A distribution network monitoring system based on 5G communication

Abstract

The present invention relates to the field of power grid monitoring technology, and in particular to a distribution network monitoring system based on 5G communication, including a distribution network data acquisition module for collecting distribution line data; a charging station data acquisition module for collecting charging station power; a stability analysis module for analyzing the state of the distribution line voltage and adjusting the analysis process; a three-phase analysis module for analyzing the three-phase unbalance index of the distribution line; a harmonic monitoring module for constructing a harmonic pollution coefficient; a charging station monitoring module for constructing a charging station impact factor and determining the operating state of the charging station; an alarm module for alarming a user according to the distribution network voltage state, the three-phase voltage unbalance index, the harmonic pollution coefficient and the operating state of the charging station within the monitoring period, and optimizing the analysis process of the distribution network operating state. The present invention improves the monitoring efficiency of the distribution network.

Description

Technical Field

[0001] The present invention relates to the field of power grid monitoring technology, and in particular to a distribution network monitoring system based on 5G communication. Background Art

[0002] With the rapid development of smart grid technology, the monitoring methods of distribution networks are gradually developing towards automation and intelligence. Some advanced monitoring systems can achieve real-time monitoring and fault diagnosis of distribution networks by introducing smart sensors, data acquisition and analysis technologies. However, existing technologies still have shortcomings in data processing, fault location, remote monitoring, etc., such as data transmission delays, low system integration, and long fault response time, which affects the operating efficiency and safety of distribution networks.

[0003] Chinese patent publication number CN101800440A discloses a distribution network status monitoring system, including: a bureau distribution network equipment data center, a station distribution network equipment data center, an infrared point temperature monitoring unit, a switch electrical parameter monitoring unit, an environmental temperature and humidity monitoring unit, an infrared thermal imager and a distribution network status monitoring software platform. The bureau distribution network equipment data center is connected to the station distribution network equipment data center through optical fiber, wireless or carrier communication, and the station distribution network equipment data center is connected to the infrared point temperature monitoring unit, the switch electrical parameter monitoring unit, and the environmental temperature monitoring unit through RS485. The station distribution network equipment data center is also connected to the infrared thermal imager through optical fiber, and the matching distribution network status monitoring software platform is installed on the host of the bureau distribution network equipment data center and the station distribution network equipment data center. This diversified measurement data information covers all the status parameters of the distribution network electrical equipment, ensuring that the equipment objects are provided with complete and comprehensive monitoring; it can be seen that when the scheme monitors the distribution network status, it only analyzes the parameters of the distribution network itself, and does not analyze the status of the power supply area, and there are problems of low efficiency and low safety in the distribution network monitoring. Summary of the invention

[0004] The object of the present invention is to provide a distribution network monitoring system based on 5G communication to solve at least one of the problems existing in the prior art.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] Distribution network data acquisition module, used to collect distribution line data;

[0007] Charging station data acquisition module, used to collect charging station power;

[0008] A stability analysis module, used to analyze the state of the distribution line voltage according to the distribution line voltage collected during the monitoring period, and to adjust the analysis process according to the distribution line voltage and distribution line current collected during the monitoring period;

[0009] A three-phase analysis module is used to analyze the three-phase imbalance index of the distribution line according to the three-phase voltage of the distribution line collected during the monitoring period;

[0010] The harmonic monitoring module is used to construct the harmonic pollution coefficient according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period;

[0011] The charging station monitoring module is used to determine the operating status of the charging station based on the collected charging station power and distribution transformer capacity;

[0012] The alarm module is used to analyze the operating status of the distribution network according to the distribution network voltage status, three-phase voltage imbalance index, harmonic pollution coefficient and the operating status of the charging station during the monitoring period, and to alarm the user. It is also used to optimize the analysis process of the distribution network operating status according to the active power and reactive power of the distribution lines collected during the monitoring period.

[0013] Furthermore, the stability analysis module is provided with a stability analysis unit, a volatility analysis unit and a utilization analysis unit. The stability analysis unit is based on the average voltage v of the distribution line collected during the monitoring period. 均 The stability coefficient W of the distribution network line is constructed with the rated voltage v0; the stability analysis unit evaluates the relationship between the stability coefficient and the preset stability threshold w0. If the stability coefficient W does not exceed the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in a normal and stable state; if W exceeds the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in an unstable state.

[0014] Furthermore, the volatility analysis unit analyzes the volatility of the distribution line voltage within the monitoring period and sets the fluctuation coefficient to E. The volatility analysis unit evaluates the relationship between the fluctuation coefficient E and the preset fluctuation threshold E0 to adjust the analysis process of the distribution network voltage stability state. If E does not exceed E0, the volatility analysis unit determines that the distribution network voltage stability in the current monitoring period is normal and no adjustment is made; conversely, if E exceeds E0, the volatility analysis unit determines that the distribution network voltage stability in the current monitoring period is abnormal, and adjusts the analysis process to adjust the preset stability threshold to w0'.

[0015] Furthermore, the utilization analysis unit constructs a utilization index L of the distribution line capacity according to the distribution line current a1 and the distribution line rated current a0 collected during the monitoring period, and the calculation formula is L=a1 / a0;

[0016] The utilization analysis unit evaluates the relationship between the utilization index and the preset utilization threshold L0 to optimize the adjustment process of the distribution network voltage stability state analysis. If L does not exceed L0, the utilization analysis unit determines that the utilization of the distribution network capacity in the current monitoring period is normal and no optimization is performed; conversely, if L exceeds L0, the utilization analysis unit determines that the utilization of the distribution network capacity in the current monitoring period is abnormal, and optimizes the adjustment process, optimizing the preset fluctuation threshold to E0'.

[0017] Furthermore, the three-phase analysis module sorts the three-phase voltages collected during the monitoring period, and constructs an imbalance index UB of the three-phase voltage according to the sorting result. The calculation formula is: UB=(Vmax-Vmin) / Vavg, wherein Vmax is the maximum value of the three-phase voltage, Vmin is the minimum value of the three-phase voltage, and Vavg is the average value of the three-phase voltage.

[0018] Furthermore, the harmonic monitoring module constructs a harmonic pollution coefficient XR according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period, and sets:

[0019] ;

[0020] Among them, R3 is the effective value of the 3rd harmonic voltage of the distribution line, R5 is the effective value of the 5th harmonic voltage of the distribution line, R7 is the effective value of the 7th harmonic voltage of the distribution line, and R1 is the effective value of the fundamental voltage collected during the monitoring period.

[0021] Furthermore, the charging station monitoring unit is provided with a construction unit and a state judgment unit, and the construction unit constructs a charging station impact factor CY according to the charging station power p0 and the distribution transformer capacity P collected during the monitoring period, and sets CY=p0 / P.

[0022] Furthermore, the state judgment unit compares the charging station impact factor CY with the preset impact factor threshold C0 to judge the abnormality of the operating state of the charging station. If the charging station impact factor CY does not exceed the preset impact factor threshold C0, the state judgment unit judges that the operating state of the charging station is normal. If the charging station impact factor CY exceeds the preset impact factor C0, the state judgment unit judges that the operating state of the charging station is abnormal.

[0023] Furthermore, the alarm module is provided with an alarm unit and a power factor analysis unit, and the alarm unit analyzes the operation status of the distribution network according to the voltage status of the distribution network, the three-phase voltage imbalance index, the harmonic pollution coefficient and the operation status of the charging station within the monitoring period, wherein:

[0024] When the charging station operates normally and the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0025] When the charging station operates normally but the voltage of the distribution network is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0026] When the charging station operates abnormally but the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, it is determined that the distribution network is operating normally and no alarm is issued; if it exceeds the correction threshold, it is determined that the distribution network is operating abnormally and an alarm is issued to the user.

[0027] When the charging station operates abnormally and the distribution network voltage is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, the distribution network is judged to be operating normally and no alarm is issued; if it exceeds the correction threshold, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0028] Among them, u1 is the voltage stability weight, u2 is the imbalance weight, and u3 is the harmonic pollution weight.

[0029] Furthermore, the power factor analysis unit constructs a power factor Q according to the active power S1 and reactive power S2 of the distribution line collected during the monitoring period, and sets:

[0030] ;

[0031] The power factor analysis unit evaluates the relationship between the power factor Q and the preset energy utilization threshold Q0 to optimize the analysis process of the distribution network operation status. If Q does not exceed Q0, the power factor analysis unit determines that the energy utilization efficiency of the distribution network in the current monitoring period is normal and no optimization is performed. On the contrary, if Q exceeds Q0, the power factor analysis unit determines that the energy utilization efficiency of the distribution network in the current monitoring period is abnormal and optimizes the analysis process. The power factor analysis unit optimizes the reference threshold for judging the abnormal state to H'.

[0032] The beneficial effects of the present invention are as follows: the distribution network data acquisition module can provide high-precision basic data for subsequent analysis by collecting data from distribution lines in real time, which is of great significance for ensuring the safe operation of the distribution network and timely responding to faults, and improves the intelligence and automation level of the distribution network. The stability analysis module can timely identify the voltage stability of the distribution network, timely discover voltage anomalies, ensure the stability and safety of the distribution system, and reduce the risk of power outages. The three-phase analysis module can timely discover the imbalance in the operation of the distribution network by analyzing the imbalance of the three-phase voltage, so as to improve the operating efficiency of the distribution network and reduce equipment losses. The harmonic monitoring module can evaluate the power quality of the distribution network by detecting the harmonic pollution coefficient, promptly discover and reduce the damage of harmonics to equipment, ensure the reliability of the distribution network and the safe operation of equipment, and help improve the durability of power facilities. The charging station monitoring module can promptly determine the impact of the charging station on the distribution network by monitoring the operating status of the charging station, and ensure the safe operation of the power grid. The alarm module can analyze the operating status of the distribution network in real time and send an alarm to the user in time according to the set threshold, ensuring that it can be notified and measures can be taken in the first time when an abnormality occurs, thereby reducing the risk of loss due to power grid failure and ultimately improving the monitoring efficiency of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a schematic diagram of the structure of the distribution network monitoring system based on 5G communication in this embodiment.

[0035] Figure 2 Schematic diagram of the structure of the stability analysis module of this embodiment.

[0036] Figure 3 Schematic diagram of the structure of the charging station monitoring module of this embodiment.

[0037] Figure 4 Schematic diagram of the structure of the alarm module in this embodiment. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0039] It should be noted that, although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0040] See also Figure 1 As shown, it is a schematic diagram of the structure of the distribution network monitoring system based on 5G communication in this embodiment, and the system includes:

[0041] The distribution network data acquisition module is used to collect distribution line data, wherein the distribution line data includes distribution line voltage, distribution line rated voltage, distribution line harmonic voltage effective value, distribution line three-phase voltage, distribution transformer capacity, distribution line current, distribution line rated current, distribution line active power and distribution line reactive power; the distribution line harmonic voltage effective value includes the 3rd harmonic voltage effective value of the distribution line, the 5th harmonic voltage effective value of the distribution line and the 7th harmonic voltage effective value of the distribution line, the 3rd harmonic voltage effective value of the distribution line is the effective value of the voltage component with a frequency of 3 times the fundamental frequency in the distribution line, the 5th harmonic voltage effective value of the distribution line is the effective value of the voltage component with a frequency of 5 times the fundamental frequency in the distribution line, and the 7th harmonic voltage effective value of the distribution line is the effective value of the voltage component with a frequency of 7 times the fundamental frequency in the distribution line. The three-phase voltage of the distribution line refers to the three-phase voltage transmitted through the distribution line in the three-phase AC system, expressed as three phase voltages with a phase difference of 120 degrees between them. The capacity of the distribution transformer is the maximum load power that the transformer can safely carry. In this embodiment, no specific limitation is made on the collection method of the distribution line data. Those skilled in the art can freely set it as long as the collection requirements of the distribution line data are met. Among them, the distribution line voltage, the effective value of the distribution line harmonic voltage, the three-phase voltage of the distribution line, the current of the distribution line, the active power of the distribution line and the reactive power of the distribution line can be obtained through the power quality analyzer. The rated voltage of the distribution line, the capacity of the distribution transformer and the rated current of the distribution line can be obtained through interaction.

[0042] The charging station data acquisition module is used to collect the power of the charging station. In this embodiment, the charging station power acquisition method is not specifically limited, and those skilled in the art can freely set it as long as the charging station power acquisition requirements are met. The charging station power can be collected through a smart meter.

[0043] A stability analysis module is used to analyze the state of the distribution line voltage according to the distribution line voltage collected during the monitoring period, and adjust the analysis process according to the distribution line voltage and the distribution line current collected during the monitoring period; the stability analysis module is connected to the distribution network data acquisition module and the charging station data acquisition module; in this embodiment, the setting of the monitoring period is not specifically limited, and those skilled in the art can freely set it, as long as the setting requirements of the monitoring period are met, wherein the monitoring period can be set to 5 seconds, 10 seconds, etc.;

[0044] A three-phase analysis module, used to analyze the three-phase imbalance index of the distribution line according to the three-phase voltage of the distribution line collected during the monitoring period, and the three-phase analysis module is connected to the stability analysis module;

[0045] A harmonic monitoring module, used to construct a harmonic pollution coefficient according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period, and the harmonic monitoring module is connected to the three-phase analysis module;

[0046] A charging station monitoring module, used to determine the operating status of the charging station according to the collected charging station power and distribution transformer capacity, the charging station monitoring module being connected to the harmonic monitoring module;

[0047] The alarm module is used to analyze the operating status of the distribution network according to the distribution network voltage status, three-phase voltage imbalance index, harmonic pollution coefficient and the operating status of the charging station during the monitoring period, and is also used to optimize the analysis process of the distribution network operating status according to the active power and reactive power of the distribution lines collected during the monitoring period. The alarm module is connected to the charging station monitoring module.

[0048] See also Figure 2 As shown, it is a schematic diagram of the structure of the stability analysis module of this embodiment, including:

[0049] The stability analysis unit is used to construct the stability coefficient of the distribution network line according to the average voltage and rated voltage of the distribution line collected during the monitoring period, and analyze the state of the distribution line voltage;

[0050] A fluctuation analysis unit, used to analyze the fluctuation of the voltage according to the distribution line voltage within the monitoring period, and adjust the analysis process of the distribution network voltage stability state according to the analysis result, the fluctuation analysis unit is connected to the stability analysis unit;

[0051] The utilization analysis unit is used to analyze the utilization of the distribution line capacity according to the distribution line current and the rated current collected during the monitoring period, and the utilization analysis unit is connected to the volatility analysis unit.

[0052] See also Figure 3As shown, it is a schematic diagram of the structure of the charging station monitoring module of this embodiment, including:

[0053] A construction unit, used to construct a charging station impact factor according to the charging station power collected during a monitoring period;

[0054] The state judgment unit is used to judge the abnormality of the operating state of the charging station according to the charging station influencing factor, and the state judgment unit is connected to the construction unit.

[0055] See also Figure 4 As shown, it is a schematic diagram of the structure of the alarm module of this embodiment, including:

[0056] An alarm unit is used to analyze the operation status of the distribution network according to the voltage status of the distribution network, the three-phase voltage imbalance index, the harmonic pollution coefficient and the operation status of the charging station within the monitoring period;

[0057] The power factor analysis unit is used to optimize the analysis process of the distribution network operation status according to the active power and reactive power of the distribution lines collected during the monitoring period. The power factor analysis unit is connected to the alarm unit.

[0058] Specifically, the distribution network monitoring system based on 5G communication described in this embodiment is applied to the monitoring of the distribution network of electric vehicle charging stations. By comprehensively analyzing the voltage, power, load, harmonics and other data of the distribution lines, the stability coefficient, fluctuation coefficient and utilization index are constructed, combined with the influencing factors of the charging station, to ensure the safety and stability of the distribution network during operation.

[0059] Specifically, the stability analysis unit is based on the average distribution line voltage v collected during the monitoring period. 均 The stability coefficient W of the distribution network line constructed with the rated voltage v0 is calculated as W=|v 均 -v0| / v0, , where vi represents the distribution network line voltage data collected during the monitoring period, and I represents the total amount of data collected during the monitoring period;

[0060] The stability analysis unit evaluates the relationship between the stability coefficient and the preset stability threshold w0. If the stability coefficient W does not exceed the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in a normal stable state; if W exceeds the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in an unstable state.

[0061] Specifically, the "exceeding" described in this embodiment does not include the case of being equal to.

[0062] Specifically, the stability analysis unit can monitor the voltage stability of the distribution network in real time, and by calculating the stability coefficient W, promptly identify the abnormality of the distribution network voltage, ensure the normal and stable operation of the power grid, avoid equipment damage or power loss due to voltage instability, and ultimately improve the monitoring efficiency of the distribution network; this embodiment does not make specific limitations on the setting of the preset stability threshold, and technical personnel in this field can set it freely, as long as the value requirements of the preset stability threshold are met, where the optimal value of W is 0.06.

[0063] Specifically, the volatility analysis unit analyzes the volatility of the distribution line voltage within the monitoring period and sets the volatility coefficient to E, which is calculated as follows:

[0064] ,

[0065] The volatility analysis unit evaluates the relationship between the fluctuation coefficient E and the preset fluctuation threshold E0 to adjust the analysis process of the distribution network voltage stability state. If E does not exceed E0, the volatility analysis unit determines that the distribution network voltage stability in the current monitoring period is normal and does not make any adjustments. On the contrary, if E exceeds E0, the volatility analysis unit determines that the distribution network voltage stability in the current monitoring period is abnormal, and adjusts the analysis process, adjusts the preset stability threshold to w0', and sets the calculation formula of w0' to w0'=w0×cos{sin[(E-E0)×(π / 2)]}.

[0066] Specifically, the volatility analysis unit sets the fluctuation coefficient E by analyzing the voltage fluctuation, so as to adjust the preset stability threshold when the voltage fluctuation coefficient exceeds the fluctuation threshold, so as to adjust the analysis process of the voltage stability state of the distribution network, ensure the stability of power supply, reduce the adverse effects on electrical equipment, and ultimately improve the monitoring efficiency of the distribution network; this embodiment does not make specific limitations on the setting of the preset fluctuation threshold, and technical personnel in this field can set it freely, as long as the value requirements of the preset fluctuation threshold are met, among which the optimal value of E0 is 0.15.

[0067] Specifically, the utilization analysis unit constructs a utilization index L of the distribution line capacity according to the distribution line current a1 and the distribution line rated current a0 collected during the monitoring period, and the calculation formula is L=a1 / a0;

[0068] The utilization analysis unit optimizes the adjustment process of the distribution network voltage stability state analysis by evaluating the relationship between the utilization index and the preset utilization threshold L0. If L does not exceed L0, the utilization analysis unit determines that the utilization of the distribution network capacity in the current monitoring period is normal and there is no need to optimize the adjustment process. On the contrary, if L exceeds L0, it is determined that the utilization of the distribution network capacity in the current monitoring period is abnormal and the adjustment process needs to be optimized. In this case, the utilization analysis unit adjusts the preset fluctuation threshold to E0' and sets the calculation formula of E0' to:

[0069] E0'=E0×{1-lg{[sin(L-L0)+1] 0.5}}.

[0070] Specifically, the utilization analysis unit evaluates the load utilization of the distribution line and calculates the utilization index L to improve the overall operation efficiency of the power grid, thereby ultimately improving the monitoring efficiency of the distribution network. This embodiment does not specifically limit the setting of the preset utilization threshold, and those skilled in the art can freely set it as long as the value requirement of the preset utilization threshold is met. Among them, the optimal value of L0 is 0.8. The distribution line current collected during the monitoring period described in this embodiment is the average current collected during the monitoring period.

[0071] Specifically, the three-phase analysis module sorts the three-phase voltages collected during the monitoring period, and constructs the three-phase voltage imbalance index UB according to the sorting result. The calculation formula is: UB=(Vmax-Vmin) / Vavg, where Vmax is the maximum value of the three-phase voltage, Vmin is the minimum value of the three-phase voltage, and Vavg is the average value of the three-phase voltage.

[0072] Specifically, the three-phase analysis module analyzes the imbalance index of the three-phase voltage to improve the operating reliability of the distribution system, reduce the failure rate and maintenance cost of the equipment, and ultimately improve the monitoring efficiency of the distribution network. In this embodiment, the sorting method is not specifically limited, and technicians in this field can set it freely as long as the sorting requirements are met. Sorting can be performed by bubble sorting.

[0073] Specifically, the harmonic monitoring module constructs the harmonic pollution coefficient XR according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period, and sets:

[0074] ;

[0075] Among them, R3 is the effective value of the 3rd harmonic voltage of the distribution line, R5 is the effective value of the 5th harmonic voltage of the distribution line, R7 is the effective value of the 7th harmonic voltage of the distribution line, and R1 is the effective value of the fundamental voltage collected during the monitoring period.

[0076] Specifically, the harmonic monitoring module monitors the harmonic pollution in the distribution line to protect the normal operation of the electrical equipment, extend the service life of the equipment, and ultimately improve the monitoring efficiency of the distribution network; in this embodiment, there is no specific limitation on the method for obtaining the effective value of the fundamental voltage, and technical personnel in this field can set it freely, as long as the requirements for obtaining the effective value of the fundamental voltage are met, wherein the effective value of the fundamental voltage can be collected and obtained by a power quality analyzer.

[0077] Specifically, the construction unit constructs the charging station impact factor CY according to the charging station power p0 and the distribution transformer capacity P collected during the monitoring period, and sets CY=p0 / P.

[0078] Specifically, the status judgment unit evaluates the abnormality of the operating status of the charging station by comparing the charging station impact factor CY with the preset impact factor threshold C0. If the charging station impact factor CY does not exceed the preset impact factor threshold C0, the status judgment unit determines that the operating status of the charging station is normal. If the charging station impact factor CY exceeds the preset impact factor C0, the status judgment unit determines that the operating status of the charging station is abnormal.

[0079] Specifically, the charging station monitoring module ensures the normal operation of the charging station under different load conditions by evaluating the impact of the charging station on the distribution network, and maintains the harmonious development of the charging station and the distribution network by calculating the impact factor CY, thereby ultimately improving the monitoring efficiency of the distribution network; this embodiment does not specifically limit the setting of the impact factor threshold, and those skilled in the art can set it freely, as long as the value requirements of the impact factor threshold are met, wherein the optimal value of C0 is 0.8, and the charging station power p0 collected during the monitoring period described in this embodiment is the average value of the charging power.

[0080] Specifically, the alarm unit analyzes the operating status of the distribution network according to the voltage status of the distribution network, the three-phase voltage imbalance index, the harmonic pollution coefficient and the operating status of the charging station within the monitoring period, wherein:

[0081] When the charging station operates normally and the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0082] When the charging station operates normally but the voltage of the distribution network is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0083] When the charging station operates abnormally but the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, it is determined that the distribution network is operating normally and no alarm is issued; if it exceeds the correction threshold, it is determined that the distribution network is operating abnormally and an alarm is issued to the user.

[0084] When the charging station operates abnormally and the distribution network voltage is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, the distribution network is judged to be operating normally and no alarm is issued; if it exceeds the correction threshold, the distribution network is judged to be operating abnormally and an alarm is issued to the user.

[0085] Among them, u1 is the voltage stability weight, u2 is the imbalance weight, u3 is the harmonic pollution weight, H is the reference threshold for abnormal state judgment, and H×exp[-(CY-C0) / C0] is the corrected threshold.

[0086] Specifically, the alarm unit conducts a comprehensive status judgment by integrating various monitoring indicators, and promptly issues an alarm to the user, thereby ensuring the safe operation of the distribution network and the charging station, reducing the risk of accidents, and improving the system response capability, thereby ultimately improving the monitoring efficiency of the distribution network. This embodiment does not specifically limit the setting of the benchmark threshold for abnormal status judgment and each weight, and those skilled in the art can set them freely, as long as the benchmark threshold for abnormal status judgment and the value requirements of each weight are met. Among them, the optimal value of u1 is 0.4, the optimal value of u2 is 0.25, the optimal value of u3 is 0.35, and the optimal value of H is 0.15.

[0087] Specifically, the power factor analysis unit constructs a power factor Q according to the active power S1 and reactive power S2 of the distribution line collected during the monitoring period, and sets:

[0088] ;

[0089] The power factor analysis unit evaluates the relationship between the power factor Q and the preset energy utilization threshold Q0 to optimize the comprehensive analysis process of the distribution network operation status. If Q does not exceed Q0, the power factor analysis unit determines that the energy utilization efficiency of the distribution network in the current monitoring period is normal and there is no need to optimize the analysis process. On the contrary, if Q exceeds Q0, it is determined that the energy utilization efficiency of the distribution network in the current monitoring period is abnormal and the analysis process needs to be optimized. In this case, the power factor analysis unit sets the reference threshold for abnormal state judgment to H' and sets the calculation formula of H' to:

[0090] H'=H×{1-ln(Q-Q0+1)×cos[arctan(Q-Q0)]}.

[0091] Specifically, the power factor analysis unit monitors the active and reactive power of the distribution lines to ensure efficient use of electric energy, thereby ultimately improving the monitoring efficiency of the distribution network. This embodiment does not specifically limit the setting of the preset energy utilization threshold, and technicians in this field can set it freely as long as the value requirements of the preset energy utilization threshold are met. Among them, the optimal value of Q0 is 0.9.

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A distribution network monitoring system based on 5G communication, characterized in that: include, Distribution network data acquisition module, used to collect distribution line data; Charging station data acquisition module, used to collect charging station power; A stability analysis module, used to analyze the state of the distribution line voltage according to the distribution line voltage collected during the monitoring period, and to adjust the analysis process according to the distribution line voltage and distribution line current collected during the monitoring period; A three-phase analysis module is used to analyze the three-phase imbalance index of the distribution line according to the three-phase voltage of the distribution line collected during the monitoring period; The harmonic monitoring module is used to construct the harmonic pollution coefficient according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period; The charging station monitoring module is used to determine the operating status of the charging station based on the collected charging station power and distribution transformer capacity; An alarm module is used to analyze the operating status of the distribution network according to the voltage status of the distribution network, the three-phase voltage imbalance index, the harmonic pollution coefficient and the operating status of the charging station during the monitoring period, and to alarm the user. It is also used to optimize the analysis process of the operating status of the distribution network according to the active power and reactive power of the distribution lines collected during the monitoring period; The stability analysis module is provided with a stability analysis unit, a volatility analysis unit and a utilization analysis unit. The stability analysis unit calculates the average voltage v of the distribution line collected during the monitoring period. 均 The stability coefficient W of the distribution network line is constructed with the rated voltage v0; The stability analysis unit evaluates the relationship between the stability coefficient and the preset stability threshold w0. If the stability coefficient W does not exceed the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in a normal and stable state; If W exceeds the stability threshold w0, the stability analysis unit determines that the distribution network voltage is in an unstable state; The volatility analysis unit analyzes the volatility of the distribution line voltage within the monitoring period and sets the fluctuation coefficient as E. The volatility analysis unit evaluates the relationship between the fluctuation coefficient E and the preset fluctuation threshold E0 to adjust the analysis process of the distribution network voltage stability state. If E does not exceed E0, the volatility analysis unit determines that the distribution network voltage stability of the current monitoring period is normal and does not make adjustments; conversely, if E exceeds E0, the volatility analysis unit determines that the distribution network voltage stability of the current monitoring period is abnormal, and adjusts the analysis process to adjust the preset stability threshold to w0'. The utilization analysis unit constructs a utilization index L of the distribution line capacity according to the distribution line current a1 and the distribution line rated current a0 collected during the monitoring period, and the calculation formula is L=a1 / a0; The utilization analysis unit evaluates the relationship between the utilization index and the preset utilization threshold L0 to optimize the adjustment process of the distribution network voltage stability state analysis. If L does not exceed L0, the utilization analysis unit determines that the utilization of the distribution network capacity in the current monitoring period is normal and does not perform optimization; On the contrary, if L exceeds L0, the utilization analysis unit determines that the utilization of the distribution network capacity in the current monitoring period is abnormal, and optimizes the adjustment process to optimize the preset fluctuation threshold to E0'; The alarm module is provided with an alarm unit and a power factor analysis unit. The alarm unit analyzes the operation status of the distribution network according to the voltage status of the distribution network, the three-phase voltage imbalance index, the harmonic pollution coefficient and the operation status of the charging station within the monitoring period, wherein: When the charging station operates normally and the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user. When the charging station operates normally but the voltage of the distribution network is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR. If the value does not exceed the threshold value H, the distribution network is judged to be operating normally and no alarm is issued; if the value exceeds the threshold value H, the distribution network is judged to be operating abnormally and an alarm is issued to the user. When the charging station operates abnormally but the distribution network voltage is stable, the alarm unit calculates the value of u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, it is determined that the distribution network is operating normally and no alarm is issued; if it exceeds the correction threshold, it is determined that the distribution network is operating abnormally and an alarm is issued to the user. When the charging station operates abnormally and the distribution network voltage is unstable, the alarm unit calculates the value of u1×(W-w0)+u2×UB+u3×XR and compares it with the correction threshold H×exp[-(CY-C0) / C0]. If it does not exceed the correction threshold, the distribution network is judged to be operating normally and no alarm is issued; if it exceeds the correction threshold, the distribution network is judged to be operating abnormally and an alarm is issued to the user. Among them, u1 is the voltage stability weight, u2 is the imbalance weight, u3 is the harmonic pollution weight, UB is the imbalance index of the three-phase voltage, XR is the harmonic pollution coefficient, CY is the charging station impact factor, and C0 is the preset impact factor threshold.

2. The distribution network monitoring system based on 5G communication according to claim 1 is characterized in that: The three-phase analysis module sorts the three-phase voltages collected during the monitoring period, and constructs the three-phase voltage imbalance index UB according to the sorting result. The calculation formula is: UB=(Vmax-Vmin) / Vavg, where Vmax is the maximum value of the three-phase voltage, Vmin is the minimum value of the three-phase voltage, and Vavg is the average value of the three-phase voltage.

3. The distribution network monitoring system based on 5G communication according to claim 2 is characterized in that: The harmonic monitoring module constructs the harmonic pollution coefficient XR according to the effective value of the harmonic voltage of the distribution line collected during the monitoring period, and sets: ； Among them, R3 is the effective value of the 3rd harmonic voltage of the distribution line, R5 is the effective value of the 5th harmonic voltage of the distribution line, R7 is the effective value of the 7th harmonic voltage of the distribution line, and R1 is the effective value of the fundamental voltage collected during the monitoring period.

4. The distribution network monitoring system based on 5G communication according to claim 3 is characterized in that: The charging station monitoring module is provided with a construction unit and a state judgment unit. The construction unit constructs a charging station impact factor CY according to the charging station power p0 and the distribution transformer capacity P collected during the monitoring period, and sets CY=p0 / P.

5. The distribution network monitoring system based on 5G communication according to claim 4 is characterized in that: The state judgment unit compares the charging station impact factor CY with the preset impact factor threshold C0 to judge the abnormality of the operating state of the charging station. If the charging station impact factor CY does not exceed the preset impact factor threshold C0, the state judgment unit judges that the operating state of the charging station is normal. If the charging station impact factor CY exceeds the preset impact factor C0, the state judgment unit judges that the operating state of the charging station is abnormal.

6. The distribution network monitoring system based on 5G communication according to claim 5, characterized in that: The power factor analysis unit constructs the power factor Q according to the active power S1 and reactive power S2 of the distribution line collected during the monitoring period, and sets: ； The power factor analysis unit evaluates the relationship between the power factor Q and the preset energy utilization threshold Q0 to optimize the analysis process of the distribution network operation status. If Q does not exceed Q0, the power factor analysis unit determines that the energy utilization efficiency of the distribution network in the current monitoring period is normal and no optimization is performed; On the contrary, if Q exceeds Q0, the power factor analysis unit determines that the energy utilization efficiency of the distribution network in the current monitoring period is abnormal, and optimizes the analysis process. The power factor analysis unit optimizes the reference threshold for abnormal state judgment to H'.

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