Partial discharge online monitoring system

Abstract

The invention discloses an online partial discharge monitoring system, and relates to the technical field of partial discharge data transmission and protection. The invention provides a partial discharge monitoring terminal to monitor a number of monitoring features of all target devices in a target substation in real time to obtain real-time partial discharge data of the target substation, converts the real-time partial discharge data of the target substation into a coding conversion package through an information conversion unit, and transmits the coding conversion package through an information interaction unit. In this way, the partial discharge data of the target substation is prevented from being transmitted in plain text in a network, and in the conversion process, a conversion element tree is pre-constructed, and a selected mapping sequence of each group of coding substrings in the partial discharge data of the target substation is selected in the conversion element tree. In this way, the conversion process of the partial discharge data of the target substation does not depend on specific encryption sequences such as keys, and additional resources for storing and maintaining these encryption sequences are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of partial discharge data transmission protection, and in particular to a partial discharge online monitoring system. Background Art

[0002] During the operation of high-voltage power equipment, partial discharge (PD) is a key monitoring indicator. It is not only an early signal of equipment insulation aging and potential failure, but also an important basis for evaluating the health of equipment.

[0003] Traditional partial discharge detection methods mainly rely on offline detection, which requires the equipment to be shut down for detection. However, this method not only affects production, but also cannot monitor the insulation status of the equipment in real time. With the advancement of technology, partial discharge online monitoring systems have emerged. This system can continuously monitor the partial discharge activities of the equipment without affecting the normal operation of the equipment, and use cloud technology to achieve real-time evaluation of the health status of the equipment.

[0004] However, although this online monitoring system can quickly and accurately identify partial discharge phenomena in equipment, it also brings a new problem: data security. Since partial discharge monitoring data contains sensitive equipment operation information, if the data is not encrypted or the encryption measures are improper during transmission and storage, it may lead to data leakage, threatening the competitive advantage of enterprises.

[0005] To solve this problem, the existing solution is to use key encryption technology to ensure the security of partial discharge information during transmission. However, this method also has problems. First, it is too dependent on the key. If the key is lost, the transmission of partial discharge information will no longer be secure. Second, the use of key technology may consume a part of the storage and maintenance resources on key management.

[0006] In order to solve the above problems, the present invention proposes a solution. Summary of the invention

[0007] The purpose of the present invention is to provide an online partial discharge monitoring system in order to solve the problems raised in the above background technology.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] The local discharge online monitoring system includes an interactive management terminal and a cloud monitoring terminal:

[0010] An interactive management terminal is used to safely manage the interactive process of the partial discharge data of the real-time target substation, and the interactive management terminal includes an information conversion unit;

[0011] After receiving the partial discharge data of the target substation at the current moment, the information conversion unit first converts it into a binary format, and obtains the initial conversion data of the target substation after the conversion;

[0012] Constructing a conversion metatree of the target substation according to a preset construction rule, wherein the conversion metatree includes 17 new nodes, each of which corresponds to a metatree identification code, and the metatree identification code includes four binary numbers: 11, 10, 01, and 00;

[0013] Mapping a hierarchical conversion code for all new nodes in the conversion meta-tree according to a preset mapping rule;

[0014] In order from left to right, every four characters in the initial conversion data of the target substation are divided into a group of coding substrings, so as to obtain a plurality of groups of coding substrings, and then a selected mapping sequence of each group of coding substrings is obtained according to a preset selected mapping rule;

[0015] The information interaction unit generates a code conversion package of the target substation at the current moment according to the selected mapping sequence of each group of coding substrings, and transmits the code conversion package of the target substation at the current moment to the cloud monitoring terminal.

[0016] Furthermore, it also includes a partial discharge monitoring terminal for real-time monitoring of a number of monitoring characteristics of a number of target devices in the target substation. The number of monitoring characteristics of the target devices are a number of characteristic parameters selected by the management personnel in the target substation in order to monitor the partial discharge of the target devices.

[0017] Furthermore, the construction rules for constructing the conversion element tree of the target substation are as follows:

[0018] S121: Use the newNode() function to create 17 new nodes in sequence, and mark the created 17 new nodes as B1, B2, ..., B17 in the order in which each new node is created;

[0019] Map the binary number 00 as the metatree identification code of the new node B1 to the new node B1;

[0020] S122: Then the new node B1 is used as the root node, and the new nodes B2, B3, B4, and B5 are used as the first left, second left, first right, and second right child nodes of the new node B1 in sequence, and the binary numbers 11, 10, 01, and 00 are used as the metatree identification codes of the new nodes B2, B3, B4, and B5, respectively, and are mapped to the new nodes B2, B3, B4, and B5 accordingly;

[0021] S123: Then the new node B2 is used as the root node, and the new nodes B6, B7, B8, and B9 are used as the first left, second left, first right, and second right child nodes of the new node B2 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B6, B7, B8, and B9, respectively, and are mapped to the new nodes B6, B7, B8, and B9 accordingly;

[0022] S124: Next, the new node B3 is used as the root node, and the new nodes B10, B11, B12, and B13 are used as the first left, second left, first right, and second right child nodes of the new node B3 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B10, B11, B12, and B13, respectively, and are mapped to the new nodes B10, B11, B12, and B13 accordingly;

[0023] S125: Finally, the new node B4 is used as the root node, and the new nodes B14, B15, B16, and B17 are used as the first left, second left, first right, and second right child nodes of the new node B4 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the meta-tree identification codes of the new nodes B14, B15, B16, and B17, respectively, and are mapped to the new nodes B14, B15, B16, and B17 accordingly;

[0024] After the mapping is completed, the conversion meta-tree of the target substation is obtained. At this time, the number of layers of the conversion meta-tree of the constructed target substation is 2, among which the new node B1 is at the 0th layer, the new nodes B2, B3, B4 and B5 are the left first, left second, right first and right second child nodes of the new node B1 at the 1st layer, and the remaining new nodes are at the 2nd layer. The layers from small to large are 0th layer, 1st layer and 2nd layer.

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention obtains real-time partial discharge data of the target substation by setting a partial discharge monitoring terminal to monitor several monitoring features of all target devices in the target substation in real time, and converts the real-time partial discharge data of the target substation into a coding conversion package through an information conversion unit, and transmits the coding conversion package through an information interaction unit. In this way, the partial discharge data of the target substation is prevented from being transmitted in plain text in the network. In the conversion process, a conversion element tree is pre-constructed, and a selected mapping sequence of each group of coding substrings in the partial discharge data of the target substation is selected in the conversion element tree. In this way, the conversion process of the partial discharge data of the target substation does not depend on specific encryption sequences such as keys, thereby avoiding additional resources for storing and maintaining these encryption sequences, and adopting encryption logic to avoid leakage.

[0027] (2) Each new node included in the conversion metatree constructed by the present invention corresponds to a metatree identification code, which is selected from four binary numbers: 11, 10, 01 and 00. The constructed conversion metatree has three layers, and the new nodes of each layer correspond to different level conversion codes, which are also selected from the binary numbers 11, 10, 01 and 00. In this way, the binary numbers 00, 01, 10, 11 correspond to different binary numbers based on their order in each group of coding substrings, and the same binary number has a corresponding different binary number based on the number of layers it is in, which increases the difficulty of three-party cracking and further enhances the security of partial discharge data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 This is a system block diagram of the present invention.

[0030] Figure 2 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figure 1 , 2 As shown, the partial discharge online monitoring system includes a partial discharge monitoring terminal and an interactive management terminal;

[0033] The partial discharge monitoring terminal is used to monitor several monitoring characteristics of several target devices in the target substation in real time, wherein the target devices are selected by the management personnel in the target substation. In this embodiment, the target devices refer to the power equipment in the target substation;

[0034] Several monitoring characteristics of the target equipment are characteristic parameters selected by the management personnel in the target substation for monitoring the partial discharge of the target equipment, and the characteristic parameters include but are not limited to the apparent charge of partial discharge, partial discharge inception voltage, partial discharge extinction voltage, discharge amount, number of discharges, mean square rate, repetition rate and NQN, etc.;

[0035] For a target device in any target substation, the partial discharge monitoring terminal monitors several monitoring characteristics of the target device in real time and collects monitoring values ​​of several monitoring characteristics, and generates real-time monitoring characteristic data of the target device according to the monitoring values ​​of several monitoring characteristics of the target device collected in real time;

[0036] The partial discharge monitoring terminal obtains the monitoring characteristic data of all target devices in the target substation in real time to generate real-time partial discharge data of the target substation, and transmits the real-time partial discharge data of the target substation to the interactive management terminal;

[0037] An interactive management terminal is used to safely manage the interactive process of the partial discharge data of the real-time target substation. The interactive management terminal includes an information conversion unit and an information interaction unit;

[0038] After receiving the partial discharge data of the target substation at the current moment, the interactive management terminal transmits it to the information conversion unit. After receiving the partial discharge data of the target substation at the current moment, the information conversion unit performs information conversion on the partial discharge data of the target substation at the current moment according to the preset information conversion rules. The information conversion rules are as follows:

[0039] S11: converting the partial discharge data of the target substation into a binary format, and recalibrating the partial discharge data of the target substation in the binary format as initial conversion data of the target substation;

[0040] S12: constructing a conversion element tree of the target substation according to a preset construction rule;

[0041] S121: Use the newNode() function to create 17 new nodes in sequence, and mark the created 17 new nodes as B1, B2, ..., B17 in the order in which each new node is created;

[0042] Map the binary number 00 as the metatree identification code of the new node B1 to the new node B1;

[0043] S122: Then the new node B1 is used as the root node, and the new nodes B2, B3, B4, and B5 are used as the first left, second left, first right, and second right child nodes of the new node B1 in sequence, and the binary numbers 11, 10, 01, and 00 are used as the metatree identification codes of the new nodes B2, B3, B4, and B5, respectively, and are mapped to the new nodes B2, B3, B4, and B5 accordingly;

[0044] S123: Then the new node B2 is used as the root node, and the new nodes B6, B7, B8, and B9 are used as the first left, second left, first right, and second right child nodes of the new node B2 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B6, B7, B8, and B9, respectively, and are mapped to the new nodes B6, B7, B8, and B9 accordingly;

[0045] S124: Next, the new node B3 is used as the root node, and the new nodes B10, B11, B12, and B13 are used as the first left, second left, first right, and second right child nodes of the new node B3 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B10, B11, B12, and B13, respectively, and are mapped to the new nodes B10, B11, B12, and B13 accordingly;

[0046] S125: Finally, the new node B4 is used as the root node, and the new nodes B14, B15, B16, and B17 are used as the first left, second left, first right, and second right child nodes of the new node B4 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the meta-tree identification codes of the new nodes B14, B15, B16, and B17, respectively, and are mapped to the new nodes B14, B15, B16, and B17 accordingly;

[0047] After the mapping is completed, the conversion meta-tree of the target substation is obtained. At this time, the number of layers of the conversion meta-tree of the constructed target substation is 2, among which the new node B1 is at the 0th layer, the new nodes B2, B3, B4 and B5 are the left first, left second, right first and right second child nodes of the new node B1 at the 1st layer, and the remaining new nodes are at the 2nd layer. The layers are 0th layer, 1st layer and 2nd layer in descending order.

[0048] S13: Use the number 0 as the level conversion code of the new node B1;

[0049] S14: Mapping is established for all new nodes in the first layer of the conversion metatree according to the preset first layer mapping rule to obtain corresponding hierarchical conversion codes of all new nodes. The first layer mapping rule is as follows:

[0050] S141: Based on the fact that the root nodes of B2, B3, B4, and B5 are all new nodes B1, and B2, B3, B4, and B5 are all at the first layer of the conversion metatree, the number 0 is used as the same-layer external distinction value of the new nodes B2 and B3 to be mapped to the new nodes B2 and B3, and the number 1 is used as the same-layer external distinction value of the new nodes B4 and B5 to be mapped to the new nodes B4 and B5;

[0051] S142: Then, the number 0 is again mapped to the new nodes B2 and B4 as the intra-layer distinguishing value, and the number 1 is mapped to the new nodes B3 and B5 as the intra-layer distinguishing value;

[0052] S143: After the mapping is completed, the same-layer external zone value and the same-layer internal zone value of the new node B2 are concatenated in the order of the same-layer external zone value and the same-layer internal zone value to obtain the level conversion code of the new node B2, the same-layer external zone value and the same-layer internal zone value of the new node B3 are concatenated to obtain the level conversion code of the new node B3, the same-layer external zone value and the same-layer internal zone value of the new node B4 are concatenated to obtain the level conversion code of the new node B4, and the same-layer external zone value and the same-layer internal zone value of the new node B5 are concatenated to obtain the level conversion code of the new node B5. At this time, the level conversion codes of the new nodes B2, B3, B4, and B5 are 00, 01, 10, and 11 respectively;

[0053] S15: Mapping is established for all new nodes in the second layer of the conversion metatree according to a preset two-layer mapping rule to obtain corresponding hierarchical conversion codes of all new nodes. The two-layer mapping rule is as follows:

[0054] S151: Based on the fact that the root nodes of B6, B7, B8, and B9 are all new nodes B2, and B6, B7, B8, and B9 are all at the second level of the conversion metatree, the number 0 is used as the same-layer external distinction value of the new nodes B6 and B7 to be mapped to the new nodes B6 and B7, and the number 1 is used as the same-layer external distinction value of the new nodes B8 and B9 to be mapped to the new nodes B8 and B9;

[0055] S152: Then, the number 0 is again mapped to the new nodes B6 and B8 as the intra-layer distinguishing value, and the number 1 is mapped to the new nodes B7 and B9 as the intra-layer distinguishing value;

[0056] S153: After the mapping is completed, the same-layer external zone value and the same-layer internal zone value of the new node B6 are concatenated in the order of the same-layer external zone value and the same-layer internal zone value to obtain the level conversion code of the new node B6, the same-layer external zone value and the same-layer internal zone value of the new node B7 are concatenated to obtain the level conversion code of the new node B7, the same-layer external zone value and the same-layer internal zone value of the new node B8 are concatenated to obtain the level conversion code of the new node B8, and the same-layer external zone value and the same-layer internal zone value of the new node B9 are concatenated to obtain the level conversion code of the new node B9. At this time, the level conversion codes of the new nodes B6, B7, B8, and B9 are 00, 01, 10, and 11 respectively;

[0057] S154: Calculate and obtain the level conversion codes of the new nodes B10, B11, ..., B17 in sequence according to S151 to S153;

[0058] S16: Divide every four characters in the initial conversion data of the target substation into a group of coding substrings in order from left to right, and obtain a plurality of groups of coding substrings;

[0059] It should be noted here that, when performing the division, if the number of characters remaining at the end is less than 4, the characters remaining at the end are temporarily stored as the supplementary substring of the target substation;

[0060] S17: according to the order of characters in each coding substring in the initial conversion data of the target substation, all coding substrings are marked as C1, C2, ..., Cc from left to right, where c is the total number of coding substrings divided according to the initial conversion data of the target substation;

[0061] S18: Obtain a selected mapping sequence of the coding substrings C1, C2, ..., Cc according to a preset selected mapping rule. The selected mapping rule is as follows:

[0062] S181: from left to right, extract the first two characters constituting the coding substring C1 and use them as the first substring of the coding substring C1, and use the remaining two characters after the extraction as the second substring of the coding substring C1;

[0063] S182: First, a plurality of new nodes whose metatree identification codes are consistent with the first substring of the coding substring C1 are obtained from the conversion metatree, and then a new node with the smallest number of layers is selected from the obtained plurality of new nodes as the first mapping node of the coding substring C1;

[0064] Then, a new node whose metatree identification code is consistent with the second substring of the coding substring C1 is selected from a layer higher than the layer where the first mapping node of the coding substring C1 is located as the second mapping node of the coding substring C1;

[0065] For example, if the first substring of the coding substring C1 is 00, the first mapping node of the coding substring C1 is the new node B1, which is at level 0. At this time, the level one higher than the level where the first mapping node of the coding substring C1 is located is level 1;

[0066] S183: According to the sequence of the first mapping node and the second mapping node of the coding substring C1, the hierarchical conversion code of the first mapping node and the hierarchical conversion code of the second mapping node are concatenated to obtain a selected mapping sequence of the coding substring C1;

[0067] S184: Calculate and obtain the selected mapping sequence of the coding substrings C1, C2, ..., Cc in sequence according to S181 to S183;

[0068] The information conversion unit transmits the selected mapping sequence of the coding substrings C1, C2, ..., Cc obtained by conversion according to the partial discharge data of the target substation at the current moment to the information interaction unit;

[0069] After receiving the selected mapping sequence of the code substrings C1, C2, ..., Cc obtained by conversion according to the partial discharge data of the target substation at the current moment, the information exchange unit generates c code conversion packages of the target substation at the current moment according to the selected mapping sequence of the code substrings C1, C2, ..., Cc, wherein one of the code conversion packages contains a selected mapping sequence of a code substring and a marking subscript of the code substring;

[0070] It should be noted here that if there is a supplementary substring of the target substation, a code conversion packet is generated based on it;

[0071] The information interaction unit transmits all the encoding conversion packets of the target substation at the current moment to the cloud monitoring terminal;

[0072] The cloud monitoring terminal is used for cloud monitoring and analyzing the partial discharge data of the target substation. After receiving the c code conversion packets of the target substation at the current moment, the cloud monitoring terminal first constructs the conversion element tree of the target substation according to the same construction rule as S12, and then restores the corresponding selected mapping sequence according to the conversion element tree in the order of the mark subscripts carried in the code conversion packet from small to large to obtain the corresponding code substring, and splices all the restored code substrings according to the order of restoration to obtain the partial discharge data of the target substation at the current moment;

[0073] The meta-monitoring terminal stores the partial discharge data of the target substation at the current moment, and provides the data for analysis and identification of the partial discharge characteristics of all target equipment in the target substation;

[0074] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0075] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

[0076] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. Partial discharge online monitoring system, characterized by: Including interactive management terminal and cloud monitoring terminal: An interactive management terminal is used to safely manage the interactive process of the partial discharge data of the real-time target substation. The interactive management terminal includes an information conversion unit and an information interaction unit; After receiving the partial discharge data of the target substation at the current moment, the information conversion unit first converts it into a binary format, and obtains the initial conversion data of the target substation after the conversion; Constructing a conversion metatree of the target substation according to a preset construction rule, wherein the conversion metatree includes 17 new nodes, each of which corresponds to a metatree identification code, and the metatree identification code includes four binary numbers: 11, 10, 01, and 00; Mapping a hierarchical conversion code for all new nodes in the conversion meta-tree according to a preset mapping rule; In order from left to right, every four characters in the initial conversion data of the target substation are divided into a group of coding substrings, so as to obtain a plurality of groups of coding substrings, and then a selected mapping sequence of each group of coding substrings is obtained according to a preset selected mapping rule; The information interaction unit generates a code conversion package of the target substation at the current moment according to the selected mapping sequence of each group of code substrings, and transmits the code conversion package of the target substation at the current moment to the cloud monitoring terminal; One of the encoding conversion packets includes a selected mapping sequence of a coding substring and includes a tag subscript of the coding substring; The cloud monitoring terminal is used for cloud monitoring and analyzing the partial discharge data of the target substation. After receiving the transmitted encoding conversion package of the target substation at the current moment, the cloud monitoring terminal first constructs the conversion element tree of the target substation according to the construction rules, and then restores the corresponding selected mapping sequence according to the conversion element tree in the order of the mark subscript carried in the encoding conversion package from small to large to obtain the corresponding encoding substring, and splices all the restored encoding substrings in the order of restoration to obtain the partial discharge data of the target substation at the current moment.

2. The partial discharge online monitoring system according to claim 1, characterized in that: It also includes a partial discharge monitoring terminal for real-time monitoring of a number of monitoring characteristics of a number of target devices in a target substation. The number of monitoring characteristics of the target devices are a number of characteristic parameters selected by management personnel in the target substation in order to monitor partial discharge of the target devices.

3. The partial discharge online monitoring system according to claim 2, characterized in that: For a target device in any target substation, the partial discharge monitoring terminal monitors several monitoring characteristics of the target device in real time and collects monitoring values ​​of several monitoring characteristics to generate real-time monitoring characteristic data of the target device; The partial discharge monitoring terminal obtains the monitoring characteristic data of all target devices in the target substation in real time to generate real-time partial discharge data of the target substation.

4. The partial discharge online monitoring system according to claim 1, characterized in that: The construction rules for constructing the conversion metatree of the target substation are as follows: S121: Use the newNode() function to create 17 new nodes in sequence, and mark the created 17 new nodes as B1, B2, ..., B17 in the order in which each new node is created; Map the binary number 00 as the metatree identification code of the new node B1 to the new node B1; S122: Then the new node B1 is used as the root node, and the new nodes B2, B3, B4, and B5 are used as the first left, second left, first right, and second right child nodes of the new node B1 in sequence, and the binary numbers 11, 10, 01, and 00 are used as the metatree identification codes of the new nodes B2, B3, B4, and B5, respectively, and are mapped to the new nodes B2, B3, B4, and B5 accordingly; S123: Then the new node B2 is used as the root node, and the new nodes B6, B7, B8, and B9 are used as the first left, second left, first right, and second right child nodes of the new node B2 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B6, B7, B8, and B9, respectively, and are mapped to the new nodes B6, B7, B8, and B9 accordingly; S124: Next, the new node B3 is used as the root node, and the new nodes B10, B11, B12, and B13 are used as the first left, second left, first right, and second right child nodes of the new node B3 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the metatree identification codes of the new nodes B10, B11, B12, and B13, respectively, and are mapped to the new nodes B10, B11, B12, and B13 accordingly; S125: Finally, the new node B4 is used as the root node, and the new nodes B14, B15, B16, and B17 are used as the first left, second left, first right, and second right child nodes of the new node B4 in sequence, and the binary numbers 00, 01, 10, and 11 are used as the meta-tree identification codes of the new nodes B14, B15, B16, and B17, respectively, and are mapped to the new nodes B14, B15, B16, and B17 accordingly; After the mapping is completed, the conversion meta-tree of the target substation is obtained. At this time, the number of layers of the conversion meta-tree of the constructed target substation is 2, among which the new node B1 is at the 0th layer, the new nodes B2, B3, B4 and B5 are the left first, left second, right first and right second child nodes of the new node B1 at the 1st layer, and the remaining new nodes are at the 2nd layer. The layers from small to large are 0th layer, 1st layer and 2nd layer.

5. The partial discharge online monitoring system according to claim 4, characterized in that: The mapping rule for mapping a level conversion code to all new nodes in the conversion meta-tree is as follows: S13: Use the number 0 as the level conversion code of the new node B1; S14: Mapping is established for all new nodes at the first layer in the conversion metatree according to the preset first-layer mapping rule to obtain corresponding hierarchical conversion codes of all new nodes. The first-layer mapping rule is as follows: S141: Based on the fact that the root nodes of B2, B3, B4, and B5 are all new nodes B1, and B2, B3, B4, and B5 are all at the first layer of the conversion metatree, the number 0 is used as the same-layer external distinction value of the new nodes B2 and B3 to be mapped to the new nodes B2 and B3, and the number 1 is used as the same-layer external distinction value of the new nodes B4 and B5 to be mapped to the new nodes B4 and B5; S142: Then, the number 0 is again mapped to the new nodes B2 and B4 as the intra-layer distinguishing value, and the number 1 is mapped to the new nodes B3 and B5 as the intra-layer distinguishing value; S143: After the mapping is completed, the same-layer external zone value and the same-layer internal zone value of the new node B2 are concatenated in the order of the same-layer external zone value and the same-layer internal zone value to obtain the level conversion code of the new node B2, the same-layer external zone value and the same-layer internal zone value of the new node B3 are concatenated to obtain the level conversion code of the new node B3, the same-layer external zone value and the same-layer internal zone value of the new node B4 are concatenated to obtain the level conversion code of the new node B4, and the same-layer external zone value and the same-layer internal zone value of the new node B5 are concatenated to obtain the level conversion code of the new node B5; S15: mapping all new nodes in the second layer in the conversion meta-tree according to a preset two-layer mapping rule, and obtaining corresponding hierarchical conversion codes of all new nodes in the second layer; The 2-layer mapping rule for obtaining the hierarchical conversion codes of all new nodes at the 2nd layer in the conversion metatree is as follows: S151: Based on the fact that the root nodes of B6, B7, B8, and B9 are all new nodes B2, and B6, B7, B8, and B9 are all at the second level of the conversion metatree, the number 0 is used as the same-layer external distinction value of the new nodes B6 and B7 to be mapped to the new nodes B6 and B7, and the number 1 is used as the same-layer external distinction value of the new nodes B8 and B9 to be mapped to the new nodes B8 and B9; S152: Then, the number 0 is again mapped to the new nodes B6 and B8 as the intra-layer distinguishing value, and the number 1 is mapped to the new nodes B7 and B9 as the intra-layer distinguishing value; S153: After the mapping is completed, the same-layer external zone value and the same-layer internal zone value of the new node B6 are concatenated in the order of the same-layer external zone value and the same-layer internal zone value to obtain the level conversion code of the new node B6, the same-layer external zone value and the same-layer internal zone value of the new node B7 are concatenated to obtain the level conversion code of the new node B7, the same-layer external zone value and the same-layer internal zone value of the new node B8 are concatenated to obtain the level conversion code of the new node B8, and the same-layer external zone value and the same-layer internal zone value of the new node B9 are concatenated to obtain the level conversion code of the new node B9; S154: Calculate and obtain the level conversion codes of the new nodes B10, B11, ..., B17 in sequence according to S151 to S153.

6. The partial discharge online monitoring system according to claim 5, characterized in that: The selected mapping rule for obtaining the selected mapping sequence of each group of encoding substrings is as follows: S16: Divide every four characters in the initial conversion data of the target substation into a group of coding substrings in order from left to right, and obtain a plurality of groups of coding substrings; S17: label all groups of coded substrings as C1, C2, ..., Cc from left to right in sequence according to the order of characters in each coded substring in the target substation initial conversion data; S18: The steps of obtaining the selected mapping sequence of the coding substrings C1, C2, ..., Cc are as follows: S181: from left to right, extract the first two characters constituting the coding substring C1 and use them as the first substring of the coding substring C1, and use the remaining two characters after the extraction as the second substring of the coding substring C1; S182: First, a number of new nodes whose metatree identification codes are consistent with the first substring of the coding substring C1 are obtained from the conversion metatree, and then a new node with the smallest number of layers is selected from the obtained new nodes as the first mapping node of the coding substring C1; Then, a new node whose metatree identification code is consistent with the second substring of the coding substring C1 is selected from a layer higher than the layer where the first mapping node of the coding substring C1 is located as the second mapping node of the coding substring C1; S183: According to the sequence of the first mapping node and the second mapping node of the coding substring C1, the hierarchical conversion code of the first mapping node and the hierarchical conversion code of the second mapping node are concatenated to obtain a selected mapping sequence of the coding substring C1; S184: Calculate and obtain the selected mapping sequence of the coding substrings C2, C3, ..., Cc in sequence according to S181 to S183.

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