Fault detection method and device, electronic equipment and storage medium

Abstract

The invention discloses a fault detection method and device, electronic equipment and a storage medium. The fault detection method can be applied to fault detection of a load side loop of a power system. The fault detection method comprises the following steps: collecting a plurality of measurement voltages and measurement currents of each load side at each moment within a set duration; according to each load side, the calculated voltage of each moment is determined according to the measured current of each moment in the multiple moments and the impedance model; based on a least square method, determining an error function according to the optimal measurement voltage in the plurality of measurement voltages at each moment and the calculation voltage at each moment, and determining an impedance value of each load side according to the error function; and determining whether each load side has a wiring fault according to the impedance value. According to the technical scheme, the accuracy of fault detection is improved, and the risk in operation of the power system is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fault detection, and in particular to a fault detection method, device, electronic equipment and storage medium. Background Art

[0002] In the context of large-scale access to smart grids and distributed power sources, the reliability of the functions and performance of energy metering devices, as the basic equipment of the power system, has received increasing attention. These devices are responsible for real-time monitoring of electricity usage, including parameters such as voltage, current and power, to ensure accurate metering and reasonable distribution of electricity. However, with the increasing complexity of load-side scenarios, the challenges faced by energy metering devices have also increased, especially in terms of abnormal problems in wiring circuits, such as loose wiring and poor contact, which directly affect the accuracy and stability of energy metering.

[0003] Traditional electrical quantity monitoring methods usually only focus on static voltage and current parameters, and it is difficult to effectively capture the dynamic characteristics of the wiring circuit, such as the transient response and fluctuation of impedance. This static monitoring method is insufficient to deal with the complexity of the load side scenario and the load fluctuation after the access of distributed power sources. It is easy to miss potential abnormal signals of the wiring circuit, resulting in untimely and incomplete detection.

[0004] Existing abnormality identification methods lack in-depth analysis of wiring circuit impedance characteristics and can only be judged through simple parameter monitoring, resulting in low identification accuracy. At the same time, existing technologies are difficult to achieve real-time identification and alarm of wiring circuit anomalies, and cannot prevent possible equipment failures or safety hazards in a timely manner, thereby increasing the risks in power system operation. Summary of the invention

[0005] The present invention provides a fault detection method, device, electronic equipment and storage medium to solve the problem that load-side faults in a power system are difficult to accurately identify.

[0006] According to one aspect of the present invention, a fault detection method is provided, the fault detection method comprising:

[0007] Collect multiple measured voltages and measured currents on each load side at each moment within a set time period;

[0008] Determine the calculated voltage at each moment according to the measured current at each moment and the impedance model;

[0009] Based on the least square method, an error function is determined according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, and an impedance value of each load side is determined according to the error function;

[0010] Whether each of the load sides has a wiring fault is determined according to the impedance value.

[0011] Optionally, before determining the error function based on the least square method according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, the method further includes:

[0012] For each load side, the optimal measured voltage at each moment is determined using a dynamic time warping method based on the multiple measured voltages at each moment.

[0013] Optionally, a dynamic time warping method is used to determine the optimal measurement voltage at each moment, including:

[0014] A difference matrix is ​​established by using the plurality of measured voltages and a reference signal at each moment, and the optimal value of the difference matrix is ​​determined by using the dynamic time warping method to determine the optimal measured voltage at each moment.

[0015] Optionally, before using the plurality of measured voltages at each moment and the reference signal to establish a difference matrix, the method further includes:

[0016] Discretizing the reference voltage to obtain a reference vector;

[0017] Performing discrete Fourier transform on the reference voltage to obtain a reference matrix;

[0018] The reference signal is determined according to the reference vector and the reference matrix.

[0019] Optionally, determining whether each load side has a wiring fault according to the impedance value includes:

[0020] When the impedance difference between the impedance value corresponding to the load side at any moment and the reference impedance value is greater than the abnormal threshold, a wiring fault on the corresponding load side is determined; wherein the reference impedance value is a historical impedance value corresponding to the wiring when there is no fault in the historical impedance value of the corresponding load side, or the reference impedance value is a preset impedance value.

[0021] Optionally, determining a corresponding load side wiring fault includes:

[0022] When the change rate of the impedance difference corresponding to the load side at any time is greater than the first preset value, or the change rate of the impedance value corresponding to the load side is greater than the second preset value, it is determined that the corresponding load side wiring has poor contact;

[0023] When the variance of the plurality of impedance values ​​corresponding to the load side within the preset time period is greater than a third preset value, it is determined that the connection on the corresponding load side is loose.

[0024] Optionally, before determining the calculated voltage at each moment according to the measured current and the impedance model at each load side at each moment in a plurality of moments, the method further includes:

[0025] The impedance model is determined according to the impedance relationship on the load side.

[0026] According to another aspect of the present invention, there is provided a fault detection device, the fault detection device comprising:

[0027] An acquisition module, used for acquiring a plurality of measured voltages and measured currents of each load side at each moment within a set time period;

[0028] A calculated voltage determination module, used to determine the calculated voltage at each moment according to the measured current and the impedance model at each moment;

[0029] an impedance value determination module, configured to determine an error function based on a least square method according to the best measured voltage among the plurality of measured voltages at each moment and the calculated voltage at each moment at each load side at a plurality of moments, and determine the impedance value of each load side according to the error function;

[0030] A fault determination module is used to determine whether each load side has a wiring fault according to the impedance value.

[0031] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0032] at least one processor; and

[0033] a memory communicatively connected to the at least one processor; wherein,

[0034] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the fault detection method described in any embodiment of the present invention.

[0035] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the fault detection method described in any embodiment of the present invention when executed.

[0036] According to another aspect of the present invention, a computer program product is provided. The computer program product comprises a computer program. When the computer program is executed by a processor, the fault detection method according to any embodiment of the present invention is implemented.

[0037] The technical solution of the embodiment of the present invention collects the measured voltage and measured current of multiple load sides at each moment within the set time length, and determines the best measured voltage among the multiple measured voltages at each moment. The error of the best measured voltage is small, which can ensure the accuracy of measurement, and then ensure the accuracy of impedance value calculation. Based on the least squares method, according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, the error function is determined, and the impedance value of each load side is determined according to the error function, so that the impedance value is determined by the best measured voltage and calculated voltage at N moments, which can improve the dynamic performance of impedance value calculation and is conducive to further improving the accuracy of impedance value determination. And it can be determined whether each load side among multiple load sides has a wiring fault, and the detection of multiple load sides can be realized. In this way, it can be accurately judged whether there is a wiring fault in the load side circuit, so that the wiring fault can be accurately and timely detected, avoiding the fault to be detected after a long time, so that an alarm can be made in time, reducing the risk in the operation of the power system.

[0038] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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.

[0040] Figure 1 is a flow chart of a fault detection method provided by an embodiment of the present invention;

[0041] Figure 2 is a flow chart of another fault detection method provided by an embodiment of the present invention;

[0042] Figure 3 is a flow chart of another fault detection method provided by an embodiment of the present invention;

[0043] Figure 4 is a flow chart of another fault detection method provided by an embodiment of the present invention;

[0044] Figure 5 is a flow chart of another fault detection method provided by an embodiment of the present invention;

[0045] Figure 6is a structural schematic diagram of a fault detection device provided by an embodiment of the present invention;

[0046] Figure 7 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] The embodiment of the present invention provides a fault detection method, which can be applied to the wiring fault detection on the heavy load side of the power system. The power system can be a photovoltaic power generation system or a wind power generation system, etc., which is not limited in this embodiment. The fault detection method can be executed by a fault detection device.

[0050] Figure 1 is a flowchart of a fault detection method provided by an embodiment of the present invention, refer to Figure 1 , the fault detection methods include:

[0051] S110 , collecting a plurality of measured voltages and measured currents on each load side at each moment within a set time period.

[0052] Among them, the load side is the load side in the power system, that is, the load side connected to the power generation system. The power system may include one load side or multiple load sides. The measured voltage is the voltage of the load side circuit, and the measured current is the current of the load side circuit. For example, if the set time length includes N moments, multiple measured voltages and measured currents corresponding to the N moments can be collected, that is, at each of the N moments, multiple measured voltages and measured currents on the load side are collected. N is an integer greater than 1. The measured voltages and measured currents at N moments are collected, and they can be collected once every preset interval, and multiple measured voltages and one measured current are collected each time. That is, the interval between two adjacent moments is a preset interval.

[0053] For example, the measured current collected at time t1 is I c (t1), the measured current collected at time t2 is I c (t2), and so on, t N The measured current collected at all times is I c (t N ), the measured current collected at N moments can be expressed in matrix form as:

[0054]

[0055] S120, determining the calculated voltage at each moment according to the measured current at each moment and the impedance model.

[0056] Specifically, the impedance model represents the corresponding relationship between voltage, current and impedance in the loop. Substituting the measured current and impedance value at each moment into the impedance model, the calculated voltage at each moment can be represented by the impedance value.

[0057] For example, the impedance model is V(t)=Z(t)·I(t), where V(t) is the load loop voltage corresponding to time t, Z(t) is the load loop impedance value corresponding to time t, and I(t) is the load loop current corresponding to time t. The measured current at N times is I c , the impedance value is Z, then the calculated voltage V at N moments m (f) Impedance can be expressed as V m (f) = Z·I c In this way, an expression for the impedance value can be established to facilitate the determination of the impedance value. Furthermore, the calculated voltage at N moments can be determined through the measured current at N moments, thereby obtaining the calculated voltage in matrix form.

[0058] S130. Based on the least square method, determine an error function according to each load side, at multiple moments, the best measured voltage among multiple measured voltages at each moment and the calculated voltage at each moment, and determine the impedance value of each load side according to the error function.

[0059] Among them, the best measurement voltage can be determined from multiple measurement voltages at each moment, and the error of the best measurement voltage is small, which can ensure the accuracy of measurement and further ensure the accuracy of impedance value calculation.

[0060] Specifically, each moment corresponds to an optimal measured voltage and a calculated voltage, and N moments correspond to N optimal measured voltages and N calculated voltages, thereby obtaining the optimal measured voltage in matrix form and the calculated voltage in matrix form. By establishing an error function and calculating the error function based on the least squares method, the corresponding impedance value when the error is minimum is determined, so that the impedance value of all load sides can be accurately determined. In addition, by determining the impedance value through the optimal measured voltage and calculated voltage at N moments, the dynamic performance of the impedance value calculation can be improved, which is conducive to further improving the accuracy of the impedance value determination.

[0061] For example, the best measured voltage at N moments is V c , then the error function can be E(Z) = ‖V c -Z·I c ‖ 2 , the error function is expanded into a matrix form: E(Z)=(V c -Z·I c ) T (V c -Z·I c ), take the derivative of the impedance value Z and set it to zero, that is, Then we can get Z=(I c T I c ) -1 I c T V c , so that the impedance value can be determined according to the best measured voltage and measured current. For example, if the impedance value Z is in matrix form, that is, it includes the impedance values ​​at N moments, it is convenient to dynamically monitor the impedance value, improve the dynamic performance of impedance value determination, and judge whether the corresponding load side is faulty according to the impedance value at any moment.

[0062] S140. Determine whether there is a wiring fault on each load side according to the impedance value.

[0063] Specifically, based on the impedance value of the load side circuit, it can be determined whether there is a wiring fault on the load side. For example, when the impedance value is too large or too small, it is determined that there is a wiring fault on the load side; or when the impedance value changes greatly or changes rapidly, it can be determined that there is a wiring fault on the load side. This embodiment does not limit this.

[0064] The technical solution of this embodiment, by collecting the measured voltage and measured current of multiple load sides at each moment, by determining the best measured voltage among the multiple measured voltages at each moment, the error of the best measured voltage is small, the accuracy of the measurement can be guaranteed, and then the accuracy of the impedance value calculation can be guaranteed. Based on the least squares method, according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, the error function is determined, and the impedance value of each load side is determined according to the error function, so that the impedance value is determined by the best measured voltage and calculated voltage at N moments, which can improve the dynamic performance of the impedance value calculation, and is conducive to further improving the accuracy of the impedance value determination. And it can be determined whether each load side among the multiple load sides has a wiring fault, and the detection of multiple load sides can be realized. In this way, it can be accurately judged whether there is a wiring fault in the load side circuit, so that the wiring fault can be accurately and timely detected, avoiding the fault being detected after a long time, so that an alarm can be made in time, reducing the risk in the operation of the power system.

[0065] Based on the above technical solution, a method for determining the optimal measurement voltage is described below, but it is not intended to limit the present application.

[0066] Figure 2 is a flowchart of another fault detection method provided by an embodiment of the present invention. Figure 2 , the fault detection methods include:

[0067] S210 , collecting a plurality of measured voltages and measured currents on each load side at each moment within a set time period.

[0068] S220 , determining the calculated voltage at each moment according to the measured current at each moment and the impedance model.

[0069] S230. For each load side, according to multiple measured voltages at each moment, a dynamic time warping method is used to determine the best measured voltage at each moment.

[0070] Specifically, the dynamic time warping (DTW) method can align two sequences. Therefore, the dynamic time adjustment method can be used to align the measured voltage with the reference voltage. If the measured voltage during alignment is close to the reference voltage, the measured voltage corresponding to the alignment will be used as the optimal measured voltage, which can ensure the accuracy of the optimal measured voltage and facilitate accurate determination of the impedance value of the load side circuit.

[0071] S240. Based on the least square method, determine an error function according to each load side, at multiple moments, the best measured voltage among multiple measured voltages at each moment and the calculated voltage at each moment, and determine the impedance value of each load side according to the error function.

[0072] S250. Determine whether there is a wiring fault on each load side according to the impedance value.

[0073] Based on the above technical solutions, Figure 3 is a flowchart of another fault detection method provided by an embodiment of the present invention. Figure 3 , the fault detection methods include:

[0074] S310 , collecting a plurality of measured voltages and measured currents on each load side at each moment within a set time period.

[0075] S320, determining the calculated voltage at each moment according to the measured current at each moment and the impedance model.

[0076] S330, discretize the reference voltage to obtain a reference vector.

[0077] The reference voltage may be a preset voltage value, or a historical voltage value corresponding to a load-side circuit when no fault occurs, which is not limited in this embodiment.

[0078] For example, if the reference voltage is composed of N voltages, the reference voltage can be discretized into N voltages to obtain a reference vector. After discretization, the reference vector v can be obtained as:

[0079]

[0080] S340, performing discrete Fourier transform on the reference voltage to obtain a reference matrix.

[0081] Specifically, by performing a discrete Fourier transform on the reference voltage, it can be converted to the frequency domain to obtain a reference matrix, so that the reference voltage is represented by multiple data. Exemplarily, the reference voltage is subjected to a discrete Fourier transform to obtain a reference matrix F as follows:

[0082]

[0083] S350: Determine a reference signal according to a reference vector and a reference matrix.

[0084] Specifically, the time domain signal can be determined based on the reference vector and the reference matrix, and then the reference signal can be determined. The determined reference signal is in matrix form and can be operated with the matrix formed by multiple measurement voltages at each moment to determine the optimal measurement voltage, which is convenient for accurately determining the impedance value of the load side loop based on the optimal measurement voltage.

[0085] For example, the reference vector is v, the reference matrix is ​​F, and the reference signal is V r =F·v.

[0086] S360, using multiple measured voltages at each moment and a reference signal to establish a difference matrix, and using a dynamic time warping method to determine the optimal value of the difference matrix to determine the optimal measured voltage at each moment.

[0087] Specifically, by establishing a difference matrix, the difference matrix can represent the deviation between the measured voltage and the reference signal. By adopting the dynamic time warping method, an optimal path can be determined, and the cumulative difference value along the optimal path is the smallest, so that the optimal value of the difference matrix can be determined, so that the difference value between the measured voltage and the reference signal is minimized, and the measured voltage corresponding to the minimum difference value is determined, that is, the optimal measured voltage. In this way, the determined optimal measured voltage is closer to the reference voltage, ensuring the accuracy of the measured optimal measured voltage, thereby improving the accuracy of the impedance value determination.

[0088] For example, at the same time, the measured voltage corresponding to any point is V c (t i ), the reference voltage in the corresponding reference signal is V r (t j ), then the difference matrix is ​​D(i, j) = V c (t i )-V r (t j The optimal path can be obtained by recursion, and the recursive formula is P(i, j) = D(i, j) + min(P(i-1, j), P(i, j-1), P(i-1, j-1)). Where P(i, j) is the measured voltage V c (t i ) and the reference voltage V r (t j ), P(i-1, j) represents a point extending in the direction of the measured voltage, P(i, j-1) represents a point extending in the direction of the reference voltage, and P(i-1, j-1) represents a point extending in the direction of both the reference voltage and the measured voltage. By recursively calculating the recursive formula, the optimal path can be determined, thereby determining the difference matrix corresponding to the optimal path, and obtaining the optimal value of the difference matrix. The measured voltage corresponding to the optimal value of the difference matrix is ​​the optimal measured voltage. In this way, the measured voltage and the reference voltage can be aligned in time, providing a more reliable similarity calculation method for fault detection, and improving the accuracy of impedance value determination.

[0089] S370. Based on the least squares method, determine an error function according to each load side, at multiple moments, the best measured voltage among multiple measured voltages at each moment and the calculated voltage at each moment, and determine the impedance value of each load side according to the error function.

[0090] S380. Determine whether there is a wiring fault on each load side according to the impedance value.

[0091] Based on the above technical solutions, the method for determining whether the load side is faulty is described below, but it is not intended to limit the present application.

[0092] Figure 4 is a flowchart of another fault detection method provided by an embodiment of the present invention. Figure 4 , the fault detection methods include:

[0093] S410 , collecting a plurality of measured voltages and measured currents on each load side at each moment within a set time period.

[0094] S420: Determine the calculated voltage at each moment according to the measured current at each moment and the impedance model.

[0095] S430. Based on the least square method, determine an error function according to each load side, at multiple moments, the best measured voltage among multiple measured voltages at each moment and the calculated voltage at each moment, and determine the impedance value of each load side according to the error function.

[0096] S440. When the impedance difference between the impedance value corresponding to the load side at any time and the reference impedance value is greater than the abnormal threshold, determine that the corresponding load side wiring fault occurs; wherein the reference impedance value is a historical impedance value corresponding to the historical impedance value of the corresponding load side when the wiring is not faulty, or the reference impedance value is a preset impedance value.

[0097] Specifically, by comparing the impedance value corresponding to the determined load side at any time with the reference impedance value, when the impedance difference between the impedance value corresponding to the load side and the reference impedance value is less than or equal to the abnormal threshold, it indicates that the determined impedance value is close to the reference impedance value, indicating that the corresponding load side wiring is normal and no fault occurs. When the impedance difference between the impedance value and the reference impedance value is greater than the abnormal threshold, it indicates that the impedance value of the corresponding load side circuit is large, thereby determining that the load side wiring fault occurs. In this way, it is possible to promptly determine whether the load side is faulty, so that timely maintenance can be performed to ensure the safety of the power system.

[0098] For example, the impedance value at the current moment is Z(t), and the reference impedance value is Z r (t), the impedance difference between the current impedance value and the reference impedance value is ΔZ(t)=|Z(t)-Z r (t)|. In multi-load scenarios, such as capacitor car charging stations, distributed photovoltaic power generation systems, and wind power generation systems, the power system includes n impedance (load) branches, and the impedance values ​​of the n branches at the current moment can form an impedance matrix, where n is an integer greater than 1. The reference impedance values ​​corresponding to the n branches form a reference impedance matrix, and the reference impedance matrix is:

[0099]

[0100] Among them, Z 11，r (t) is the reference impedance value corresponding to the first branch, Z 22，r (t) is the reference impedance value corresponding to the second branch, and so on, Z nn，r (t) is the reference impedance value corresponding to the nth branch.

[0101] For each branch, the impedance difference is ΔZ aa (t)=|Z aa (t)-Z aa,r (t)|, where Z aa (t) represents the impedance value corresponding to the a-th branch, Z aa,r (t) represents the reference impedance value corresponding to the a-th branch. a is an integer greater than or equal to 1 and less than or equal to n. For example, the abnormal threshold is ΔZ b , then when ΔZ aa (t)>ΔZ b , it indicates that a wiring fault occurs in the ath branch at the current moment.

[0102] In this way, the wiring of each branch can be judged, so as to determine whether the wiring is faulty in multi-load scenarios, and can flexibly respond to complex power load distribution to ensure the stable operation of the power system.

[0103] Based on the above technical solutions, Figure 5 is a flowchart of another fault detection method provided by an embodiment of the present invention. Figure 5 , the fault detection methods include:

[0104] S510 , collecting a plurality of measured voltages and measured currents on each load side at each moment within a set time period.

[0105] S520: Determine the calculated voltage at each moment according to the measured current at each moment and the impedance model.

[0106] S530. Based on the least square method, determine an error function according to each load side, at multiple moments, the best measured voltage among multiple measured voltages at each moment and the calculated voltage at each moment, and determine the impedance value of each load side according to the error function.

[0107] S540, determining whether the impedance difference between the impedance value corresponding to the load side at any time and the reference impedance value is greater than the abnormal threshold value, if not, executing step S550; if yes, executing step S560.

[0108] S550: Determine whether the wiring on the corresponding load side is normal.

[0109] S560: When the change rate of the impedance difference corresponding to the load side at any time is greater than the first preset value, or the change rate of the impedance value corresponding to the load side is greater than the second preset value, it is determined that the corresponding load side wiring has poor contact.

[0110] Specifically, when the rate of change of the impedance difference corresponding to the load side at any moment is greater than the first preset value, it indicates that the rate of change of the impedance difference corresponding to the load side is large, and the impedance difference corresponding to the load side rises rapidly, or the rate of change of the impedance value corresponding to the load side is greater than the second preset value, indicating that the rate of change of the impedance value is large, and the impedance value rises rapidly, which indicates that the corresponding load side wiring contact is poor, so that when a wiring fault occurs, the fault type can be determined to facilitate timely maintenance.

[0111] For example, the impedance difference is ΔZ aa (t), if the impedance difference ΔZ aa (t) rises rapidly, indicating poor wiring contact. The impedance value at the current moment is Z aa (t), after a time interval of Δt, the impedance value is Z aa (t+Δt), the change in impedance is Z aa (t+Δt)-Z aa (t), if Z aa (t+Δt)-Z aa (t)>αΔt, indicating that the impedance value rises rapidly, indicating that the wiring contact is poor. Among them, α is the change rate of the impedance value, that is, the parameter for detecting whether the impedance value rises rapidly.

[0112] S570: When the variance of the multiple impedance values ​​corresponding to the load side within the preset time is greater than the third preset value, it is determined that the connection of the corresponding load side is loose. The preset time may be the same as the set time in any embodiment of the present invention, or may be greater than or less than the set time, which is not limited in this embodiment.

[0113] Specifically, the variance of the multiple impedance values ​​within the preset time length is greater than the third preset value, indicating that the variance of the multiple impedance values ​​is large, that is, the impedance value corresponding to the load side fluctuates greatly in a short period of time, thereby indicating that the corresponding load side wiring is loose.

[0114] For example, if the preset time duration is the same as the set time duration in any embodiment of the present invention, then the impedance values ​​at N moments can be determined within the preset time duration. i At this moment, the impedance value corresponding to the ath branch is Z aa (t i ). Obtain the impedance value corresponding to the a-th branch at N moments, and determine the impedance mean μ of the a-th branch at N moments Z , then the variance of multiple impedance values ​​within the preset time length is If the variance σZ 2 If the impedance value is greater than the third preset value, it indicates that the impedance value fluctuates greatly in a short period of time, thereby indicating that the connection on the load side is loose.

[0115] Based on the above technical solutions, optionally, before determining the calculated voltage at each moment according to the measured current and the impedance model at each load side at multiple moments, the method further includes:

[0116] The impedance model is determined based on the impedance relationship on the load side.

[0117] For example, in a power system including n branches, the impedance of the ath branch is Z aa (t), the total impedance matrix Z(t) of the entire power system is expressed as:

[0118]

[0119] For example, if the voltage on the load side of the power system is V(t) and the current is I(t), then the voltages of the n branches are:

[0120]

[0121] Then the current in the n branches is:

[0122]

[0123] According to the impedance relationship, the impedance model can be determined as V(t)=Z(t)·I(t). In this way, it is convenient to establish the corresponding relationship between the impedance value and the calculated voltage according to the impedance model, thereby facilitating the determination of the impedance value.

[0124] An embodiment of the present invention provides a fault detection device, which is used to execute the fault detection method provided by any of the above implementation schemes. Figure 6 is a schematic diagram of a fault detection device provided by an embodiment of the present invention, with reference to Figure 6 , the fault detection device comprises:

[0125] The acquisition module 610 is used to acquire a plurality of measured voltages and measured currents of each load side at each moment within a set time period;

[0126] A calculated voltage determination module 620, for determining the calculated voltage at each moment according to the measured current at each moment and the impedance model;

[0127] The impedance value determination module 630 is used to determine an error function based on the least square method according to the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment at each load side at multiple moments, and determine the impedance value of each load side according to the error function;

[0128] The fault determination module 640 is used to determine whether there is a connection fault on each load side according to the impedance value.

[0129] The fault detection device provided in the embodiment of the present invention can execute the fault detection method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0130] An embodiment of the present invention further provides an electronic device. Figure 7 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 7 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0131] like Figure 7 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0132] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0133] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a fault detection method.

[0134] In some embodiments, the fault detection method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the fault detection method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the fault detection method in any other appropriate manner (e.g., by means of firmware).

[0135] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0136] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0137] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0138] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0139] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0140] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0141] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0142] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fault detection method, characterized in that: include: Collect multiple measured voltages and measured currents on each load side at each moment within a set time period; Determine the calculated voltage at each moment according to the measured current at each moment and the impedance model; Based on the least square method, an error function is determined according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, and an impedance value of each load side is determined according to the error function; Whether each of the load sides has a wiring fault is determined according to the impedance value.

2. The method according to claim 1, characterized in that Before determining the error function based on the least square method according to each load side, at multiple moments, the best measured voltage among the multiple measured voltages at each moment and the calculated voltage at each moment, the method further includes: For each load side, the optimal measured voltage at each moment is determined using a dynamic time warping method based on the multiple measured voltages at each moment.

3. The method according to claim 2, characterized in that The dynamic time warping method is used to determine the optimal measurement voltage at each moment, including: A difference matrix is ​​established by using the plurality of measured voltages and a reference signal at each moment, and the optimal value of the difference matrix is ​​determined by using the dynamic time warping method to determine the optimal measured voltage at each moment.

4. The method according to claim 3, characterized in that: Before using the plurality of measured voltages at each moment and the reference signal to establish a difference matrix, the method further includes: Discretizing the reference voltage to obtain a reference vector; Performing discrete Fourier transform on the reference voltage to obtain a reference matrix; The reference signal is determined according to the reference vector and the reference matrix.

5. The method according to claim 1, characterized in that Determining whether each load side has a wiring fault according to the impedance value includes: When the impedance difference between the impedance value corresponding to the load side at any moment and the reference impedance value is greater than the abnormal threshold, a wiring fault on the corresponding load side is determined; wherein the reference impedance value is a historical impedance value corresponding to the wiring when there is no fault in the historical impedance value of the corresponding load side, or the reference impedance value is a preset impedance value.

6. The method according to claim 5, characterized in that Determine the corresponding load side wiring fault, including: When the change rate of the impedance difference corresponding to the load side at any time is greater than the first preset value, or the change rate of the impedance value corresponding to the load side is greater than the second preset value, it is determined that the corresponding load side wiring has poor contact; When the variance of the plurality of impedance values ​​corresponding to the load side within the preset time period is greater than a third preset value, it is determined that the connection on the corresponding load side is loose.

7. The method according to claim 1, characterized in that Before determining the calculated voltage at each moment according to the measured current and the impedance model at each load side at each moment in a plurality of moments, the method further includes: The impedance model is determined according to the impedance relationship on the load side.

8. A fault detection device, characterized in that: include: An acquisition module, used for acquiring a plurality of measured voltages and measured currents of each load side at each moment within a set time period; A calculated voltage determination module, used to determine the calculated voltage at each moment according to the measured current and the impedance model at each moment; an impedance value determination module, configured to determine an error function based on a least square method according to the best measured voltage among the plurality of measured voltages at each moment and the calculated voltage at each moment at each load side at a plurality of moments, and determine the impedance value of each load side according to the error function; A fault determination module is used to determine whether each load side has a wiring fault according to the impedance value.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the fault detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the fault detection method according to any one of claims 1 to 7 when executed.

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