A smart grid low voltage intelligent compensation method and system

Abstract

The present invention discloses a smart grid low-voltage intelligent compensation method and system, which relates to the technical field of power grid compensation, including analyzing the previous relevant parameters of the power grid under each load interval to set the thresholds of the relevant parameters under different load intervals, thereby improving the reliability of the thresholds of the relevant parameters. The performance parameter changes of the components are analyzed to define the aging effect factor and the harmonic component, and the influence of component aging and harmonics is considered. Then, the power parameters are corrected according to the influence of component aging and harmonics, thereby improving the accuracy of the power parameters and ensuring the basic stability of subsequent compensation calculations. By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has a low-voltage situation and determines the calibration value, and a reactive power compensation strategy is formulated based on the calibration value, thereby improving the effect and adaptability of the low-voltage compensation of the power grid and ensuring the safe and stable operation of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid compensation, and in particular to a method and system for low-voltage intelligent compensation of a smart grid. Background Art

[0002] The main reason for the low-voltage compensation scheme of smart grids is the continuous growth of electricity demand and the increasing load of power systems, which leads to frequent problems such as voltage drop and low power factor, which in turn cause grid instability and increased energy consumption. Traditional reactive power compensation technology is difficult to effectively cope with these challenges and meet the needs of modern power systems for efficient and stable power supply. With the rapid development of information technology and communication technology, smart grid low-voltage intelligent compensation technology has emerged. It aims to improve the reliability and stability of the power grid, reduce energy consumption, and reduce operating costs by monitoring the reactive power of the power grid in real time and using intelligent control devices to automatically adjust the reactive power, so as to provide strong support for the safe and economical operation of the power system.

[0003] In the prior art, the accuracy of power parameters is poor due to harmonic conditions, which results in poor low-voltage compensation effect and low compensation adaptability of the power grid, and does not ensure safe and stable operation of the power grid.

[0004] Therefore, how to improve the low-voltage compensation effect and adaptability of the power grid is a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of poor low-voltage compensation effect and low compensation adaptability of the power grid in the prior art, and to propose a smart grid low-voltage intelligent compensation method, the method comprising:

[0006] Obtain the past load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the past relevant parameters of the power grid in each load interval, and set the threshold value of each relevant parameter in each load interval;

[0007] Obtain the load conditions and related parameters of the power grid in the current period of time. The related parameters include power parameters and non-power parameters. The non-power parameters include voltage. Determine the load range to which the current power grid belongs based on the load conditions. Analyze the performance parameter changes of components in the power grid to define the aging effect factor. Determine the harmonic components in the power grid based on the non-power parameters.

[0008] The power parameters are corrected according to the aging effect factors and harmonic components of the components in the power grid. By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has low voltage and the calibration value is determined.

[0009] If low voltage exists in the power grid, a reactive power compensation strategy is formulated based on the calibration value. The reactive power compensation strategy realizes intelligent compensation of the power grid by adjusting the input or removal of reactive compensation devices.

[0010] In some embodiments of the present application, the load range of the power grid is determined, and the load range is divided into multiple load intervals, including:

[0011] Draw a load curve of the load changes over time of the power grid's past load changes, determine the load range of the power grid based on all values ​​of the load size on the load curve, split the load curve into partial load curves under multiple time periods according to a preset cycle, evenly select multiple points on each partial load curve, calculate the slope change between adjacent points, obtain the slope change of the point, integrate the slope changes of all points to determine the slope change value of the partial load curve, and use the slope change value of each partial load curve to split the load range under the time period into multiple load intervals, so as to split the load range of the power grid under all time periods.

[0012] In some embodiments of the present application, the threshold value of each relevant parameter in each load interval is set, including:

[0013] Determine the typical value range, abnormal value range and change rate of the relevant parameters in each load interval, calculate the distance between the typical value range and the abnormal value range of the relevant parameters, and record it as the middle distance. The distance between the typical value range and the abnormal value range is the distance between the close endpoints of the two ranges. According to the change rate of the relevant parameters, a surplus ratio is mapped to obtain a typical value range. The typical value range is expanded in the middle distance through the surplus ratio to obtain the expanded typical value range, and the expanded typical value range is used as the threshold of the relevant parameter in the load interval.

[0014] In some embodiments of the present application, the aging effect factor is defined by analyzing the performance parameter changes of the components in the power grid, including:

[0015] Confirm the location of each component in the power grid, obtain the maintenance records of each component in the power grid, determine the aging effect of the component by comparing multiple maintenance records of the same component and the location of the component in the power grid, and thus determine the aging effect factor.

[0016] In some embodiments of the present application, the power parameters are corrected according to the aging effect factors and harmonic components of the components in the power grid, including:

[0017] The power parameters include the original reactive power and the original power factor. The reactive power generated by the harmonics is calculated by analyzing the harmonic components. The corrected reactive power is determined based on the original reactive power, the aging effect factor of the components and the reactive power generated by the harmonics.

[0018] ;

[0019] in, is the corrected reactive power, is the original reactive power, is the reactive power generated by harmonics, is the aging effect factor of the component, is a preset constant;

[0020] Determine the corrected power factor by the original power factor, harmonic components and component aging effect factors;

[0021] The corrected power factor is determined by the original power factor, harmonic components and component aging effect factors.

[0022] In some embodiments of the present application, by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, and the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has a low voltage situation and the calibration value is determined, including:

[0023] Align the corrected power parameters and voltage on a time scale, and compare the relationship between the corrected power parameters and voltage and their respective thresholds to generate a determination index, which is used to determine whether the power grid has a low voltage condition;

[0024] The calibration value is determined based on the judgment index, the corrected power parameter and the voltage change trend.

[0025] In some embodiments of the present application, the relationship between the corrected power parameter and voltage and the respective thresholds is compared to generate a determination index, and the determination index is used to determine whether the power grid has a low voltage condition, including:

[0026] The voltage index is defined by the extent to which the voltage is lower than its threshold, the first power index is defined by the extent to which the reactive power is higher than its threshold, and the second power index is defined by the extent to which the power factor is lower than its threshold;

[0027] generating a determination index through the voltage index, the first power index and the second power index;

[0028] ;

[0029] in, As the judging indicator, , , are the judgment weights of the voltage index, the first power index and the second power index, is the voltage indicator, is the first power indicator, is the second power indicator;

[0030] It is determined whether there is a low voltage situation in the power grid according to the determination index. If there is a low voltage situation, the calibration value is calculated, otherwise the calibration value is not calculated.

[0031] In some embodiments of the present application, the calibration value is determined according to the determination index and the modified power parameter and the voltage change trend, including:

[0032] Determine the change rate of the main change trends of voltage, reactive power and power factor, and determine the calibration value through the change rate of the main change trends of voltage, reactive power and power factor and the judgment index;

[0033] ;

[0034] in, is the calibration value, is the rate of change of the main trend of voltage change, is the rate of change of the main trend of reactive power, is the rate of change of the main trend of power factor change, , , are the first constant, the second constant and the third constant respectively, is the conversion factor, is the adjustment factor, Represents the adjustment coefficient obtained by mapping the judgment index.

[0035] Correspondingly, the present application also provides a smart grid low-voltage intelligent compensation system, comprising:

[0036] The setting module is used to obtain the past load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the previous relevant parameters of the power grid in each load interval, and set the threshold value of each relevant parameter in each load interval;

[0037] A determination module is used to obtain the load conditions and related parameters of the power grid during a current period of time. The related parameters include power parameters and non-power parameters. The non-power parameters include voltage. The load range to which the current power grid belongs is determined by the load conditions. The performance parameter changes of the components in the power grid are analyzed to define the aging effect factor. The harmonic components in the power grid are determined based on the non-power parameters.

[0038] A judgment module is used to correct the power parameters according to the aging effect factors and harmonic components of the components in the power grid, and to judge whether there is a low voltage situation in the power grid and determine the calibration value by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage;

[0039] The compensation module is used to formulate a reactive power compensation strategy based on the calibration value if there is a low voltage in the power grid. The reactive power compensation strategy achieves intelligent compensation of the power grid by adjusting the input or removal of the reactive compensation device.

[0040] By applying the above technical solutions, the previous relevant parameters of the power grid under each load interval are analyzed to set the thresholds of the relevant parameters under different load intervals, thereby improving the reliability of the thresholds of the relevant parameters. The changes in the performance parameters of the components are analyzed to define the aging effect factors and harmonic components, taking into account the influence of component aging and harmonics, and then correcting the power parameters according to the influence of component aging and harmonics, thereby improving the accuracy of the power parameters and ensuring the basic stability of subsequent compensation calculations. By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has a low voltage condition and the calibration value is determined. The reactive power compensation strategy is formulated based on the calibration value, thereby improving the effect and adaptability of the low-voltage compensation of the power grid and ensuring the safe and stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a flow chart of a low-voltage intelligent compensation method for a smart grid proposed by the present invention;

[0042] Figure 2 This is a structural schematic diagram of a smart grid low-voltage intelligent compensation system proposed by the present invention. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0044] Reference Figure 1 , a smart grid low voltage intelligent compensation method, comprising the following steps:

[0045] Step S101, obtain the previous load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the previous relevant parameters of the power grid in each load interval, and set the threshold of each relevant parameter in each load interval.

[0046] In this embodiment, under different load conditions of the power grid, the thresholds of its related parameters may fluctuate. The related parameters include power parameters (reactive power, power factor, etc.) and non-power parameters (current, voltage, etc.). The reasons for the low voltage of the power grid are:

[0047] The power supply radius is too long:

[0048] In some remote areas or rural power grids, the terminal voltage is reduced due to long power supply lines and large line losses.

[0049] Insufficient reactive power compensation:

[0050] Reactive power compensation is an important means to maintain grid voltage stability. If the capacity of reactive power compensation equipment is insufficient or the setting is unreasonable, the grid voltage will drop.

[0051] Concentrated load growth:

[0052] With the rapid development of urban and rural economy and the improvement of residents' living standards, the electricity load is growing rapidly. During peak hours, if the power supply capacity of the power grid cannot meet the load demand, it will cause voltage drop.

[0053] Equipment aging or failure:

[0054] Some old equipment in the power grid may have performance degradation or failure problems, affecting the voltage stability of the power grid.

[0055] Three-phase load unbalance:

[0056] In a low-voltage power grid, if the three-phase load is unevenly distributed, it will cause three-phase voltage imbalance, which will lead to low voltage problems.

[0057] In some embodiments of the present application, the load range of the power grid is determined, and the load range is divided into multiple load intervals, including:

[0058] Draw a load curve of the load changes over time of the power grid's past load changes, determine the load range of the power grid based on all values ​​of the load size on the load curve, split the load curve into partial load curves under multiple time periods according to a preset cycle, evenly select multiple points on each partial load curve, calculate the slope change between adjacent points, obtain the slope change of the point, integrate the slope changes of all points to determine the slope change value of the partial load curve, and use the slope change value of each partial load curve to split the load range under the time period into multiple load intervals, so as to split the load range of the power grid under all time periods.

[0059] In this embodiment, the load range in the period is divided into multiple load intervals by the slope change value of each partial load curve. Here, the slope change value indicates the load stability or fluctuation. When the load is relatively stable, the number of split intervals is small. When the load is relatively volatile, the number of split intervals is large. This is to more accurately divide the intervals and monitor or monitor the load and related data. Different slope change values ​​correspond to different numbers of intervals.

[0060] In some embodiments of the present application, the threshold value of each relevant parameter in each load interval is set, including:

[0061] Determine the typical value range, abnormal value range and change rate of the relevant parameters in each load interval, calculate the distance between the typical value range and the abnormal value range of the relevant parameters, and record it as the middle distance. The distance between the typical value range and the abnormal value range is the distance between the close endpoints of the two ranges. According to the change rate of the relevant parameters, a surplus ratio is mapped to obtain a typical value range. The typical value range is expanded in the middle distance through the surplus ratio to obtain the expanded typical value range, and the expanded typical value range is used as the threshold of the relevant parameter in the load interval.

[0062] In this embodiment, the typical value range refers to the value range or normal value range where the relevant parameters often appear, the abnormal value range refers to the value range of the relevant parameters under abnormal conditions, and the rate of change refers to the change of the relevant parameters within the interval. A normal threshold range is set for each relevant parameter in each load interval. The threshold range should include the typical value range and leave a certain margin to accommodate normal fluctuations and changes. At the same time, it is necessary to ensure that the threshold range can effectively exclude the influence of abnormal values. The typical value range is extended in the middle distance through the surplus ratio, and a certain end point of the typical value range is extended in the middle distance according to the surplus ratio.

[0063] Step S102, obtaining the load condition and related parameters of the power grid during the current period of time, the related parameters include power parameters and non-power parameters, the non-power parameters include voltage, judging the load range to which the current power grid belongs through the load condition, defining the aging effect factor by analyzing the performance parameter changes of the components in the power grid, and determining the harmonic components in the power grid based on the non-power parameters.

[0064] In this embodiment, the power factor and reactive power directly measured or calculated are affected by the two factors of harmonics and component aging, so the two parameters are corrected. Reactive power is the power loss caused by the presence of components such as inductance and capacitance during the transmission of alternating current in the power grid. It does not directly do work, but is used to maintain the existence and change of the electromagnetic field. The power factor is an indicator that measures the ratio of active power to apparent power in the power grid. It reflects the power utilization efficiency and the quality of electric energy in the power grid.

[0065] In this embodiment, the load range to which the current power grid belongs is judged by the load situation, and the load range to which the current power grid belongs is determined by the time period and the load range, so as to determine the threshold value corresponding to the relevant parameters. The components of the power grid include transformers, cables, motors, etc. The components will gradually age during use, causing changes in their performance parameters. The aging effect mainly includes material degradation, reduced insulation performance, increased contact resistance, etc. These changes will directly affect the electrical and mechanical properties of the components. In order to analyze the aging effect of components, it is necessary to understand the service life and aging law of the components. The aging degree of the components can be evaluated by regularly detecting the performance parameters of the components, and corresponding maintenance measures can be taken to extend their service life. For example, for key components such as transformers, insulation resistance tests, oil quality analysis and other inspections can be performed regularly to ensure that their performance is stable and reliable.

[0066] In this embodiment, the harmonic components in the power grid are determined according to non-power parameters, and the pre-processed current and voltage signals are Fourier transformed to convert the time domain signals into frequency domain signals. The frequency domain signals are analyzed to identify the harmonic components and their amplitudes and phases, and the reactive power of the harmonics is calculated through the harmonic components. Under normal circumstances, the reactive power directly measured and calculated usually only considers the fundamental reactive power, while ignoring the existence of harmonic reactive power. In the power system, current and voltage are often not perfect sine waves, but contain certain harmonic components. These harmonic components will affect the measurement of reactive power, resulting in inaccurate measurement results. The correction method is to add the fundamental reactive power to the harmonic reactive power. The fundamental reactive power is the reactive power generated by the fundamental components of current and voltage, while the harmonic reactive power is the reactive power generated by the harmonic components of current and voltage. By adding these two parts, we can get the corrected reactive power, which more accurately reflects the actual situation in the power system.

[0067] In some embodiments of the present application, the aging effect factor is defined by analyzing the performance parameter changes of the components in the power grid, including:

[0068] Confirm the location of each component in the power grid, obtain the maintenance records of each component in the power grid, determine the aging effect of the component by comparing multiple maintenance records of the same component and the location of the component in the power grid, and thus determine the aging effect factor.

[0069] In this embodiment, multiple maintenance records are used to compare the changes in component performance parameters (inductance, resistance, etc.) in each maintenance record. The location of the component in the power grid (power station, transmission line, high-voltage location, substation, etc.) is also used. Different locations have different effects on the components. An aging effect factor is determined by combining multiple maintenance records and the effect of the location on the component.

[0070] In some embodiments of the present application, the power parameters are corrected according to the aging effect factors and harmonic components of the components in the power grid, including:

[0071] The power parameters include the original reactive power and the original power factor. The reactive power generated by the harmonics is calculated by analyzing the harmonic components. The corrected reactive power is determined based on the original reactive power, the aging effect factor of the components and the reactive power generated by the harmonics.

[0072] ;

[0073] in, is the corrected reactive power, is the original reactive power, is the reactive power generated by harmonics, is the aging effect factor of the component, is a preset constant;

[0074] Determine the corrected power factor by the original power factor, harmonic components and component aging effect factors;

[0075] The corrected power factor is determined by the original power factor, harmonic components and component aging effect factors.

[0076] In this embodiment, for reactive power, the original reactive power is the fundamental reactive power calculated based on the current and voltage of the fundamental wave (i.e., the rated frequency component of the power grid). Based on the identified harmonic components, the reactive power generated by the harmonics is calculated. This usually involves accumulating the reactive power of each harmonic component. The fundamental reactive power is added to the harmonic reactive power to obtain the corrected reactive power. This process takes into account the impact of harmonics on reactive power measurement, thereby improving the accuracy of the measurement. Component aging may affect harmonic current and voltage, so it indicates the adjustment of component aging to harmonic reactive power.

[0077] In this embodiment, for the power factor, the original power factor, the harmonic component and the aging effect factor of the component are used to determine the corrected power factor. The phase difference between the harmonic current and the voltage is different from the phase difference between the fundamental current and the voltage, which will cause the total power factor of the power grid to decrease. Component aging may cause the waveforms of the harmonic current and voltage to change, thereby changing the phase difference between them. The change in phase difference will directly affect the calculation of the power factor. The corrected power factor is determined by comprehensively considering the original power factor, the harmonic component and the aging effect factor of the component, and it can be corrected by a preset correction model.

[0078] Step S103, correcting the power parameters according to the aging effect factors and harmonic components of the components in the power grid, and judging whether there is a low voltage situation in the power grid and determining the calibration value by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, and the changing trends of the corrected power parameters and voltage.

[0079] In this embodiment, voltage is one of the most direct parameters in the power grid. If the voltage is lower than the normal threshold, it indicates that there may be a low voltage situation. When the power grid is in a low voltage situation, the reactive power may increase due to the change in the impedance of the load or the unstable output of the power supply. This means that in a low voltage state, the value of reactive power may exceed its normal operating threshold. When the power grid is low voltage, the power factor may decrease due to the decrease in the proportion of active power in the total power. Therefore, in a low voltage state, the value of the power factor may be lower than its normal operating threshold. Whether low voltage occurs is determined based on the relationship between the above-mentioned related parameters and the threshold. For the change trend, the increase in reactive power may mean that there are too many inductive or capacitive loads in the power grid, which consume more reactive power, resulting in a voltage drop. Therefore, a continuous increase in reactive power may be a precursor to a low voltage situation. A decrease in power factor indicates that the proportion of active power in the power grid is decreasing, which is usually caused by an increase in load or an unstable output of the power supply. A decrease in power factor may also indicate the occurrence of a low voltage situation, and a decrease in voltage is direct evidence of a low voltage situation. If the voltage is continuously below the normal threshold, then there may be a low voltage problem on the grid.

[0080] In some embodiments of the present application, by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, and the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has a low voltage situation and the calibration value is determined, including:

[0081] Align the corrected power parameters and voltage on a time scale, and compare the relationship between the corrected power parameters and voltage and their respective thresholds to generate a determination index, which is used to determine whether the power grid has a low voltage condition;

[0082] The calibration value is determined based on the judgment index, the corrected power parameter and the voltage change trend.

[0083] In some embodiments of the present application, the relationship between the corrected power parameter and voltage and the respective thresholds is compared to generate a determination index, and the determination index is used to determine whether the power grid has a low voltage condition, including:

[0084] The voltage index is defined by the extent to which the voltage is lower than its threshold, the first power index is defined by the extent to which the reactive power is higher than its threshold, and the second power index is defined by the extent to which the power factor is lower than its threshold;

[0085] generating a determination index through the voltage index, the first power index and the second power index;

[0086] ;

[0087] in, As the judging indicator, , , are the judgment weights of the voltage index, the first power index and the second power index, is the voltage indicator, is the first power indicator, is the second power indicator;

[0088] It is determined whether there is a low voltage situation in the power grid according to the determination index. If there is a low voltage situation, the calibration value is calculated, otherwise the calibration value is not calculated.

[0089] In this embodiment, the determination index reflects the response of the voltage index, the first power index and the second power index to the low voltage.

[0090] In some embodiments of the present application, the calibration value is determined according to the determination index and the modified power parameter and the voltage change trend, including:

[0091] Determine the change rate of the main change trends of voltage, reactive power and power factor, and determine the calibration value through the change rate of the main change trends of voltage, reactive power and power factor and the judgment index;

[0092] ;

[0093] in, is the calibration value, is the rate of change of the main trend of voltage change, is the rate of change of the main trend of reactive power, is the rate of change of the main trend of power factor change, , , are the first constant, the second constant and the third constant respectively, is the conversion factor, is the adjustment factor, Represents the adjustment coefficient obtained by mapping the judgment index.

[0094] In this embodiment, the calibration value here can be understood as the overall influence of voltage, reactive power and power factor, and the specific compensation amount of reactive power is determined by the overall influence. The rate of change of the main change trend of voltage, reactive power and power factor refers to the degree of change of the change that accounts for a large proportion during this period of time. For example, in 60% of the time, the voltage is increasing, and the main trend here is growth, and the rate of change of the growth part is counted. The voltage index is adjusted by the rate of change, and the change trend reflects the influence to a certain extent. The same is true for the other two parameters. The influence of the three parameters is adjusted as a whole by judging the index.

[0095] Step S104: if there is a low voltage in the power grid, a reactive power compensation strategy is formulated according to the calibration value. The reactive power compensation strategy achieves intelligent compensation for the power grid by adjusting the input or removal of reactive compensation devices.

[0096] In this embodiment, commonly used reactive power compensation devices include capacitor banks, static VAR compensators (SVGs), etc. A specific compensation strategy is set according to the calibration value and related parameter conditions, and the capacitor bank is automatically switched. The capacitor bank can generate or absorb reactive power, thereby balancing the reactive power demand in the power grid. SVG achieves continuous regulation of reactive power through the rapid switching action of power electronic devices. It has the advantages of fast response speed, wide adjustment range, and low harmonic content.

[0097] By applying the above technical solutions, the previous relevant parameters of the power grid under each load interval are analyzed to set the thresholds of the relevant parameters under different load intervals, thereby improving the reliability of the thresholds of the relevant parameters. The changes in the performance parameters of the components are analyzed to define the aging effect factors and harmonic components, taking into account the influence of component aging and harmonics, and then correcting the power parameters according to the influence of component aging and harmonics, thereby improving the accuracy of the power parameters and ensuring the basic stability of subsequent compensation calculations. By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has a low voltage condition and the calibration value is determined. The reactive power compensation strategy is formulated based on the calibration value, thereby improving the effect and adaptability of the low-voltage compensation of the power grid and ensuring the safe and stable operation of the power grid.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or by software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present invention.

[0099] Correspondingly, the present application also provides a smart grid low voltage intelligent compensation system, such as Figure 2 As shown, including

[0100] The setting module is used to obtain the past load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the previous relevant parameters of the power grid in each load interval, and set the threshold value of each relevant parameter in each load interval;

[0101] A determination module is used to obtain the load conditions and related parameters of the power grid during a current period of time. The related parameters include power parameters and non-power parameters. The non-power parameters include voltage. The load range to which the current power grid belongs is determined by the load conditions. The performance parameter changes of the components in the power grid are analyzed to define the aging effect factor. The harmonic components in the power grid are determined based on the non-power parameters.

[0102] A judgment module is used to correct the power parameters according to the aging effect factors and harmonic components of the components in the power grid, and to judge whether there is a low voltage situation in the power grid and determine the calibration value by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage;

[0103] The compensation module is used to formulate a reactive power compensation strategy based on the calibration value if there is a low voltage in the power grid. The reactive power compensation strategy achieves intelligent compensation of the power grid by adjusting the input or removal of the reactive compensation device.

[0104] Those skilled in the art will appreciate that the modules in the system in the implementation scenario can be distributed in the system of the implementation scenario according to the implementation scenario description, or can be changed accordingly and located in one or more systems different from the implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple submodules.

[0105] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A smart grid low voltage intelligent compensation method, characterized in that: include, Obtain the past load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the past relevant parameters of the power grid in each load interval, and set the threshold value of each relevant parameter in each load interval; Obtain the load conditions and related parameters of the power grid in the current period of time. The related parameters include power parameters and non-power parameters. The non-power parameters include voltage. Determine the load range to which the current power grid belongs based on the load conditions. Analyze the performance parameter changes of components in the power grid to define the aging effect factor. Determine the harmonic components in the power grid based on the non-power parameters. The power parameters are corrected according to the aging effect factors and harmonic components of the components in the power grid. By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is determined whether the power grid has low voltage and the calibration value is determined. If there is low voltage in the power grid, a reactive power compensation strategy is formulated based on the calibration value. The reactive power compensation strategy achieves intelligent compensation of the power grid by adjusting the input or removal of reactive compensation devices. in, Analyze the performance parameter changes of components in the power grid to define aging effect factors, including, Confirm the location of each component in the power grid, obtain the maintenance records of each component in the power grid, and determine the aging effect of the component by comparing multiple maintenance records of the same component and the location of the component in the power grid, thereby determining the aging effect factor; Correction of power parameters based on aging effect factors and harmonic components of components in the power grid, including: The power parameters include the original reactive power and the original power factor. The reactive power generated by the harmonics is calculated by analyzing the harmonic components. The corrected reactive power is determined based on the original reactive power, the aging effect factor of the components and the reactive power generated by the harmonics. ； in, is the corrected reactive power, is the original reactive power, is the reactive power generated by harmonics, is the aging effect factor of the component, is a preset constant; Determine the corrected power factor by the original power factor, harmonic components and component aging effect factors; By comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage, it is possible to determine whether the power grid has a low voltage condition and determine the calibration value, including: Align the corrected power parameters and voltage on a time scale, and compare the relationship between the corrected power parameters and voltage and their respective thresholds to generate a determination index, which is used to determine whether the power grid has a low voltage condition; Determine the calibration value based on the judgment index, the corrected power parameter and the voltage change trend; And compare the relationship between the corrected power parameters and voltage and their respective thresholds to generate a judgment index, which is used to determine whether the power grid has a low voltage condition, including: The voltage index is defined by the extent to which the voltage is lower than its threshold, the first power index is defined by the extent to which the reactive power is higher than its threshold, and the second power index is defined by the extent to which the power factor is lower than its threshold; generating a determination index through the voltage index, the first power index and the second power index; ； in, As the judging indicator, , , are the judgment weights of the voltage index, the first power index and the second power index, is the voltage indicator, is the first power indicator, is the second power indicator; The voltage index is defined by the extent to which the voltage is lower than the voltage threshold, the first power index is defined by the extent to which the reactive power is higher than the reactive power threshold, and the second power index is defined by the extent to which the power factor is lower than the power factor threshold; The calibration value is determined based on the judgment index, the corrected power parameters and the voltage change trend, including: Determine the change rate of the main change trends of voltage, reactive power and power factor, and determine the calibration value through the change rate of the main change trends of voltage, reactive power and power factor and the judgment index; ； in, is the calibration value, is the rate of change of the main trend of voltage change, is the rate of change of the main trend of reactive power, is the rate of change of the main trend of power factor change, , , are the first constant, the second constant and the third constant respectively, is the conversion factor, is the adjustment factor, Represents the adjustment coefficient obtained by mapping the judgment index.

2. The smart grid low voltage intelligent compensation method according to claim 1 is characterized in that: And determine the load range of the power grid, split the load range into multiple load intervals, including, Draw a load curve of the load changes over time of the power grid's past load changes, determine the load range of the power grid based on all values ​​of the load size on the load curve, split the load curve into partial load curves under multiple time periods according to a preset cycle, evenly select multiple points on each partial load curve, calculate the slope change between adjacent points, obtain the slope change of the point, integrate the slope changes of all points to determine the slope change value of the partial load curve, and use the slope change value of each partial load curve to split the load range under the time period into multiple load intervals, so as to split the load range of the power grid under all time periods.

3. The smart grid low voltage intelligent compensation method according to claim 2 is characterized in that: And set the threshold value of each relevant parameter in each load range, including, Determine the typical value range, abnormal value range and change rate of the relevant parameters in each load interval, calculate the distance between the typical value range and the abnormal value range of the relevant parameters, and record it as the middle distance. The distance between the typical value range and the abnormal value range is the distance between the close endpoints of the two ranges. According to the change rate of the relevant parameters, a surplus ratio is mapped to obtain a typical value range. The typical value range is expanded in the middle distance through the surplus ratio to obtain the expanded typical value range, and the expanded typical value range is used as the threshold of the relevant parameter in the load interval.

4. A smart grid low voltage intelligent compensation system, characterized in that: Used to implement the smart grid low-voltage intelligent compensation method according to any one of claims 1 to 3, the system comprises: The setting module is used to obtain the past load changes of the power grid and determine the load range of the power grid, split the load range into multiple load intervals, each load interval corresponds to a different load level, obtain the previous relevant parameters of the power grid in each load interval, and set the threshold value of each relevant parameter in each load interval; A determination module is used to obtain the load conditions and related parameters of the power grid during a current period of time. The related parameters include power parameters and non-power parameters. The non-power parameters include voltage. The load range to which the current power grid belongs is determined by the load conditions. The performance parameter changes of the components in the power grid are analyzed to define the aging effect factor. The harmonic components in the power grid are determined based on the non-power parameters. A judgment module is used to correct the power parameters according to the aging effect factors and harmonic components of the components in the power grid, and to judge whether there is a low voltage situation in the power grid and determine the calibration value by comparing the relationship between the corrected power parameters and voltage and their respective thresholds, as well as the changing trends of the corrected power parameters and voltage; The compensation module is used to formulate a reactive power compensation strategy based on the calibration value if there is a low voltage in the power grid. The reactive power compensation strategy achieves intelligent compensation of the power grid by adjusting the input or removal of the reactive compensation device.

Images