CN111308333B - Relay protection tripping circuit contact resistance detection device and method - Google Patents
Relay protection tripping circuit contact resistance detection device and method Download PDFInfo
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- CN111308333B CN111308333B CN201911083074.5A CN201911083074A CN111308333B CN 111308333 B CN111308333 B CN 111308333B CN 201911083074 A CN201911083074 A CN 201911083074A CN 111308333 B CN111308333 B CN 111308333B
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- 238000001514 detection method Methods 0.000 title claims abstract description 105
- 238000000034 method Methods 0.000 title claims description 11
- 230000000737 periodic effect Effects 0.000 abstract description 2
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- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/08—Measuring resistance by measuring both voltage and current
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/20—Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
- G01R27/205—Measuring contact resistance of connections, e.g. of earth connections
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
- G01R31/3271—Testing of circuit interrupters, switches or circuit-breakers of high voltage or medium voltage devices
- G01R31/3275—Fault detection or status indication
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The application discloses a relay protection tripping circuit contact resistance detection device and a relay protection tripping circuit contact resistance detection method. According to the relay protection tripping circuit contact resistance detection device, the detection circuit is added on the basis of the tripping circuit, and the contact resistance of the tripping circuit is calculated in a numerical solution mode based on the equality relation of the circuit structure of the relay protection tripping circuit contact resistance detection device and each parameter in the circuit, so that the technical problem that the reliability of the existing relay protection tripping circuit is poor because the contact resistance of the existing relay protection device and the existing relay protection tripping circuit cannot be measured in time due to the fact that the contact resistance of the existing relay protection device and the existing relay protection tripping circuit are checked in a manual periodic check mode is solved.
Description
Technical Field
The application relates to the technical field of relay protection, in particular to a relay protection tripping circuit contact resistance detection device and method.
Background
In the currently used relay protection tripping circuit of the power system, as the tripping outlet pressing plate passes through the tripping holding relay coil and then passes through the position contact of the breaker to reach the tripping coil, the whole circuit passes through the protection cell to the outdoor switching field, the related cable is longer, the problem that the contact resistance of the tripping circuit is increased due to the reasons of secondary cable disconnection, loose terminal strip terminals, poor contact of the pressing plate or equipment aging and the like is difficult to avoid in an intermediate link, the tripping circuit is finally caused to fail, the switch is refused, even the power grid accident is possibly caused, and the important economic loss is caused.
The existing relay protection tripping circuit contact resistance detection device lacks a detection circuit for contact resistance, and the size of the circuit contact resistance cannot be accurately measured, so that the technical problem of poor reliability of the existing relay protection tripping circuit is caused.
Disclosure of Invention
The application provides a device and a method for detecting contact resistance of a relay protection tripping circuit, and the technical problem of poor reliability of the existing relay protection tripping circuit.
In view of this, a first aspect of the present application provides a relay protection trip circuit contact resistance detection apparatus disposed in association with a trip circuit, the trip circuit comprising: the position relay, trip outlet clamp plate, trip hold-down relay, trip coil, protection trip contact and circuit breaker position contact, the voltage source positive pole protection trip contact, trip outlet clamp plate the coil of trip hold-down relay, circuit breaker position contact, trip coil and voltage source negative pole establish ties in proper order, trip hold-down relay's contact with protection trip contact reaches trip outlet clamp plate is parallelly connected, position relay with trip hold-down relay's coil is parallelly connected, relay protection trip return circuit contact resistance detection device includes: a detection loop;
the detection circuit includes: the device comprises a detection switch, a detection resistor and a controller;
the voltage source anode, the detection switch and the detection resistor are sequentially connected in series and are connected in parallel with the protection tripping contact;
A current detection point is arranged between a parallel point of the coil of the tripping hold relay and the position relay and a position contact of the circuit breaker;
The controller is used for controlling the detection switch to be opened or closed, and calculating the contact resistance of the tripping circuit in a numerical solution mode according to a first state current, a second state current and a third state current obtained from the current detection point, wherein the first state current is a tripping circuit current value measured when the detection switch is opened, the second state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a first preset resistance value, and the third state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a second preset resistance value.
Optionally, the detection resistor is specifically an adjustable resistor.
The second aspect of the present application provides a method for detecting contact resistance of a relay protection tripping circuit, which is applied to the device for detecting contact resistance of a relay protection tripping circuit according to the first aspect of the present application, and comprises the following steps:
Acquiring a first state current, a second state current and a third state current of a tripping circuit, wherein the first state current is a tripping circuit current value measured when a detection switch is opened, the second state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of a detection resistor is a first preset resistance value, and the third state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a second preset resistance value;
obtaining direct current voltage between positive and negative poles of a voltage source;
and according to the first state current, the second state current, the third state current, the first preset resistance, the second preset resistance and the direct current voltage, calculating the contact resistance by combining a preset circuit parameter calculation formula in a numerical solution mode.
Optionally, the circuit parameter calculation formula specifically includes:
Wherein U dc is the dc voltage, I 0 is the first state current, I 1 is the second state current, I 2 is the third state current, R 1 is the equivalent resistance of the position relay, R 2 is the equivalent resistance of the trip coil, R 3 is the contact resistance, R 4-1 is the first preset resistance of the detection resistor, and R 4-2 is the second preset resistance of the detection resistor.
Optionally, the method further comprises:
And comparing the contact resistance with a preset standard resistance value, and triggering a resistance fault alarm if the contact resistance is larger than the standard resistance value.
From the above technical scheme, the application has the following advantages:
the application provides a relay protection tripping circuit contact resistance detection device, which is used for being arranged in association with a tripping circuit and comprises the following components: a detection loop; the detection circuit includes: the device comprises a detection switch, a detection resistor and a controller; the voltage source anode, the detection switch and the detection resistor are sequentially connected in series and are connected in parallel with the protection tripping contact; a current detection point is arranged between a parallel point of the coil of the tripping hold relay and the position relay and a position contact of the circuit breaker; the controller is used for controlling the detection switch to be opened or closed, and calculating the contact resistance of the tripping circuit in a numerical solution mode according to the first state current, the second state current and the third state current obtained from the current detection point.
According to the relay protection tripping circuit contact resistance detection device, the detection circuit is added on the basis of the tripping circuit, and the contact resistance of the tripping circuit is calculated in a numerical solution mode based on the equality relation of the circuit structure of the relay protection tripping circuit contact resistance detection device and each parameter in the circuit, so that the technical problem that the reliability of the existing relay protection tripping circuit is poor because the contact resistance of the existing relay protection device and the existing relay protection tripping circuit cannot be measured in time due to the fact that the contact resistance of the existing relay protection device and the existing relay protection tripping circuit are checked in a manual periodic check mode is solved.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a schematic diagram of a contact resistance detection device for a relay protection trip circuit and a trip circuit provided by the application;
fig. 2 is a schematic flow chart of a method for detecting contact resistance of a relay protection tripping circuit.
Detailed Description
The embodiment of the application provides a device and a method for detecting contact resistance of a relay protection tripping circuit, which solve the technical problem of poor reliability of the traditional relay protection tripping circuit.
In order to make the objects, features and advantages of the present application more comprehensible, the technical solutions in the embodiments of the present application are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Referring to fig. 1, a first embodiment of the present application provides a relay protection trip circuit contact resistance detection apparatus, which comprises, based on the existing trip circuit: a detection loop;
Wherein, the trip circuit of this embodiment includes: a position relay R 1, a trip outlet hold-down plate K 1, a trip hold-down relay, a trip coil R 2, a protection trip contact BT and a circuit breaker position contact DL; the positive electrode of the voltage source, the protective trip contact BT, the trip outlet pressing plate K 1, the coil TBJI of the trip holding relay, the position contact DL of the circuit breaker, the trip coil R 2 and the negative electrode of the voltage source are sequentially connected in series; the trip hold relay contact TBJ is connected in parallel with the protection trip contact BT and the trip outlet pressure plate K 1, and the position relay R 1 is connected in parallel with the trip hold relay coil TBJI.
The detection circuit comprises: a detection switch K 2, a detection resistor R 4, and a controller (not shown);
The positive electrode of the voltage source and the detection switch K 2 are sequentially connected in series with the detection resistor R 4 and are connected in parallel with the protection tripping contact BT;
A current detection point is arranged between the coil TBJI of the trip holding relay and the parallel point of the position relay R 1 and the position contact DL of the circuit breaker;
The controller is used for controlling the detection switch K 2 to be opened or closed, and calculating the contact resistance R 3 of the tripping circuit in a numerical solution mode according to the first state current I 0, the second state current I 1 and the third state current I 2 which are obtained from the current detection points.
More specifically, the detection resistor R 4 is specifically an adjustable resistor.
As shown in fig. 1. The direct current voltage U dc between the positive electrode and the negative electrode, the switch position relay equivalent resistor R 1, the tripping coil equivalent resistor R 2 and the resistance values of the detection resistors when the detection switch is closed twice are R 4-1 and R 4-2 respectively. Of the above parameters, U dc、R4-1 and R 4-2 are known parameters. At this time, the magnitudes of R 1、R2 and the contact resistance R 3 are unknown. TBJI is the equivalent resistance of the current coil of the tripping hold relay, and the calculation is negligible because the resistance value is very small. TBJ is a trip hold relay operation contact, BT is a protection trip contact, DL is a breaker position contact. When the circuit breaker is in a closing position, the DL contact is in a closing state, and the resistance of the DL contact is negligible. TBJ and BT contacts are in the off state.
According to the relay protection tripping circuit contact resistance detection device provided by the first embodiment of the application, the detection circuit is added on the basis of the tripping circuit, and the contact resistance of the tripping circuit is calculated in a numerical solution mode based on the circuit structure of the relay protection tripping circuit contact resistance detection device and the equality relation of each parameter in the circuit, so that the technical problem that the reliability of the existing relay protection tripping circuit is poor because the contact resistance of the existing relay protection device and the secondary circuit is inspected manually and regularly is not measured in time is solved.
The above is a detailed description of a relay protection tripping circuit contact resistance detection device provided by the present application, and the following is a detailed description of one embodiment of a relay protection tripping circuit contact resistance detection method applied to the relay protection tripping circuit contact resistance detection device provided by the first embodiment.
Referring to fig. 2, based on the structure of the relay protection trip circuit contact resistance detection device provided by the first embodiment of the present application, a relay protection trip circuit contact resistance detection method provided by a second embodiment of the present application includes:
Step 101, acquiring a first state current I 0, a second state current I 1 and a third state current I 2 of the tripping circuit.
The first state current is a tripping circuit current value measured when the detection switch is opened, the second state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a first preset resistance value R 4-1, and the third state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a second preset resistance value R 4-2;
More specifically, the three-state current in this embodiment is obtained in the following specific ways:
1) When the detection switch is disconnected, measuring and recording the tripping circuit current I=I 0 of the detection point, wherein the current value corresponding to the I 0 is the first state current;
2) Setting the resistance value of the detection resistor as a first preset resistance value, closing the detection switch, and measuring and recording the tripping circuit current I=I 1, wherein the current value corresponding to I 1 is the second state current;
3) And setting the resistance value of the detection resistor as a second preset resistance value, then closing the detection switch again, and measuring and recording the tripping circuit current I=I 2, wherein the current value corresponding to I 2 is the third state current.
Step 102, obtaining a direct current voltage U dc between the positive electrode and the negative electrode of the voltage source.
Step 103, according to the first state current I 0, the second state current I 1, the third state current I 2, the first preset resistance R 4-1, the second preset resistance R 4-2 and the dc voltage U dc, the contact resistance R 3 is calculated by combining a preset circuit parameter calculation formula through a numerical solution mode.
More specifically, after parameters such as the direct current voltage, the first state current, the second state current and the third state current are obtained, the equality relation of each parameter of the circuit structure is determined based on the circuit structure provided in the first embodiment, and then the solution is performed by a numerical solution mode.
The equation relationship of this embodiment is specifically:
Wherein U dc is direct current voltage, I 0 is first state current, I 1 is second state current, I 2 is third state current, R 1 is equivalent resistance of a position relay, R 2 is equivalent resistance of a tripping coil, R 3 is contact resistance of a tripping circuit, R 4-1 is a first preset resistance value, and R 4-2 is a second preset resistance value.
After the above formula is simplified, the following ternary quadratic equation set can be obtained:
When the parameters U dc、I0、I1、I2 and R 4-1、R4-2 are known, the resistance values of the resistor R 1、R2 and the contact resistor R 3 can be obtained by a numerical method (e.g., newton method).
Further, step 103 further includes:
step 104, determining whether the contact resistance R 3 is greater than a preset standard resistance, if yes, executing step 105.
Step 105, triggering a resistance fault alarm.
After the contact resistance is calculated, the contact resistance can be compared with a preset standard resistance value, and if the contact resistance is larger than the standard resistance value, a resistance fault alarm is triggered.
The standard resistance can be set by a user, a specific value can be set according to the application scene of the relay protection tripping circuit contact resistance detection device, the standard resistance can be set to be a milliohm level or a micro ohm level value if the relay protection tripping circuit contact resistance detection device is used in the weak current field, and the standard resistance can be set to be an ohm level value if the relay protection tripping circuit contact resistance detection device is used in the strong current field.
And the resistance fault alarm can be sent in one or more manners of optical signal alarm, acoustic signal alarm and message signal alarm, which are not particularly limited herein.
In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (3)
1. A relay protection trip circuit contact resistance detection method, applied to a relay protection trip circuit contact resistance detection device, the relay protection trip circuit contact resistance detection device being disposed in association with a trip circuit, the trip circuit comprising: the position relay, trip outlet clamp plate, trip hold-down relay, tripping coil, protection tripping contact and circuit breaker position contact, the voltage source positive pole protection tripping contact, tripping outlet clamp plate the coil of trip hold-down relay, circuit breaker position contact, tripping coil and voltage source negative pole establish ties in proper order, tripping hold-down relay's contact with protection tripping contact reaches tripping outlet clamp plate is parallelly connected, position relay with tripping hold-down relay's coil is parallelly connected, its characterized in that includes:
Acquiring a first state current, a second state current and a third state current of a tripping circuit, wherein the first state current is a tripping circuit current value measured when a detection switch is opened, the second state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of a detection resistor is a first preset resistance value, and the third state current is a tripping circuit current value measured when the detection switch is closed and the resistance value of the detection resistor is a second preset resistance value;
obtaining direct current voltage between positive and negative poles of a voltage source;
According to the first state current, the second state current, the third state current, the first preset resistance value, the second preset resistance value and the direct current voltage between the positive electrode and the negative electrode of the voltage source, the contact resistance of the tripping circuit is calculated by combining a preset circuit parameter calculation formula in a numerical solution mode, wherein the circuit parameter calculation formula specifically comprises the following components:
；
Wherein U dc is the direct current voltage, I 0 is the first state current, I 1 is the second state current, I 2 is the third state current, R 1 is the equivalent resistance of a position relay, R 2 is the equivalent resistance of a trip coil, R 3 is the contact resistance of a trip circuit, R 4-1 is a first preset resistance value of the detection resistor, and R 4-2 is a second preset resistance value of the detection resistor;
wherein, relay protection tripping operation return circuit contact resistance detection device includes: a detection loop;
the detection circuit includes: the device comprises a detection switch, a detection resistor and a controller;
the voltage source anode, the detection switch and the detection resistor are sequentially connected in series and are connected in parallel with the protection tripping contact;
A current detection point is arranged between a parallel point of the coil of the tripping hold relay and the position relay and a position contact of the circuit breaker;
The controller is used for controlling the detection switch to be opened or closed, and calculating the contact resistance of the tripping circuit in a numerical solution mode according to the first state current, the second state current and the third state current obtained from the current detection point.
2. The relay protection trip circuit contact resistance detection method of claim 1, further comprising:
And comparing the contact resistance with a preset standard resistance value, and triggering a resistance fault alarm if the contact resistance is larger than the standard resistance value.
3. The method for detecting contact resistance of relay protection tripping circuit according to claim 1, wherein the detection resistance is specifically an adjustable resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201911083074.5A CN111308333B (en) | 2019-11-07 | 2019-11-07 | Relay protection tripping circuit contact resistance detection device and method |
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| CN201911083074.5A CN111308333B (en) | 2019-11-07 | 2019-11-07 | Relay protection tripping circuit contact resistance detection device and method |
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| CN111308333A CN111308333A (en) | 2020-06-19 |
| CN111308333B true CN111308333B (en) | 2024-07-02 |
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| CN211426707U (en) * | 2019-11-07 | 2020-09-04 | 广东电网有限责任公司 | Contact resistance detection device for relay protection tripping circuit |
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| CN102749552B (en) * | 2012-07-31 | 2014-12-10 | 天津市电力公司 | Complete online monitoring device of relay protection outlet circuit |
| CN202940578U (en) * | 2012-12-12 | 2013-05-15 | 国电南瑞科技股份有限公司 | Current detection circuit for breaker trip |
| CN103208861B (en) * | 2013-04-19 | 2015-04-01 | 上海毅昊自动化有限公司 | Real-time online monitoring system of relay protection tripping and closing circuit |
| CN103515921B (en) * | 2013-09-25 | 2015-09-16 | 国家电网公司 | A kind of online protective circuit of high-voltage circuit breaker/closing coil and guard method thereof |
| CN203932976U (en) * | 2014-06-10 | 2014-11-05 | 新疆特变电工自控设备有限公司 | The protective relaying device of monitoring switch operation circuit voltage |
| CN104808102B (en) * | 2015-04-29 | 2017-11-03 | 中国电力科学研究院 | A kind of relay protection DC control circuit in-service monitoring and method for early warning |
| CN106814313B (en) * | 2017-01-13 | 2019-05-17 | 天津大学 | The intellectual faculties in breaker operator circuit |
| CN108089119B (en) * | 2017-11-17 | 2021-01-29 | 国网湖南省电力有限公司 | Secondary circuit electrification detection method and system for relay protection secondary equipment of transformer substation |
| CN109119964B (en) * | 2018-10-29 | 2023-12-05 | 国网辽宁省电力有限公司沈阳供电公司 | Intelligent controller for preventing switch tripping coil from burning |
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| CN211426707U (en) * | 2019-11-07 | 2020-09-04 | 广东电网有限责任公司 | Contact resistance detection device for relay protection tripping circuit |
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