A fault detection method and device, electronic equipment and storage medium

Abstract

The application discloses a fault detection method and device, electronic equipment and 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 measured voltages and measured currents of each load side at each moment within a set time length; determining a calculated voltage at each moment according to the measured current and an impedance model at each moment among a plurality of moments according to each load side; determining an error function according to the best measured voltage among the plurality of measured voltages at each moment and the calculated voltage at each moment based on a least square method, and determining an impedance value of each load side according to the error function; and determining whether each load side is in wiring fault according to the impedance value. The technical scheme of the application improves the accuracy of fault detection and reduces the risk in the operation of the power system.

Description

TECHNICAL FIELD

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

[0002] Under the background of large-scale access of smart grids and distributed power sources, the reliability of the functions and performances of electric energy metering devices, as basic equipment of power systems, is increasingly valued. These devices are responsible for real-time monitoring of the use of electric power, including parameters such as voltage, current and power, to ensure accurate metering and reasonable distribution of electric energy. However, as the load side scene becomes increasingly complex, the challenges faced by electric energy metering devices also increase, especially in terms of abnormal problems in the wiring loop, such as loose wiring, poor contact, etc., which directly affect the accuracy and stability of electric energy metering.

[0003] Traditional electrical quantity monitoring methods usually only focus on static voltage and current parameters, and are difficult to effectively capture the dynamic change characteristics of the wiring loop, such as the transient response and fluctuations of impedance. This static monitoring method is insufficient in dealing with the complexification of the load side scene and the load fluctuations after the access of distributed power sources, and is likely to miss potential abnormal signals of the wiring loop, resulting in untimely and incomplete detection.

[0004] Existing abnormality recognition methods often only make judgments through simple parameter monitoring due to the lack of in-depth analysis of the impedance characteristics of the wiring loop, resulting in low recognition accuracy. At the same time, existing technologies are difficult to achieve real-time recognition and alarm of the wiring loop abnormalities, and cannot timely prevent possible equipment failures or safety hazards, thereby increasing the risks in the operation of the power system. SUMMARY

[0005] The present application provides a fault detection method, device, electronic equipment and storage medium to solve the problem of difficult accurate identification of load side faults in a power system.

[0006] According to an aspect of the present application, a fault detection method is provided, which comprises:

[0007] collecting a plurality of measured voltages and measured currents of each load side at each time within a set time period;

[0008] determining a calculated voltage at each time according to the measured current at each time and an impedance model;

[0009] determining an error function according to the best measured voltage in the plurality of measured voltages at each time and the calculated voltage at each time of each load side at a plurality of times based on the least square method, and determining an impedance value of each load side according to the error function;

[0010] determining whether each of the load sides is faulty according to the impedance values.

[0011] Optionally, before determining the error function according to the best measurement voltage of each time and the calculated voltage of each time based on the least square method, the method further comprises:

[0012] For each load side, the best measurement voltage of each time is determined according to the plurality of measurement voltages of each time by using a dynamic time warping method.

[0013] Optionally, the best measurement voltage of each time is determined by using the dynamic time warping method, comprising:

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

[0015] Optionally, before the difference matrix is established by using the plurality of measurement voltages of each time and the reference signal, the method further comprises:

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

[0017] Discrete Fourier transform is performed 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 of the load sides is faulty according to the impedance values, comprising:

[0020] When the impedance difference value between the impedance value corresponding to any time of the load side and a reference impedance value is greater than an abnormal threshold value, it is determined that the corresponding load side is faulty; wherein the reference impedance value is a historical impedance value corresponding to the time when the load side is not faulty in the historical impedance values of the corresponding load side, or the reference impedance value is a preset impedance value.

[0021] Optionally, determining that the corresponding load side is faulty, comprising:

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

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

[0024] Optionally, before the calculating the calculated voltage of each time according to the measured current of each time and the impedance model, the method further comprises:

[0025] determining the impedance value of each of the load sides according to the error function.

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

[0027] a collecting module configured to collect a plurality of measured voltages and a plurality of measured currents of each of the load sides at each time within a set time period;

[0028] a calculating voltage determining module configured to determine a calculated voltage of each time according to the measured current of each time and the impedance model;

[0029] an impedance value determining module configured to determine an error function according to the best measured voltage of each of the plurality of measured voltages of each time and the calculated voltage of each time of each of the load sides based on a least square method, and determine an impedance value of each of the load sides according to the error function;

[0030] a fault determining module configured to determine whether each of the load sides is faulty according to the impedance value.

[0031] According to another aspect of the present application, there is provided an electronic device, 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 to enable the at least one processor to perform the fault detection method according to any one of the embodiments of the present application.

[0035] According to another aspect of the present application, there is provided a computer readable storage medium storing computer instructions for enabling a processor to perform the fault detection method according to any one of the embodiments of the present application when executed by the processor.

[0036] According to another aspect of the present application, there is provided a computer program product comprising a computer program for enabling a processor to perform the fault detection method according to any one of the embodiments of the present application when executed by the processor.

[0037] The technical scheme of the embodiment of the present application collects the measured voltage and the measured current of the plurality of load sides at each moment within the set time length, determines the optimal measured voltage in the plurality of measured voltages at each moment, the error of the optimal measured voltage is small, and the accuracy of measurement can be ensured, and then the accuracy of impedance value calculation is ensured. According to the least square method, the error function is determined according to the optimal measured voltage in the plurality of measured voltages at each moment and the calculated voltage at each moment of each load side at a plurality of moments, and the impedance value of each load side is determined according to the error function, the impedance value is determined by the optimal measured voltage and the calculated voltage at N moments, the dynamic performance of impedance value calculation can be improved, and the accuracy of impedance value determination can be further improved. And whether each load side in the plurality of load sides is wired fault can be determined, and the detection of the plurality of load sides can be realized. In this way, whether the load side loop exists wiring fault can be accurately judged, so that detection can be accurately and timely performed when wiring fault occurs, detection is avoided after fault for a long time, so that timely alarm can be performed, and the risk in the operation of the power system is reduced.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0040] Figure 1 is a flowchart of a fault detection method provided by the embodiment of the present application;

[0041] Figure 2 is a flowchart of another fault detection method provided by the embodiment of the present application;

[0042] Figure 3 is a flowchart of another fault detection method provided by the embodiment of the present application;

[0043] Figure 4 is a flowchart of another fault detection method provided by the embodiment of the present application;

[0044] Figure 5 is a flowchart of another fault detection method provided by the embodiment of the present application;

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

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

[0047] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the protection scope of the present application.

[0048] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can 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 application provides a fault detection method, which can be applied to connection fault detection of a heavy load side of a power system. The power system can be a photovoltaic power generation system, or a wind power generation system, etc., and the embodiment is not limited thereto. 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 application, referring to Figure 1 , the fault detection method comprises:

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

[0052] 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 can 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 time length includes N time points, the multiple measured voltages and measured currents corresponding to the N time points can be collected, that is, at each of the N time points, the multiple measured voltages and measured currents of the load side are collected. N is an integer greater than 1. The measured voltages and measured currents at the N time points can be collected once every preset interval time length, and multiple measured voltages and a measured current are collected each time. That is, the interval between two adjacent time points is a preset interval time length.

[0053] For example, the measured current collected at t1 is I c (t1), the measured current collected at t2 is I c (t2), and so on, the measured current collected at t N is I c (t N ), and so on. The measured currents collected at the N time points can be represented in matrix form as follows:

[0054]

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

[0056] Specifically, the impedance model represents the corresponding relationship between the voltage, current and impedance in the circuit. Therefore, by substituting the measured current and impedance value at each time point into the impedance model, the calculated voltage at each time point can be represented by the impedance value.

[0057] For example, the impedance model is V(t)=Z(t)·I(t), V(t) is the voltage of the load circuit corresponding to t, Z(t) is the impedance value of the load circuit corresponding to t, and I(t) is the current of the load circuit corresponding to t. The measured currents at the N time points are I c , and the impedance values are Z. The calculated voltages V m (f) at the N time points can be represented by the impedance values as follows: m (f)=Z·I c . In this way, the expression of the impedance value can be established, which facilitates the determination of the impedance value. Moreover, by the measured currents at the N time points, the calculated voltages at the N time points can be determined, thereby obtaining the calculated voltages in matrix form.

[0058] S130, determining the error function according to the best measured voltage in the multiple measured voltages at each time point and the calculated voltage at each time point for each load side based on the least square method, and determining the impedance value of each load side according to the error function.

[0059] Among them, the optimal measurement voltage can be determined in a plurality of measurement voltages at each moment, the error of the optimal measurement voltage is smaller, and the accuracy of the measurement can be ensured, thereby ensuring the accuracy of the impedance value calculation.

[0060] Specifically, each moment corresponds to an optimal measurement voltage and a calculation voltage, and N moments correspond to N optimal measurement voltages and N calculation voltages, so as to obtain the optimal measurement voltage in the form of a matrix and the calculation voltage in the form of a matrix. By establishing an error function and calculating the error function based on the least square method, the impedance value corresponding to the minimum error is determined, so that the impedance values of all load sides can be accurately determined. Moreover, the impedance value is determined by the optimal measurement voltage and the calculation voltage at N moments, which can improve the dynamic performance of the impedance value calculation and is beneficial to further improve the accuracy of the impedance value determination.

[0061] For example, the optimal measurement voltage at N moments is V c , and 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 ), the derivative of the impedance value Z is taken and set to zero, that is , that is, Z = (I c T I c ) -1 I c T V c , so that the impedance value can be determined according to the optimal measurement voltage and the measurement current. For example, the impedance value Z is in the form of a matrix, that is, it includes impedance values at N moments, so as to facilitate dynamic monitoring of the impedance value and improve the dynamic performance of the impedance value determination. The impedance value at any moment can be used to determine whether the corresponding load side is faulty.

[0062] S140, determining whether each load side is connected with a fault according to the impedance value.

[0063] Specifically, the impedance value of the load side circuit can be used to determine whether the load side has a wiring fault, for example, when the impedance value is too large or too small, it is determined that the load side has a wiring fault, or when the impedance value changes greatly or quickly, it can be determined that the load side has a wiring fault. The present embodiment is not limited.

[0064] The technical scheme of the embodiment collects the measurement voltage and the measurement current of each load side at each moment, determines the optimal measurement voltage in the multiple measurement voltages at each moment, the error of the optimal measurement voltage is small, and the measurement accuracy can be ensured, and then the impedance value calculation accuracy can be ensured. According to each load side, the optimal measurement voltage in the multiple measurement voltages at each moment and the calculation voltage at each moment are used to determine the error function based on the least square method, and the impedance value of each load side is determined according to the error function. The impedance value is determined by the optimal measurement voltage and the calculation voltage at N moments, which can improve the dynamic performance of the impedance value calculation and is beneficial to further improve the accuracy of the impedance value determination. Whether each load side in the multiple load sides is wired faulty can be determined, and the multiple load sides can be detected. In this way, whether the load side loop is wired faulty can be accurately judged, so that detection can be accurately and timely performed when the wiring is faulty, detection is avoided after the fault for a long time, and timely alarm can be performed, thereby reducing the risk in the power system operation.

[0065] On the basis of the above technical scheme, the determination method of the optimal measurement voltage is described below, but is not limited to the present application.

[0066] Figure 2 is a flowchart of another fault detection method provided by the embodiment of the present application. Optionally, reference can be made to Figure 2 The fault detection method comprises the following steps.

[0067] S210, the multiple measurement voltages and the measurement current of each load side are collected at each moment within a set time length.

[0068] S220, the calculation voltage at each moment is determined according to the measurement current at each moment and the impedance model.

[0069] S230, for each load side, the optimal measurement voltage at each moment is determined by using the dynamic time warping method according to the multiple measurement voltages at each moment.

[0070] Specifically, the dynamic time warping (DTW) method can align two sequences, so that the measurement voltage and the reference voltage can be aligned by using the dynamic time warping method. The measurement voltage and the reference voltage are close when aligned, the measurement voltage corresponding to the alignment is used as the optimal measurement voltage, the accuracy of the optimal measurement voltage can be ensured, and the impedance value of the load side loop can be accurately determined.

[0071] S240, according to each load side, the optimal measurement voltage in the multiple measurement voltages at each moment and the calculation voltage at each moment are used to determine the error function based on the least square method, and the impedance value of each load side is determined according to the error function.

[0072] S250, determining whether each load side is wired faulty according to the impedance value.

[0073] On the basis of the technical solution, Figure 3 is a flowchart of another fault detection method provided by the embodiment of the application, and optionally, reference Figure 3 , the fault detection method comprises:

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

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

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

[0077] The reference voltage can be a preset voltage value or a historical voltage value corresponding to the time when the load side circuit is not faulty, and the embodiment is not limited.

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

[0079]

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

[0081] Specifically, by performing discrete Fourier transform on the reference voltage, the reference matrix can be obtained in the frequency domain, so that the reference voltage is represented by a plurality of data. For example, the reference matrix F is obtained by performing discrete Fourier transform on the reference voltage:

[0082]

[0083] S350, determining a reference signal according to the reference vector and the reference matrix.

[0084] Specifically, the time domain signal can be determined according to the reference vector and the reference matrix, and then the reference signal is determined, and the determined reference signal is in the form of a matrix, which can be operated with the matrix formed by the plurality of measured voltages at each time, so as to determine the optimal measured voltage, thereby accurately determining the impedance value of the load side circuit according to the optimal measured 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, a difference matrix is established by using the multiple measurement voltages at each moment and the reference signal, and an optimal value of the difference matrix is determined by using a dynamic time warping method to determine the optimal measurement voltage at each moment.

[0087] Specifically, by establishing the difference matrix, the difference matrix can represent the deviation of the measurement voltage from the reference signal, and by using the dynamic time warping method, an optimal path can be determined, along which the cumulative difference value is the smallest, so that the optimal value of the difference matrix is determined, so that the difference value between the measurement voltage and the reference signal is the smallest, and thus the measurement voltage corresponding to the smallest difference value is determined as the optimal measurement voltage. In this way, the optimal measurement voltage determined is close to the reference voltage, ensuring the accuracy of the optimal measurement voltage measured, thereby improving the accuracy of the impedance value determination.

[0088] For example, at the same moment, the measurement voltage corresponding to a point is V c (t i ), the reference voltage in the corresponding reference signal is V r (t j ), and 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)). Wherein, P(i, j) is the point corresponding to the measurement voltage V c (t i ) and the reference voltage V r (t j ), P(i-1, j) represents a point extending along the measurement voltage direction, P(i, j-1) represents a point extending along the reference voltage direction, and P(i-1, j-1) represents a point extending along the reference voltage and measurement voltage directions. By recursion, the optimal path can be determined, and thus the difference matrix corresponding to the optimal path is determined, the optimal value of the difference matrix is obtained, and the measurement voltage corresponding to the optimal value of the difference matrix is the optimal measurement voltage. In this way, the measurement voltage and the reference voltage can be aligned in time, a more reliable similarity calculation method is provided for fault detection, and the accuracy of the impedance value determination can be improved.

[0089] S370, based on the least square method, the optimal measurement voltage in the multiple measurement voltages at each moment and the calculated voltage at each moment are used to determine an error function for each load side at multiple moments, and the impedance value of each load side is determined according to the error function.

[0090] S380, whether each load side is connected with a fault is determined according to the impedance value.

[0091] On the basis of each of the above technical solutions, the method for determining whether the load side is faulty will be described below, but 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 application. Alternatively, reference can be made to Figure 4 The fault detection method comprises:

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

[0094] S420, determining a calculated voltage at each time according to the measured current at each time and an impedance model.

[0095] S430, determining an error function according to the best measured voltage in the plurality of measured voltages at each time and the calculated voltage at each time of each load side based on the least square method, and determining an impedance value of each load side according to the error function.

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

[0097] Specifically, by comparing the determined impedance value corresponding to any time of the load side 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, and then it indicates that the wiring of the corresponding load side 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 loop is large, and thus it is determined that the wiring of the load side is faulty. In this way, whether the load side is faulty can be determined in time, so that timely maintenance can be ensured to ensure the safety of the power system.

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

[0099]

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

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

[0102] In this way, the wiring of each branch can be judged, so that the wiring fault in the multi-load scenario can be judged, the complex power load distribution can be flexibly coped with, and the stable operation of the power system can be ensured.

[0103] On the basis of the above technical solutions, Figure 5 is a flowchart of another fault detection method provided by the embodiment of the present application, and optionally, reference Figure 5 is made to the above technical solutions.

[0104] S510, a plurality of measured voltages and measured currents of each load side at each time within a set time length are collected.

[0105] S520, a calculated voltage at each time is determined according to the measured current at each time and an impedance model.

[0106] S530, according to the least square method, a best measured voltage in the plurality of measured voltages at each time and the calculated voltage at each time are determined for each load side at each time, an error function is determined, and an impedance value of each load side is determined according to the error function.

[0107] S540, it is judged whether the impedance difference value between the impedance value corresponding to any time of the load side and the reference impedance value is greater than the abnormal threshold value, if not, step S550 is performed, and if yes, step S560 is performed.

[0108] S550, it is determined that the wiring of the corresponding load side is normal.

[0109] S560, when the change rate of the impedance difference corresponding to any moment of the load side is greater than a first preset value, or the change rate of the impedance value corresponding to the load side is greater than a second preset value, it is determined that the wiring contact of the corresponding load side is poor.

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

[0111] For example, the impedance difference is ΔZ aa (t), if the impedance difference ΔZ aa (t) rises rapidly, it indicates that the wiring contact is poor. 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), and the change of the impedance value is Z aa (t+Δt)-Z aa (t), if Z aa (t+Δt)-Z aa (t) > αΔt, it indicates that the impedance value rises rapidly, which indicates that the wiring contact is poor. Wherein, 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 plurality of impedance values corresponding to the load side within a preset time period is greater than a third preset value, it is determined that the wiring of the corresponding load side is loose. Wherein, the preset time period can be the same as the set time period in any embodiment of the present application, or can be greater or less than the set time period, and the present embodiment is not limited.

[0113] Specifically, when the variance of the plurality of impedance values within the preset time period is greater than a third preset value, it indicates that the variance of the plurality of impedance values is large, that is, the impedance value corresponding to the load side fluctuates greatly within a short time, which indicates that the wiring of the corresponding load side is loose.

[0114] For example, the preset time period is the same as the set time period in any embodiment of the present application. Then, within the preset time period, the impedance values at N moments can be determined. i The impedance value corresponding to the a-th branch at the t aa moment is Z i (t Z ). The impedance values corresponding to the a-th branch at N moments are obtained, and the mean impedance value μ Z of the a-th branch at N moments is determined, and then the variance of the plurality of impedance values within the preset time period is If the variance σZ 2 Greater than the third preset value, indicating that the impedance value appears a larger fluctuation in a short time, thereby indicating that the load side wiring is loose.

[0115] On the basis of the above technical solutions, optionally, before the calculated voltage of each time is determined according to the measured current of each time and the impedance model of each load side in a plurality of times, the method further comprises:

[0116] According to the impedance relationship of the load side, the impedance model is determined.

[0117] For example, the power system comprises n branches, the impedance of the a th branch is Z aa (t), and the total impedance matrix Z(t) of the entire power system is represented as:

[0118]

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

[0120]

[0121] The current of the n branches is:

[0122]

[0123] According to the impedance relationship, the impedance model V(t) = Z(t) I(t) can be determined, so that the corresponding relationship between the impedance value and the calculated voltage can be established according to the impedance model, thereby facilitating the determination of the impedance value.

[0124] The embodiment of the application provides a fault detection device for executing the fault detection method provided by any of the above embodiments. Figure 6 Fig. 1 is a structural schematic diagram of a fault detection device provided by the embodiment of the application, referring to Figure 6 The fault detection device comprises:

[0125] The acquisition module 610 is configured to acquire a plurality of measured voltages and measured currents of each load side at each time within a set time length.

[0126] The calculated voltage determination module 620 is configured to determine a calculated voltage of each time according to the measured current of each time and the impedance model.

[0127] The impedance value determination module 630 is configured to determine an error function according to the best measured voltage of each time and the calculated voltage of each time of each load side in a plurality of times based on the least square method, and determine the impedance value of each load side according to the error function.

[0128] The fault determination module 640 is configured 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 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 claimed herein.

[0131] like Figure 7 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which is communicatively connected to the at least one processor 11. The memory stores a computer program that can be executed by the at least one processor. 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 into the random access memory (RAM) 13. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12, and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0132] Multiple 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 magnetic 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 via a computer network such as the Internet and / or various telecommunication networks.

[0133] The processor 11 can be various general and / or special purpose 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 specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, and the like. The processor 11 performs various methods and processes described above, such as the fault detection method.

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

[0135] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a programmable logic device (PLD), a computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0136] Computer programs used to implement the methods of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the computer program, when executed by the processor, implements the functions / acts specified in the flowcharts and / or block diagrams. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, partially on a machine and partially on a remote machine or entirely on a remote machine or server.

[0137] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, 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 disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0138] To provide for interaction with a user, the systems and techniques described here can 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 a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0139] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can 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), blockchain network, and the Internet.

[0140] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can 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 large management difficulty and weak business scalability in traditional physical host and VPS service.

[0141] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0142] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A fault detection method characterized by, The method comprises the following steps: collecting a plurality of measured voltages and measured currents of each load side at each moment within a set time period; determining a calculated voltage at each moment according to the measured current at each moment and an impedance model; determining an error function according to the best measured voltage in the plurality of measured voltages at each moment and the calculated voltage at each moment of each load side based on the least square method, and determining an impedance value of each load side according to the error function; determining whether the wiring of each load side is faulty according to the impedance value.

2. The method of claim 1, wherein, Before determining the error function according to the best measured voltage in the plurality of measured voltages at each moment and the calculated voltage at each moment of each load side based on the least square method, the method further comprises the following steps: for each load side, determining the best measured voltage at each moment according to the plurality of measured voltages at each moment by using a dynamic time warping method.

3. The method of claim 2, wherein, The method of determining the best measured voltage at each moment by using the dynamic time warping method comprises the following steps: establishing a difference matrix by using the plurality of measured voltages at each moment and a reference signal, and determining the best value of the difference matrix by using the dynamic time warping method to determine the best measured voltage at each moment.

4. The method of claim 3, wherein, Before establishing the difference matrix by using the plurality of measured voltages at each moment and a reference signal, the method further comprises the following steps: discretizing the reference voltage to obtain a reference vector; performing a discrete Fourier transform on the reference voltage to obtain a reference matrix; determining the reference signal according to the reference vector and the reference matrix.

5. The method of claim 1, wherein, The method of determining whether the wiring of each load side is faulty according to the impedance value comprises the following steps: when the impedance difference value between the impedance value corresponding to any moment of the load side and a reference impedance value is greater than an abnormal threshold value, it is determined that the wiring of the corresponding load side is faulty; wherein the reference impedance value is a historical impedance value corresponding to a time when the wiring of the corresponding load side is not faulty in historical impedance values of the corresponding load side, or the reference impedance value is a preset impedance value.

6. The method of claim 5, wherein, The method of determining that the wiring of the corresponding load side is faulty comprises the following steps: when the change rate of the impedance difference value corresponding to any moment of the load side is greater than a first preset value, or the change rate of the impedance value corresponding to the load side is greater than a second preset value, it is determined that the wiring of the corresponding load side is poor in contact; when the variance of the plurality of impedance values corresponding to the load side within a preset time period is greater than a third preset value, it is determined that the wiring of the corresponding load side is loose.

7. The method of claim 1, wherein, Before determining the calculated voltage at each moment according to the measured current at each moment and an impedance model of each load side, the method further comprises the following steps: determining the impedance model according to the impedance relationship of the load side.

8. A fault detection apparatus characterized by comprising: The method comprises the following steps: a collection module, configured to collect 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, configured to determine a calculated voltage at each moment according to the measured current at each moment and an impedance model; an impedance value determination module, configured to determine an error function according to the best measured voltage in the plurality of measured voltages at each moment and the calculated voltage at each moment of each load side based on the least square method, and determine an impedance value of each load side according to the error function; A fault determination module is configured to determine whether each of the load sides is connected with a fault according to the impedance values.

9. An electronic device, comprising: The electronic device comprises: at least one processor; and a memory connected with the at least one processor in communication; 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 to enable the at least one processor to execute the fault detection method in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for enabling the processor to implement the fault detection method in any one of claims 1-7 when executed.

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