of the same park. There are large equipment groups in the production area, and the start and stop of the equipment will cause large load fluctuations, resulting in a decline in power quality and affecting the stability of the entire distribution network. At the same time, problems such as voltage deviation, harmonic pollution and three-phase imbalance are common, which will not only cause increased transformer losses, but also reduce power quality, affecting equipment life and production quality. The existing management methods are difficult to accurately obtain the relationship between these power quality parameters and transformer losses, and it is impossible to take effective measures to reduce losses and improve power quality in a targeted manner. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a comprehensive power quality management system and method for distribution network transformers, so that the power quality can be effectively managed.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A comprehensive power quality management system for transformers in a distribution network, comprising a data acquisition module, a load distribution module, a power quality optimization module, and a production area load timing optimization module, wherein the data acquisition module, the load distribution module, the power quality optimization module, and the production area load timing optimization module are sequentially connected in communication; The data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the park, namely the office area, the production area and the public area, and obtain the load task data of the production area, the office time pattern of the office area and the usage time data of the facilities in the public area; The load distribution module plans the electric energy load of the three areas according to the load task data of the production area; The power quality optimization module is used to calculate voltage deviation, harmonic pollution, and three-phase imbalance data, and to establish parameters with the calculated data and transformer parameters to describe the relationship with transformer loss and further optimize power quality; The production area load timing optimization module plans the equipment group operation timing according to the maximum load situation of the production area, so as to match the equipment group operation timing with the power grid carrying capacity.

[0006] Furthermore, the data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the office area, the production area and the public area, and the load task data processing process of the production area is as follows: Collect electrical energy parameters such as voltage, current, frequency, harmonic content, and power factor in office areas, production areas, and public areas; Collect transformer oil temperature, winding temperature, oil level, and winding loss parameters; Obtain load task data from the production management system in the production area, including the operation plan of production equipment, equipment start and stop time.

[0007] By collecting electricity data from office areas, production areas and public areas, solid data support can be provided for subsequent analysis and research.

[0008] Furthermore, the load distribution module plans the electric energy load of the three areas according to the load task data as follows: According to the production task data, combined with the equipment's operating efficiency and historical electricity consumption, the load demand of the production area in different time periods is predicted; the load changes in the office area are predicted based on the office hours; the load demand in the public area is predicted based on the usage time of the public area facilities; When predicting the load demand of the production area, consider the uncertainties in the production process, such as equipment failures, temporary increase in orders, etc., and set a certain load forecast buffer; Set the load in the production area as the highest priority, the office area as the second priority, and the public area as the low priority; according to the predicted load demand, set the upper limit of the allowable power consumption in each time period to ensure that the power supply in the production area is sufficient, and the power supply in the office area should be allocated after the power supply in the production area is met, and the power supply in the public area should be allocated after the power supply in the production area and the office area is met.

[0009] Furthermore, the power quality optimization module is used to calculate voltage deviation, harmonic pollution, and three-phase unbalance data, and to establish parameters with the calculated data and transformer parameters to describe the relationship with transformer loss, and further optimize the power quality processing process as follows: Calculate voltage deviation, harmonic pollution, and three-phase unbalance values ​​based on the obtained power quality parameters; Calculate the percentage of voltage deviation. The specific formula is: ; in, is the percentage of voltage deviation, is the actual voltage, is the rated voltage; Calculate the voltage harmonic distortion rate and current harmonic distortion rate used to describe harmonic pollution. The specific formula is: ; ; in, is the voltage harmonic distortion rate, is the current harmonic distortion rate, and Respectively The voltage and current amplitudes of the subharmonics, and are the fundamental voltage and current amplitudes, respectively, is the highest harmonic order considered; Calculate the three-phase voltage unbalance and three-phase current unbalance used to describe the three-phase imbalance. The specific formula is: ; ; in, and are the negative sequence voltage and current amplitudes, respectively, and are the positive sequence voltage and current amplitudes, To calculate the unbalanced degree of the three-phase voltage, is the calculated three-phase current unbalance; Comprehensive consideration of voltage harmonic distortion rate and current harmonic distortion , the formula is: ; in, is the comprehensive harmonic distortion rate, is the weight coefficient of voltage harmonics, which indicates the importance of voltage harmonics in the calculation of harmonic distortion rate. is the weight coefficient of current harmonics, indicating the importance of current harmonics in the calculation of harmonic distortion rate, and ; Taking into account the voltage and current imbalance, the formula is: ; in, is the calculated comprehensive three-phase unbalance degree, is the weight coefficient of voltage imbalance, which indicates the importance of three-phase voltage imbalance in the calculation of imbalance index. is the weight coefficient of current imbalance, which indicates the importance of three-phase current imbalance in the calculation of imbalance index, and ; Establishing transformer losses With voltage deviation , comprehensive harmonic distortion rate And comprehensive three-phase unbalance The relationship model between , the formula is: ; in, is the regression coefficient, which is fitted according to the collected data by the least square method; After the model is established, a part of the data that is not involved in the model fitting is used to verify the established relationship model and evaluate the accuracy and reliability of the model; According to the established model, the numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance for the lowest transformer loss are obtained, the preset numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance are narrowed, and the power quality adjustment parameters are obtained so that the actual voltage deviation, harmonic pollution and three-phase imbalance values ​​are within the narrowed range; Using the established loss model, the transformer loss data is obtained, and the error parameters of power quality regulation are obtained based on the transformer loss data, and the error parameters are used to correct the actual regulation parameters.

[0010] Further, the process of obtaining the voltage deviation, harmonic pollution, and three-phase imbalance value ranges of the transformer with the lowest loss according to the established model, narrowing the preset voltage deviation, harmonic pollution, and three-phase imbalance value ranges, and obtaining the power quality adjustment parameters so that the actual voltage deviation, harmonic pollution, and three-phase imbalance values ​​are within the narrowed range is as follows: The preset voltage deviation range, harmonic pollution range, and three-phase unbalance range are , , , discretize the preset ranges of voltage deviation, harmonic pollution, and three-phase imbalance respectively, divide them into several small intervals, substitute each combination into the relationship model to calculate the corresponding transformer loss, compare all the calculated loss values, find the minimum value and the corresponding voltage deviation, harmonic pollution, and three-phase imbalance; According to the obtained minimum value, the numerical range of the preset voltage deviation, harmonic pollution, and three-phase imbalance is narrowed, and the voltage deviation adjustment parameter, the harmonic pollution adjustment parameter, and the three-phase imbalance adjustment parameter are calculated according to the obtained numerical range.

[0011] Furthermore, the error parameters of power quality regulation are obtained according to the obtained transformer loss data, and the actual regulation parameters are corrected using the error parameters. The process is as follows: Receive the monitored load data, compare the average load within the current 15 minutes with the average load of the previous 15 minutes, calculate the relative change rate, and if the load change rate is between ±5%, it means the load is stable. When the load is stable, set 1h to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Receive the monitored load data, if the load change rate within the adjacent 15 minutes is not between ±5%, it means the load is unstable. When the load is unstable, set 15min to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Add up the loss data obtained in a single time to obtain the final loss data; The voltage, current and power factor are corrected using the total loss data obtained.

[0012] Furthermore, the production area load timing optimization module plans the equipment group operation timing according to the maximum load of the production area, and realizes the matching process of the equipment group operation timing and the grid carrying capacity as follows: Classify the equipment groups in the production area according to their functions and load levels, and clarify the production tasks that need to be completed in different time periods and the corresponding equipment usage requirements based on the production plan of the production area; With the minimum load fluctuation in the production area as the main goal, the load is decomposed and estimated according to each production task, a comprehensive load model of the production area is constructed, the total load changes under different production task combinations and production sequences are simulated, and the production plan is obtained using an optimization algorithm.

[0013] Furthermore, the main goal is to minimize the load fluctuation in the production area, decompose and estimate the load according to each production task, build a comprehensive load model for the production area, simulate the total load changes under different production task combinations and production sequences, and use the optimization algorithm to obtain the production plan processing process as follows: The entire production time range T is divided into time steps of equal length Δt, calculate the total load for each time step, time steps ( =1,2,⋯ ), if task i is running in this time step, it contributes to the total load, and the production area is Total load for each time step for: ; Where M is the total number of production tasks, Indicates that task i is in The load of a time step, if task i does not run in this time step, then ; With the goal of minimizing load fluctuation in the production area and the equipment capacity as the constraint, an optimization algorithm is used to obtain a production plan.

[0014] A method for comprehensive power quality management of a distribution network transformer comprises the following steps: S1. Divide the park into office area, production area and public area, monitor the power quality parameters and transformer parameters of these three areas, and obtain the load task data of the production area; S2. Plan the power load for the three areas based on the load task data of the production area to ensure the power supply of the three areas; S3. Based on the specific data and transformer parameters of voltage deviation, harmonic pollution, and three-phase imbalance, a model is established to describe the relationship with transformer loss, narrow the preset voltage deviation, harmonic pollution, and three-phase imbalance range, and reduce transformer loss; S4. Obtain error parameters through the established transformer loss relationship model, and use the error parameters to correct the actual adjustment parameters so that the output voltage, current and power are consistent with the set values, thereby improving the power quality; S5. Plan the operation sequence of the equipment group to match the maximum load of the production area, match the operation sequence of the equipment group with the carrying capacity of the power grid, and stabilize the load.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention plans the power load of the production area, office area and public area in advance by clarifying the load task data of the production area, so as to ensure the power quality of the three areas and avoid the effect of affecting the power quality due to power fluctuations in different areas.

[0016] The present invention obtains specific data of voltage deviation, harmonic pollution and three-phase imbalance, combines them with transformer parameters, and establishes the relationship between these data and transformer loss; based on this relationship, targeted measures can be taken to effectively reduce transformer loss and thus improve power quality; when the preset voltage deviation, harmonic pollution and three-phase imbalance range are further reduced, the adjustment parameters will be modified accordingly according to the reduced range; the modified parameters can maintain the transformer loss within the minimum range, and continuously achieve the effect of improving power quality.

[0017] The present invention calculates the load fluctuation. When the load fluctuation is not within ±5%, the loss values ​​caused by the primary voltage deviation, harmonic pollution and three-phase imbalance are calculated within 15 minutes and multiplied by the time interval. When the load fluctuation is between ±5%, the loss values ​​caused by the primary voltage deviation, harmonic pollution and three-phase imbalance are calculated within 1 hour and multiplied by the time interval to obtain the final loss data. According to the obtained transformer loss data, the voltage, current and power factor are corrected so that the output voltage, current and power are consistent with the set values, thereby achieving the effect of accurately regulating the electric energy parameters and improving the electric energy quality. Since there are large equipment groups in the production area, when different equipment groups are started and stopped, it will cause large load fluctuations and affect the power quality. The present invention can further plan the load of the production area, not only to achieve the matching of the operating sequence of the equipment groups in the production area with the carrying capacity of the power grid, but also to make the load of the production area always in a stable state, thereby achieving the effect of improving the power quality; by establishing a comprehensive load model of the production area and simulating the total load changes under different production task combinations and production sequences, it can provide accurate data support for production scheduling; on this basis, the optimization algorithm is used to deeply analyze and process the simulation data, and finally a load stabilization solution is obtained to ensure power quality.

[0018] The present invention first divides the load into the production area, office area and public area within the park, so that the use of electricity in these three areas is guaranteed. Secondly, by obtaining the relationship between voltage deviation, harmonic pollution, three-phase imbalance data and transformer loss, the preset voltage deviation, harmonic pollution, three-phase imbalance range can be narrowed, and the actual adjustment parameters can be corrected according to the loss data, so as to achieve the effect of reducing transformer loss and accurately regulating power quality parameters. Finally, by further planning the load of the production area, the load of the production area can always be in a stable state, so as to achieve the effect of preventing the load of the production area from fluctuating greatly and affecting the power quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a block diagram of a comprehensive power quality management system for distribution network transformers. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than 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.

[0021] like Figure 1As shown, a comprehensive power quality management system for transformers in a distribution network includes a data acquisition module, a load distribution module, a power quality optimization module, and a production area load timing optimization module, wherein the data acquisition module, the load distribution module, the power quality optimization module, and the production area load timing optimization module are sequentially connected in communication; The data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the park: the office area, the production area, and the public area. At the same time, it obtains the load task data of the production area, the office time pattern of the office area, and the usage time data of the facilities in the public area; In this embodiment, the data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the office area, the production area and the public area, and the load task data processing process of the production area is as follows: Collect electrical energy parameters such as voltage, current, frequency, harmonic content, and power factor in office areas, production areas, and public areas; It should be noted that the park uses a distribution network, and the park is divided into office area, production area and public area. The office area is mainly the place where employees of the company carry out daily office activities, equipped with a large number of office equipment such as computers, printers, copiers, etc.; the production area is the core area for product manufacturing, with various types of production machinery and equipment in continuous operation; the public area provides public services and activity space for park personnel, covering public facilities such as lighting, elevators, and air conditioning; in the park's power supply system, the office area, production area and public area share the same distribution network. As the core infrastructure for power transmission and distribution in the park, this distribution network distributes the electric energy transmitted by the upper power grid to various areas in a safe, stable and efficient manner through reasonable line layout and equipment configuration; Collect transformer oil temperature, winding temperature, oil level, and winding loss parameters; Obtain load task data from the production management system in the production area, including the operation plan of production equipment, equipment start and stop time; The load distribution module plans the power load of the three areas according to the load task data of the production area; In this embodiment, the load distribution module plans the electric energy load of the three areas according to the load task data as follows: According to the production task data, combined with the equipment's operating efficiency and historical electricity consumption, the load demand of the production area in different time periods is predicted; the load changes in the office area are predicted according to the office hours; the load demand in the public area is predicted according to the usage time of the public area facilities; the load in the production area is set as the highest priority, the office area is set as the second priority, and the public area is set as the low priority; According to the predicted load demand, set the upper limit of the allowable power consumption in each time period to ensure that the power supply in the production area is sufficient, and the power supply in the office area should be allocated after the power supply in the production area is met, and the power supply in the public area should be allocated after the power supply in the production area and the office area is met; The power quality optimization module is used to calculate voltage deviation, harmonic pollution, and three-phase imbalance data, and to establish parameters with the calculated data and transformer parameters to describe the relationship with transformer losses and further optimize power quality; In this embodiment, the power quality optimization module is used to calculate the voltage deviation, harmonic pollution, and three-phase imbalance data, and the calculated data and transformer parameters are used to establish parameters to describe the relationship with the transformer loss. The power quality processing process is further optimized as follows: Calculate voltage deviation, harmonic pollution, and three-phase unbalance values ​​based on the obtained power quality parameters; Calculate the percentage of voltage deviation. The specific formula is: ; in, is the percentage of voltage deviation, is the actual voltage, is the rated voltage; Calculate the voltage harmonic distortion rate and current harmonic distortion rate used to describe harmonic pollution. The specific formula is: ; ; in, is the voltage harmonic distortion rate, is the current harmonic distortion rate, and Respectively The voltage and current amplitudes of the subharmonics, and are the fundamental voltage and current amplitudes, respectively, is the highest harmonic order considered; Calculate the three-phase voltage unbalance and three-phase current unbalance used to describe the three-phase imbalance. The specific formula is: ; ; in, and are the negative sequence voltage and current amplitudes, respectively, and are the positive sequence voltage and current amplitudes, To calculate the unbalanced degree of the three-phase voltage, is the calculated three-phase current unbalance; Comprehensive consideration of voltage harmonic distortion rate and current harmonic distortion , the formula is: ; in, is the comprehensive harmonic distortion rate, is the weight coefficient of voltage harmonics, which indicates the importance of voltage harmonics in the calculation of harmonic distortion rate. is the weight coefficient of current harmonics, indicating the importance of current harmonics in the calculation of harmonic distortion rate, and ; Taking into account the voltage and current imbalance, the formula is: ; in, is the calculated comprehensive three-phase unbalance degree, is the weight coefficient of voltage imbalance, which indicates the importance of three-phase voltage imbalance in the calculation of imbalance index. is the weight coefficient of current imbalance, which indicates the importance of three-phase current imbalance in the calculation of imbalance index, and ; Establishing transformer losses With voltage deviation , comprehensive harmonic distortion rate And comprehensive three-phase unbalance The relationship model between , the formula is: ; in, is the regression coefficient, which is fitted according to the collected data by the least square method; According to the established model, the numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance for the lowest transformer loss are obtained, the preset numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance are narrowed, and the power quality adjustment parameters are obtained so that the actual voltage deviation, harmonic pollution and three-phase imbalance values ​​are within the narrowed range; Using the established loss model, the transformer loss data is obtained, and the error parameters of the power quality regulation are obtained according to the transformer loss data, and the error parameters are used to correct the actual regulation parameters; In this embodiment, the value ranges of voltage deviation, harmonic pollution, and three-phase imbalance for the lowest loss of the transformer are obtained according to the established model, the preset value ranges of voltage deviation, harmonic pollution, and three-phase imbalance are narrowed, and the power quality adjustment parameters are obtained so that the actual voltage deviation, harmonic pollution, and three-phase imbalance values ​​are within the narrowed range. The process is as follows: The preset voltage deviation range, harmonic pollution range, and three-phase unbalance range are , , , discretize the preset ranges of voltage deviation, harmonic pollution, and three-phase imbalance respectively, divide them into several small intervals, substitute each combination into the relationship model to calculate the corresponding transformer loss, compare all the calculated loss values, find the minimum value and the corresponding voltage deviation, harmonic pollution, and three-phase imbalance; According to the obtained minimum value, the numerical range of the preset voltage deviation, harmonic pollution, and three-phase imbalance is narrowed, and the voltage deviation adjustment parameter, the harmonic pollution adjustment parameter, and the three-phase imbalance adjustment parameter are calculated according to the obtained numerical range.

[0022] It should be noted that transformers may cause losses due to voltage deviation, harmonic pollution, and three-phase imbalance. By establishing the relationship between voltage deviation, harmonic pollution, three-phase imbalance and transformer damage, the range with the smallest transformer loss can be found within the preset voltage deviation, harmonic pollution, and three-phase imbalance range. Based on this range, the preset voltage deviation, harmonic pollution, and three-phase imbalance range can be narrowed, so that the transformer loss can be effectively reduced while the power quality is guaranteed. The reduction of transformer loss not only directly reduces the energy waste in the power transmission process, but also makes the transformer operation condition more stable, thereby achieving the effect of improving the power quality; In this embodiment, according to the obtained transformer loss data, the error parameter of the power quality regulation is obtained, and the actual regulation parameter is corrected using the error parameter. The process is as follows: Receive the monitored load data, compare the average load within the current 15 minutes with the average load of the previous 15 minutes, calculate the relative change rate, and if the load change rate is between ±5%, it means the load is stable. When the load is stable, set 1h to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Receive the monitored load data, if the load change rate within the adjacent 15 minutes is not between ±5%, it means the load is unstable. When the load is unstable, set 15min to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Add up the loss data obtained in a single time to obtain the final loss data; The voltage, current and power factor are corrected using the total loss data obtained.

[0023] It should be noted that correcting the transformer setting parameters to compensate for losses can significantly improve the efficiency and stability of the system. By compensating for transformer losses, it is possible to ensure that the output voltage, current and power are consistent with the set values, avoiding performance degradation or equipment failure caused by losses. In addition, the corrected parameters can reduce energy waste, improve the reliability and power quality of the overall power grid, meet load requirements, and reduce unnecessary energy losses; The production area load timing optimization module plans the equipment group operation timing according to the maximum load of the production area, so as to match the equipment group operation timing with the grid carrying capacity; In this embodiment, the production area load timing optimization module plans the equipment group operation timing according to the maximum load of the production area, and realizes the matching process of the equipment group operation timing and the grid carrying capacity as follows: Classify the equipment groups in the production area by function and load level, and clarify the production tasks that need to be completed in different time periods and the corresponding equipment usage requirements according to the production plan of the production area; With the minimum load fluctuation in the production area as the main goal, the load is decomposed and estimated according to each production task, a comprehensive load model of the production area is constructed, the total load changes under different production task combinations and production sequences are simulated, and the production plan is obtained using an optimization algorithm.

[0024] It should be noted that the final optimized order planning scheme needs to be evaluated using the load stability index. This evaluation can accurately measure the effectiveness of the scheme in maintaining load stability in the production area, thereby providing a reliable basis for the dynamic adjustment and continuous optimization of subsequent production plans.

[0025] In this embodiment, the main goal is to minimize the load fluctuation in the production area. According to the decomposition and load estimation of each production task, a comprehensive load model of the production area is constructed, the total load changes under different production task combinations and production sequences are simulated, and the production plan processing process is obtained by using an optimization algorithm as follows: The entire production time range T is divided into time steps of equal length Δt, calculate the total load for each time step, time steps ( =1,2,⋯ ), if task i is running in this time step, it contributes to the total load, and the production area is Total load for each time step for: ; Where M is the total number of production tasks, Indicates that task i is in The load of a time step, if task i does not run in this time step, then ; With the goal of minimizing load fluctuation in the production area and the equipment capacity as the constraint, an optimization algorithm is used to obtain a production plan.

[0026] It should be noted that the final production plan can not only match the operating sequence of the equipment group with the carrying capacity of the power grid, but also make the load in the production area stable, without large fluctuations affecting the power quality.

[0027] A method for comprehensive power quality management of a distribution network transformer comprises the following steps: S1. Divide the park into office area, production area and public area, monitor the power quality parameters and transformer parameters of these three areas, and obtain the load task data of the production area; S2. Plan the power load for the three areas based on the load task data of the production area to ensure the power supply of the three areas; S3. Based on the specific data and transformer parameters of voltage deviation, harmonic pollution, and three-phase imbalance, a model is established to describe the relationship with transformer loss, narrow the preset voltage deviation, harmonic pollution, and three-phase imbalance range, and reduce transformer loss; S4. Obtain error parameters through the established transformer loss relationship model, and use the error parameters to correct the actual adjustment parameters so that the output voltage, current and power are consistent with the set values, thereby improving the power quality; S5. Plan the operation sequence of the equipment group to match the maximum load of the production area, match the operation sequence of the equipment group with the carrying capacity of the power grid, and stabilize the load.

[0028] In the embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of modules is only a logical function division, and there may be other division methods in actual implementation; the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the method of this embodiment.

[0029] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A comprehensive power quality management system for transformers in distribution networks, characterized in that: It includes a data acquisition module, a load distribution module, a power quality optimization module, and a production area load timing optimization module, and the data acquisition module, the load distribution module, the power quality optimization module, and the production area load timing optimization module are sequentially connected in communication; The data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the park, namely the office area, the production area and the public area, and obtain the load task data of the production area, the office time pattern of the office area and the usage time data of the facilities in the public area; The load distribution module plans the electric energy load of the three areas according to the load task data of the production area; The power quality optimization module is used to calculate voltage deviation, harmonic pollution, and three-phase imbalance data, and to establish parameters with the calculated data and transformer parameters to describe the relationship with transformer loss and further optimize power quality; The production area load timing optimization module plans the equipment group operation timing according to the maximum load situation of the production area, so as to match the equipment group operation timing with the power grid carrying capacity.

2. A distribution network transformer power quality comprehensive management system according to claim 1, characterized in that: The data acquisition module is used to monitor the power quality parameters and transformer parameters of the three areas of the office area, the production area and the public area, and the load task data processing process of the production area is as follows: Collect electrical energy parameters such as voltage, current, frequency, harmonic content, and power factor in office areas, production areas, and public areas; Collect transformer oil temperature, winding temperature, oil level, and winding loss parameters; Obtain load task data from the production management system in the production area, including the operation plan of production equipment, equipment start and stop time.

3. A distribution network transformer power quality comprehensive management system according to claim 1, characterized in that: The load distribution module plans the electric energy load of the three areas according to the load task data as follows: According to the production task data, combined with the equipment's operating efficiency and historical electricity consumption, the load demand of the production area in different time periods is predicted; the load changes in the office area are predicted according to the office hours; the load demand in the public area is predicted according to the usage time of the public area facilities; the load in the production area is set as the highest priority, the office area is set as the second priority, and the public area is set as the low priority; According to the predicted load demand, set the upper limit of the allowable power consumption in each time period to ensure that the power supply in the production area is sufficient. The power supply in the office area should be allocated after the power supply in the production area is met, and the power supply in the public area should be allocated after the power supply in the production area and the office area is met.

4. A distribution network transformer power quality comprehensive management system according to claim 1, characterized in that: The power quality optimization module is used to calculate voltage deviation, harmonic pollution, and three-phase unbalance data, and to establish parameters with the calculated data and transformer parameters to describe the relationship with transformer loss. The power quality processing process is further optimized as follows: Calculate voltage deviation, harmonic pollution, and three-phase unbalance values ​​based on the obtained power quality parameters; Calculate the percentage of voltage deviation. The specific formula is: ； in, is the percentage of voltage deviation, is the actual voltage, is the rated voltage; Calculate the voltage harmonic distortion rate and current harmonic distortion rate used to describe harmonic pollution. The specific formula is: ； ； in, is the voltage harmonic distortion rate, is the current harmonic distortion rate, and Respectively The voltage and current amplitudes of the subharmonics, and are the fundamental voltage and current amplitudes, respectively. is the highest harmonic order considered; Calculate the three-phase voltage unbalance and three-phase current unbalance used to describe the three-phase imbalance. The specific formula is: ； ； in, and are the negative sequence voltage and current amplitudes, respectively, and are the positive sequence voltage and current amplitudes, To calculate the unbalanced degree of the three-phase voltage, is the calculated three-phase current unbalance; Comprehensive consideration of voltage harmonic distortion rate and current harmonic distortion , the formula is: ； in, is the comprehensive harmonic distortion rate, is the weight coefficient of voltage harmonics, which indicates the importance of voltage harmonics in the calculation of harmonic distortion rate. is the weight coefficient of current harmonics, indicating the importance of current harmonics in the calculation of harmonic distortion rate, and ; Taking into account the voltage and current imbalance, the formula is: ； in, is the calculated comprehensive three-phase unbalance, is the weight coefficient of voltage imbalance, which indicates the importance of three-phase voltage imbalance in the calculation of imbalance index. is the weight coefficient of current imbalance, which indicates the importance of three-phase current imbalance in the calculation of imbalance index, and ; Establishing transformer losses With voltage deviation , comprehensive harmonic distortion rate And comprehensive three-phase unbalance The relationship model between , the formula is: ； in, is the regression coefficient, which is fitted according to the collected data by the least square method; According to the established model, the numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance for the lowest transformer loss are obtained, the preset numerical ranges of voltage deviation, harmonic pollution and three-phase imbalance are narrowed, and the power quality adjustment parameters are obtained so that the actual voltage deviation, harmonic pollution and three-phase imbalance values ​​are within the narrowed range; Using the established loss model, the transformer loss data is obtained, and the error parameters of power quality regulation are obtained based on the transformer loss data, and the error parameters are used to correct the actual regulation parameters.

5. A distribution network transformer power quality comprehensive management system according to claim 4, characterized in that: The process of obtaining the voltage deviation, harmonic pollution, and three-phase imbalance value ranges of the transformer with the lowest loss according to the established model, narrowing the preset voltage deviation, harmonic pollution, and three-phase imbalance value ranges, and obtaining the power quality adjustment parameters so that the actual voltage deviation, harmonic pollution, and three-phase imbalance values ​​are within the narrowed range is as follows: The preset voltage deviation range, harmonic pollution range, and three-phase unbalance range are , , , discretize the preset ranges of voltage deviation, harmonic pollution, and three-phase imbalance respectively, divide them into several small intervals, substitute each combination into the relationship model to calculate the corresponding transformer loss, compare all the calculated loss values, find the minimum value and the corresponding voltage deviation, harmonic pollution, and three-phase imbalance; According to the obtained minimum value, the numerical range of the preset voltage deviation, harmonic pollution, and three-phase imbalance is narrowed, and the voltage deviation adjustment parameter, the harmonic pollution adjustment parameter, and the three-phase imbalance adjustment parameter are calculated according to the obtained numerical range.

6. A distribution network transformer power quality comprehensive management system according to claim 5, characterized in that: The process of obtaining the error parameter of power quality regulation based on the obtained transformer loss data and using the error parameter to correct the actual regulation parameter is as follows: Receive the monitored load data, compare the average load within the current 15 minutes with the average load of the previous 15 minutes, calculate the relative change rate, and if the load change rate is between ±5%, it means the load is stable. When the load is stable, set 1h to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Receive the monitored load data, if the load change rate within the adjacent 15 minutes is not between ±5%, it means the load is unstable. When the load is unstable, set 15min to calculate the primary voltage deviation, harmonic pollution, and three-phase unbalance values, and multiply the values ​​by the time interval to obtain the loss data; Add up the loss data obtained in a single time to obtain the final loss data; The voltage, current and power factor are corrected using the total loss data obtained.

7. A distribution network transformer power quality comprehensive management system according to claim 1, characterized in that: The production area load timing optimization module plans the equipment group operation timing according to the maximum load of the production area, and realizes the matching process of the equipment group operation timing and the grid carrying capacity as follows: Classify the equipment groups in the production area by function and load level, and clarify the production tasks that need to be completed in different time periods and the corresponding equipment usage requirements according to the production plan of the production area; With the minimum load fluctuation in the production area as the main goal, the load is decomposed and estimated according to each production task, a comprehensive load model of the production area is constructed, the total load changes under different production task combinations and production sequences are simulated, and the production plan is obtained using an optimization algorithm.

8. A distribution network transformer power quality comprehensive management system according to claim 7, characterized in that: The main goal is to minimize the load fluctuation in the production area. According to the decomposition and load estimation of each production task, a comprehensive load model of the production area is constructed to simulate the total load changes under different production task combinations and production sequences, and the production plan processing process is obtained by using the optimization algorithm as follows: The entire production time range T is divided into time steps of equal length Δt, calculate the total load for each time step, time steps ( =1,2,⋯ ), if task i is running in this time step, it contributes to the total load, and the production area is Total load for each time step for: ； Where M is the total number of production tasks, Indicates that task i is in The load of a time step, if task i does not run in this time step, then ; With the goal of minimizing load fluctuation in the production area and the equipment capacity as the constraint, an optimization algorithm is used to obtain a production plan.

9. A comprehensive power quality management method for distribution network transformers, characterized in that: The following steps are involved: S1. Divide the park into office area, production area and public area, monitor the power quality parameters and transformer parameters of these three areas, and obtain the load task data of the production area; S2. Plan the power load for the three areas based on the load task data of the production area to ensure the power supply of the three areas; S3. Based on the specific data and transformer parameters of voltage deviation, harmonic pollution, and three-phase imbalance, a model is established to describe the relationship with transformer loss, narrow the preset voltage deviation, harmonic pollution, and three-phase imbalance range, and reduce transformer loss; S4. Obtain error parameters through the established transformer loss relationship model, and use the error parameters to correct the actual adjustment parameters so that the output voltage, current and power are consistent with the set values, thereby improving the power quality; S5. Plan the operation sequence of the equipment group to match the maximum load of the production area, match the operation sequence of the equipment group with the carrying capacity of the power grid, and make the load stable.

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