A city power grid risk monitoring system

Abstract

The present invention relates to the technical field of power grid monitoring, and in particular to a city power grid risk monitoring system, comprising an operation unit, a collection unit, a transmission unit, a processing unit, an analysis unit and an alarm unit, wherein the power grid is monitored during its operation, a transmission evaluation value is calculated based on data collected by the collection unit to evaluate the overall operation status of the operation unit, and whether the operation of the operation unit is normal is determined based on the obtained transmission evaluation value. When the transmission evaluation value is less than or equal to a first preset transmission evaluation value, corresponding measures are determined for abnormal operation of the operation unit in this case. When the transmission evaluation value is less than or equal to a second preset transmission evaluation value and greater than the first preset transmission evaluation value, the operation status of the operation unit is comprehensively determined in combination with the total power consumption of each user, the operation status of the power grid is accurately monitored in real time, and whether there is abnormality in the operation status of the power grid is determined, thereby effectively improving the monitoring efficiency of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid monitoring, and in particular to a city power grid risk monitoring system. Background Art

[0002] Power reliability reflects the degree to which the power industry meets the national economy's electricity demand and is an important guarantee for the safe and economical operation of the power system. Risk monitoring, as part of power reliability, plays an extremely important role. Automatically monitoring the risks of the power grid can not only eliminate manual investigations, improve the level of risk pre-control of the power grid, and provide guarantees for the safe operation of the power grid; it can also provide a basis for the operation of the power grid and provide future big data analysis, so as to better monitor the risks of the power grid and improve power reliability.

[0003] Chinese Patent Publication No.: CN117713386B discloses a method and device for intelligent monitoring and control of a power grid, which analyzes various characteristics of power outage events and power outage event triggering component locations in a preset time period in the power grid in a target area, i.e., various characteristics of fault power outages, and performs various correlation feature calculations according to the geographical location X, power consumption nature Y, and line configuration characteristics Z; it can be seen that the above technical solution has the following problems: it does not take into account the monitoring of the operating status of the power grid according to the collected operating electrical data of various parts of the power grid during the operation of the power grid, and does not take into account the corresponding response measures when it is determined that an abnormality exists, which affects the safety of the power grid operation, and further affects the monitoring efficiency of the power grid. Summary of the invention

[0004] To this end, the present invention provides a city power grid risk monitoring system to overcome the problems in the prior art that the operating status of the power grid is not monitored according to the operating electrical data of each part of the power grid collected during the operation of the power grid, and corresponding response measures are not taken when an abnormality is determined, which affects the safety of the power grid operation and further affects the monitoring efficiency of the power grid.

[0005] To achieve the above object, the present invention provides a city power grid risk monitoring system, comprising:

[0006] An operating unit, which includes a power plant for generating electric energy, a substation for converting low-voltage electric energy generated by the power plant into high-voltage electric energy, a plurality of high-voltage transmission lines for transmitting electric energy, a plurality of distribution stations for reducing the voltage of high-voltage electricity, and a user end connected to the distribution station;

[0007] A collection unit, which includes a plurality of path voltage monitors uniformly arranged on the high-voltage transmission line for obtaining node voltages, a plurality of transmission voltage monitors arranged at the input end of each distribution station for obtaining transmission voltages, a first electric energy meter respectively arranged at the output end of the substation for obtaining total output power, and a plurality of port electric energy meters arranged at each user end for respectively obtaining user power consumption at each user end;

[0008] A transmission unit, connected to the acquisition unit, for transmitting the data acquired by the acquisition unit;

[0009] A processing unit connected to the transmission unit for preprocessing the data transmitted by the transmission unit, including classifying and recording each data and archiving it according to the collection time;

[0010] an analysis unit connected to the processing unit, for calculating a power transmission evaluation value based on the acquired pre-processed information, determining whether the operation of the operation unit is normal based on the power transmission evaluation value, and controlling the substation based on the voltage of each node;

[0011] An alarm unit is connected to the analysis unit and is used to issue corresponding alarm information based on the determination result of the analysis unit.

[0012] Furthermore, the analysis unit calculates the power transmission evaluation value by formula (1) at intervals of a predetermined time length.

[0013]

[0014] In the formula, S is the transmission evaluation value, U is the average transmission voltage, Wt is the total power consumption, D is the voltage loss, U0 is the mean of the historical average transmission voltage, Wi is the total output power of the substation, D0 is the average of the historical voltage losses, α is the transmission weight coefficient, β is the power weight coefficient, and γ is the loss weight coefficient;

[0015] The average transmission voltage is the average value of each transmission voltage;

[0016] The total power consumption is the sum of the power consumption of each user;

[0017] The analysis unit is used to determine the voltage loss based on each of the path voltage monitors, including:

[0018] For a single high-voltage transmission line, calculate the voltage difference between its starting point voltage and its end point voltage;

[0019] Solve the ratio of the voltage difference to the total length of a single high-voltage transmission line to obtain the branch voltage loss;

[0020] The average value of the branch voltage loss of each high-voltage transmission line is calculated to obtain the voltage loss.

[0021] Further, the analysis unit determines whether the operation of the operation unit is normal based on the power transmission evaluation value, including:

[0022] If the power transmission evaluation value is less than or equal to the first preset power transmission evaluation value, controlling the substation based on the voltage of each node;

[0023] If the power transmission evaluation value is less than or equal to the second preset power transmission evaluation value and greater than the first preset power transmission evaluation value, determining whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption;

[0024] If the power transmission evaluation value is greater than the second preset power transmission evaluation value, it is determined that the operation of the operation unit is normal.

[0025] Further, the analysis unit determines whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption, including:

[0026] If the total power consumption is less than or equal to the preset total power consumption, the substation is controlled based on the voltage of each node;

[0027] If the total power consumption is greater than the preset total power consumption, the first preset power transmission evaluation value and the second preset power transmission evaluation value are re-determined based on the total power consumption.

[0028] Furthermore, the analysis unit re-determines the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the power consumption difference between the total power consumption and the preset total power consumption, including:

[0029] If the power consumption difference is less than or equal to the first preset power consumption difference, adjusting the first preset power transmission evaluation value and the second preset power transmission evaluation value to corresponding values ​​using the first preset reference correction coefficient;

[0030] If the power consumption difference is less than or equal to the second preset power consumption difference and greater than the first preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the second preset reference correction coefficient;

[0031] If the power consumption difference is greater than the second preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the third preset reference correction coefficient.

[0032] Furthermore, the analysis unit controls the substation based on the voltage of each node, including:

[0033] For a single high-voltage transmission line, the analysis unit draws a distance-node voltage curve for the single high-voltage transmission line based on each node voltage;

[0034] Fitting the distance-node voltage curve corresponding to each high-voltage transmission line and obtaining the fitted voltage curve;

[0035] The analysis unit calculates the integral value of the fitted voltage curve;

[0036] If the integral value is less than or equal to the first preset integral value, adjusting the voltage amplification factor of the substation to a corresponding value based on the integral value;

[0037] If the integral value is less than or equal to the second preset integral value and greater than the first preset integral value, determining whether to control the alarm unit to operate based on the slope curve of the fitted voltage curve;

[0038] If the integral value is greater than the second preset integral value, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

[0039] Further, the analysis unit adjusts the voltage amplification factor of the substation to a corresponding value based on the integral difference between the integral value and the first preset integral value, wherein:

[0040] If the integral difference is less than or equal to the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the first preset magnification adjustment coefficient;

[0041] If the integral difference is less than or equal to the second preset integral difference and greater than the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the second preset magnification adjustment coefficient;

[0042] If the integral difference is greater than the second preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the third preset magnification adjustment coefficient.

[0043] Furthermore, the analysis unit determines whether to control the alarm unit to operate based on the slope deviation between the starting point bit value and the ending point bit value in the slope curve of the fitted voltage curve, including:

[0044] If the slope deviation is greater than a preset slope deviation, controlling the alarm unit to issue an abnormal alarm message for the high-voltage transmission line;

[0045] If the slope deviation is less than or equal to the preset slope deviation, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

[0046] Further, the analysis unit adjusts the transmission weight coefficient to a corresponding value based on the average voltage value of the fitted voltage curve, including:

[0047] If the average voltage value is less than or equal to the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the first preset evaluation adjustment coefficient;

[0048] If the average voltage value is less than or equal to the second preset average voltage value and greater than the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the second preset evaluation adjustment coefficient;

[0049] If the average voltage value is greater than the second preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using a third preset evaluation adjustment coefficient.

[0050] Compared with the prior art, the beneficial effects of the present invention are that the power grid is monitored during its operation, a transmission evaluation value is calculated based on data collected by a collection unit to evaluate the overall operation of the operation unit, and whether the operation of the operation unit is normal is determined based on the obtained transmission evaluation value. When the transmission evaluation value is less than or equal to a first preset transmission evaluation value, corresponding measures are determined in this case if the operation of the operation unit is abnormal. When the transmission evaluation value is less than or equal to a second preset transmission evaluation value and greater than the first preset transmission evaluation value, the operation of the operation unit is comprehensively determined in combination with the total power consumption of each user, the operation of the power grid is accurately monitored in real time, and whether there is any abnormality in the operation of the power grid is determined, thereby effectively improving the monitoring efficiency of the power grid.

[0051] Furthermore, the specific voltage of the high-voltage electricity transmitted to the distribution station is determined by the specific conditions of each transmission voltage, and its ratio to the historical average transmission voltage is determined to determine whether there is a voltage mutation, so as to take timely response measures to the emergency; the power loss is determined by the ratio of the total power consumption to the total output power of the substation; the voltage loss is determined to characterize the voltage loss of high-voltage electricity during the transmission process. Excessive voltage loss will cause the transmitted voltage to be too low, resulting in increased current. According to the power loss formula P=I²R, where P is power loss, I is current, and R is resistance, an increase in current will lead to increased energy loss, that is, increased line loss; at the same time, excessive current will cause overheating of the high-voltage transmission line, increasing safety hazards such as fire; the transmission evaluation value is calculated to characterize the operation status of the operating unit, provide data support for the subsequent determination of whether the operation of the operating unit is normal, and characterize the operation status of the operating unit through a small amount of calculation, effectively reducing the amount of data processing, thereby improving the monitoring efficiency of the power grid.

[0052] Furthermore, the operating status of the operating unit is determined comprehensively in combination with the transmission evaluation value and the total power consumption of each user. When the total power consumption is greater than the preset total power consumption, in this case, the power consumption increases due to seasonal and other reasons. In the actual operation of the operating unit, during peak power consumption, due to increased power demand, the voltage loss and power loss on the high-voltage transmission line will increase. This is unavoidable in actual operation and does not mean that the operating unit is abnormal. In this case, the first preset transmission evaluation value and the second preset transmission evaluation value are adjusted down to make the evaluation standard applicable to various operating conditions of the operating unit, thereby improving the accuracy of determining whether the operation of the operating unit is normal, and further improving the monitoring efficiency of the power grid.

[0053] Furthermore, when determining that the operation of the operating unit is abnormal, the substation is controlled based on the voltage of each node, and the change of the node voltage with the change of the transmission distance is determined. When the integral value is less than or equal to the first preset integral value, the node voltage decreases too fast. In this case, the longer the transmission distance, the greater the resistance loss and inductance loss, and the greater the power loss. In order to ensure the transmission efficiency, the voltage amplification factor of the substation is increased, and the transmission voltage is increased to reduce the current, thereby reducing the resistance loss; when the integral difference is less than or equal to the second preset integral difference and greater than the first preset integral difference, the slope change speed of the fitted voltage curve is determined. When the slope deviation is greater than the preset slope deviation, the slope decreases too fast. In this case, power transmission loss occurs, and a notification of unqualified transmission loss rate is issued, and the alarm unit is controlled to issue abnormal alarm information for the high-voltage transmission line; when the slope deviation is less than or equal to the preset slope deviation In this case, the slope remains flat or decreases slowly, and the operating unit operates normally, but the calculation formula for the transmission evaluation value of the power grid is selected abnormally. The transmission weight coefficient is increased to reduce the power weight coefficient and the loss weight coefficient. In this case, since the transmission distance is too long, the resistance loss and inductance loss caused by the transmission distance are also greater. The transmission evaluation value is adjusted, and the corresponding evaluation formula is determined according to the actual power grid situation, which improves the accuracy of the judgment on the operating unit. At the same time, when the integral value is greater than the second preset integral value, the node voltage decreases slowly, and the operating unit operates normally. It is also because the calculation formula for the transmission evaluation value of the power grid is selected abnormally, which leads to a deviation in the judgment. The judgment unit adjusts the evaluation formula in a targeted manner; when it is determined that there is an abnormality, corresponding countermeasures are taken to improve the safety of power grid operation, thereby improving the monitoring efficiency of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a module block diagram of a city power grid risk monitoring system according to an embodiment of the present invention;

[0055] Figure 2The present invention is a flowchart of determining whether the operation of an operating unit is normal based on a power transmission evaluation value according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0057] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0058] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0059] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] See also Figure 1 as well as Figure 2 As shown, they are respectively a module block diagram of a city power grid risk monitoring system according to an embodiment of the present invention, and a flow chart for determining whether the operation of an operation unit is normal based on a transmission evaluation value; a city power grid risk monitoring system according to an embodiment of the present invention comprises:

[0061] An operating unit, which includes a power plant for generating electric energy, a substation for converting low-voltage electric energy generated by the power plant into high-voltage electric energy, a plurality of high-voltage transmission lines for transmitting electric energy, a plurality of distribution stations for reducing the voltage of high-voltage electricity, and a user end connected to the distribution station;

[0062] A collection unit, which includes a plurality of path voltage monitors uniformly arranged on the high-voltage transmission line for obtaining node voltages, a plurality of transmission voltage monitors arranged at the input end of each distribution station for obtaining transmission voltages, a first electric energy meter respectively arranged at the output end of the substation for obtaining total output power, and a plurality of port electric energy meters arranged at each user end for respectively obtaining user power consumption at each user end;

[0063] A transmission unit, connected to the acquisition unit, for transmitting the data acquired by the acquisition unit;

[0064] A processing unit connected to the transmission unit for preprocessing the data transmitted by the transmission unit, including classifying and recording each data and archiving it according to the collection time;

[0065] an analysis unit connected to the processing unit, for calculating a power transmission evaluation value based on the acquired pre-processed information, determining whether the operation of the operation unit is normal based on the power transmission evaluation value, and controlling the substation based on the voltage of each node;

[0066] An alarm unit is connected to the analysis unit and is used to issue corresponding alarm information based on the determination result of the analysis unit.

[0067] The power grid is monitored during its operation, a transmission evaluation value is calculated based on data collected by a collection unit to evaluate the overall operation of the operation unit, and whether the operation of the operation unit is normal is determined based on the obtained transmission evaluation value. When the transmission evaluation value is less than or equal to a first preset transmission evaluation value, corresponding measures are determined in this case if the operation of the operation unit is abnormal. When the transmission evaluation value is less than or equal to a second preset transmission evaluation value and greater than the first preset transmission evaluation value, the operation of the operation unit is comprehensively determined based on the total power consumption of each user. The operation of the power grid is accurately monitored in real time, and it is determined whether the operation of the power grid is abnormal, thereby effectively improving the monitoring efficiency of the power grid.

[0068] Specifically, the analysis unit calculates the power transmission evaluation value by formula (1) at intervals of a predetermined time length.

[0069]

[0070] In the formula, S is the transmission evaluation value, U is the average transmission voltage, Wt is the total power consumption, D is the voltage loss, U0 is the mean of the historical average transmission voltage, Wi is the total output power of the substation, D0 is the average of the historical voltage losses, α is the transmission weight coefficient, β is the power weight coefficient, and γ is the loss weight coefficient;

[0071] The average transmission voltage is the average value of each transmission voltage;

[0072] The total power consumption is the sum of the power consumption of each user;

[0073] The analysis unit is used to determine the voltage loss based on each of the path voltage monitors, including:

[0074] For a single high-voltage transmission line, calculate the voltage difference between its starting point voltage and its end point voltage;

[0075] Solve the ratio of the voltage difference to the total length of a single high-voltage transmission line to obtain the branch voltage loss;

[0076] The average value of the branch voltage loss of each high-voltage transmission line is calculated to obtain the voltage loss.

[0077] Specifically, β:γ=1:1, and α+β+γ=1.

[0078] Specifically, α is 0.4, β is 0.3, and γ is 0.3.

[0079] It can be understood that the data used in formula (1), the sum of the power consumption of each user, and the total output power of the substation are all accumulated power within a predetermined time period.

[0080] The specific voltage of the high-voltage electricity transmitted to the distribution station is determined by the specific conditions of each transmission voltage, and its ratio to the historical average transmission voltage is determined to determine whether there is a voltage mutation, so as to take timely response measures to emergencies; the power loss is determined by the ratio of total power consumption to the total output power of the substation; the voltage loss is determined to characterize the voltage loss of high-voltage electricity during transmission. Excessive voltage loss will cause the transmitted voltage to be too low, resulting in increased current. According to the power loss formula P=I²R, where P is power loss, I is current, and R is resistance, increased current will lead to increased energy loss, that is, increased line loss; at the same time, excessive current will cause overheating of high-voltage transmission lines, increasing safety hazards such as fire; the transmission evaluation value is calculated to characterize the operating status of the operating unit, provide data support for the subsequent determination of whether the operation of the operating unit is normal, and characterize the operating status of the operating unit through a small amount of calculation, effectively reducing the amount of data processing, thereby improving the monitoring efficiency of the power grid.

[0081] Specifically, the analyzing unit determines whether the operation of the operating unit is normal based on the power transmission evaluation value, including:

[0082] If the power transmission evaluation value is less than or equal to the first preset power transmission evaluation value, controlling the substation based on the voltage of each node;

[0083] If the power transmission evaluation value is less than or equal to the second preset power transmission evaluation value and greater than the first preset power transmission evaluation value, determining whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption;

[0084] If the power transmission evaluation value is greater than the second preset power transmission evaluation value, it is determined that the operation of the operation unit is normal.

[0085] Specifically, the first preset power transmission evaluation value is 0.98, and the second preset power transmission evaluation value is 1.23.

[0086] Specifically, the analyzing unit determines whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption, including:

[0087] If the total power consumption is less than or equal to the preset total power consumption, the substation is controlled based on the voltage of each node;

[0088] If the total power consumption is greater than the preset total power consumption, the first preset power transmission evaluation value and the second preset power transmission evaluation value are re-determined based on the total power consumption.

[0089] Specifically, the preset total power consumption E0 is selected within the interval [1.7Q0, 2.1Q0], and Q0 is the average of the historical total power consumption.

[0090] Specifically, it can be understood that the monitoring data in the historical records for determining whether the operation of the operating unit is normal each time can be selected as the reference historical data, and there is no limit on the number of selected historical records. Those skilled in the art can understand that each user can be divided according to whether they are in the peak electricity consumption period, and no further details will be given.

[0091] The operation status of the operating unit is determined comprehensively by combining the transmission evaluation value and the total power consumption of each user. When the total power consumption is greater than the preset total power consumption, the power consumption increases due to seasonal and other reasons. In the actual operation of the operating unit, during peak power consumption, due to increased power demand, the voltage loss and power loss on the high-voltage transmission line will increase. This is unavoidable in actual operation and does not mean that the operating unit is abnormal. In this case, the first preset transmission evaluation value and the second preset transmission evaluation value are adjusted down to make the evaluation standard applicable to various operating conditions of the operating unit, thereby improving the accuracy of determining whether the operation of the operating unit is normal and further improving the monitoring efficiency of the power grid.

[0092] Specifically, the analysis unit re-determines the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the power consumption difference between the total power consumption and the preset total power consumption, including:

[0093] If the power consumption difference is less than or equal to the first preset power consumption difference, adjusting the first preset power transmission evaluation value and the second preset power transmission evaluation value to corresponding values ​​using the first preset reference correction coefficient;

[0094] If the power consumption difference is less than or equal to the second preset power consumption difference and greater than the first preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the second preset reference correction coefficient;

[0095] If the power consumption difference is greater than the second preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the third preset reference correction coefficient.

[0096] Specifically, the first preset power difference is 1.2E0, the second preset power difference is 2.4E0, the first preset reference correction coefficient is 0.93, the second preset reference correction coefficient is 0.82, and the third preset reference correction coefficient is 0.77.

[0097] Specifically, the analysis unit controls the substation based on the voltage of each node, including:

[0098] For a single high-voltage transmission line, the analysis unit draws a distance-node voltage curve for the single high-voltage transmission line based on each node voltage;

[0099] Fitting the distance-node voltage curve corresponding to each high-voltage transmission line and obtaining the fitted voltage curve;

[0100] The analysis unit calculates the integral value of the fitted voltage curve;

[0101] If the integral value is less than or equal to the first preset integral value, adjusting the voltage amplification factor of the substation to a corresponding value based on the integral value;

[0102] If the integral value is less than or equal to the second preset integral value and greater than the first preset integral value, determining whether to control the alarm unit to operate based on the slope curve of the fitted voltage curve;

[0103] If the integral value is greater than the second preset integral value, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

[0104] Specifically, the first preset integral value F1 is selected within the interval [0.8F0, 0.85F0], the second preset integral value F2 is selected within the interval [2.8F0, 3F0], and F0 is the average value of the integrals corresponding to several corresponding monitoring data in the selected historical data that are judged to be operating normally for the operating unit.

[0105] Specifically, it can be understood that the process of obtaining the slope curve of the fitted voltage curve can be to randomly select several reference points in the fitted voltage curve, solve the slope corresponding to each reference point, and draw the slope curve based on each slope, which will not be repeated here.

[0106] Specifically, it can be understood that for the fitting of each distance-node voltage curve, a number of X nodes can be uniformly selected, and for a single X node, the average value of the node voltage corresponding to the X node on each distance-node voltage curve is solved, and the solved average value is determined as the Y value of the fitting voltage curve at the corresponding X node, which will not be repeated.

[0107] When determining that the operation of the operating unit is abnormal, the substation is controlled based on the voltage of each node, and the change of the node voltage with the change of the transmission distance is determined. When the integral value is less than or equal to the first preset integral value, the node voltage decreases too fast. In this case, the longer the transmission distance, the greater the resistance loss and inductance loss, and the greater the power loss. In order to ensure the transmission efficiency, the voltage amplification factor of the substation is increased, and the transmission voltage is increased to reduce the current, thereby reducing the resistance loss; when the integral difference is less than or equal to the second preset integral difference and greater than the first preset integral difference, the slope change speed of the fitted voltage curve is determined. When the slope deviation is greater than the preset slope deviation, the slope decreases too fast. In this case, power transmission is lost, and a notification of unqualified transmission loss rate is issued, and the alarm unit is controlled to issue abnormal alarm information for the high-voltage transmission line; when the slope deviation is less than or equal to the preset slope deviation, In this case, the slope remains flat or decreases slowly, and the operating unit operates normally, but the calculation formula for the transmission evaluation value of the power grid is abnormally selected. The transmission weight coefficient is increased to lower the electricity weight coefficient and the loss weight coefficient. In this case, since the transmission distance is too long, the resistance loss and inductance loss caused by the transmission distance are also greater. The transmission evaluation value is adjusted, and the corresponding evaluation formula is determined according to the actual power grid situation, which improves the accuracy of the judgment on the operating unit. At the same time, when the integral value is greater than the second preset integral value, the node voltage decreases slowly, and the operating unit operates normally. It is also because the calculation formula for the transmission evaluation value of the power grid is abnormally selected, which leads to deviations in the judgment. The judgment unit adjusts the evaluation formula in a targeted manner; when it is determined that there is an abnormality, corresponding countermeasures are taken to improve the safety of power grid operation, thereby improving the monitoring efficiency of the power grid.

[0108] Specifically, the analysis unit adjusts the voltage amplification factor of the substation to a corresponding value based on the integral difference between the integral value and the first preset integral value, wherein:

[0109] If the integral difference is less than or equal to the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the first preset magnification adjustment coefficient;

[0110] If the integral difference is less than or equal to the second preset integral difference and greater than the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the second preset magnification adjustment coefficient;

[0111] If the integral difference is greater than the second preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the third preset magnification adjustment coefficient.

[0112] Specifically, the first preset integral difference is 0.2F1, the second preset integral difference is 0.5F1, the first preset magnification adjustment coefficient is 1.11, the second preset magnification adjustment coefficient is 1.21, and the third preset magnification adjustment coefficient is 1.31.

[0113] Specifically, the analysis unit determines whether to control the alarm unit to operate based on the slope deviation between the starting point bit value and the ending point bit value in the slope curve of the fitted voltage curve, including:

[0114] If the slope deviation is greater than a preset slope deviation, controlling the alarm unit to issue an abnormal alarm message for the high-voltage transmission line;

[0115] If the slope deviation is less than or equal to the preset slope deviation, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

[0116] Specifically, the preset slope deviation A0 is selected within the interval [1.2V0, 1.25V0], and V0 is the average value of each slope deviation corresponding to the corresponding monitoring data of each operating unit determined to be operating normally in the historical data.

[0117] Specifically, the analysis unit adjusts the transmission weight coefficient to a corresponding value based on the average voltage value of the fitted voltage curve, including:

[0118] If the average voltage value is less than or equal to the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the first preset evaluation adjustment coefficient;

[0119] If the average voltage value is less than or equal to the second preset average voltage value and greater than the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the second preset evaluation adjustment coefficient;

[0120] If the average voltage value is greater than the second preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using a third preset evaluation adjustment coefficient.

[0121] Specifically, the first preset average voltage value is 472 kV, the second preset average voltage value is 485 kV, the first preset evaluation adjustment coefficient is 1.3, the second preset evaluation adjustment coefficient is 1.2, and the third preset evaluation adjustment coefficient is 1.1.

[0122] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0123] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A city power grid risk monitoring system, characterized in that: include: An operating unit, which includes a power plant for generating electric energy, a substation for converting low-voltage electric energy generated by the power plant into high-voltage electric energy, a plurality of high-voltage transmission lines for transmitting electric energy, a plurality of distribution stations for reducing the voltage of high-voltage electricity, and a user end connected to the distribution station; A collection unit, which includes a plurality of path voltage monitors uniformly arranged on the high-voltage transmission line for obtaining node voltages, a plurality of transmission voltage monitors arranged at the input end of each distribution station for obtaining transmission voltages, a first electric energy meter respectively arranged at the output end of the substation for obtaining total output power, and a plurality of port electric energy meters arranged at each user end for respectively obtaining user power consumption at each user end; A transmission unit, connected to the acquisition unit, for transmitting the data acquired by the acquisition unit; A processing unit connected to the transmission unit for preprocessing the data transmitted by the transmission unit, including classifying and recording each data and archiving it according to the collection time; an analysis unit connected to the processing unit, for calculating a power transmission evaluation value based on the acquired pre-processed information, determining whether the operation of the operation unit is normal based on the power transmission evaluation value, and controlling the substation based on the voltage of each node; an alarm unit connected to the analysis unit and configured to issue corresponding alarm information based on the determination result of the analysis unit; The analysis unit calculates the power transmission evaluation value by formula (1) at intervals of a predetermined time length. In the formula, S is the transmission evaluation value, U is the average transmission voltage, Wt is the total power consumption, D is the voltage loss, U0 is the mean of the historical average transmission voltage, Wi is the total output power of the substation, D0 is the average of the historical voltage losses, α is the transmission weight coefficient, β is the power weight coefficient, and γ is the loss weight coefficient; The average transmission voltage is the average value of each transmission voltage; The total power consumption is the sum of the power consumption of each user; The analysis unit is used to determine the voltage loss based on each of the path voltage monitors, including: For a single high-voltage transmission line, calculate the voltage difference between its starting point voltage and its end point voltage; Solve the ratio of the voltage difference to the total length of a single high-voltage transmission line to obtain the branch voltage loss; Calculate the average value of branch voltage loss of each high-voltage transmission line to obtain voltage loss; The analyzing unit determines whether the operation of the operating unit is normal based on the power transmission evaluation value, including: If the power transmission evaluation value is less than or equal to the first preset power transmission evaluation value, controlling the substation based on the voltage of each node; If the power transmission evaluation value is less than or equal to the second preset power transmission evaluation value and greater than the first preset power transmission evaluation value, determining whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption; If the power transmission evaluation value is greater than the second preset power transmission evaluation value, it is determined that the operation of the operation unit is normal; The analysis unit controls the substation based on the voltage of each node, including: For a single high-voltage transmission line, the analysis unit draws a distance-node voltage curve for the single high-voltage transmission line based on each node voltage; Fitting the distance-node voltage curve corresponding to each high-voltage transmission line and obtaining the fitted voltage curve; The analysis unit calculates the integral value of the fitted voltage curve; If the integral value is less than or equal to the first preset integral value, adjusting the voltage amplification factor of the substation to a corresponding value based on the integral value; If the integral value is less than or equal to the second preset integral value and greater than the first preset integral value, determining whether to control the alarm unit to operate based on the slope curve of the fitted voltage curve; If the integral value is greater than the second preset integral value, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

2. The urban power grid risk monitoring system according to claim 1 is characterized in that: The analyzing unit determines whether to redetermine the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the total power consumption, include, If the total power consumption is less than or equal to the preset total power consumption, the substation is controlled based on the voltage of each node; If the total power consumption is greater than the preset total power consumption, the first preset power transmission evaluation value and the second preset power transmission evaluation value are re-determined based on the total power consumption.

3. The urban power grid risk monitoring system according to claim 2 is characterized in that: The analyzing unit re-determines the first preset power transmission evaluation value and the second preset power transmission evaluation value based on the power consumption difference between the total power consumption and the preset total power consumption, including: If the power consumption difference is less than or equal to the first preset power consumption difference, adjusting the first preset power transmission evaluation value and the second preset power transmission evaluation value to corresponding values ​​using the first preset reference correction coefficient; If the power consumption difference is less than or equal to the second preset power consumption difference and greater than the first preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the second preset reference correction coefficient; If the power consumption difference is greater than the second preset power consumption difference, the first preset power transmission evaluation value and the second preset power transmission evaluation value are adjusted to corresponding values ​​using the third preset reference correction coefficient.

4. The urban power grid risk monitoring system according to claim 3 is characterized in that: The analysis unit adjusts the voltage amplification factor of the substation to a corresponding value based on the integral difference between the integral value and the first preset integral value, wherein: If the integral difference is less than or equal to the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the first preset magnification adjustment coefficient; If the integral difference is less than or equal to the second preset integral difference and greater than the first preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the second preset magnification adjustment coefficient; If the integral difference is greater than the second preset integral difference, the voltage amplification factor of the substation is adjusted to a corresponding value using the third preset magnification adjustment coefficient.

5. The urban power grid risk monitoring system according to claim 4 is characterized in that: The analysis unit determines whether to control the alarm unit to operate based on the slope deviation between the starting point bit value and the ending point bit value in the slope curve of the fitted voltage curve, including: If the slope deviation is greater than a preset slope deviation, controlling the alarm unit to issue an abnormal alarm message for the high-voltage transmission line; If the slope deviation is less than or equal to the preset slope deviation, the transmission weight coefficient is adjusted to a corresponding value based on the average voltage value of the fitted voltage curve.

6. The urban power grid risk monitoring system according to claim 5, characterized in that: The analyzing unit adjusts the transmission weight coefficient to a corresponding value based on the average voltage value of the fitted voltage curve, including: If the average voltage value is less than or equal to the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the first preset evaluation adjustment coefficient; If the average voltage value is less than or equal to the second preset average voltage value and greater than the first preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using the second preset evaluation adjustment coefficient; If the average voltage value is greater than the second preset average voltage value, the transmission weight coefficient is adjusted to a corresponding value using a third preset evaluation adjustment coefficient.

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