Cable partial discharge positioning method, device and equipment and storage medium

Abstract

The invention relates to the technical field of electric power, and discloses a cable partial discharge positioning method, device and equipment and a storage medium, and the method comprises the steps: obtaining a first signal waveform, a second signal waveform and a third signal waveform when a partial discharge signal reaches monitoring terminals at the head end, the middle position and the tail end of a cable; determining a first time, a second time and a third time when the signal reaches the monitoring terminals at the head end, the middle position and the tail end of the cable by adopting a wavelet decomposition algorithm; determining a position interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform and the third signal waveform; and based on the position interval of the partial discharge fault point, the first time, the second time and the third time, determining the position of the partial discharge fault point by adopting a double-end traveling wave distance measurement algorithm. According to the method, the partial discharge fault point is accurately calculated through the double-end traveling wave distance measurement algorithm, the accuracy and efficiency of partial discharge positioning are improved, and safe and stable operation of a power system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method, device, equipment and storage medium for locating partial discharge of a cable. Background Art

[0002] Due to the development of urbanization, the power system has to transmit a large amount of electrical energy at high voltage through long-distance cables. High and medium voltage AC underground transmission cables have the advantages of high reliability, low interference to adjacent communication lines, safety, and small footprint, and are replacing overhead lines in the power system. When the electric field strength that the solid and liquid insulating materials used in the insulation system of underground transmission cables can withstand exceeds the normal operating field strength of the cable itself and other high-voltage equipment, it is very easy to cause partial discharge. If the partial discharge fault point is not located in time, the free initial electrons will be accelerated in the electric field to a level sufficient to trigger a discharge avalanche, aggravating the partial discharge. When the partial discharge amount reaches a certain threshold, the cable will fail, causing the motor to suddenly shut down, directly affecting the power supply of the grid after grid connection, and causing serious economic losses. Therefore, how to locate the partial discharge fault point in the cable is a problem that needs to be solved.

[0003] At present, conventional single-end positioning and dual-end positioning methods are usually used for positioning, but the above two positioning methods have poor accuracy and low efficiency. Summary of the invention

[0004] In view of this, the present invention provides a method, device, equipment and storage medium for locating partial discharge of a cable to solve the problems of poor accuracy and low efficiency in locating partial discharge.

[0005] In a first aspect, the present invention provides a method for locating partial discharge of a cable, the method comprising:

[0006] Respectively acquiring a first signal waveform, a second signal waveform and a third signal waveform when the partial discharge signal reaches the monitoring terminals located at the head end, the middle position and the tail end of the cable;

[0007] Using a wavelet decomposition algorithm, the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminal at the beginning, the middle and the end of the cable are determined respectively;

[0008] Determine a location interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform, and the third signal waveform;

[0009] Based on the location interval, the first time, the second time and the third time of the partial discharge fault point, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point.

[0010] The cable partial discharge positioning method provided by the embodiment of the present invention can ensure that partial discharge signals are obtained from different distances by arranging monitoring terminals at the head end, middle position and tail end of the cable, which helps to improve the reliability and accuracy of partial discharge positioning. The partial discharge signals at different positions are analyzed by wavelet decomposition to accurately determine the time when the partial discharge signals arrive at different positions. The position interval of the partial discharge fault point is analyzed based on the waveform, which provides a focus area for subsequent precise positioning, reduces the search space, and improves the positioning efficiency. The partial discharge fault point is accurately calculated by a double-end traveling wave ranging algorithm, which improves the accuracy and efficiency of partial discharge positioning and ensures the safe and stable operation of the power system.

[0011] In an optional implementation, determining a location interval where a partial discharge fault point of a cable is located based on the first signal waveform, the second signal waveform, and the third signal waveform includes:

[0012] When the first signal waveform is similar to the second signal waveform, the position interval where the partial discharge fault point is located is the interval between the middle position and the tail end of the cable; or,

[0013] When the second signal waveform is similar to the third signal waveform, the position interval where the partial discharge fault point is located is the interval between the head end and the middle position of the cable.

[0014] The cable partial discharge positioning method provided by the embodiment of the present invention determines the location interval of the partial discharge fault point through the signal waveform monitored by the monitoring terminals arranged at the head end, middle position and tail end of the cable, which can reduce unnecessary inspection range and improve positioning efficiency.

[0015] In an optional implementation, based on the location interval of the partial discharge fault point, the second time, and the third time, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point, including:

[0016] When the position interval is the interval between the middle position and the tail end of the cable, obtaining a first assumed position of the partial discharge fault point;

[0017] Determine a first distance and a second distance between the first assumed position and the monitoring terminal located at the middle position and the tail end of the cable respectively;

[0018] determining a third distance between monitoring terminals located at a mid-point and a tail end of the cable;

[0019] The location of the partial discharge fault point is determined based on the first assumed location, the first distance, the second distance, the third distance, the second time, the third time, and the transmission speed of the partial discharge signal.

[0020] The cable partial discharge positioning method provided by the embodiment of the present invention adopts a double-end traveling wave ranging algorithm when the partial discharge fault point is located in the position interval between the middle position and the tail end of the cable, and performs analysis based on the first assumed position of the partial discharge fault point in the position interval to determine the exact position of the partial discharge fault point, thereby improving the accuracy of partial discharge positioning.

[0021] In an optional implementation, based on the location interval of the partial discharge fault point, the first time and the second time, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point, further comprising:

[0022] When the position interval is the interval between the head end and the middle position of the cable, obtaining a second assumed position of the partial discharge fault point;

[0023] Determining a fourth distance and a fifth distance between the second assumed position and the monitoring terminal located at the head end and the middle position of the cable respectively;

[0024] determining a sixth distance between monitoring terminals located at a mid-point and a tail end of the cable;

[0025] The location of the partial discharge fault point is determined based on the second assumed location, the fourth distance, the fifth distance, the sixth distance, the first time, the second time, and the transmission speed of the partial discharge signal.

[0026] The cable partial discharge positioning method provided by the embodiment of the present invention adopts a double-end traveling wave ranging algorithm when the partial discharge fault point is located in the position interval between the head end and the middle position of the cable, and performs analysis based on the second assumed position of the partial discharge fault point in the position interval to determine the exact position of the partial discharge fault point, thereby improving the accuracy of partial discharge positioning.

[0027] In an optional implementation, a wavelet decomposition algorithm is used to respectively determine the first time, the second time and the third time when the partial discharge signal reaches the monitoring terminal at the beginning, the middle and the end of the cable, including:

[0028] Respectively acquiring first signal data, second signal data and third signal data of the monitoring terminal where the partial discharge signal reaches the head end, the middle position and the tail end of the cable;

[0029] Determine the wavelet basis function;

[0030] Based on the wavelet basis function, the first signal data, the second signal data and the third signal data are respectively subjected to wavelet decomposition of a preset number of layers;

[0031] In each layer after wavelet decomposition, the relevant features of the partial discharge signal are determined;

[0032] Based on the changes of the relevant features of each layer and the wavelet coefficients of each layer, the first time, the second time and the third time are determined.

[0033] The cable partial discharge positioning method provided by the embodiment of the present invention obtains signal data from three monitoring terminals respectively, then selects wavelet basis functions adapted to the characteristics of the partial discharge signal, and performs multi-layer wavelet decomposition on the signal data. Each layer of decomposition can extract signal features related to the arrival of the partial discharge signal, identifies the features of the partial discharge signal in each layer of decomposition, and monitors the change of the wavelet coefficient. By comparing the change trends of the wavelet coefficients of different monitoring terminals, the time point of the arrival of the partial discharge signal can be accurately positioned, thereby improving the accuracy of determining the time and providing an accurate time reference for subsequent partial discharge positioning.

[0034] In a second aspect, the present invention provides a device for locating partial discharge of a cable, the device comprising:

[0035] An acquisition module, used to respectively acquire a first signal waveform, a second signal waveform and a third signal waveform when the partial discharge signal reaches the monitoring terminals located at the head end, the middle position and the tail end of the cable;

[0036] A decomposition module, for respectively determining the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminal at the beginning, the middle and the end of the cable by using a wavelet decomposition algorithm;

[0037] A determination module, used to determine a location interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform and the third signal waveform;

[0038] The positioning module is used to determine the position of the partial discharge fault point by using a double-terminal traveling wave ranging algorithm based on the position interval, the first time, the second time and the third time of the partial discharge fault point.

[0039] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for locating partial discharge of a cable according to the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0040] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for locating partial discharge of a cable according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 is a flow chart of a method for locating partial discharge of a cable according to an embodiment of the present invention;

[0043] Figure 2 is a flow chart of another cable partial discharge location method according to an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of a partial discharge fault point according to an embodiment of the present invention;

[0045] Figure 4 is a schematic diagram of another partial discharge fault point according to an embodiment of the present invention;

[0046] Figure 5 is a structural block diagram of a cable partial discharge positioning device according to an embodiment of the present invention;

[0047] Figure 6 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] When the electric field strength that the solid and liquid insulating materials used in the insulation system of underground power transmission cables can withstand exceeds the normal operating field strength of the cable itself and other high-voltage equipment, it is very easy to cause partial discharge. If the partial discharge fault point is not located in time, when the local discharge amount reaches a certain threshold, the cable will fail, causing the motor to suddenly shut down, directly affecting the power supply of the grid after grid connection, causing serious economic losses. However, the traditional single-end positioning and double-end positioning methods have poor accuracy and low efficiency. The cable partial discharge positioning method provided in the embodiment of the present invention accurately locates the partial discharge fault point, improves the accuracy and efficiency of partial discharge positioning, and ensures the safe and stable operation of the power system.

[0050] According to an embodiment of the present invention, an embodiment of a method for locating partial discharge of a cable is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0051] In this embodiment, a method for locating partial discharge of a cable is provided, which can be used in electronic equipment. Figure 1 : is a flow chart of a method for locating partial discharge of a cable according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0052] Step S101, respectively obtain the first signal waveform, the second signal waveform and the third signal waveform when the local discharge signal arrives at the monitoring terminals located at the head end, the middle position and the tail end of the cable. Specifically, the three monitoring terminals located at the head end, the middle position and the tail end of the cable should be set to the same direction. Each monitoring terminal is equipped with a Rogowski coil sensor, which couples the instantaneous electromagnetic field changes generated by the local discharge and completes the collection of the local discharge signal in the ultra-high frequency field (30MHZ~900MHZ) to reduce interference. According to the electrical properties of the cable system and the attenuation characteristics of the local discharge signal in the cable, the typical bandwidth of the local discharge activity in the cable is usually in the range of tens of MHz to hundreds of MHz, which is consistent with the bandwidth range of the Rogowski coil sensor used by the monitoring terminal. When the local discharge signal arrives at the monitoring terminals at three different positions, the signal waveforms monitored by the three monitoring terminals are obtained. The signal waveform contains the characteristic information of the local discharge signal and is the basis for local discharge positioning.

[0053] Step S102, using a wavelet decomposition algorithm, respectively determine the first time, the second time and the third time when the partial discharge signal reaches the monitoring terminals at the head end, the middle position and the tail end of the cable. Specifically, wavelet decomposition helps to separate the characteristics of the partial discharge signal when it reaches each monitoring terminal from the partial discharge signal, and identifies the characteristic moments of the partial discharge signal, that is, the first time, the second time and the third time, which is helpful for subsequent partial discharge positioning.

[0054] Step S103, based on the first signal waveform, the second signal waveform and the third signal waveform, determine the location interval of the partial discharge fault point of the cable. Specifically, based on the similarities and differences between the signal waveforms monitored by the monitoring terminals at three different locations, the location interval of the partial discharge fault point is determined, and the location range of the partial discharge fault point is initially narrowed.

[0055] Step S104, based on the location interval of the partial discharge fault point, the first time, the second time and the third time, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point. Specifically, the double-terminal traveling wave ranging algorithm accurately locates the partial discharge fault point based on the time difference of the partial discharge signal propagating in the cable, and accurately determines the location of the partial discharge fault point in combination with the physical parameters of the cable.

[0056] The cable partial discharge positioning method provided by the embodiment of the present invention can ensure that partial discharge signals are obtained from different distances by arranging monitoring terminals at the head end, middle position and tail end of the cable, which helps to improve the reliability and accuracy of partial discharge positioning. The partial discharge signals at different positions are analyzed by wavelet decomposition to accurately determine the time when the partial discharge signals arrive at different positions. The position interval of the partial discharge fault point is analyzed based on the waveform, which provides a focus area for subsequent precise positioning, reduces the search space, and improves the positioning efficiency. The partial discharge fault point is accurately calculated by a double-end traveling wave ranging algorithm, which improves the accuracy and efficiency of partial discharge positioning and ensures the safe and stable operation of the power system.

[0057] In this embodiment, a method for locating partial discharge of a cable is provided, which can be used for the above-mentioned electronic equipment. Figure 2 FIG. 4 is a flow chart of another method for locating partial discharge of a cable according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0058] Step S201, respectively obtain the first signal waveform, the second signal waveform and the third signal waveform when the partial discharge signal reaches the monitoring terminals located at the beginning, the middle and the end of the cable. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0059] Step S202, using a wavelet decomposition algorithm, respectively determining the first time, the second time and the third time when the partial discharge signal reaches the monitoring terminals at the beginning, the middle and the end of the cable.

[0060] Specifically, the above step S202 includes:

[0061] Step S2021, respectively obtain the first signal data, the second signal data and the third signal data of the monitoring terminals where the partial discharge signal reaches the head end, the middle position and the tail end of the cable. Specifically, the signal data are respectively obtained from the three monitoring terminals, and the signal data includes the information of the partial discharge signal reaching each monitoring terminal, such as the time domain waveform, frequency domain distribution, background noise, amplitude and phase information.

[0062] Step S2022, determine the wavelet basis function. Specifically, the wavelet basis function is the core element in wavelet decomposition, and determines how to decompose the signal. In the embodiment of the present invention, a wavelet basis function suitable for the characteristics of the partial discharge signal is determined.

[0063] Step S2023, based on the wavelet basis function, the first signal data, the second signal data and the third signal data are respectively subjected to a preset number of wavelet decompositions. Specifically, the selected wavelet basis function is used to perform a preset number of wavelet decompositions on the three signal data, for example, a 5-layer wavelet decomposition. The signal data is decomposed into a plurality of sub-band signals of different scales, each layer corresponding to a different frequency component.

[0064] Step S2024, determining the relevant features of the partial discharge signal in each layer after wavelet decomposition. Specifically, after each layer of wavelet decomposition, analyzing the relevant features of the signal, such as the mutation point of the wavelet coefficient, energy distribution, etc., to reveal the existence and intensity of the partial discharge signal.

[0065] Step S2025, based on the changes of the relevant features of each layer and the wavelet coefficients of each layer, determine the first time, the second time and the third time. Specifically, by comparing the wavelet coefficients of each layer and tracking the changes of the relevant features, the time when the partial discharge signal first appears at different monitoring terminals can be accurately located, and the relative time delay of the partial discharge signal propagating along the cable can be reflected, providing a basis for subsequent positioning. Optionally, the process of using wavelet decomposition to determine the time when the partial discharge signal arrives at the three monitoring terminals can be performed in simulation software, such as MATLAB, and the embodiment of the present invention does not limit this.

[0066] Step S203: determining a location interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform and the third signal waveform.

[0067] Specifically, the above step S203 includes:

[0068] Step S2031, when the first signal waveform is similar to the second signal waveform, the position interval of the partial discharge fault point is the interval between the middle position and the tail end of the cable. Specifically, since the first signal waveform is monitored by the monitoring terminal at the head end, and the second signal waveform is monitored by the monitoring terminal at the middle position, if the first signal waveform is similar to the second signal waveform, it means that the influence of the partial discharge activity on the head end and the middle position is similar, and the attenuation of the signal characteristics between these two positions of the cable is not large. Therefore, the partial discharge fault point is not located between the head end and the middle position of the cable, but between the middle position and the tail end. Among them, similar comparison can be made based on the shape, peak intensity, frequency component, etc. of the signal waveform, and this is only an example and is not limited to it.

[0069] Alternatively, in step S2032, when the second signal waveform is similar to the third signal waveform, the position interval where the partial discharge fault point is located is the interval between the head end and the middle position of the cable. Specifically, referring to the above step S2031, if the second signal waveform is similar to the third signal waveform, it means that the influence of the partial discharge activity on the middle position and the tail end is similar, and the attenuation of the signal characteristics between these two positions of the cable is not large, therefore, the partial discharge fault point is located between the head end and the middle position of the cable.

[0070] Step S204, based on the location interval of the partial discharge fault point, the first time, the second time and the third time, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point.

[0071] Specifically, the above step S204 includes:

[0072] Step S2041, when the position interval is the interval between the middle position and the tail end of the cable, obtain a first assumed position of the partial discharge fault point. Specifically, when the partial discharge fault point is located in the interval between the middle position and the tail end of the cable, the position of the partial discharge fault point is determined through steps S2041 to S2044. Figure 3 is a schematic diagram of a partial discharge fault point according to an embodiment of the present invention. Figure 3 As shown, the monitoring terminal L is located at the head end of the cable, the monitoring terminal M is located in the middle of the cable, the monitoring terminal R is located at the tail end of the cable, and point C is the first assumed position of the partial discharge fault point.

[0073] Step S2042, respectively determining a first distance and a second distance between the first assumed position and the monitoring terminal located at the middle position and the tail end of the cable. Figure 3 As shown, a first distance MC between point C and the monitoring terminal M is determined, and a second distance CR between point C and the monitoring terminal R is determined.

[0074] Step S2043, determining a third distance between the monitoring terminals located at the middle position and the tail end of the cable. Figure 3 As shown, a third distance MR between the monitoring terminal M and the monitoring terminal R is determined.

[0075] Step S2044, based on the first assumed position, the first distance, the second distance, the third distance, the second time, the third time and the transmission speed of the local discharge signal, the position of the local discharge fault point is determined. Specifically, the principle of the double-end traveling wave ranging algorithm is to use the propagation speed of the local discharge signal in the cable, combined with the time difference of the two monitoring terminals located at different positions receiving the signal to calculate the position of the local discharge fault point. Among them, the local discharge signal is a traveling wave, which propagates in the cable at an approximately constant speed. Optionally, the position of the local discharge fault point can be determined by the following formula (1), and the analysis is performed based on the first assumed position of the local discharge fault point in the position interval to determine the exact position of the local discharge fault point, thereby improving the accuracy of local discharge positioning.

[0076]

[0077] Among them, L MC represents the first distance; v represents the transmission speed of the partial discharge signal; T M The second time when the partial discharge signal reaches the monitoring terminal located in the middle of the cable; T R Indicates the third time when the partial discharge signal reaches the monitoring terminal at the tail end of the cable; L MR Indicates the third distance; L CR Indicates the second distance.

[0078] Step S2045, when the position interval is the interval between the head end and the middle position of the cable, obtain a second assumed position of the partial discharge fault point. Specifically, when the partial discharge fault point is located in the interval between the head end and the middle position of the cable, the position of the partial discharge fault point is determined through steps S2045 to S2048. Figure 4 is a schematic diagram of another partial discharge fault point according to an embodiment of the present invention, such as Figure 4 As shown, the monitoring terminal L is located at the head end of the cable, the monitoring terminal M is located at the middle position of the cable, the monitoring terminal R is located at the tail end of the cable, and point D is the second assumed position of the partial discharge fault point.

[0079] Step S2046, respectively determine the fourth distance and the fifth distance between the second assumed position and the monitoring terminal located at the head end and the middle position of the cable. Figure 4 As shown, the fourth distance LD between point D and the monitoring terminal L is determined, and the fifth distance DM between point D and the monitoring terminal M is determined.

[0080] Step S2047, determining a sixth distance between the monitoring terminals at the middle and the end of the cable. Figure 4 As shown, a sixth distance ML between the monitoring terminal L and the monitoring terminal M is determined.

[0081] Step S2048, based on the second assumed position, the fourth distance, the fifth distance, the sixth distance, the first time, the second time and the transmission speed of the partial discharge signal, the position of the partial discharge fault point is determined. Specifically, a double-terminal traveling wave ranging algorithm is used to analyze the second assumed position of the partial discharge fault point within the position interval, and the position of the partial discharge fault point is determined by the following formula (2), thereby improving the accuracy of partial discharge positioning.

[0082]

[0083] Among them, L LD represents the fourth distance; v represents the transmission speed of the partial discharge signal; T L Indicates the first time when the partial discharge signal reaches the monitoring terminal at the head end of the cable; T M Indicates the second time when the partial discharge signal reaches the monitoring terminal located in the middle of the cable; L DM Indicates the fifth distance; L ML Indicates the sixth distance.

[0084] The cable partial discharge positioning method provided by the embodiment of the present invention can ensure that partial discharge signals are obtained from different distances by arranging monitoring terminals at the head end, middle position and tail end of the cable, which helps to improve the reliability and accuracy of partial discharge positioning. The partial discharge signals at different positions are analyzed by wavelet decomposition to accurately determine the time when the partial discharge signals arrive at different positions. The position interval of the partial discharge fault point is analyzed based on the waveform, which provides a focus area for subsequent precise positioning, reduces the search space, and improves the positioning efficiency. The partial discharge fault point is accurately calculated by a double-end traveling wave ranging algorithm, which improves the accuracy and efficiency of partial discharge positioning and ensures the safe and stable operation of the power system.

[0085] In this embodiment, a cable partial discharge positioning device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made are not repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0086] This embodiment provides a cable partial discharge positioning device, such as Figure 5 As shown, including:

[0087] The acquisition module 501 is used to respectively acquire the first signal waveform, the second signal waveform and the third signal waveform when the partial discharge signal reaches the monitoring terminals located at the head end, the middle position and the tail end of the cable.

[0088] The decomposition module 502 is used to use a wavelet decomposition algorithm to determine the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminals at the beginning, the middle and the end of the cable respectively.

[0089] The determination module 503 is used to determine the location interval of the partial discharge fault point of the cable based on the first signal waveform, the second signal waveform and the third signal waveform.

[0090] The positioning module 504 is used to determine the position of the partial discharge fault point by using a double-terminal traveling wave ranging algorithm based on the position interval of the partial discharge fault point, the first time, the second time and the third time.

[0091] In some optional implementations, the determining module 503 includes:

[0092] The first determining unit is used to determine that, when the first signal waveform is similar to the second signal waveform, the location interval of the partial discharge fault point is the interval between the middle position and the tail end of the cable. Or,

[0093] The second determining unit is used for determining that, when the second signal waveform is similar to the third signal waveform, the position interval where the partial discharge fault point is located is the interval between the head end and the middle position of the cable.

[0094] In some optional implementations, the positioning module 504 includes:

[0095] The first acquisition unit is used to acquire a first assumed position of a partial discharge fault point when the position interval is the interval between the middle position and the tail end of the cable.

[0096] The third determining unit is used to respectively determine a first distance and a second distance between the first assumed position and the monitoring terminal located at the middle position and the tail end of the cable.

[0097] The fourth determining unit is used to determine a third distance between the monitoring terminals located at the middle position and the tail end of the cable.

[0098] The first positioning unit is used to determine the position of the partial discharge fault point based on the first assumed position, the first distance, the second distance, the third distance, the second time, the third time and the transmission speed of the partial discharge signal.

[0099] In some optional implementations, the positioning module 504 further includes:

[0100] The second acquisition unit is used to acquire a second assumed position of the partial discharge fault point when the position interval is the interval between the head end and the middle position of the cable.

[0101] The fifth determining unit is used to respectively determine a fourth distance and a fifth distance between the second assumed position and the monitoring terminal located at the head end and the middle position of the cable.

[0102] The sixth determining unit is used to determine a sixth distance between the monitoring terminals located at the middle position and the tail end of the cable.

[0103] The second positioning unit is used to determine the position of the partial discharge fault point based on the second assumed position, the fourth distance, the fifth distance, the sixth distance, the first time, the second time and the transmission speed of the partial discharge signal.

[0104] In some optional implementations, the decomposition module 502 includes:

[0105] The third acquisition unit is used to respectively acquire the first signal data, the second signal data and the third signal data of the monitoring terminals where the partial discharge signal reaches the head end, the middle position and the tail end of the cable.

[0106] The seventh determining unit is used to determine the wavelet basis function.

[0107] The decomposition unit is used to perform wavelet decomposition of a preset number of layers on the first signal data, the second signal data and the third signal data based on the wavelet basis function.

[0108] The eighth determination unit is used to determine the relevant features of the partial discharge signal in each layer after the wavelet decomposition.

[0109] The ninth determining unit is used to determine the first time, the second time and the third time based on the changes of the relevant features of each layer and the wavelet coefficients of each layer.

[0110] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0111] The cable partial discharge locating device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0112] The embodiment of the present invention also provides a computer device having the above Figure 5 The device for locating partial discharge of cables is shown.

[0113] See also Figure 6 , Figure 6 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 6As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 6 A processor 10 is taken as an example.

[0114] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0115] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0116] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0117] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0118] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 6 The example of connecting through bus is taken in the following.

[0119] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0120] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0121] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0122] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for locating partial discharge of a cable, characterized in that: The method comprises: Respectively acquiring a first signal waveform, a second signal waveform and a third signal waveform when the partial discharge signal reaches the monitoring terminals located at the head end, the middle position and the tail end of the cable; Using a wavelet decomposition algorithm, determining the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminals at the head end, the middle position and the tail end of the cable respectively; Determine a location interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform, and the third signal waveform; Based on the location interval of the partial discharge fault point, the first time, the second time and the third time, a double-terminal traveling wave ranging algorithm is used to determine the location of the partial discharge fault point.

2. The method according to claim 1, characterized in that: The determining, based on the first signal waveform, the second signal waveform and the third signal waveform, a location interval where a partial discharge fault point of the cable is located comprises: In the case where the first signal waveform is similar to the second signal waveform, the position interval where the partial discharge fault point is located is the interval between the middle position and the tail end of the cable; or, In the case where the second signal waveform is similar to the third signal waveform, the position interval where the partial discharge fault point is located is the interval between the head end and the middle position of the cable.

3. The method according to claim 2, characterized in that The method of determining the location of the partial discharge fault point by using a double-terminal traveling wave ranging algorithm based on the location interval of the partial discharge fault point, the second time, and the third time includes: When the position interval is the interval between the middle position and the tail end of the cable, obtaining a first assumed position of the partial discharge fault point; Determining a first distance and a second distance between the first assumed position and a monitoring terminal located at a middle position and a tail end of the cable respectively; determining a third distance between monitoring terminals located at a mid-point and a tail end of the cable; The location of the partial discharge fault point is determined based on the first assumed location, the first distance, the second distance, the third distance, the second time, the third time, and a transmission speed of the partial discharge signal.

4. The method according to claim 2, characterized in that: The determining the location of the partial discharge fault point by using a double-terminal traveling wave ranging algorithm based on the location interval of the partial discharge fault point, the first time and the second time also includes: When the position interval is the interval between the head end and the middle position of the cable, obtaining a second assumed position of the partial discharge fault point; Determining a fourth distance and a fifth distance between the second assumed position and a monitoring terminal located at a head end and a middle position of the cable respectively; determining a sixth distance between monitoring terminals located at a mid-point and a tail end of the cable; The location of the partial discharge fault point is determined based on the second assumed location, the fourth distance, the fifth distance, the sixth distance, the first time, the second time, and a transmission speed of the partial discharge signal.

5. The method according to claim 1, characterized in that The wavelet decomposition algorithm is used to respectively determine the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminal at the head end, the middle position and the tail end of the cable, including: Respectively acquiring first signal data, second signal data and third signal data of the partial discharge signal arriving at the monitoring terminals at the head end, the middle position and the tail end of the cable; Determine the wavelet basis function; Based on the wavelet basis function, the first signal data, the second signal data and the third signal data are respectively subjected to wavelet decomposition of a preset number of layers; In each layer after wavelet decomposition, the relevant features of the partial discharge signal are determined; The first time, the second time and the third time are determined based on changes in the relevant features of each layer and the wavelet coefficients of each layer.

6. A cable partial discharge positioning device, characterized in that: The device comprises: An acquisition module, used to respectively acquire a first signal waveform, a second signal waveform and a third signal waveform when the partial discharge signal reaches the monitoring terminals located at the head end, the middle position and the tail end of the cable; A decomposition module, used to use a wavelet decomposition algorithm to respectively determine the first time, the second time and the third time when the partial discharge signal arrives at the monitoring terminals at the head end, the middle position and the tail end of the cable; A determination module, configured to determine a location interval of a partial discharge fault point of the cable based on the first signal waveform, the second signal waveform, and the third signal waveform; A positioning module is used to determine the position of the partial discharge fault point by using a double-terminal traveling wave ranging algorithm based on the position interval of the partial discharge fault point, the first time, the second time and the third time.

7. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the cable partial discharge locating method according to any one of claims 1 to 5 by executing the computer instructions.

8. 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 computer to execute the method for locating partial discharge of a cable according to any one of claims 1 to 5.

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