CN112083256B

CN112083256B - A hazard assessment method for human ventricular fibrillation with different electric shock areas in complex environment

Info

Publication number: CN112083256B
Application number: CN202010987674.0A
Authority: CN
Inventors: 张栋; 周利军; 黄林
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2021-07-02
Anticipated expiration: 2040-09-18
Also published as: CN112083256A

Abstract

A hazard evaluation method for human ventricular fibrillation with different electric shock areas in a complex environment, which mainly includes a disc electrode, a layered earth module, a power supply module, a zero potential electrode, a host computer, a surface potential measurement module, and a typical circuit module; the disc electrode belongs to The surface potential measurement module, the disc electrode can be replaced, the surface potential measurement module is placed on the surface of the layered earth module, the power supply module provides electrical energy to the typical line module, the surface potential measurement module can be moved at will, and can measure the electrical value at different positions, And wirelessly transmit the measured electrical quantity to the upper computer. The invention can test the surface potential affected by different electric shock areas of the human body in a non-uniform earth environment, and can evaluate the risk of ventricular fibrillation of the human body, providing effective safety protection guidance for the operation and maintenance personnel in the power sector, and reducing the occurrence of ground faults. The resulting risk of electric shock can also improve operation and maintenance efficiency and power service levels.

Description

Human body ventricular fibrillation hazard evaluation method for different electric shock areas in complex environment

Technical Field

The invention belongs to the technical field of grounding analysis of power systems, and particularly relates to a method for evaluating human ventricular fibrillation hazards of different electric shock areas in a complex environment.

Background

The grounding system in the smart grid plays an important role in protecting the power system, can guarantee the safety of people and equipment, ensures that the people and the equipment are not threatened by step voltage and contact voltage, provides a circulation path for fault current, and creates a zero potential for electric and electronic equipment. Generally, the grounding system comprises a vertical grounding electrode, a horizontal grounding electrode and a grounding grid, and reasonable and accurate personal electric shock risk calculation can provide guarantee for accurate operation of electrical equipment, insulation matching and life safety of operation and maintenance personnel.

After a human body is shocked, ventricular fibrillation (ventricular fibrillation) can be caused, namely, disordered excitation of the ventricles of the human body can occur, so that ordered excitation and relaxation functions of the ventricles are eliminated, the ventricular fibrillation is also called functional cardiac arrest and is one of the most main reasons for sudden cardiac death. The safety assessment aiming at the ventricular fibrillation caused by human body electric shock is a key problem which needs to be solved urgently by scientific research personnel all the time. At present, the research of scholars at home and abroad lacks the research of human ventricular fibrillation risk assessment methods with different electric shock areas under complex earth structures. In order to guarantee the life safety of operation and maintenance personnel of a transformer substation and residents near a fault grounding point in a large power grid in a power system, an accurate, various and comprehensive human ventricular fibrillation risk evaluation method which can process complex dependency relations among parameters and adapt to relevant safety standards and grounding design is urgently needed, and scientific mathematical calculation support and rich theoretical data support are provided for design of an intelligent power grid grounding system and formulation of an international standard for calculating ventricular fibrillation risk caused by human body electric shock.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a method for evaluating human ventricular fibrillation hazards in different electric shock areas under a complex environment.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

firstly, building a surface potential measurement test system under the influence of different electric shock areas in a complex environment, wherein the surface potential measurement test system comprises a layered earth module, a power supply module, a zero potential pole, an upper computer, a surface potential measurement module and a typical circuit module;

the layered ground module comprises a horizontal first layer of soil and a horizontal second layer of soil;

the power module comprises a power frequency 220V power supply, a rectifier, an inverter and a transformer, and all parts of the power module are connected through a single wire; the power frequency 220V power supply is 220V commercial power, the rectifier rectifies single-phase alternating current into direct current, the inverter inverts the direct current into three-phase alternating current, and the voltage grade required by the test system can be regulated and controlled through the transformer;

the earth surface potential measuring module comprises an insulating box, an insulating interlayer, a disc electrode, an insulating disc, a metal support I, an insulating support II, an insulating support III, an insulating handle I, an insulating handle II, an insulating support I, an insulating support II, a Rogowski coil, a lithium battery pack, a wireless transmission module, an electrical parameter recorder and a resistor; the Rogowski coil, the lithium battery pack, the wireless transmission module, the electrical parameter recorder and the resistor are all horizontally arranged on the insulating interlayer, and the top of the first insulating support and the top of the second insulating support are symmetrically and fixedly connected with the bottom of the insulating box; the top of the first metal support is fixedly connected with the bottom of the first insulating support; the top of the first insulating support is fixedly connected with the bottom of the second insulating support; the disc electrode is electrically connected with the bottom of the metal support, and the disc electrode can be detached and replaced; the insulating disc is fixedly connected with the bottom of the insulating support; the second insulating support and the third insulating support are respectively fixed on two sides of the insulating box; the first insulating handle is fixedly connected with the second insulating support; the second insulating handle is fixedly connected with the third insulating support; the left end of the resistor is electrically connected with the top of the first metal support through the first insulating support; the electric parameter recorder is respectively and electrically connected with the lithium battery pack, the wireless transmission module and the Rogowski coil; the earth surface potential measuring module is in close contact with the layered earth module through the disc electrode and the insulating disc;

the zero potential pole is electrically connected with the right end of the resistor through the Rogowski coil;

the upper computer can receive the electrical quantity value recorded by the electrical parameter recorder through the wireless transmission module;

the typical circuit module is electrically connected with one of the power supply modules through a single lead;

and secondly, carrying out a surface potential test of the earth:

a) the power supply module is turned on, current is injected into the typical line module, the electric potential of any point on the surface of the layered earth module is tested by the earth potential measuring module, and the electric potential value recorded by the electric parameter recorder is wirelessly transmitted to the upper computer by the wireless transmission module;

b) moving the earth surface potential measuring module at different places of the surface change of the layered earth module (34), and repeating the step a);

c) changing the disc electrodes with different areas, and then repeating the steps a) and b);

thirdly, calculating a human ventricular fibrillation hazard evaluation factor, namely a human ventricular fibrillation hazard evaluation factor Q:

j＝1,2,...,N

wherein N is the number of the total test points, and Q is a human ventricular fibrillation hazard evaluation factor; u shape_mjIs the potential measurement value of the jth test point, d_jIs the straight-line distance from the jth test point to the geometric center of the line module, I is the current injected into the typical line module, p₁Is the horizontal first layer soil resistivity, rho₂Horizontal second layer soil resistivity, h₁Is the horizontal first layer soil thickness;

and fourthly, evaluating the human ventricular fibrillation hazard level:

if Q belongs to [0,0.5), judging that the four-stage ventricular fibrillation hazard has almost no influence on the human body; if Q belongs to [0.5,5 ], judging that the damage of the ventricular fibrillation is three-level, and the human body has small muscle reaction; if Q belongs to [5,500 ], judging that the damage of the second-level ventricular fibrillation is caused, and inhibiting the human body activity is difficult to get rid of; if Q ∈ [500, + ∞), the first-order ventricular fibrillation hazard is judged, the probability of ventricular fibrillation hazard is high, and the human heart is easily damaged.

Compared with the prior art, the invention has the beneficial effects that:

1) the established experimental device is reliable and practical, is convenient to operate, and has safety, simplicity and convenience for measuring the ground potential of the target earth;

2) the earth surface potential measurement values of different human foot electric shock areas under the consideration of a complex layered earth structure can be effectively obtained and can be remotely and wirelessly transmitted to a cloud end and upper computer software;

3) the damage degree of ventricular tremor of human bodies with different electric shock areas under a complex earth structure can be subjected to multi-factor universal evaluation by combining the measured surface potential distribution condition and the evaluation method, and the evaluation factor has the advantages of complex property and integrity.

Drawings

FIG. 1 is a schematic diagram of the general structure of a complex earth surface potential measurement test platform in use according to the present invention;

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

Fig. 1 shows that the experimental platform and method provided by the present invention include the following steps:

firstly, constructing a ground surface potential measurement test system under the influence of different electric shock areas in a complex environment, wherein the ground surface potential measurement test system comprises a layered ground module (34), a power supply module (9), a zero potential pole (25), an upper computer (22), a ground surface potential measurement module (31) and a typical line module (21);

the layered ground module (34) comprises a horizontal first layer of soil (33), a horizontal second layer of soil (32);

the power module (9) comprises a power frequency 220V power supply (5), a rectifier (6), an inverter (7) and a transformer (8), and all parts of the power module are connected through a single wire; the power frequency 220V power supply (5) is 220V commercial power, the rectifier (6) rectifies single-phase alternating current into direct current, the inverter (7) inverts the direct current into three-phase alternating current, and the voltage grade required by the test system can be regulated and controlled through the transformer (8);

the earth surface potential measuring module (31) comprises an insulation box (30), an insulation interlayer (20), a disc electrode (1), an insulation disc (4), a metal support I (2), an insulation support I (3), an insulation support II (12), an insulation support III (14), an insulation handle I (13), an insulation handle II (15), an insulation support I (10), an insulation support II (11), a Rogowski coil (19), a lithium battery pack (16), a wireless transmission module (17), an electrical parameter recorder (18) and a resistor (50); the Rogowski coil (19), the lithium battery pack (16), the wireless transmission module (17), the electrical parameter recorder (18) and the resistor (50) are all horizontally placed on the insulating interlayer (20), and the top of the first insulating support (10) and the top of the second insulating support (11) are symmetrically and fixedly connected with the bottom of the insulating box (30); the top of the first metal support (2) is fixedly connected with the bottom of the first insulating support (10); the top of the first insulating support (3) is fixedly connected with the bottom of the second insulating support (11); the disc electrode (1) is electrically connected with the bottom of the first metal support (2), and the disc electrode (1) can be detached and replaced; the insulating disc (4) is fixedly connected with the bottom of the first insulating support (3); the second insulating support (12) and the third insulating support (14) are respectively fixed on two sides of the insulating box (30); the first insulating handle (13) is fixedly connected with the second insulating support (12); the second insulating handle (15) is fixedly connected with the third insulating support (14); the left end of the resistor (50) is electrically connected with the top of the first metal support (2) through a first insulating support (10); the electric parameter recorder (18) is respectively and electrically connected with the lithium battery pack (16), the wireless transmission module (17) and the Rogowski coil (19); the earth surface potential measuring module (31) is in close contact with the layered earth module (34) through the disc electrode (1) and the insulating disc (4);

the zero potential electrode (25) is electrically connected with the right end of the resistor (50) through a Rogowski coil (19);

the upper computer (22) can receive the electric quantity value recorded by the electric parameter recorder (18) through the wireless transmission module (17);

the typical line module (21) is electrically connected with one of the power supply modules (9) through a single lead;

and secondly, carrying out a surface potential test of the earth:

a) the power supply module (9) is turned on, current is injected into the typical line module (21), the surface potential of any point on the surface of the layered earth module (34) is tested by the earth surface potential measuring module (31), and the potential value recorded by the electrical parameter recorder (18) is wirelessly transmitted to the upper computer (22) by the wireless transmission module (17);

b) moving the earth surface potential measuring module (31) at different places of the surface change of the layered earth module (34), and repeating the step a);

c) changing the disc electrode (1) with different areas, and then repeating the steps a) and b);

j＝1,2,...,N

wherein N is the number of the total test points, and Q is a human ventricular fibrillation hazard evaluation factor; u shape_mjIs the potential measurement value of the jth test point, d_jIs the straight-line distance from the jth test point to the geometric center of the line module (21), I is the current injected into the typical line module (21), and p₁Is the horizontal first layer soil (33) resistivity, rho₂Is the horizontal second layer soil (32) resistivity, h₁Is the horizontal first layer soil (33) thickness;

and fourthly, evaluating the human ventricular fibrillation hazard level:

Claims

1. the human ventricular fibrillation hazard evaluation method of different electric shock areas under a complex environment, is characterized in that, comprises the following steps:

The first step is to build a surface potential measurement test system under the influence of different electric shock areas in a complex environment, including a layered earth module (34), a power module (9), a zero potential pole (25), a host computer (22), and the surface potential a measurement module (31), a typical line module (21);

The layered earth module (34) includes a horizontal first layer of soil (33) and a horizontal second layer of soil (32);

The power supply module (9) comprises a power frequency 220V power supply (5), a rectifier (6), an inverter (7) and a transformer (8), each part of which is connected by a single wire; the power frequency 220V power supply (5) is: 220V commercial power, the rectifier (6) rectifies the single-phase alternating current into direct current, the inverter (7) inverts the direct current into three-phase alternating current, and the voltage level required by the measurement test system can be regulated by the transformer (8);

The surface potential measurement module (31) includes an insulating box (30), an insulating interlayer (20), a disc electrode (1), an insulating disc (4), a metal bracket (2), and an insulating bracket (3) , insulating support two (12), insulating support three (14), insulating handle one (13), insulating handle two (15), insulating strut one (10), insulating strut two (11), Rogowski coil ( 19), lithium battery pack (16), wireless transmission module (17), electrical parameter recorder (18), resistance (50); the Rogowski coil (19), lithium battery pack (16), wireless The transmission module (17), the electrical parameter recorder (18), and the resistance (50) are placed horizontally on the insulating spacer (20). (30) The bottom is symmetrically and fixedly connected; the top of the first metal support (2) is fixedly connected to the bottom of the insulating support column one (10); the top of the insulating support one (3) is fixedly connected to the bottom of the second insulating support column (11); the The disc electrode (1) is electrically connected to the bottom of the metal bracket one (2), and the disc electrode (1) can be disassembled and replaced; the insulating disc (4) is fixedly connected to the bottom of the insulating bracket one (3); The second bracket (12) and the third insulating bracket (14) are respectively fixed on both sides of the insulating box (30); the first insulating handle (13) is fixedly connected with the second insulating bracket (12); the second insulating handle (15) is connected with The insulating support three (14) are fixedly connected; the left end of the resistor (50) is electrically connected with the top of the metal support one (2) through the insulating support column one (10); the electrical parameter recorder (18) is respectively connected with the lithium battery pack (16). ), the wireless transmission module (17), and the Rogowski coil (19) are electrically connected; the surface potential measurement module (31) is connected to the layered earth module (34) through the disc electrode (1), the insulating disc (4) Close contact;

The zero potential pole (25) is electrically connected to the right end of the resistor (50) through the Rogowski coil (19);

The upper computer (22) can receive the electrical quantity value recorded by the electrical parameter recorder (18) through the wireless transmission module (17);

The typical line module (21) is electrically connected with a phase in the power module (9) through a single wire;

The second step is to test the ground surface potential:

a) Turn on the power module (9), inject current into the typical line module (21), use the ground potential measuring module (31) to test the potential of any point on the surface of the layered earth module (34), and the wireless transmission module (17) will The potential value recorded by the electrical parameter recorder (18) is wirelessly transmitted to the upper computer (22);

b) moving the surface potential measurement module (31) at different locations on the surface of the layered earth module (34), and repeating step a);

c) Change the disc electrodes (1) of different areas, and then repeat steps a) and b);

The third step is to calculate the human ventricular fibrillation hazard evaluation factor, the human ventricular fibrillation hazard evaluation factor Q:

Among them, N is the number of total test points, Q is the human ventricular fibrillation hazard evaluation factor; U _mj is the potential measurement value of the jth test point, and dj is the distance from the _jth test point to the geometric center of the typical circuit module (21). Straight-line distance, I is the current injected into the typical line module (21), ρ1 is the resistivity of the horizontal _first layer of soil (33), ρ2 is the resistivity of the horizontal _second layer of soil (32), and _h1 is the horizontal first layer of soil (32) resistivity. A layer of soil (33) thickness;

The fourth step is to evaluate the hazard level of human ventricular fibrillation.