CN-118604599-B - Method and system for evaluating recovery performance of environment-friendly mixed gas after switching on and switching off

CN118604599BCN 118604599 BCN118604599 BCN 118604599BCN-118604599-B

Abstract

The invention discloses a method and a system for evaluating recovery performance of an environment-friendly mixed gas after switching on and switching off. The method comprises the steps of detecting arc voltage, arc current, gas pressure and temperature in an arc extinguishing chamber, calculating arc conductance and time change rate of the arc conductance, substituting the arc voltage, the arc current, the arc conductance and the time change rate into an arc model, calculating to obtain post-arc current after zero crossing of the arc current, judging whether post-arc heat recovery performance meets the breaking requirement or not based on the post-arc current, determining a net ionization coefficient of the environment-friendly mixed gas based on the gas pressure and the temperature in the arc extinguishing chamber if the breaking requirement is met, obtaining critical discharge field intensity based on the net ionization coefficient, applying system operation voltage on a switch device, calculating electric field distribution in the arc extinguishing chamber, comparing the critical discharge field intensity with the electric field distribution, and determining whether the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement or not.

Inventors

YAN XIANGLIAN
GAO KELI
WANG WEN
GAO FEI
LIU WEI
HUANG YIN
LI JUNFENG
CAO JUN

Assignees

中国电力科学研究院有限公司
国网安徽省电力有限公司电力科学研究院
平高集团有限公司

Dates

Publication Date: 20260508
Application Date: 20240619

Claims (11)

1. The method for evaluating the recovery performance of the environment-friendly mixed gas switch after the arc is characterized by comprising the following steps of: Detecting arc voltage, arc current, gas pressure and temperature in an arc extinguishing chamber generated by an on-off test, and calculating arc conductance and time change rate thereof; Substituting the arc voltage, the arc current, the arc conductance and the time change rate thereof into an arc model, calculating to obtain the post-arc current after the zero crossing of the arc current, and judging whether the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement or not based on the post-arc current; if the heat recovery performance of the environment-friendly mixed gas after the arc meets the breaking requirement, determining a net ionization coefficient of the environment-friendly mixed gas based on the gas pressure and the temperature in the arc extinguishing chamber, and obtaining critical discharge field intensity based on the net ionization coefficient; And applying system operation voltage to the switching equipment, calculating electric field distribution in the arc extinguishing chamber, comparing the critical discharge field intensity with the electric field distribution, and determining whether the electric recovery performance of the environment-friendly mixed gas after the arc meets the breaking requirement.
2. The method of claim 1, wherein detecting the arc voltage, the arc current, the gas pressure in the arc chamber, the temperature generated by the open test, and calculating the arc conductance and the rate of change thereof with time, comprises: and filling the environment-friendly mixed gas into a switching device with an arc-generating function, conducting an on-off test on the switching device, determining test current, changing air pressure and environment-friendly insulating gas volume ratio, detecting arc voltage u, arc current i, gas pressure P and temperature T change rules in an arc extinguishing chamber under each test condition, and calculating arc conductance g=i/u and time change rate dg/dt thereof.
3. The method of claim 1, wherein substituting the arc voltage, the arc current, the arc conductance, and the time variation rate thereof into an arc model, calculating a post-arc current after zero crossing of the arc current, and determining whether the post-arc heat recovery performance of the environmentally friendly mixed gas meets the on-off requirement based on the post-arc current comprises: the arc voltage u, the arc current i, the arc conductance g obtained by calculation and the time change rate dg/dt of the arc conductance g detected by the test are substituted into a Mayr arc model, and the expression is as follows: Wherein, theta and Q are respectively arc time constant and energy dissipation coefficient, arc voltage u and arc current i waveforms within 50 mu s before the zero crossing of the arc current are fitted, and corresponding g and dg/dt are substituted into formula (1), so as to obtain theta and Q by calculation; applying recovery voltages u with different rising rates, substituting the recovery voltages u into an arc model, and calculating to obtain an arc current i after the zero crossing of the arc current; if the instantaneous value of the current i after the arc is reduced to be larger than a preset value in a preset time after the zero crossing, changing the air pressure of the environment-friendly mixed gas or the volume ratio of the environment-friendly insulating gas, and carrying out switching-on and switching-off tests on the switching equipment again; if the instantaneous value of the current i after the arc is reduced to be not more than a preset value in the preset time after the zero crossing, determining that the heat recovery performance of the environment-friendly mixed gas after the arc meets the switching-on and switching-off requirements, and obtaining a corresponding recovery voltage rising value.
4. The method according to claim 1, wherein if the post-arc heat recovery performance of the environmentally friendly mixed gas satisfies the on-off requirement, determining a net ionization coefficient of the environmentally friendly mixed gas based on the gas pressure and the temperature in the arc extinguishing chamber, and obtaining the critical discharge field intensity based on the net ionization coefficient, comprises, if the post-arc heat recovery performance of the environmentally friendly mixed gas satisfies the on-off requirement, obtaining the pressure P e and the temperature T e at the time based on the gas pressure and the temperature in the arc extinguishing chamber, and determining the net ionization coefficient of the environmentally friendly mixed gas The expression is: Wherein N is the number of particles, k is the volume ratio of the environment-friendly insulating gas, E/N is the reduced discharge field intensity (Td), the formula (2) is equal to zero, the critical reduced discharge field intensity (E/N) c is obtained through calculation, Ideal gas state equation, expression: P e V＝NRT e (3) Wherein V is the volume of the arc extinguishing chamber, R is a constant of 8.31J/(mol.K), and N is calculated by using the formula (3) in combination with the pressure P e and the temperature T e and substituted into the formula (2) to obtain the critical discharge field intensity E c .
5. The method of claim 1, wherein applying a system operating voltage across the switching device, calculating an electric field distribution within the arc chute, comparing the critical discharge field strength with the electric field distribution, and determining whether a post-arc electrical recovery performance of the environmentally friendly gas mixture meets an on-off requirement, comprises: applying system operation voltage to the switching equipment, and calculating electric field distribution in the arc extinguishing chamber; If the electric field distribution at each position in the arc extinguishing chamber is not smaller than the critical discharge field intensity, determining that the electric recovery performance of the environment-friendly mixed gas after the arc meets the switching-on and switching-off requirements; otherwise, the structural design of the part of the arc extinguishing chamber, the electric field distribution of which is smaller than the critical discharge field intensity, is perfected, so that the thermal state environment-friendly mixed gas has the electric recovery performance meeting the breaking requirement.
6. An environmental protection mixed gas switch after-arc recovery performance evaluation system, which is characterized by comprising: the detection test parameter module is used for detecting arc voltage, arc current, gas pressure and temperature in the arc extinguishing chamber generated by the breaking test and calculating arc conductance and time change rate thereof; The heat recovery performance judging module is used for substituting the arc voltage, the arc current, the arc conductance and the time change rate thereof into an arc model, calculating to obtain the post-arc current after the zero crossing of the arc current, and judging whether the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement or not based on the post-arc current; The critical discharge field intensity module is used for determining a net ionization coefficient of the environment-friendly mixed gas based on the gas pressure and the temperature in the arc extinguishing chamber if the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement, and obtaining the critical discharge field intensity based on the net ionization coefficient; And the power restoration performance judging module is used for applying system running voltage to the switch equipment, calculating electric field distribution in the arc extinguishing chamber, comparing the critical discharge field intensity with the electric field distribution, and determining whether the power restoration performance of the environment-friendly mixed gas after the arc meets the switching-on and switching-off requirements.
7. The system of claim 6, wherein the test parameter module comprises: The testing parameter determination submodule is used for filling the environment-friendly mixed gas into a switching device with the function of generating an arc by switching on and off, conducting switching-on and off testing on the switching device, determining a testing current, changing the air pressure and the environment-friendly insulating gas volume ratio, detecting the arc voltage u, the arc current i, the gas pressure P and the temperature T change rule in an arc extinguishing chamber under each testing condition, and calculating the arc conductance g=i/u and the time change rate dg/dt thereof.
8. The system of claim 6, wherein determining the thermal recovery performance module comprises: The submodule for obtaining the arc time constant and the energy dissipation coefficient is used for substituting the arc voltage u, the arc current i, the calculated arc conductance g and the time change rate dg/dt of the arc conductance g detected by the test into a Mayr arc model, and the expression is as follows: Wherein, theta and Q are respectively arc time constant and energy dissipation coefficient, arc voltage u and arc current i waveforms within 50 mu s before the zero crossing of the arc current are fitted, and corresponding g and dg/dt are substituted into formula (1), so as to obtain theta and Q by calculation; the post-arc current calculation sub-module is used for applying recovery voltages u with different rising rates, substituting the recovery voltages u into an arc model, and calculating to obtain post-arc current i after the zero crossing of the arc current; the retest sub-module is used for changing the air pressure of the environment-friendly mixed gas or the volume ratio of the environment-friendly insulating gas if the instantaneous value of the current i after the arc is reduced to be larger than a preset value in a preset time after the zero crossing, and retesting the switching equipment; The sub-module for obtaining the recovery voltage rise value is used for determining that the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement if the instantaneous value of the post-arc current i falls to be not more than a preset value within a preset time after zero crossing, and obtaining the corresponding recovery voltage rise value.
9. The system of claim 6, wherein obtaining a critical discharge field strength module comprises: The critical discharge field sub-module is used for determining the net ionization coefficient of the environment-friendly mixed gas if the post-arc heat recovery performance of the environment-friendly mixed gas meets the on-off requirement, and based on the gas pressure and the temperature in the arc extinguishing chamber, the pressure P e and the temperature T e are obtained at the moment The expression is: Wherein N is the number of particles, k is the volume ratio of the environment-friendly insulating gas, E/N is the reduced discharge field intensity (Td), the formula (2) is equal to zero, the critical reduced discharge field intensity (E/N) c is obtained through calculation, Ideal gas state equation, expression: P e V＝NRT e (3) Wherein V is the volume of the arc extinguishing chamber, R is a constant of 8.31J/(mol.K), and N is calculated by using the formula (3) in combination with the pressure P e and the temperature T e and substituted into the formula (2) to obtain the critical discharge field intensity E c .
10. The system of claim 6, wherein determining an electrical recovery performance module comprises: The electric field distribution calculating submodule is used for applying system running voltage to the switching equipment and calculating electric field distribution in the arc extinguishing chamber; The submodule is used for determining that the electric recovery performance of the environment-friendly mixed gas after the arc meets the breaking requirement if the electric field distribution of each part in the arc extinguishing chamber is not smaller than the critical discharge field intensity; And the perfecting structural design submodule is used for perfecting structural design of a part of which the electric field distribution in the arc extinguishing chamber is smaller than the critical discharge field intensity, so that the thermal state environment-friendly mixed gas has the electric recovery performance meeting the switching-on and switching-off requirements.
11. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method according to any of claims 1-5.

Description

Method and system for evaluating recovery performance of environment-friendly mixed gas after switching on and switching off Technical Field The invention relates to the technical field of environment-friendly gas-insulated power transmission and distribution equipment, in particular to a method and a system for evaluating recovery performance of an environment-friendly mixed gas switch after arc. Background Sulfur hexafluoride (SF 6) gas is widely used in electrical equipment as an excellent insulating and arc extinguishing medium, but the greenhouse effect of SF 6 is 24,300 times that of CO 2, and the life time in the atmosphere is as long as 3,200 years, which has a great adverse effect on the environment. Research at home and abroad shows that the mixed gas formed by environment-friendly gases such as perfluoroisobutyronitrile (C 4F7 N), trifluoromethyl sulfonyl fluoride (CF 3SO2 F) and CO 2、O2、N2 has high insulating strength and low greenhouse effect, is considered as SF 6 environment-friendly substitute gas with better performance at present, and gradually realizes engineering application in insulating substitute scenes of switch equipment such as GIS, GIL, ring main units and the like. However, aiming at the arc extinguishing performance and the large-capacity breaking technology of the environment-friendly mixed gas, research and public report are lacked, and larger uncertainty still exists. Because the environment-friendly gas has lower greenhouse effect, the degradation in the atmosphere is faster, and the stability of the gas and the recombination performance of the ionized gas are limited. Disclosure of Invention According to the invention, an evaluation method and system for the recovery performance of the environment-friendly mixed gas after switching on and off is provided, so that the problems of arc extinguishing performance and large-capacity switching-on and switching-off technology aiming at the environment-friendly mixed gas are solved, research and public report lack are avoided, and larger uncertainty still exists. Because the environment-friendly gas has lower greenhouse effect, the degradation in the atmosphere is faster, and the stability of the gas and the recombination performance of the ionized gas are limited. According to a first aspect of the present invention, there is provided a method for evaluating recovery performance after an arc of an environment-friendly mixed gas switch, comprising: Detecting arc voltage, arc current, gas pressure and temperature in an arc extinguishing chamber generated under the breaking test condition, and calculating arc conductance and time change rate thereof; Substituting the arc voltage, the arc current, the arc conductance and the time change rate thereof into an arc model, calculating to obtain the post-arc current after the zero crossing of the arc current, and judging whether the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement or not based on the post-arc current; if the heat recovery performance of the environment-friendly mixed gas after the arc meets the breaking requirement, determining a net ionization coefficient of the environment-friendly mixed gas based on the gas pressure and the temperature in the arc extinguishing chamber, and obtaining critical discharge field intensity based on the net ionization coefficient; And applying system operation voltage to the switching equipment, calculating electric field distribution in the arc extinguishing chamber, comparing the critical discharge field intensity with the electric field distribution, and determining whether the electric recovery performance of the environment-friendly mixed gas after the arc meets the breaking requirement. Optionally, detecting the arc voltage, the arc current, the gas pressure in the arc extinguishing chamber, the temperature generated by the breaking test, and calculating the arc conductance and the time change rate thereof, including: and filling the environment-friendly mixed gas into a switching device with an arc-generating function, conducting an on-off test on the switching device, determining test current, changing air pressure and environment-friendly insulating gas volume ratio, detecting arc voltage u, arc current i, gas pressure P and temperature T change rules in an arc extinguishing chamber under each test condition, and calculating arc conductance g=i/u and time change rate dg/dt thereof. Optionally, substituting the arc voltage, the arc current, the arc conductance and the time change rate thereof into an arc model, calculating to obtain a post-arc current after the zero crossing of the arc current, and judging whether the post-arc heat recovery performance of the environment-friendly mixed gas meets the breaking requirement based on the post-arc current, including: the arc voltage u, the arc current i, the arc conductance g obtained by calculation and the time change rate dg/dt of the ar