CN110954785A - On-site protection prefabricated cable calibration device and method - Google Patents
On-site protection prefabricated cable calibration device and method Download PDFInfo
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- G—PHYSICS
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- 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
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/083—Locating faults in cables, transmission lines, or networks according to type of conductors in cables, e.g. underground
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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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
Abstract
The invention belongs to the technical field of smart power grids, particularly relates to a device and a method for verifying an in-situ protected prefabricated cable, and particularly relates to a device and a method for verifying an in-situ protected prefabricated cable applied to a smart power grid. The cable group testing device comprises a source end device, a terminal device and a wireless communication part, wherein two ends of a cable group to be tested are respectively connected with the source end device and the terminal device, and the source end device and the terminal device are in communication connection in a wireless mode. The invention has the advantages of small volume, light weight, portability and convenience for field test work. The test precision and the test efficiency are obviously improved, and the test continuity can be kept. The system also has the advantages of long communication transmission distance, strong anti-interference capability, low power consumption, strong barrier passing capability, strong confidentiality and high real-time property. The device is suitable for occasions with strong electromagnetic interference, multiple obstacles and the like, such as a transformer substation and the like, is also suitable for devices powered by batteries, and is suitable for various field application conditions.
Description
Technical Field
The invention belongs to the technical field of smart power grids, particularly relates to a device and a method for verifying an in-situ protected prefabricated cable, and particularly relates to a device and a method for verifying an in-situ protected prefabricated cable applied to a smart power grid.
Background
The on-site relay protection device is a new state of relay protection of a third-generation intelligent substation of a national power grid company and is a new direction for development of future relay protection devices. The prefabricated optical cable is an important matching link of on-site protection, and the inspection work of the prefabricated optical cable also becomes one of important contents of the on-site inspection work of the on-site relay protection device and is one of key factors for improving the on-site operation and maintenance efficiency of the relay protection.
The on-site protection prefabricated cable is laid by double-end prefabrication, and the double ends of the cable are standard high-protection-level aviation connectors and are plug-and-play. After the field cable laying is finished, the interface forms of the two ends of the cable are fixed, and a special test tool for the interface is not available at present.
In order to realize the detection of the prefabricated cable of the in-place relay protection device, two cores of the cable are automatically selected one by one to serve as a loop, an excitation signal is applied to the loop, and the type of test excitation tool cannot be found in the market at present. In addition, the types of on-site protection cable interfaces in the field of smart power grids are not unified at present, and three aviation connectors are mainly used. Therefore, the interface for testing should also have these three types of interfaces, so as to be able to adapt to different requirements on the site; the method has strong practical significance for solving the two problems.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a device and a method for verifying a locally protected prefabricated cable, and aims to provide a device and a method for verifying the prefabricated cable, which have the advantages of small size, light weight, convenience in carrying and field test work and high test precision.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the on-site protection prefabricated cable calibration device comprises a source end device, a terminal device and a wireless communication part, wherein two ends of a cable group to be tested are respectively connected with the source end device and the terminal device, and the source end device and the terminal device are in communication connection in a wireless mode.
Any end of the cable to be tested can be connected with a source end device or a terminal device.
The source end device and the terminal device respectively select two wire cores which are the same as those of the cable to be tested as a loop, the source end device applies an excitation signal to one wire core of the loop, the excitation signal is short-circuited to the other wire core through the inside of the terminal device, the excitation signal returns to the source end device through the wire core to realize measurement, and the conditions of contact resistance between a cable plug and an aviation socket, whether an open circuit exists and whether short circuit or insulation exists between the inner wire cores are known.
The source end device is used as a communication host, the terminal device is used as a slave, the host sends an instruction, and the slave receives the instruction and performs corresponding operation.
The source end device adopts a high-definition liquid crystal touch screen.
The wireless mode is Lora wireless communication.
The source end device comprises a CPU, a wireless communication module, a battery, a high-precision direct current constant current source, a double-pole multi-throw change-over switch, an ADC acquisition part and an aviation plug, wherein the CPU is used as the core of the source end device and is connected with the wireless communication module, the battery, the high-precision direct current constant current source, the double-pole multi-throw change-over switch and the ADC acquisition part; the double-pole multi-throw change-over switch is connected with the aviation plug.
The terminal device comprises a CPU, a wireless communication module, a battery, a precise fixed power resistor, a double-pole multi-throw change-over switch and an aviation plug; the CPU is used as the core of the terminal device and is connected with a wireless communication module, a battery, a precise fixed power resistor and a double-pole multi-throw change-over switch; the double-pole multi-throw change-over switch is connected with the aviation plug.
The on-site chemical protection prefabricated cable checking method comprises the following steps:
after the test is started, the source end device switches the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable, the terminal device is set through a wireless signal to switch the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable, the constant current source forms a loop through the double-pole multi-throw switch SW1, the wire core R1, the wire core R2 and the double-pole multi-throw switch SW2, and the resistor RT; the source end device starts the constant current source module to output a 0.5A current I, and after the output is stable, the voltage U1 at two ends of the constant current source is detected through the ADC; in the above-described circuit, ohm's law states:
U1/I = R1+ R2+ RT, wherein: the U1, I, RT values are known;
switching the switches to R1, R3 simultaneously at the source and terminal yields the equation:
U2/I=R1+R3+RT
switching the switches to R1, R4 simultaneously at the source and terminal yields the equation:
U3/I=R1+R4+RT
switching the switches to R2, R3 simultaneously at the source and terminal yields the equation:
U4/I=R2+R3+RT
switching the switches to R2, R4 simultaneously at the source and terminal yields the equation:
U5/I=R2+R4+RT
switching the switches to R2, R4 simultaneously at the source and terminal yields the equation:
U6/I=R3+R4+RT
simultaneously establishing the above equations, and calculating the resistance values of the wire core R1, the wire core R2, the wire core R3 and the wire core R4 to obtain the resistance values of the four wire cores in the tested cable, including the contact resistance with an aviation connector;
according to the actual cable length, if the calculated resistance value is less than 1 ohm, the wire core is considered to be in a conducting state; if the calculated resistance value is larger than 1 ohm, judging that the contact resistance is too large and the aviation connector has poor contact; and if the voltage at the two ends of the constant current source is detected to be close to the maximum output voltage of 24V, judging that the open circuit condition of the loop cable core occurs.
The resistor RT is 10 ohms, if the voltage at two ends of the current source collected and detected by the ADC is less than 5V, a short circuit occurs in a loop, and the current short circuit state between the two cores is judged; at the moment, the loop calculation formula is abandoned, other groups of formulas are adopted to calculate the resistance value of the cable core, and the detection result of the short circuit between the cores is given.
The invention has the following advantages and beneficial technical effects:
(1) the invention introduces the change-over switch triggered by the high-sensitivity relay into the device, thereby not only having very high precision, but also having very high testing efficiency. The switching time is guaranteed to be within 0.5 second. Cable test times of 20 cores require approximately 95 seconds.
(2) The invention adopts a stable and accurate linear constant current source for triggering excitation introduced in the source end device, thereby not only ensuring the testing precision, but also maintaining the testing continuity.
(3) The invention introduces the Lora wireless communication scheme into the device, and has the advantages of long communication transmission distance, strong anti-interference capability, low power consumption, strong barrier passing capability, strong confidentiality and high real-time performance. The device is very suitable for occasions with strong electromagnetic interference, multiple obstacles and the like, such as a transformer substation and the like, and is also suitable for a device powered by a battery.
(4) The invention introduces 3 in-situ cable group aviation connectors which are mainstream at the site of the transformer substation at present into the device, and is suitable for various site application conditions.
(5) The calibration device also has the advantages of small volume, light weight and portability, and is convenient for field test work.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments of the present invention will be briefly described below. Wherein the drawings are only for purposes of illustrating some embodiments of the invention and are not to be construed as limiting the invention to all embodiments thereof.
FIG. 1 is a field test connection diagram provided by an embodiment of the present invention;
FIG. 2 is a schematic diagram of a test protocol implemented in the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Example 1
The invention relates to a checking device for a locally protected prefabricated cable, which is shown in figure 1, wherein figure 1 is a wiring diagram of a checking test for the locally protected prefabricated cable. The invention comprises a source end device, a terminal device and a wireless communication part. The two ends of the cable group to be tested are respectively connected with the source end device and the terminal device, and the source end device and the terminal device are in communication connection in a wireless mode.
Any end of the cable to be tested can be connected with a source end device or a terminal device.
The source end device and the terminal device respectively select two wire cores identical to a tested cable to serve as a loop, the source end device applies an excitation signal to one wire core of the loop, the excitation signal is short-circuited to the other wire core through the inside of the terminal device, the excitation signal returns to the source end device through the wire core to achieve measurement, and the conditions of contact resistance between a cable plug and an aviation socket, whether an open circuit exists, and whether a short circuit or an insulation situation exists between the inner wire cores are known.
The source end device is used as a communication host, the terminal device is used as a slave, the host sends an instruction, and the slave receives the instruction and performs corresponding operation.
Example 2
As shown in fig. 2, fig. 2 is a schematic diagram of a testing scheme for verifying on-site protection of a prefabricated cable according to the present invention, and a source end device is designed by using a battery, so that the testing scheme is suitable for field portable application of a transformer substation, and does not depend on whether a power supply exists near a testing cable. The battery adopts the lithium battery scheme, and has the advantages of short charging time, long electric quantity endurance time and long service life.
The source end device adopts a high-definition liquid crystal touch screen, and is suitable for the use and operation habits of most people at present; in addition, the method has a friendly human-computer interaction interface, the interface is simple and easy to operate, and the test result is clear. In the testing process, manual interference is not needed, and all performance indexes of the prefabricated cable are automatically tested by the device.
The source end device comprises a CPU, a wireless communication module, a battery, a high-precision direct current constant current source, a double-pole multi-throw change-over switch SW1, ADC acquisition (analog-to-digital conversion) and an aviation plug. The core of the CPU as a source end device is connected with a wireless communication module, a battery, a high-precision direct current constant current source, a double-pole multi-throw change-over switch SW1 and an ADC acquisition; the double-pole multi-throw change-over switch SW1 is connected with the aviation plug.
The terminal device comprises a CPU, a wireless communication module, a battery, a precise fixed power resistor, a double-pole multi-throw change-over switch SW2 and an aviation plug. The CPU is used as the core of the terminal device and is connected with a wireless communication module, a battery, a precise fixed power resistor and a double-pole multi-throw change-over switch SW 2; the double-pole multi-throw change-over switch SW2 is connected with an aviation plug.
And completing the interaction between the source end device and the terminal device through wireless communication. For simplifying the description, the cable to be tested only shows four wire cores R1, R2, R3 and R4.
The communication between the source end device and the terminal device adopts a Lora wireless communication scheme. The Lora communication transmission distance is far, the anti-interference capability is strong, the power consumption is low, the barrier passing capability is strong, the confidentiality is strong, and the real-time performance is high. The device is very suitable for occasions with strong electromagnetic interference, multiple obstacles and the like, such as a transformer substation and the like, and is also suitable for a device powered by a battery.
The source end device is used as a communication host, the terminal device is used as a slave, the host sends an instruction, and the slave receives the instruction and performs corresponding operation. If the distance between the two ends of the in-situ protection cable is far, the corresponding wire cores at the two ends are not required to be arranged back and forth during testing, so that the testing efficiency is improved, and human errors in the testing are avoided.
The device can be used for verifying whether an open circuit exists between the prefabricated cable plug and the aviation socket or not and verifying the contact resistance. Whether short circuit between the inside sinle silk of prefabricated cable carries out the check and insulation resistance between the sinle silk carries out the check still.
The CPU triggering excitation of the source end device adopts a stable and accurate linear constant current source, and the testing precision is ensured.
The change over switch adopts high sensitivity relay to trigger, under the prerequisite of guaranteeing ageing, and the precision is also very high.
The ADC is used for collecting and measuring the output current of the constant current source by adopting a high-precision chip, so that the test precision is ensured.
In the above test scheme, the output current of the constant current source module in the source end device is 0.5A, the precision is 0.1%, and the maximum output voltage is 24V. The fixed resistor of the terminal device is selected to have the resistance value of 10 ohms, the power of 5W, the precision of 0.1 percent and the temperature coefficient of 50 ppm. The value of each test is automatically stored in the device, and the object to which the tested cable belongs and the test time are recorded, so that the user can conveniently recall the test result.
The invention discloses a method for verifying a prefabricated cable with in-situ protection, which comprises the following operation steps of:
after the test is started, the source end device switches the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable, and also switches the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable through the wireless signal setting terminal device, and at the moment, the constant current source forms a loop through the double-pole multi-throw switch SW1, the wire core R1, the wire core R2, the double-pole multi-throw switch SW2 and the resistor RT. And then the source end device starts the constant current source module to output a 0.5A current I, and after the output is stable, the voltage U1 at two ends of the constant current source is detected through the ADC. In the above-described circuit, ohm's law states:
U1/I = R1+ R2+ RT, wherein: the U1, I, RT values are known;
the source end and the terminal switch to the wire core R1 and the wire core R3 at the same time to obtain an equation:
U2/I=R1+R3+RT
the source end and the terminal switch to the wire core R1 and the wire core R4 at the same time to obtain an equation:
U3/I=R1+R4+RT
the source end and the terminal switch to the wire core R2 and the wire core R3 at the same time to obtain an equation:
U4/I=R2+R3+RT
the source end and the terminal switch to the wire core R2 and the wire core R4 at the same time to obtain an equation:
U5/I=R2+R4+RT
the source end and the terminal switch to the wire core R2 and the wire core R4 at the same time to obtain an equation:
U6/I=R3+R4+RT
by combining the above equations, the resistances of the wire core R1, the wire core R2, the wire core R3 and the wire core R4 can be calculated, namely the resistances of the four wire cores in the tested cable, including the contact resistance with the aviation connector, can be obtained.
If the calculated resistance value is very small, for example less than 1 ohm, the core is considered to be conductive, and the criterion needs to be determined according to the actual cable length; if the calculated resistance value is large, for example, several ohms, the situation that the contact resistance is too large and the aviation connector is in poor contact is judged. (ii) a If the voltage at the two ends of the constant current source is detected to be close to the maximum output voltage of 24V, the open-circuit condition of the loop cable core can be judged.
The fixed resistor RT is set to be 10 ohms, if the voltage of two ends of the current source detected by the ADC at a certain time is less than 5V, the short circuit of the current loop is shown, and the short circuit state between two current cores can be judged. At the moment, the loop calculation formula is abandoned, other groups of formulas are adopted to calculate the resistance value of the cable core, and the detection result of the short circuit between the cores is given.
The number of the equations is obviously more than that of the unknown numbers, the equations with abnormal occurrence are abandoned, and the resistance value of the normal cable core can be solved. Through above measurement scheme, can test out the on resistance of each cable core, whether the contact of aviation connector is good to and whether there are abnormal conditions such as the short circuit of opening a way, between the cable core in the cable core, convenient and practical.
Taking the number of cable cores N =4 as an example, the number of loops required to be switched and constructed is: n (N-1)/2 = 6. The switching measurement time for one loop is about 0.5 seconds, then the total test time is 6 x 0.5=3 seconds. By analogy, the 20-core cable test time was (20 × 19/2) × 0.5=95 seconds.
The traditional manual testing method is not only time-consuming, but also easy to confuse and make mistakes. In the test scheme, a tester does not need to manually switch and select the electric core in the cable, the test is automatically switched by the test device, and the measurement result is calculated, so that the test is quick and accurate. The only work the tester needs is to connect the tested cable to the aviation plug of the testing device and then select which type of aviation plug to test at present in the man-machine interface of the device. After the test is finished, the test result is checked in the human-computer interface, and the test report is exported through the device, so that the test is convenient and quick.
The testing device can provide a testing and checking device for the on-site protection prefabricated cable of the intelligent substation, the device is designed aiming at the prefabricated cable uniform interfaces of the protection devices with different voltage grades and different types, and the testing device can complete the checking work of the prefabricated cables of the protection devices with different voltage grades and different types.
The device of the invention is suitable for the situation that after the on-site cable laying is finished, the interface forms at two ends of the cable are fixed, and a loop is not formed in the cable when the two ends are not connected with the device. The interior of the aviation connector is a precise component, and a special interface is required to be in butt joint test with the aviation connector. In the testing process, manual interference is not needed, and all performance indexes of the prefabricated cable are automatically tested by the device.
The invention has clear structure, simplicity and clarity, fast research and development progress and low hardware cost; the constant current source, the double-pole multi-throw change-over switch and the ADC chip have high precision performance, and the invention has excellent test performance.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.
The embodiments of the invention are intended to embrace all such alternatives, modifications and variances that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements and the like that may be made without departing from the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (10)
1. Prefabricated cable calibration equipment of on-the-spot chemical protection, its characterized in that: the cable group testing device comprises a source end device, a terminal device and a wireless communication part, wherein two ends of a cable group to be tested are respectively connected with the source end device and the terminal device, and the source end device and the terminal device are in communication connection in a wireless mode.
2. The pre-engineered protection in place cable verification device of claim 1, wherein: any end of the cable to be tested can be connected with a source end device or a terminal device.
3. The pre-engineered protection in place cable verification device of claim 1, wherein: the source end device and the terminal device respectively select two wire cores which are the same as those of the cable to be tested as a loop, the source end device applies an excitation signal to one wire core of the loop, the excitation signal is short-circuited to the other wire core through the inside of the terminal device, the excitation signal returns to the source end device through the wire core to realize measurement, and the conditions of contact resistance between a cable plug and an aviation socket, whether an open circuit exists and whether short circuit or insulation exists between the inner wire cores are known.
4. The pre-engineered protection in place cable verification device of claim 1, wherein: the source end device is used as a communication host, the terminal device is used as a slave, the host sends an instruction, and the slave receives the instruction and performs corresponding operation.
5. The pre-engineered protection in place cable verification device of claim 1, wherein: the source end device adopts a high-definition liquid crystal touch screen.
6. The pre-engineered protection in place cable verification device of claim 1, wherein: the wireless mode is Lora wireless communication.
7. The pre-engineered protection in place cable verification device of claim 1, wherein: the source end device comprises a CPU, a wireless communication module, a battery, a high-precision direct current constant current source, a double-pole multi-throw change-over switch, an ADC acquisition part and an aviation plug; the CPU is used as the core of the source end device and is connected with a wireless communication module, a battery, a high-precision direct current constant current source, a double-pole multi-throw change-over switch and an ADC (analog to digital converter) acquisition; the double-pole multi-throw change-over switch is connected with the aviation plug.
8. The pre-engineered protection in place cable verification device of claim 1, wherein: the terminal device comprises a CPU, a wireless communication module, a battery, a precise fixed power resistor, a double-pole multi-throw change-over switch and an aviation plug; the CPU is used as the core of the terminal device and is connected with a wireless communication module, a battery, a precise fixed power resistor and a double-pole multi-throw change-over switch; the double-pole multi-throw change-over switch is connected with the aviation plug.
9. The on-site chemical protection prefabricated cable checking method is characterized by comprising the following steps: the method comprises the following steps:
after the test is started, the source end device switches the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable, the terminal device is set through a wireless signal to switch the double-pole multi-throw switch SW1 to the wire core R1 and the wire core R2 of the cable, the constant current source forms a loop through the double-pole multi-throw switch SW1, the wire core R1, the wire core R2 and the double-pole multi-throw switch SW2, and the resistor RT; the source end device starts the constant current source module to output a 0.5A current I, and after the output is stable, the voltage U1 at two ends of the constant current source is detected through the ADC; in the above-described circuit, ohm's law states:
U1/I = R1+ R2+ RT, wherein: the U1, I, RT values are known;
switching the switches to R1, R3 simultaneously at the source and terminal yields the equation:
U2/I=R1+R3+RT
switching the switches to R1, R4 simultaneously at the source and terminal yields the equation:
U3/I=R1+R4+RT
switching the switches to R2, R3 simultaneously at the source and terminal yields the equation:
U4/I=R2+R3+RT
switching the switches to R2, R4 simultaneously at the source and terminal yields the equation:
U5/I=R2+R4+RT
switching the switches to R2, R4 simultaneously at the source and terminal yields the equation:
U6/I=R3+R4+RT
simultaneously establishing the above equations, and calculating the resistance values of the wire core R1, the wire core R2, the wire core R3 and the wire core R4 to obtain the resistance values of the four wire cores in the tested cable, including the contact resistance with an aviation connector;
according to the actual cable length, if the calculated resistance value is less than 1 ohm, the wire core is considered to be in a conducting state; if the calculated resistance value is larger than 1 ohm, judging that the contact resistance is too large and the aviation connector has poor contact; and if the voltage at the two ends of the constant current source is detected to be close to the maximum output voltage of 24V, judging that the open circuit condition of the loop cable core occurs.
10. A method of verifying a pre-engineered protection cable in place as in claim 1, wherein: the resistor RT is 10 ohms, if the voltage at two ends of the current source collected and detected by the ADC is less than 5V, a short circuit occurs in a loop, and the current short circuit state between the two cores is judged; at the moment, the loop calculation formula is abandoned, other groups of formulas are adopted to calculate the resistance value of the cable core, and the detection result of the short circuit between the cores is given.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112180292A (en) * | 2020-09-30 | 2021-01-05 | 中国核动力研究设计院 | System and method for detecting on-off of cables between nuclear power plant reactor control system cabinets |
| CN114113940A (en) * | 2021-11-24 | 2022-03-01 | 国网辽宁省电力有限公司朝阳供电公司 | Transformer substation cable calibration detection device and method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112180292A (en) * | 2020-09-30 | 2021-01-05 | 中国核动力研究设计院 | System and method for detecting on-off of cables between nuclear power plant reactor control system cabinets |
| CN114113940A (en) * | 2021-11-24 | 2022-03-01 | 国网辽宁省电力有限公司朝阳供电公司 | Transformer substation cable calibration detection device and method |
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