A leakage current monitoring method and device for non-power-off operation

Abstract

The present invention proposes a leakage current monitoring method and device for non-stop power supply operation, the method comprising the following steps: constructing a human body impedance model, a lining impedance model and a protective equipment impedance model; obtaining sample data, constructing a multivariate impedance model about the human body impedance model, the lining impedance model and the protective equipment impedance model; using the least square method to solve the regression coefficient of the multivariate impedance model, thereby determining the multivariate impedance model; connecting the multivariate impedance model to the distribution network to form a leakage current monitoring model; based on the leakage current monitoring model, calculating the leakage current and the zero-sequence current, when the current amplitude of the leakage current and the zero-sequence current exceeds the set threshold, the protection circuit connected to the distribution network is activated. The present invention can accurately characterize the overall impedance state of the operator, and by cyclically monitoring the contact state of the operator, if an abnormality is detected, the protection circuit is activated, thereby fully ensuring the personal safety of the operator.

Description

Technical Field

[0001] The present invention relates to the technical field of non-stop power supply operation, and in particular to a leakage current monitoring method and device for non-stop power supply operation. Background Art

[0002] The rise of non-stop power supply in the last century has greatly reduced the economic losses caused by power failures. In many areas of my country, there are a large number of cable segments in the cable feeder lines and overhead lines, which makes it impossible for operators to transfer the power load of the maintenance section when carrying out maintenance operations. There is a complex working environment. Therefore, once a power accident occurs, the operators have to spend a long time to repair it. At present, with the development and application of informatization and high technology, users need power supply companies to provide safe, reliable, qualified and uninterrupted power. The longer the power outage time, the greater the impact on power users, which greatly reduces the power supply safety and stability of the power grid. Line non-stop power supply can effectively reduce the power outage time of power equipment, improve user experience, and reduce the average failure time of users. It has gradually become a focus of the power industry construction, and the application and promotion of its key technologies are urgent. In order to ensure the stability of electricity consumption, relevant operators must regularly inspect and maintain overhead lines. Therefore, how to provide personal safety protection for overhead line workers is the key content of non-stop power supply.

[0003] At present, in non-stop power supply work, workers need to directly contact high-voltage equipment and inevitably face the threat of high-voltage power supply. Although workers adopt passive work protection measures such as insulating clothing, insulating blankets, and insulating gloves to ensure the personal safety of workers during the operation. However, in fact, almost no insulating material is absolutely non-conductive. When a voltage is applied to any insulating material at both ends, there will always be a certain current passing through. The active component of this current is called leakage current. When the leakage current exceeds a certain amplitude, it will pose a great threat to the personal safety of the workers. However, at present, in non-stop power supply work, only insulating protective equipment is relied on to protect the human body, and there is a lack of a technical means to effectively evaluate and monitor the leakage current. Summary of the invention

[0004] In view of the above problems, the present invention provides a leakage current monitoring method and device for non-stop power supply operation, which solves the problem in the prior art of lack of effective monitoring of leakage current in non-stop power supply operation.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a leakage current monitoring method for non-stop operation, comprising the following steps: constructing a human body impedance model, a lining impedance model and a protective equipment impedance model; acquiring sample data, and constructing a multivariate impedance model about the human body impedance model, the lining impedance model and the protective equipment impedance model; using the least squares method to solve the regression coefficient of the multivariate impedance model, so as to determine the multivariate impedance model; connecting the multivariate impedance model to the distribution network to form a leakage current monitoring model; based on the leakage current monitoring model, calculating the leakage current and the zero-sequence current, when the current amplitude of the leakage current and the zero-sequence current exceeds the set threshold value, the protection circuit connected to the distribution network is actuated.

[0006] As a preferred embodiment, the steps of constructing the human body impedance model include: according to the dispersion characteristics of human biological tissue, using a multi-order Cole-Cole model to characterize the dielectric characteristics of human biological tissue, wherein the dielectric characteristics include conductivity and dielectric constant; calculating the functional relationship between the dielectric characteristics and the applied voltage and current; and importing the functional relationship into a human body finite element model to obtain a human body impedance model.

[0007] As a preferred embodiment, the protective equipment includes insulating clothing, insulating pants, insulating shoes, insulating gloves and insulating pads, and the steps of constructing the impedance model of the protective equipment include: building an impedance network of the protective equipment according to the wearing order of the protective equipment; applying voltage and current to the impedance network of the protective equipment to obtain the impedance model of the protective equipment.

[0008] As a preferred solution, when the insulating glove on the left hand contacts the power distribution network, the impedance expression of the impedance model of the protective equipment is:

[0009]

[0010] When the right hand insulating glove contacts the power distribution network, the impedance expression of the protective equipment impedance model is:

[0011]

[0012] When the insulating gloves on both hands are in contact with the distribution network, the impedance expression of the impedance model of the protective equipment is:

[0013]

[0014] In the above formula, R1 is the impedance value of the insulating suit, R2 is the impedance value of the insulating glove on the left hand, R3 is the impedance value of the insulating glove on the right hand, R4 is the impedance value of the insulating pants, R5 is the impedance value of the insulating shoe on the left foot, R6 is the impedance value of the insulating shoe on the right foot, R7 is the impedance value of the insulating blanket, I Lea is the leakage current, U Ap To apply voltage.

[0015] As a preferred solution, the lining impedance model is the work clothes impedance, and the work clothes impedance is related to the material of the work clothes and is a fixed value.

[0016] As a preferred solution, the expression of the multivariate impedance model is:

[0017] R total =b 1 H R +b 2 L R +b 3 P R +ε;

[0018] In the above formula, R total is the multivariate impedance model function, H R is the human body impedance model function, L R is the lining impedance model function, P R is the impedance model function of protective equipment, b 1 、b 2 、b 3 is the regression coefficient and ε is the error.

[0019] As a preferred embodiment, the leakage current and zero-sequence current are calculated based on the leakage current monitoring model, including: solving the electromagnetic field equation according to the leakage current monitoring model, cyclically calculating the leakage current and zero-sequence current flowing through the operator when the left hand, right hand and both hands of insulating gloves are in contact with the distribution network, judging the degree of burning according to the leakage current, and judging whether to start the protection circuit according to the zero-sequence current.

[0020] The present invention also provides a leakage current monitoring device for non-stop operation, comprising: a sub-model construction module, used to construct a human body impedance model, a lining impedance model and a protective equipment impedance model; a multivariate model construction module, used to obtain sample data and construct a multivariate impedance model about the human body impedance model, the lining impedance model and the protective equipment impedance model; a multivariate model determination module, used to use the least squares method to solve the regression coefficient of the multivariate impedance model, so as to determine the multivariate impedance model; a monitoring model assembly module, used to connect the multivariate impedance model to a distribution network to form a leakage current monitoring model; a leakage current monitoring module, used to calculate the leakage current and the zero-sequence current based on the leakage current monitoring model, and when the current amplitudes of the leakage current and the zero-sequence current exceed the set threshold value, the protection circuit connected to the distribution network is actuated.

[0021] Compared with the prior art, the beneficial effects of the present invention include: according to the dispersion characteristics of human biological tissue, a multi-order Cole-Cole model is used to characterize the dielectric characteristics of human biological tissue, and then the functional relationship between the dielectric characteristics and the applied voltage and current is introduced into the human finite element model to obtain a human impedance model, which can reflect the impedance situation under different human characteristics and has a good characterization effect; according to the wearing order of protective equipment, a protective equipment impedance network is built to obtain a protective equipment impedance model, which can well match the working state of the operator, has high adaptability, and can reflect the impedance distribution of the operator after wearing the protective equipment. A multivariate impedance model of the human impedance model, the lining impedance model and the protective equipment impedance model is established by a multivariate regression algorithm. The multivariate impedance model can accurately characterize the overall impedance state of the operator, and all the contact situations between the operator and the distribution network during the operation are taken into account. The three contact states are monitored cyclically. If the maximum value of the leakage current in one of the contact states exceeds the set threshold, the protection circuit is activated to fully ensure the personal safety of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0023] Figure 1 A schematic flow chart of a leakage current monitoring method for non-power-off operation according to an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of building an impedance network of protective equipment according to the wearing order of protective equipment according to an embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of a leakage current monitoring device for non-power-off operation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0027] According to one embodiment of the present invention, Figure 1 A leakage current monitoring method for non-power-off operation comprises the following steps:

[0028] S101, construct human body impedance model, lining impedance model and protective equipment impedance model.

[0029] The steps of constructing the human body impedance model include:

[0030] 1) According to the dispersion characteristics of human biological tissue, the multi-order Cole-Cole model is used to characterize the dielectric characteristics of human biological tissue. The dielectric characteristics include conductivity and dielectric constant.

[0031] 2) Calculate the functional relationship between dielectric characteristics and applied voltage and current. This functional relationship is the function of the impedance value of each layer of the human body (stratum corneum, epidermis, dermis, subcutaneous tissue, muscle, bone, etc.) at different voltages and frequencies.

[0032] 3) Import the functional relationship into the human body finite element model to obtain the human body impedance model.

[0033] The above-mentioned human body finite element model is constructed using the finite element method. The basic principle of the finite element method is: first, the area to be solved is discretized and divided into a certain number of units or grids, and the connection points between the units are represented by nodes; after discretization, a complete continuum is divided into entities composed of a finite number of units or grids.

[0034] See also Figure 2 The protective equipment worn by the workers includes insulating clothing, insulating pants, insulating shoes, insulating gloves and insulating pads. The steps of constructing the above-mentioned protective equipment impedance model include: building a protective equipment impedance network according to the wearing order of the protective equipment; applying voltage and current to the protective equipment impedance network to obtain the protective equipment impedance model.

[0035] When the left hand insulating glove contacts the distribution network, the impedance expression of the protective equipment impedance model is:

[0036]

[0037] When the right hand insulating glove contacts the distribution network, the impedance expression of the protective equipment impedance model is:

[0038]

[0039] When the insulating gloves on both hands are in contact with the distribution network, the impedance expression of the impedance model of the protective equipment is:

[0040]

[0041] In the above formula, R1 is the impedance value of the insulating suit, R2 is the impedance value of the insulating glove on the left hand, R3 is the impedance value of the insulating glove on the right hand, R4 is the impedance value of the insulating pants, R5 is the impedance value of the insulating shoe on the left foot, R6 is the impedance value of the insulating shoe on the right foot, R7 is the impedance value of the insulating blanket, ILea is the leakage current, U Ap To apply voltage.

[0042] In the embodiment of the present invention, the lining impedance model is the impedance of the work clothes, and the impedance of the work clothes is related to the material of the work clothes and is a fixed value. For example, work clothes can be divided into two types, spring and autumn, and the corresponding impedance values ​​can be obtained by measuring the two types of work clothes respectively.

[0043] S102, obtain sample data, and construct a multivariate impedance model for a human body impedance model, a lining impedance model, and a protective equipment impedance model. In this embodiment, the sample data includes the human body characteristics of the operator (such as body shape, age, gender, etc.), the fixed impedance value of each protective equipment (insulating clothing, insulating pants, insulating shoes, insulating gloves, and insulating pads), the type of work clothes and its fixed impedance value, and also includes the overall impedance value of the operator after wearing the protective equipment and work clothes.

[0044] Specifically, the expression of the multivariate impedance model is:

[0045] R total =b 1 H R +b 2 L R +b 3 P R +ε;

[0046] In the above formula, R total is the multivariate impedance model function, H R is the human body impedance model function, L R is the lining impedance model function, P R is the impedance model function of protective equipment, b 1 , b 2 , b 3 is the regression coefficient and ε is the error.

[0047] S103, using the least square method to solve the regression coefficient of the multivariate impedance model, so as to determine the multivariate impedance model.

[0048] S104, the multi-element impedance model is connected to the distribution network to form a leakage current monitoring model. The multi-element impedance model is connected to the distribution network through a data interface, and the distribution network can adopt a multi-layer topology model, as described in the invention patent No. CN201510528623.0.

[0049] S105, based on the leakage current monitoring model, the leakage current and the zero-sequence current are calculated, and when the current amplitudes of the leakage current and the zero-sequence current exceed the set threshold, the protection circuit connected to the distribution network is activated.

[0050] Solve the electromagnetic field equations based on the leakage current monitoring model, and cyclically calculate the leakage current and zero-sequence current flowing through the operator when the left, right, and double-hand insulating gloves are in contact with the distribution network. The degree of burning is determined based on the leakage current, and whether to activate the protection circuit is determined based on the zero-sequence current. The impedance model of protective equipment under different contact states is substituted into the multivariate impedance model to calculate the overall impedance value, for example, the contact state is switched every 500us.

[0051] See also Figure 3 The present invention also provides a leakage current monitoring device for non-stop operation, comprising:

[0052] The sub-model building model 101 is used to build a human body impedance model, a lining impedance model and a protective equipment impedance model.

[0053] The multivariate model building module 102 is used to obtain sample data and build a multivariate impedance model regarding a human body impedance model, a lining impedance model, and a protective equipment impedance model.

[0054] The multivariate model determination module 103 is used to solve the regression coefficient of the multivariate impedance model by using the least square method, so as to determine the multivariate impedance model.

[0055] The monitoring model assembly module 104 is used to connect the multi-element impedance model to the distribution network to form a leakage current monitoring model.

[0056] The leakage current monitoring module 105 is used to calculate the leakage current and the zero-sequence current based on the leakage current monitoring model. When the current amplitudes of the leakage current and the zero-sequence current exceed a set threshold, the protection circuit connected to the distribution network is activated.

[0057] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0058] In summary, the beneficial effects of the present invention include: according to the dispersion characteristics of human biological tissue, a multi-order Cole-Cole model is used to characterize the dielectric characteristics of human biological tissue, and then the functional relationship between the dielectric characteristics and the applied voltage and current is introduced into the human finite element model to obtain a human impedance model, which can reflect the impedance situation under different human characteristics, and has a good characterization effect; according to the wearing order of protective equipment, a protective equipment impedance network is built to obtain a protective equipment impedance model, which can well match the working state of the operator, has high adaptability, and can reflect the impedance distribution of the operator after wearing the protective equipment. A multivariate impedance model of the human impedance model, the lining impedance model and the protective equipment impedance model is established by using a multivariate regression algorithm. The multivariate impedance model can accurately characterize the overall impedance state of the operator, and all the contact situations between the operator and the distribution network during the operation are taken into account. The three contact states are monitored cyclically. If the maximum value of the leakage current in one of the contact states exceeds the set threshold, the protection circuit is started to fully ensure the personal safety of the operator.

[0059] It should be understood that if the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0060] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A leakage current monitoring method for non-power-off operation, characterized in that: The steps include: Construct human body impedance model, lining impedance model and protective equipment impedance model; Acquire sample data and construct a multivariate impedance model regarding the human body impedance model, the lining impedance model, and the protective equipment impedance model; The least square method is used to solve the regression coefficient of the multivariate impedance model, thereby determining the multivariate impedance model; Connecting the multi-element impedance model to the distribution network to form a leakage current monitoring model; Based on the leakage current monitoring model, the leakage current and the zero-sequence current are calculated, and when the current amplitudes of the leakage current and the zero-sequence current exceed a set threshold, a protection circuit connected to the distribution network is actuated; Wherein, the protective equipment includes insulating clothing, insulating pants, insulating shoes, insulating gloves and insulating pads, and the steps of constructing the impedance model of the protective equipment include: building an impedance network of the protective equipment according to the wearing order of the protective equipment; applying voltage and current to the impedance network of the protective equipment to obtain the impedance model of the protective equipment; When the left hand insulating glove is in contact with the distribution network, the impedance expression of the protective equipment impedance model is: When the right hand insulating glove contacts the power distribution network, the impedance expression of the protective equipment impedance model is: When the insulating gloves on both hands are in contact with the distribution network, the impedance expression of the impedance model of the protective equipment is: In the above formula, R1 is the impedance value of the insulating suit, R2 is the impedance value of the insulating glove on the left hand, R3 is the impedance value of the insulating glove on the right hand, R4 is the impedance value of the insulating pants, R5 is the impedance value of the insulating shoe on the left foot, R6 is the impedance value of the insulating shoe on the right foot, R7 is the impedance value of the insulating blanket, I Lea is the leakage current, U Ap To apply voltage.

2. The leakage current monitoring method for non-stop operation according to claim 1 is characterized in that: The steps of constructing the human body impedance model include: According to the dispersion characteristics of human biological tissue, a multi-order Cole-Cole model is used to characterize the dielectric characteristics of human biological tissue, wherein the dielectric characteristics include conductivity and dielectric constant; Calculating the functional relationship between the dielectric characteristics and the applied voltage and current; The functional relationship is introduced into a human body finite element model to obtain a human body impedance model.

3. The leakage current monitoring method for non-stop operation according to claim 1 is characterized in that: The lining impedance model is the work clothes impedance, and the work clothes impedance is related to the material of the work clothes and is a fixed value.

4. The leakage current monitoring method for non-stop operation according to claim 1 is characterized in that: The expression of the multivariate impedance model is: R total =b1H R +b2L R +b3P R +e; In the above formula, R total is the multivariate impedance model function, H R is the human body impedance model function, L R is the lining impedance model function, P R is the impedance model function of protective equipment, b1, b2, b3 are regression coefficients, and ε is the error.

5. The leakage current monitoring method for non-stop operation according to claim 1 is characterized in that: The calculating of leakage current and zero-sequence current based on the leakage current monitoring model includes: The electromagnetic field equation is solved according to the leakage current monitoring model, and the leakage current and zero-sequence current flowing through the operator when the left hand, right hand and both hands of the insulating gloves are in contact with the distribution network are cyclically calculated, the degree of burning is determined according to the leakage current, and whether to start the protection circuit is determined according to the zero-sequence current.

6. A leakage current monitoring device for non-stop operation, used to implement the leakage current monitoring method for non-stop operation as claimed in claim 1, characterized in that: include: Sub-model construction module, used to construct human body impedance model, lining impedance model and protective equipment impedance model; A multivariate model building module, used to obtain sample data and build a multivariate impedance model about the human body impedance model, the lining impedance model and the protective equipment impedance model; A multivariate model determination module, used to solve the regression coefficient of the multivariate impedance model by using the least square method, so as to determine the multivariate impedance model; A monitoring model assembly module, used for connecting the multi-element impedance model to the distribution network to form a leakage current monitoring model; The leakage current monitoring module is used to calculate the leakage current and the zero-sequence current based on the leakage current monitoring model. When the current amplitudes of the leakage current and the zero-sequence current exceed a set threshold, the protection circuit connected to the distribution network is activated.

Images