An overload monitoring method, device and power supply for industrial mining power supply

Abstract

The present invention relates to the technical field of power supply load analysis, and specifically to an overload monitoring method, device and power supply for industrial mining power supplies. The method obtains a current duration segment according to the size of the current data in each phase line during the monitoring time period; obtains the load abnormality degree according to the degree of sudden change abnormality of the current duration segment on each phase line circuit and the distribution size of the current data; analyzes the degree of synchronous change of the current duration segment between the three phase lines, and obtains the load abnormality synchronization degree in combination with the deviation between the load abnormalities, and obtains the possible overload index of the power supply in combination with the current vector sum in the monitoring period, and obtains the overload analysis result. The present invention determines the overload condition of the current power supply through the current load change condition on each phase line and the synchronous load balancing condition, improves the overload analysis accuracy of the three-phase power supply load imbalance condition, and thus improves the reliability and control accuracy of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply load analysis, and in particular to an overload monitoring method, device and power supply for an industrial mining power supply. Background Art

[0002] Industrial mining power supplies are used in mining environments such as coal mines and metal mines, especially in underground coal mine comprehensive mining automation control systems, to provide power for intelligent devices such as sensors, communication stations and controllers. The space underground in coal mines is small, there are many large electromechanical equipment and their locations are relatively concentrated, and high-power equipment is frequently started or shut down, and the three-phase circuit of the power supply is unbalanced in mine recruitment and ventilation lamp equipment, which will cause industrial mining power supplies to frequently experience abnormal loads.

[0003] Normally, when testing the load of mining power supplies, the current of the phase line in the power supply is detected to see if it exceeds the maximum current value that the equipment or line can withstand. If this happens, it can be determined that there is an overload problem. However, since the load is not evenly distributed in the three-phase line circuit, the industrial mining power supply is more frequent and has higher power in the operation of connected equipment, and the imbalance of the three-phase line is more complicated. The general current analysis threshold will increase the risk of abnormalities being masked when considering reducing the impact of access mutations on overload judgment. This makes it impossible for a single current judgment to accurately analyze the power overload caused by load imbalance, and the overall load analysis of the three-phase power supply is unreliable, making the control accuracy of the industrial mining power system low. Summary of the invention

[0004] In order to solve the technical problem that the overall load analysis of the three-phase power supply in the prior art is unreliable, resulting in low control accuracy of the power system for industrial mines, the purpose of the present invention is to provide an overload monitoring method, device and power supply for industrial mine power supply. The technical solution adopted is as follows:

[0005] The present invention provides an overload monitoring method for an industrial mining power supply, the method comprising:

[0006] During the monitoring period, the current data of each phase line of the three-phase power supply at each sampling time is obtained, and the current duration of each phase line is obtained according to the size of the current data in each phase line;

[0007] In each phase line, according to the current data mutation between each current segment and the adjacent current segment, and the current data distribution size of each current segment, the load abnormality degree of each current segment is obtained;

[0008] According to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load abnormality degrees, the load abnormality synchronization degree of the monitoring time period is obtained;

[0009] According to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree in the monitoring time period, the possible overload index of the current three-phase power supply is obtained; according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index, the overload analysis result of the three-phase power supply is obtained.

[0010] Furthermore, the method for obtaining the load abnormality degree includes:

[0011] The mean value of all current data in each current duration is taken as the current distribution value of each current duration;

[0012] For any current segment in each phase line, the difference in the circuit distribution value between the current segment and each adjacent current segment in the time sequence is calculated to obtain the mutation difference between the current segment and each adjacent current segment; the sum of the mutation differences between the current segment and all adjacent current segments is calculated to obtain the mutation index of the current segment;

[0013] Performing negative correlation mapping on the difference between the current distribution value of the current continuous segment and the preset maximum current threshold value to obtain the distribution abnormality index of the current continuous segment;

[0014] The load abnormality degree of the current duration section is obtained by combining the mutation index and the distribution abnormality index of the current duration section.

[0015] Furthermore, the method for acquiring the abnormal synchronization degree of the load includes:

[0016] The phase line with the largest number of current duration segments in the three-phase line is taken as the analysis phase line;

[0017] Each current duration in the analyzed phase line is taken as the target period in turn, and the possible synchronization index of the target period is obtained according to the time distribution of the corresponding current duration on each other phase line during the target period;

[0018] Obtaining a load deviation index for the target period according to the pairwise deviation degree of load anomaly between the target period and the corresponding current duration on each other phase line;

[0019] The synchronization possibility index and load deviation index of each target period are combined to obtain the synchronization anomaly index of each target period; the load anomaly synchronization degree of the monitoring period is obtained by combining the synchronization anomaly index of all current duration segments in the phase line.

[0020] Furthermore, the method for obtaining the synchronization possibility indicator includes:

[0021] The current durations corresponding to the center moment of the target time period on the other two phase lines are used as the two matching time periods of the target time;

[0022] The intersection of the target period and the time distribution of the two matching periods in the time series is taken as the time series union of the target period; the union of the time distribution of the target period and the two matching periods in the time series is taken as the time series union of the target moment;

[0023] The ratio of the time series intersection to the time series union of the target period is used as a possible synchronization indicator of the target period.

[0024] Furthermore, the method for obtaining the load deviation index includes:

[0025] Calculate the average of the load anomaly of the target period and all matching periods as the anomaly average of the target period;

[0026] Calculate the difference in load anomaly between the target period and each matching period to obtain the anomaly difference between the target period and each matching period; calculate the difference in load anomaly between two matching periods to obtain the anomaly difference between the matching periods; and take the sum of all anomaly differences as the anomaly deviation value of the target period;

[0027] The inverse proportional value of the abnormal deviation value in the target period and the sum of the abnormal mean value are used as the load deviation index of the target period.

[0028] Furthermore, the method for obtaining the possible overload indicator includes:

[0029] Calculate the cumulative value of the current vector sum of the three-phase lines at the sampling time in the monitoring time period, and obtain the current fluctuation degree in the monitoring time period after normalization;

[0030] The product of the current fluctuation degree and the abnormal load synchronization degree in the monitoring time period is taken as the synchronous overload degree; the sum of the synchronous overload degree and the current fluctuation degree is normalized and taken as a possible overload indicator.

[0031] Furthermore, the overload analysis result of the three-phase power supply is obtained according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index, including:

[0032] When the current data of any phase line at the current moment is greater than the preset maximum current threshold, or the overload possibility index is greater than the preset overload threshold, the overload analysis result at the current moment is recorded as the power supply overload state.

[0033] Furthermore, the method for obtaining the current duration includes:

[0034] The current data of each phase line in the monitoring time period is segmented by an adaptive piecewise constant approximation algorithm to obtain the current duration segment.

[0035] The present invention also provides an overload monitoring device for an industrial mining power supply, comprising:

[0036] The phase line current division unit is used to obtain the current data of each phase line of the three-phase power supply at each sampling time in the monitoring time period, and divide the current data in each phase line according to the size of the current data in each phase line to obtain the current duration in each phase line;

[0037] The load abnormality analysis unit is used to obtain the load abnormality degree of each current segment in each phase line according to the current data mutation between each current segment and the adjacent current segment and the current data distribution size of each current segment;

[0038] An abnormal synchronization analysis unit is used to obtain the load abnormal synchronization degree in the monitoring time period according to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load abnormality degrees;

[0039] The overload analysis unit is used to obtain the possible overload index of the current three-phase power supply according to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree in the monitoring time period; and obtain the overload analysis result of the three-phase power supply according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index.

[0040] The present invention also provides an industrial mining power supply, which is a three-phase power supply and includes an overload monitoring device for an industrial mining power supply as described above.

[0041] The present invention has the following beneficial effects:

[0042] The present invention first divides the current duration according to the current data size in each phase line in the current monitoring time period, and makes a preliminary division and judgment on the current continuous stability of each phase line. Each current duration reflects an operating condition. Further, the load abnormality degree can be obtained according to the degree of mutation abnormality of the current duration on each phase line circuit and the distribution size of the current data, and the possibility of abnormal load change can be reflected from the mutation situation, and the significant load abnormality of the current can be characterized in combination with the current data size, so as to facilitate the subsequent comprehensive analysis of the load conditions of different current durations. The degree of synchronous change of the current duration between the three phase lines is analyzed, and the different load conditions between the load abnormality degrees are combined. When the changes in the three phase lines are more synchronous, the load analysis can better reflect the abnormal conditions of the overall three-phase line load. Considering the characteristic that the current vector sum is zero under the ideal load balance condition, the current vector sum situation and the load abnormality synchronization degree in the monitoring period are used to comprehensively evaluate the overload possibility of the current power supply, so that the load analysis is more accurate, and finally the current analysis of each phase line is combined with the overload possibility to obtain the overload analysis result for early warning. The present invention determines the overload condition of the current power supply through the current load change condition on each phase line and the synchronous load balance condition, thereby improving the overload analysis accuracy of the three-phase power supply load imbalance condition, and further improving the reliability and control accuracy of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A flow chart of an overload monitoring method for an industrial mining power supply provided by an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of current time sequence changes in a three-phase line circuit provided by an embodiment of the present invention;

[0046] Figure 3 A flow chart of a method for acquiring abnormal synchronization of a load provided by an embodiment of the present invention;

[0047] Figure 4 A schematic diagram of a time sequence intersection and a time sequence union provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of an overload monitoring method, device and power supply for an industrial mining power supply proposed by the present invention, its specific implementation, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0049] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0050] The following is a detailed description of an overload monitoring method, device and power supply for an industrial mining power supply provided by the present invention in conjunction with the accompanying drawings.

[0051] Example 1: Please refer to Figure 1 , which shows a flow chart of an overload monitoring method for an industrial mining power supply provided by an embodiment of the present invention, the method comprising the following steps:

[0052] S1: During the monitoring period, the current data of each phase line of the three-phase power supply at each sampling time is obtained, and the current duration of each phase line is obtained according to the size of the current data in each phase line.

[0053] In industry and mining, current is usually three-phase, which helps to reduce transmission loss. Three-phase power is composed of three AC potentials with the same frequency, equal amplitude, and phase difference of 120°. In the power system, the three-phase power is transmitted to the load end through a three-phase cable to provide power for various equipment. In the industrial mining power supply system, due to the different equipment on the three-phase line, the current load change of each phase line will also be different. Please refer to Figure 2 , which shows a schematic diagram of current time-series changes in a three-phase line circuit provided by an embodiment of the present invention, wherein the horizontal axis is time and the vertical axis is current data.

[0054] When the equipment is running smoothly, the current data is usually maintained within a stable range. However, when the load is abnormal or the equipment startup situation changes, the current will change to a certain extent. Therefore, the current data can be segmented and analyzed in time series. In an embodiment of the present invention, during the monitoring time period, the current data in each phase line is collected by a sensor. For any phase line, the continuous current data in time series is segmented using an adaptive piecewise constant approximation algorithm (APCA) to obtain a current continuous segment.

[0055] The adaptive piecewise constant approximation algorithm (APCA) is a method for denoising and compressing time series data. The idea of ​​APCA is to split the original time series data into multiple segments, each of which is approximated by a constant. This method can automatically select appropriate segmentation points and constant values ​​according to the characteristics of the data and the error tolerance, thereby achieving the purpose of denoising and compression.

[0056] In a specific implementation method of an embodiment of the present invention, the monitoring time period can be set to 10 minutes, and the current data collection frequency can be set to 1Hz. Considering that the current duration needs to be analyzed between the subsequent three-phase lines, the value of the current data in each phase line is normalized to the [-1,1] interval to reduce the impact of different changes in the value range. It should be noted that the specific value setting implementer can adjust it according to the specific implementation scenario, and there is no limitation here.

[0057] At this point, the segmentation of the current data in each phase line is completed, and different current duration segments in each phase line are obtained.

[0058] S2: In each phase line, according to the current data mutation between each current segment and the adjacent current segment, and the current data distribution size of each current segment, the load abnormality degree of each current segment is obtained.

[0059] When mining equipment such as large motors and hoists are started or stopped, the current will change significantly, resulting in a sudden change in current. At the same time, when a short circuit or ground fault occurs in the equipment or line, the current will increase instantly, triggering a sudden change in current. The sudden change in current will cause the power supply to overload. The higher the current change value, the higher the possibility of power supply overload. Therefore, the degree of load abnormality that may be caused by the continuous current segment can be reflected based on the comparison of the current data between the continuous current segment and the adjacent time segments, as well as the degree of the current data itself being too high.

[0060] Preferably, in some possible implementations of the embodiments of the present invention, the method for acquiring the load abnormality degree includes:

[0061] Firstly, the mean value of all current data in each current duration is taken as the current distribution value of each current duration to characterize the current distribution of each current duration.

[0062] Furthermore, for any current segment in each phase line, the difference in the circuit distribution value between the current segment and each adjacent current segment in the time sequence is calculated to obtain the mutation difference between the current segment and each adjacent current segment. Usually, there are two adjacent current segments in the time sequence for each current segment, so two mutation differences can be obtained to reflect the change amplitude of the current segment. The mutation index of the current segment is obtained by summing the mutation differences between the current segment and all adjacent current segments. The overall change amplitude between each current segment and the adjacent time period is reflected by accumulation. The larger the change amplitude, the greater the possibility of abnormal mutation.

[0063] The difference between the current distribution value of the current continuous segment and the preset maximum current threshold is further negatively correlated to obtain the distribution abnormality index of the current continuous segment. The preset maximum current threshold is the maximum preset value of the phase line current. When the current distribution in the current continuous segment is closer to the maximum preset situation, that is, the difference between the current distribution value and the preset maximum current threshold is smaller, it means that the current load phenomenon in the corresponding time period is more serious, so the distribution abnormality index is larger.

[0064] In an embodiment of the present invention, the preset maximum current threshold can be set to 0.95, and the specific value can be adjusted by the implementer at will, and there is no limitation here. It should be noted that negative correlation mapping is a technical means well known to technicians in this field, and can be in the form of inverse proportion or negative exponential power, and there is no limitation here.

[0065] Finally, the load abnormality of the current continuous segment is obtained by combining the mutation index and the distribution abnormality index of the current continuous segment. In the embodiment of the present invention, the product of the mutation index and the distribution abnormality index of the current continuous segment is used as the load abnormality of the current continuous segment. When the mutation index and the distribution abnormality index are larger, it means that the change amplitude between the current data of the current continuous segment and the adjacent time period is higher, and the current data distribution is closer to the limit, the load abnormality of the current continuous segment is more significant, and therefore the load abnormality is greater. As an example, the expression of the load abnormality is:

[0066] ; In the formula, Expressed as The load abnormality of the current duration period, Indicates The mutation index of the current sequence, Expressed as The current distribution value of the current duration period, Represents the preset maximum current threshold, Expressed as an absolute value extraction function, It is represented as a preset adjustment coefficient, which is set to 0.001 in the embodiment of the present invention. Its purpose is to prevent the denominator from being zero and making the formula meaningless. The specific value is not limited here. Expressed as The distribution abnormality index of a current duration segment.

[0067] At this point, based on the change distribution of the current data, the possible load anomaly analysis of each current duration of each phase line is completed to obtain the load anomaly degree.

[0068] S3: According to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load anomaly degrees, the load anomaly synchronization degree of the monitoring time period is obtained.

[0069] Since the change of single-phase current may produce a short-term mutation due to the change of load, it will not cause the actual overload of the power supply. For example, in the mine, the mine lighting or ventilation equipment is usually a single-phase load, which leads to the imbalance of the power consumption of the three-phase power supply. At the same time, when the motor or other three-phase equipment used in the mine fails, such as the damage of a phase winding, the current will also be unbalanced. For example, when mechanical equipment such as conveyor belts or electric pumps are running in stages, the loads on different phases are unbalanced, so it is necessary to further analyze the overall load changes of the three-phase line circuit to see if the abnormal situation is significant.

[0070] In the overall analysis of the three-phase line, the influence of the degree of synchronous change on the load abnormality overload is considered. When the synchronous change is higher, it means that the load pressure is generated from multiple phase lines at the same time, and the load overload may be higher. Therefore, the deviation distribution analysis of the load abnormality is further adjusted by the degree of synchronous change between the three-phase lines to obtain the load abnormality synchronization and improve the accuracy of abnormality analysis.

[0071] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the abnormal synchronization degree of the load can be found in Figure 3 , which shows a flow chart of a method for obtaining abnormal synchronization of a load provided by an embodiment of the present invention, the method comprising the following steps:

[0072] S301: The phase line having the largest number of current duration segments among the three-phase lines is selected as the analysis phase line.

[0073] In order to more completely analyze the synchronization of changes, the phase line with the most changes, that is, the phase line with the largest number of current durations, is taken as the main focus. The current duration after each change can be synchronously analyzed to make the synchronous change analysis more comprehensive.

[0074] S302: taking each current duration in the analyzed phase line as the target period in turn, and obtaining the synchronization possible index of the target period according to the time distribution intersection of the current duration corresponding to the target period on each other phase line.

[0075] Each current duration in the phase line is traversed and analyzed to analyze the abnormal synchronization. The synchronization analysis can be characterized by the intersection and union of the current durations. When the intersection between the target period and the current durations of other phase lines, that is, the overlap time, is greater, and the union of the current durations of the target period and other phase lines is smaller, that is, the beginning and end moments of the target period are close to the beginning and end moments of the current durations of other phase lines, it means that the current changes of the target period and the current durations of other phase lines are relatively synchronized.

[0076] Preferably, in an embodiment of the present invention, the method for acquiring synchronization possible indicators includes:

[0077] First, the current duration corresponding to the center moment of the target time period on the other two phase lines is taken as the two matching time periods of the target moment, and the sampling moments are matched to match the current duration corresponding to the target time period in the other two phase lines in terms of timing.

[0078] Furthermore, the intersection of the target time period and the two matching time periods in the time series is taken as the time series union of the target time period, that is, to obtain the longest time period of the three time periods of the target time period and the two matching time periods in the time series. The intersection of the target time period and the two matching time periods in the time series is taken as the time series union of the target time, that is, to obtain the longest time period of the three time periods of the target time period and the two matching time periods in the time series. Please refer to Figure 4 , which shows a schematic diagram of a timing intersection and a timing union provided by an embodiment of the present invention.

[0079] Finally, the ratio of the time series intersection to the time series union of the target period is used as the synchronization possibility index of the target period. Since the union is greater than or equal to the intersection, the synchronization possibility index is a value less than or equal to 1. When the time series intersection is larger and the time series union is smaller, the current change of the three-phase line is more synchronized, so the synchronization possibility index is larger and closer to 1.

[0080] S303: Obtain a load deviation index for the target period according to the pairwise deviations of load anomalies between the target period and the corresponding current durations on each other phase line.

[0081] Through the joint analysis of the load anomaly on the three phase lines, the overall overload possibility can be reflected from the common load anomaly of the three phase lines. When the load anomaly between the corresponding matching current durations of the three phase lines is more consistent and the value is higher, it means that the degree of current load pressure generated by the three phase lines is greater and consistent, and the overload possibility of the power supply is higher.

[0082] Preferably, in an embodiment of the present invention, a method for obtaining a load deviation indicator includes:

[0083] First, the mean of the load anomaly degree of the target period and all matching periods is calculated as the abnormal mean of the target period, which reflects the distribution size of the overall load anomaly degree in the three-phase line.

[0084] Furthermore, the difference in load anomaly between the target period and each matching period is calculated to obtain the abnormal difference between the target period and each matching period. The difference in load anomaly between two matching periods is calculated to obtain the abnormal difference between matching periods, that is, the difference between the load anomaly between the target period and the two matching periods is calculated as the abnormal difference. The sum of all abnormal differences is used as the abnormal deviation value of the target period to reflect the degree of mutual deviation between the three-phase lines. The larger the abnormal deviation value, the more different the load anomaly between the three-phase lines is, and the weaker the synchronization performance is.

[0085] Finally, the inverse proportional value of the abnormal deviation value of the target period and the sum of the abnormal mean value are used as the load deviation index of the target period. The smaller the abnormal deviation value is and the larger the abnormal mean value is, the more consistent the load abnormality performance of the three-phase line is in the target period and the larger the value is, so the load deviation index of the target period is larger.

[0086] S304: combining the synchronization possibility index and the load deviation index of each target period to obtain the synchronization abnormality index of each target period; combining and analyzing the synchronization abnormality index of all current durations in the phase line to obtain the load abnormal synchronization degree of the monitoring period.

[0087] Further, the degree of synchronization of the three-phase lines in the target period and the degree of abnormality in the load abnormality performance are combined to obtain the abnormality index at each target period. In the embodiment of the present invention, the product of the synchronization possibility index and the load deviation index of each target period is used as the synchronization abnormality index of each target period. The larger the synchronization possibility index and the load deviation index, the higher the degree of synchronization at the target period and the more significant the abnormal performance. Therefore, the more significant the synchronization abnormality is, the higher the possibility of overload. As an example, the expression of the synchronization abnormality index is:

[0088] ; In the formula, Expressed as Synchronous abnormality index of the current duration segment, Indicates The synchronization possible index of the current duration, Indicates The abnormal mean value of the current duration, Expressed as The abnormal deviation value of the current duration period, Expressed as The load deviation index of the current duration period, Expressed as a preset adjustment factor.

[0089] Finally, the synchronization anomaly index of all current segments in the phase line is analyzed to characterize the overall synchronization anomaly significance in the monitoring time period. In an embodiment of the present invention, the average value of the synchronization anomaly index of all current segments in the phase line is analyzed as the load anomaly synchronization degree of the monitoring time period. The greater the load anomaly synchronization degree, the higher the possibility of overload anomaly.

[0090] S4: According to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree during the monitoring time period, the possible overload index of the current three-phase power supply is obtained; according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index, the overload analysis result of the three-phase power supply is obtained.

[0091] Further considering the characteristic that the current vector sum on the three-phase line is zero when the ideal three-phase load is completely balanced, if the load on one or several phases of the three-phase line is heavier, the current increases and the degree of imbalance is higher, which in turn increases the possibility of power supply overload. Therefore, the current vector sum at the sampling time during the monitoring period is analyzed, and the possibility of power supply overload is comprehensively determined in combination with the abnormal synchronization of the load.

[0092] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the possible overload indicator includes:

[0093] First, the cumulative value of the current vector sum of the three-phase lines at the sampling moments in the monitoring time period is calculated, and the current fluctuation degree of the monitoring time period is obtained after normalization. The higher the overall current vector sum of the three-phase lines at each sampling moment in the monitoring time period, the more unstable the current as a whole is, and the higher the possibility of overload.

[0094] It should be noted that normalization is a technical means well known to those skilled in the art, and the normalization method may be linear normalization or standard normalization, etc. The specific normalization method is not limited here.

[0095] The product of the current fluctuation degree and the load abnormal synchronization degree in the monitoring period is further used as the synchronous overload degree to reflect the degree of increase in the judgment of the possibility of overload due to the influence of the synchronous abnormality. The sum of the synchronous overload degree and the current fluctuation degree is normalized to obtain the possible overload index, and the possible overload possibility of the power supply is obtained from the overall current change of the three-phase line.

[0096] When the overload possibility index is larger, it indicates that an overload may occur during the monitoring time period, and if the current data of a phase line of the power supply exceeds the maximum preset value of the current, it also indicates that an overload has occurred. Both situations indicate that the power supply has circuit overload behavior. Preferably, in an embodiment of the present invention, based on the current data size of each phase line of the three-phase power supply at the current moment and the overload possibility index, the overload analysis result of the three-phase power supply is obtained, including:

[0097] When the current data of any phase line at the current moment is greater than the preset maximum current threshold, or the overload possible index is greater than the preset overload threshold, the overload analysis result at the current moment is recorded as the power supply overload state. In a specific implementation of the embodiment of the present invention, the preset overload threshold is set to 0.8, and the specific value can be adjusted by the implementer, and is not limited here.

[0098] In the embodiment of the present invention, the overload analysis results can be recorded and an alarm can be issued through the protection device and power monitoring system of the industrial mining power supply. When the power supply is in an overload state, the power supply protection device should be activated within 20 minutes and automatically reset. The power supply continues to record the current of each phase to determine whether the power supply can be restored. If the power supply overload state cannot be restored, an alarm reminder is issued.

[0099] In summary, in the current monitoring time period, the present invention first divides the current duration according to the current data size in each phase line to obtain the current duration, and makes a preliminary division and judgment on the current continuity and stability of each phase line, and each current duration reflects an operating condition. Further, the load abnormality degree can be obtained according to the degree of sudden change abnormality of the current duration on each phase line circuit and the distribution size of the current data, and the possibility of abnormal load change can be reflected from the sudden change, and the current load abnormality is characterized by the current data size, which is convenient for the subsequent comprehensive analysis of the load conditions of different current durations. The degree of synchronous change of the current duration between the three phase lines is analyzed, and the different load conditions between the load abnormality degrees are combined. When the changes in the three phase lines are more synchronous, the load analysis can better reflect the abnormal conditions of the overall three-phase line load. Considering the characteristic that the current vector sum is zero under the ideal load balance condition, the current vector sum condition and the load abnormality synchronization degree in the monitoring period are used to comprehensively evaluate the overload possibility of the current power supply, so that the load analysis is more accurate, and finally the current analysis of each phase line is combined with the overload possibility to obtain an overload analysis combined with an early warning. The present invention determines the overload condition of the current power supply through the current load change condition on each phase line and the synchronous load balance condition, thereby improving the overload analysis accuracy of the three-phase power supply load imbalance condition, and further improving the reliability and control accuracy of the power system.

[0100] Embodiment 2: The present invention also provides an overload monitoring device for an industrial mining power supply, comprising:

[0101] The phase line current division unit is used to obtain the current data of each phase line of the three-phase power supply at each sampling time in the monitoring time period, and divide the current data in each phase line according to the size of the current data in each phase line to obtain the current duration in each phase line;

[0102] The load abnormality analysis unit is used to obtain the load abnormality degree of each current segment in each phase line according to the current data mutation between each current segment and the adjacent current segment and the current data distribution size of each current segment;

[0103] An abnormal synchronization analysis unit is used to obtain the load abnormal synchronization degree in the monitoring time period according to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load abnormality degrees;

[0104] The overload analysis unit is used to obtain the possible overload index of the current three-phase power supply according to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree in the monitoring time period; and obtain the overload analysis result of the three-phase power supply according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index.

[0105] It should be noted that the device provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functional distribution can be completed by different functional module units as needed, that is, the internal structure of the device is divided into different functional module units to complete all or part of the functions described above. Since the specific implementation process of an overload monitoring device for an industrial mining power supply in this embodiment is the same as the specific implementation process of an overload monitoring method for an industrial mining power supply described above, it will not be described in detail here.

[0106] Embodiment 3: The present invention also provides an industrial mining power supply, which is a three-phase power supply and includes an overload monitoring device for an industrial mining power supply as described above, and can implement the steps of an overload monitoring method for an industrial mining power supply as described above.

[0107] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0108] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A method for monitoring overload of industrial mining power supply, characterized in that: The method comprises: During the monitoring period, the current data of each phase line of the three-phase power supply at each sampling time is obtained, and the current duration of each phase line is obtained according to the size of the current data in each phase line; In each phase line, according to the current data mutation between each current segment and the adjacent current segment, and the current data distribution size of each current segment, the load abnormality degree of each current segment is obtained; According to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load abnormality degrees, the load abnormality synchronization degree of the monitoring time period is obtained; According to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree in the monitoring time period, the possible overload index of the current three-phase power supply is obtained; according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index, the overload analysis result of the three-phase power supply is obtained; The method for obtaining the load abnormality degree includes: The mean value of all current data in each current duration is taken as the current distribution value of each current duration; For any current segment in each phase line, the difference in current distribution value between the current segment and each adjacent current segment in time sequence is calculated to obtain the mutation difference between the current segment and each adjacent current segment; the sum of the mutation differences between the current segment and all adjacent current segments is calculated to obtain the mutation index of the current segment; Performing negative correlation mapping on the difference between the current distribution value of the current continuous segment and the preset maximum current threshold value to obtain the distribution abnormality index of the current continuous segment; Combining the mutation index and the distribution abnormality index of the current duration period, obtaining the load abnormality degree of the current duration period; The method for acquiring the abnormal synchronization degree of the load includes: The phase line with the largest number of current duration segments in the three-phase line is taken as the analysis phase line; Each current duration in the analyzed phase line is taken as the target period in turn, and the possible synchronization index of the target period is obtained according to the time distribution of the corresponding current duration on each other phase line during the target period; Obtaining a load deviation index for the target period according to the pairwise deviation degree of load anomaly between the target period and the corresponding current duration on each other phase line; Combine the synchronization possibility index and load deviation index of each target period to obtain the synchronization abnormality index of each target period; combine and analyze the synchronization abnormality index of all current durations in the phase line to obtain the load abnormal synchronization degree of the monitoring period; The method for obtaining the possible overload indicator includes: Calculate the cumulative value of the current vector sum of the three-phase lines at the sampling time in the monitoring time period, and obtain the current fluctuation degree in the monitoring time period after normalization; The product of the current fluctuation degree and the abnormal load synchronization degree in the monitoring time period is taken as the synchronous overload degree; the sum of the synchronous overload degree and the current fluctuation degree is normalized and taken as a possible overload indicator.

2. The overload monitoring method for industrial mining power supply according to claim 1, characterized in that: The method for obtaining the synchronization possible indicator includes: The current durations corresponding to the center moment of the target time period on the other two phase lines are used as the two matching time periods of the target time; The intersection of the target period and the two matching periods in time series is taken as the time series intersection of the target period; the union of the target period and the two matching periods in time series is taken as the time series union of the target period; The ratio of the time series intersection to the time series union of the target period is used as a possible synchronization indicator of the target period.

3. The overload monitoring method for industrial mining power supply according to claim 2 is characterized in that: The method for obtaining the load deviation index includes: Calculate the average of the load anomaly of the target period and all matching periods as the anomaly average of the target period; Calculate the difference in load anomaly between the target period and each matching period to obtain the anomaly difference between the target period and each matching period; calculate the difference in load anomaly between two matching periods to obtain the anomaly difference between the matching periods; and take the sum of all anomaly differences as the anomaly deviation value of the target period; The inverse proportional value of the abnormal deviation value in the target period and the sum of the abnormal mean value are used as the load deviation index of the target period.

4. The overload monitoring method for industrial mining power supply according to claim 1, characterized in that: The overload analysis result of the three-phase power supply is obtained according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index, including: When the current data of any phase line at the current moment is greater than the preset maximum current threshold, or the overload possibility index is greater than the preset overload threshold, the overload analysis result at the current moment is recorded as the power supply overload state.

5. The overload monitoring method for industrial mining power supply according to claim 1, characterized in that: The method for obtaining the current duration includes: The current data of each phase line in the monitoring time period is segmented by an adaptive piecewise constant approximation algorithm to obtain the current duration segment.

6. An overload monitoring device for an industrial mining power supply, used to implement an overload monitoring method for an industrial mining power supply as claimed in claim 1, characterized in that: include: The phase line current division unit is used to obtain the current data of each phase line of the three-phase power supply at each sampling time in the monitoring time period, and divide the current data in each phase line according to the size of the current data in each phase line to obtain the current duration in each phase line; The load abnormality analysis unit is used to obtain the load abnormality degree of each current segment in each phase line according to the current data mutation between each current segment and the adjacent current segment and the current data distribution size of each current segment; An abnormal synchronization analysis unit is used to obtain the load abnormal synchronization degree in the monitoring time period according to the degree of synchronization of the change of the current duration between the three-phase lines at the same sampling time and the deviation between the load abnormality degrees; The overload analysis unit is used to obtain the possible overload index of the current three-phase power supply according to the current vector sum of the three-phase line at each sampling moment and the abnormal load synchronization degree in the monitoring time period; and obtain the overload analysis result of the three-phase power supply according to the current data size of each phase line of the three-phase power supply at the current moment and the possible overload index.

7. An industrial mining power supply, characterized in that: The power supply is a three-phase power supply, including an overload monitoring device for an industrial mining power supply as described in claim 6.

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