Current transformer secondary circuit wire checking method and system

Abstract

The invention discloses a current transformer secondary circuit wire checking method and system, and the method comprises the steps: obtaining the wiring information of a transformer secondary circuit, and configuring a transformer secondary circuit wire checking module according to the wiring information of the transformer secondary circuit; performing wire checking detection on the wiring condition of the secondary circuit wire checking module; in the case of wiring errors, the type of the wiring errors is identified through the response of the secondary circuit wire checking module, and the type of the wiring errors is correspondingly corrected, so that the wire checking time is short, and the wire checking accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automation detection, and in particular to a current transformer secondary circuit calibration method and system. Background Art

[0002] The terminal box taps of the current transformer and the terminals of the terminal box must correspond one by one according to the standard design requirements of the substation. If there is a wiring error, it will cause the current circuit to be open or the winding to be used incorrectly. In severe cases, it will cause the protection to refuse to operate or malfunction, which will seriously affect the safe and stable operation of the power grid. The secondary circuit calibration of the current transformer is one of the important acceptance contents of the new construction or renovation of the substation. Electromagnetic current transformers are almost all in operation. During the acceptance of the secondary circuit of the electromagnetic current transformer, there are two commonly used methods for CT secondary circuit calibration. One is the primary current increase method. This method requires a large current to be directly applied to the primary device, and the secondary circuit cable is verified by measuring whether the secondary current is correct. This method requires the use of professional equipment with large volume and weight and expensive, and the process is complicated and time-consuming. For construction units, some units do not have the conditions such as current increase and qualifications. For the acceptance unit, this method is time-consuming and laborious to implement, and even some regional power grids often do not use this method. Using a multimeter to measure the continuity of the ground is another method for CT secondary circuit calibration. It requires two people to cooperate, first remove all the cables to be checked, and then calibrate the wires by connecting and disconnecting the grounding at both ends. However, this method has the problem of slow calibration speed, and it is easy to make mistakes again when restoring the wiring, especially when the secondary circuit cables in the terminal box of the current transformer are distributed in a messy way. The redundant and error-prone secondary circuit calibration of the transformer has always troubled grassroots power workers.

[0003] Although the circuit is correct, the workload faced by the staff during the acceptance or renovation of the entire station is very large due to the dozens of current transformers involved. At the same time, the wiring may be wrong during the recovery process after calibration, which may lead to secondary open circuit or protection tripping or even more serious consequences. A new calibration method and equipment are urgently needed to solve this frequent and troublesome problem caused by on-site work. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a current transformer secondary circuit calibration method and system to solve the problems that the traditional secondary circuit calibration method is time-consuming and labor-intensive, the process is complicated and time-consuming, the calibration speed is slow, and the secondary circuit cable distribution is messy.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for calibrating a secondary circuit of a current transformer, comprising:

[0008] Acquire the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information;

[0009] Performing calibration detection on the wiring condition of the secondary circuit calibration module;

[0010] In the case of wiring errors, the type of wiring error is identified through the response of the secondary circuit calibration module, and the wiring error type is corrected accordingly.

[0011] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, the configuration of the transformer secondary circuit calibration module includes: an AC power supply, a DC power supply, a detection lamp, a photoresistor, an indicator light and an alarm electronic component;

[0012] The detection lamp and the photoresistor are reliably packaged to form an electro-optical coupling module, and the detection lamp is the only internal power source;

[0013] The AC power supply and the detection light form a detection circuit;

[0014] The photoresistor, indicator light and alarm electronic components constitute an alarm circuit.

[0015] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, it also includes:

[0016] When the calibration is not performed, the detection light and the AC power supply circuit are not connected, the detection circuit resistance is equal to infinity, and the detection light is off;

[0017] When the calibration is not performed, the light intensity inside the electro-optical coupling module is zero, the resistance of the photoresistor is greater than the first threshold, the current in the detection circuit is less than the second threshold, the indicator light is off, and the alarm electronic component does not sound.

[0018] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, wherein: calibrating the wiring condition of the secondary circuit calibration module comprises:

[0019] The first operator grounds the tap to be checked at the transformer terminal box with a grounding wire, and the second operator connects one end of the transformer secondary circuit calibration module to the terminal to be checked at the terminal box, and grounds the other end of the transformer secondary circuit calibration module.

[0020] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, it also includes:

[0021] When the transformer secondary circuits are correctly wired, the transformer secondary circuit calibration module access circuit does not contain windings, and the external circuit to be connected is equivalent to a short circuit. The indicator light is on and the alarm electronic components are turned on.

[0022] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, the wiring error situation includes:

[0023] When the wiring is wrong, the external circuit to be connected is connected to a winding with a resistance greater than the third threshold, and the current of the response circuit does not reach the response value of the indicator light and the alarm electronic component, then the indicator light will not light up and the alarm electronic component will not sound.

[0024] As a preferred solution of the current transformer secondary circuit calibration method of the present invention, the wiring error types include:

[0025] Cable open circuit, reverse cable connection, and wrong connection of cables with different windings;

[0026] When the cable is open or connected in reverse during calibration, the external circuit to be connected of the transformer secondary circuit calibration module is equivalent to an open circuit, the AC current and the detection light form a circuit that is not conductive, the detection light is not on, the photoresistor resistance in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound;

[0027] When cables of different windings are connected incorrectly during calibration, the external waiting circuit of the transformer secondary circuit calibration module is equivalent to connecting one winding, the impedance of the internal winding of the transformer is greater than the third threshold, the circuit formed by the AC power supply and the detection light is not conductive, the detection light is not on, the resistance of the photoresistor in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound.

[0028] In a second aspect, the present invention provides a current transformer secondary circuit calibration system, comprising:

[0029] A configuration module, used to obtain the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information;

[0030] A calibration module, used for calibrating the wiring condition of the secondary circuit calibration module;

[0031] The correction module is used to identify the type of wiring error through the response of the secondary circuit calibration module in the case of wiring error, and perform corresponding correction on the wiring error type.

[0032] In a third aspect, the present invention provides a computing device, comprising:

[0033] Memory and processor;

[0034] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the current transformer secondary circuit calibration method are implemented.

[0035] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the current transformer secondary circuit calibration method.

[0036] Compared with the prior art, the invention has the following beneficial effects: the invention can calibrate the secondary circuit of the current transformer without removing the wires, and the calibration is time-saving and accurate. The method is simple to operate and has no requirements on the professional and technical level of the calibration personnel. The calibration only needs to use the device to measure the grounding one by one, and the calibration work can be completed by observing the buzzer and indicator light of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the overall process logic of a current transformer secondary circuit calibration method according to an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a current transformer secondary circuit calibration method during normal calibration according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a current transformer secondary circuit calibration method according to an embodiment of the present invention when a wiring error occurs;

[0041] Figure 4 A schematic diagram of a current transformer secondary circuit calibration method during normal calibration according to an embodiment of the present invention;

[0042] Figure 5 The present invention is a schematic diagram of a current transformer secondary circuit calibration method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0044] Example 1

[0045] Reference Figure 1-Figure 5 , as an embodiment of the present invention, provides a current transformer secondary circuit calibration method, comprising:

[0046] S100: Acquire the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information;

[0047] S200: Perform calibration test on the wiring condition of the secondary circuit calibration module;

[0048] S300: In the case of wiring error, the wiring error type is identified through the response of the secondary circuit calibration module, and the wiring error type is corrected accordingly;

[0049] It should be noted that the electro-optical coupling module can be used to quickly detect the wiring status and greatly shorten the calibration time. Compared with the traditional method, the calibration efficiency is significantly improved. Only two people are needed to complete the calibration work, which reduces the required human resources and reduces labor costs. The intuitive response of the electro-optical coupling module can accurately determine whether the wiring is correct, reducing human errors.

[0050] In the embodiment of the present application, the above step S100 includes the following sub-steps A1-A4;

[0051] In A1: the transformer secondary circuit calibration module includes: AC power supply, DC power supply, detection lamp, photoresistor, indicator light and alarm electronic components;

[0052] In A2: the detection lamp and the photoresistor are reliably packaged to form an electro-optical coupling module, and the detection lamp is the only internal power source;

[0053] In A3: the AC power supply and the detection light form a detection circuit;

[0054] In A4: the photoresistor, indicator light and alarm electronic components constitute the alarm circuit.

[0055] Specifically, the types of detection lights include but are not limited to conventional small bulbs and various types of light-emitting diodes. The alarm electronic components include but are not limited to buzzers, vibrators and speakers. The detection lights and photoresistors are reliably packaged to form an electro-optical coupling module. The detection lights are the only internal power source and external light cannot enter. The AC power supply and the detection light form a detection circuit, and the external circuit to be connected is the circuit connected to the lead-out terminal of the device. The photoresistor, indicator light and buzzer light form an alarm circuit. When the external wiring is correct, the circuit is turned on and various prompt signals are released. When the external wiring is wrong, the device will not release any signal.

[0056] It should be noted that, through the electro-optical coupling module, utilizing the high sensitivity of the photoresistor to changes in light intensity, the optical signal of the detection lamp can be accurately detected, thereby judging the correctness of the wiring. The reliable packaging of the detection lamp and the photoresistor ensures the stability and durability of the module, and prevents the external environment from interfering with the detection results. The detection lamp, as the only internal light source, ensures the accuracy of the detection, and external light cannot enter, thus avoiding the interference of external light on the detection results. Intuitive feedback is provided through indicator lights and alarm electronic components (such as buzzers, vibrators and speakers, etc.), so that the operator can quickly judge whether the wiring is correct.

[0057] In the embodiment of the present application, after completing steps A1-A4 in the above step S200, the following steps A5-A6 are also included;

[0058] In A5: When the calibration is not performed, the detection light and the AC power supply circuit are not connected, the detection circuit resistance is equal to infinity, and the detection light is off;

[0059] In A6: when the calibration is not performed, the light intensity inside the electro-optical coupling module is zero, the resistance of the photoresistor is greater than the first threshold, the current in the detection circuit is less than the second threshold, the indicator light is off, and the alarm electronic component does not sound.

[0060] Specifically, when the calibration is not performed, the detection lamp and the AC power supply circuit are not connected, and the detection circuit loop resistance is equal to infinity, so the detection lamp is not lit. According to the formula of the photoresistor, it is expressed as:

[0061]

[0062] Among them, I is the light intensity, R is the resistance of the photoresistor, and k is a constant that depends on the characteristics of the photoresistor and the unit of light intensity.

[0063] The resistance of a photoresistor is inversely proportional to the light intensity, that is, the greater the light intensity, the smaller the resistance of the photoresistor; the greater the light intensity, the greater the resistance of the photoresistor;

[0064] When the calibration is not performed, the light intensity inside the electro-optical coupling module is zero, so the resistance of the photoresistor is greater than the first threshold value of 100MΩ. At this time, the current in the detection circuit is less than the second threshold value of 1mA, so the indicator light does not light up and the buzzer does not sound.

[0065] It should be noted that by defining the initial state when no calibration is performed, the operator can clearly know the state of the system before starting the calibration, which helps to reduce misoperation and misunderstanding. It can also make it clear that the detection light and the AC power supply circuit are not conductive, and that the photoresistor is in a high resistance state, thereby ensuring that the system will not mistakenly trigger the alarm circuit when there is no external interference, thereby improving the accuracy of detection. By setting the threshold, the system can work stably under different environmental conditions and will not make misjudgments due to slight changes in ambient light.

[0066] In the embodiment of the present application, the above step S200 includes the following sub-steps B1-B2;

[0067] In B1: the first operator grounds the tap to be checked at the transformer terminal box with a grounding wire nearby, and the second operator connects one end of the transformer secondary circuit calibration module to the terminal to be checked at the terminal box, and grounds the other end of the transformer secondary circuit calibration module nearby;

[0068] In B2: When the transformer secondary circuits are correctly wired, the transformer secondary circuit calibration module access circuit does not contain windings, and the external circuit to be connected is equivalent to a short circuit, the indicator light is on, and the alarm electronic components are turned on.

[0069] Specifically, Figure 2 As shown, it requires the cooperation of two operators. When the wiring is correct, the external circuit to be connected is equivalent to a short circuit. At this time, the internal AC power supply and the light circuit are turned on, so the light intensity inside the electro-optical coupling module increases significantly. Since the resistance of the photoresistor is inversely proportional to the light intensity and changes very sensitively, the resistance of the photoresistor quickly decreases to zero. At this time, the current inside the response circuit increases significantly and reaches the response current of the indicator light and the buzzer 1mA, the indicator light of the corresponding circuit is on and the buzzer is turned on.

[0070] It should be noted that the collaborative work of the two operators can significantly improve the efficiency of the calibration work and reduce the workload that a single operator needs to complete. Through the cooperation of the two operators, the safety of the operators can be ensured during the calibration operation, especially in a high-voltage environment. When the wiring is correct, the transformer secondary circuit calibration module can respond quickly and give instructions, so that the operator can immediately know the calibration results.

[0071] In the embodiment of the present application, the above step S300 includes the following sub-step C1:

[0072] In C1: when the wiring is wrong, the external circuit to be connected is connected to a winding with a resistance greater than the third threshold value, and the current of the response circuit cannot reach the response value of the indicator light and the alarm electronic component, then the indicator light will not light up and the alarm electronic component will not sound.

[0073] Specifically, when a wiring error occurs, the external circuit to be connected will be open or connected to a winding with an impedance greater than the third threshold of 60Ω. The current of the left detection circuit in the schematic diagram is very small, and the detection light intensity is significantly reduced to nearly extinguished. At this time, the light intensity inside the electro-optical coupling module is very small, and the resistance of the photoresistor increases rapidly to near infinity, resulting in the current of the right response circuit being very small and unable to reach the response value of the indicator light and the buzzer, so the indicator light does not light up and the buzzer does not sound. This can achieve accurate judgment of the wiring of the secondary circuit of the current transformer.

[0074] It should be noted that by setting the third threshold, wiring errors can be accurately identified, because only when the external circuit is connected to a winding with a resistance greater than this threshold, the current of the response circuit will not reach the response value of the indicator light and the alarm electronic components. When the wiring is wrong, the indicator light will not light up and the alarm electronic components will not sound. This instant feedback mechanism allows the operator to quickly identify the problem and take corresponding corrective measures. Through the changes in the light intensity inside the electro-optical coupling module and the rapid changes in the resistance of the photoresistor, it is possible to accurately determine whether the external wiring is correct, thereby improving the accuracy of the calibration.

[0075] In the embodiment of the present application, after completing step C1 in the above step S300, the following sub-steps C2-C4 are also included;

[0076] In C2: open circuit of cables, reverse connection of cables, and wrong connection of cables of different windings;

[0077] In C3: When the cable is open or connected in reverse during calibration, the external circuit to be connected of the transformer secondary circuit calibration module is equivalent to an open circuit, the circuit formed by the AC current and the detection light is not conductive, the detection light is not on, the photoresistor resistance in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound;

[0078] In C4: When cables of different windings are connected incorrectly during calibration, the external waiting circuit of the transformer secondary circuit calibration module is equivalent to connecting one winding, the impedance of the internal winding of the transformer is greater than the third threshold, the circuit formed by the AC power supply and the detection light is not conductive, the detection light is not on, the resistance of the photoresistor in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound.

[0079] Specifically, Figure 3 As shown in the figure, there are three situations when the secondary circuit has wiring errors:

[0080] The cable is open-circuited due to cable damage and crimped insulation. At this time, the external circuit to be connected to the device can be directly equivalent to an open circuit;

[0081] Due to negligence, the two cables of the same winding are connected reversely, as shown in the attached Figure 3 In the middle upper part 3S1 and 3S3, the external circuit to be connected can be directly equivalent to an open circuit;

[0082] The cables of different windings are connected incorrectly, i.e. Figure 3 In the middle and upper parts 1S1, 1S2, 2S1 and 2S2, the external circuit to be connected to the device can be directly equivalent to the inductance equivalent to the winding;

[0083] For example, in a substation, there is a current transformer terminal box on the ground near the current transformer, and the current transformer to be calibrated is located at a high place nearby. When using the device to calibrate the line, one person holds the calibration device and directs at the ground terminal box. Another person carries a ground wire and climbs up to the current transformer tap box, opens the box cover and waits.

[0084] Assume that the normal wiring in the attached figure should be TA1-1S1, TA2-1S2, TA3-2S1, TA4-2S2, TA5-3S1, TA6-3S2, TA7-3S3. Due to negligence and other reasons, the windings are connected incorrectly, but the personnel cannot directly see it. Now it is necessary to check whether the cables are correct. The steps for calibrating the line using this method and device are as follows:

[0085] The command personnel at the terminal box should reliably ground the grounding end of the device and reliably contact the TA1 terminal with the other terminal wire of the handheld device. At the same time, command the cooperating personnel on the current transformer to reliably ground the 1S1 terminal by shouting or calling. If the device indicator light is on and the buzzer sounds, it means that the cable is correctly wired according to the expected requirements. Here, due to the wiring error, the device obviously has no response, and it is judged that the line is wired incorrectly.

[0086] After detecting the wiring error of TA1 and 1S1, the command personnel at the terminal box keep the ground wire of the device unchanged and touch the other lead-out terminal of the device to the terminals (TA2-TA7) except TA1 in sequence. If the device alarm light turns on and the buzzer sounds when touching a terminal, it means that the 1S1 tap is connected to this position. Here, because 1S1 is actually connected to TA3 by mistake, the device will respond when TA3 is touched.

[0087] After the error was found, the terminal box commander swapped the cables of the TA1 and TA3 terminals. At this point, 1S1-TA1 completed the line calibration and error correction.

[0088] Similarly, the personnel at the current transformer ground the 1S2 tap, and the personnel at the terminal box contact TA1-TA7 in sequence. If and only if the indicator light at TA2 is on and the buzzer sounds, it indicates that 1S2 is correctly connected to TA2. If an error occurs, follow the above steps to correct the cable.

[0089] After completing the calibration of the TA1-TA7 terminals and each tap and restoring the cables, recheck each terminal in turn to ensure that the device responds only at the expected terminal.

[0090] Specifically, Figure 4 and Figure 5 As shown, if the cable is open or connected in reverse during calibration, the external waiting circuit of the device is equivalent to an open circuit. At this time, the working principle of the device is as follows Figure 4 As shown, the left AC power supply and the lamp form a circuit that is not conductive, the detection lamp is not on, the light intensity in the electro-optical coupling module is insufficient, and the photoresistor resistance is greater than the first threshold value of 100MΩ. At this time, the right alarm circuit is not conductive, so the indicator light is not on and the buzzer does not sound.

[0091] When the cables of different windings are connected incorrectly during line calibration, the external circuit to be connected to the device is equivalent to connecting to one winding. At this time, the working principle of the device is as follows: Figure 5 As shown. Since the impedance of the winding inside the current transformer is greater than the third threshold value of 60Ω, the left AC power supply and the lamp form a circuit that is not conductive, the detection lamp is not on, and the light intensity in the electro-optical coupling module is insufficient, and the photoresistor resistance is greater than the first threshold value of 100MΩ. At this time, the right alarm circuit is not conductive, so the indicator light is not on and the buzzer does not sound.

[0092] It should be noted that by specifically defining situations such as open cables, reversed cables, and incorrect connections of cables for different windings, the type of wiring error can be accurately diagnosed, thereby improving the accuracy of fault diagnosis. When a wiring error occurs, the indicator light does not light up and the alarm electronic components do not sound, providing immediate fault feedback so that operators can quickly identify and respond to faults. Through accurate error identification and feedback, operators can troubleshoot in a safe manner, thus avoiding safety accidents that may be caused by incorrect wiring.

[0093] The above is a schematic scheme of a current transformer secondary circuit calibration method of this embodiment. It should be noted that the technical scheme of the current transformer secondary circuit calibration system and the technical scheme of the current transformer secondary circuit calibration method described above belong to the same concept, and the details of the technical scheme of the current transformer secondary circuit calibration system in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the current transformer secondary circuit calibration method described above.

[0094] The current transformer secondary circuit calibration system in this embodiment includes:

[0095] A configuration module, used to obtain the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information;

[0096] A calibration module, used for calibrating the wiring condition of the secondary circuit calibration module;

[0097] The correction module is used to identify the type of wiring error through the response of the secondary circuit calibration module in the case of wiring error, and perform corresponding correction on the wiring error type.

[0098] This embodiment further provides a computing device, which is applicable to the current transformer secondary circuit calibration, and includes:

[0099] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the current transformer secondary circuit calibration method proposed in the above embodiment.

[0100] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for calibrating a secondary circuit of a current transformer as proposed in the above embodiment is implemented.

[0101] The storage medium proposed in this embodiment and the method for realizing current transformer secondary circuit calibration proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0102] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (Random Access Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0103] Example 2

[0104] Referring to Table 1-Table 2, this embodiment is different from the first embodiment in that it provides a verification test of a current transformer secondary circuit calibration method to verify and illustrate the technical effects used in this method.

[0105] The secondary circuit acceptance link of a 220kV substation main transformer expansion project was selected for on-site testing.

[0106] During the test, one person climbed up the main transformer and grounded the terminal boxes of the medium, high and low current transformers. Another person held a calibration device and performed calibration at the terminal box of the main transformer. The transformer secondary circuit calibration device was used to calibrate the secondary circuit of the main CT of the expanded main transformer. The test results are shown in Table 1 below. The results show that the device successfully detected two secondary wiring errors in the main transformer.

[0107] Table 1 Field test results of transformer secondary circuit calibration method

[0108]

[0109]

[0110] As shown in Table 1, the calibration process only requires the cooperation of two groups of people. The calibration process does not require the removal of both ends of the wiring to be tested, and only requires cooperation over the phone. The entire calibration process takes only about 10 minutes. The calibration device is easy and simple to use. The traditional multimeter-based transformer secondary circuit calibration method takes a total of 1 hour, which greatly reduces the calibration time and cost, and effectively improves the accuracy of the transformer secondary circuit wiring work.

[0111] Table 2 Comparison between the present application method and the existing method

[0112]

[0113]

[0114] Compared with the various calibration indicators of the two traditional calibration methods, the calibration time required for this application is shorter, the calibration efficiency is greatly improved, the manpower cost required for calibration is lower, and there is no problem of calibration failure in special circumstances. It is low-cost and compact and portable.

[0115] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for calibrating a secondary circuit of a current transformer, characterized in that: include: Acquire the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information; Performing calibration detection on the wiring condition of the secondary circuit calibration module; In the case of wiring errors, the type of wiring error is identified through the response of the secondary circuit calibration module, and the wiring error type is corrected accordingly.

2. The current transformer secondary circuit calibration method according to claim 1, characterized in that: The transformer secondary circuit calibration module includes: AC power supply, DC power supply, detection lamp, photoresistor, indicator light and alarm electronic components; The detection lamp and the photoresistor are reliably packaged to form an electro-optical coupling module, and the detection lamp is the only internal power source; The AC power supply and the detection light form a detection circuit; The photoresistor, indicator light and alarm electronic components constitute an alarm circuit.

3. The current transformer secondary circuit calibration method according to claim 2, characterized in that: Also includes: When the calibration is not performed, the detection light and the AC power supply circuit are not connected, the detection circuit resistance is equal to infinity, and the detection light is off; When the calibration is not performed, the light intensity inside the electro-optical coupling module is zero, the resistance of the photoresistor is greater than the first threshold, the current in the detection circuit is less than the second threshold, the indicator light is off, and the alarm electronic component does not sound.

4. The current transformer secondary circuit calibration method according to claim 1 or 3, characterized in that: The wiring calibration detection of the secondary circuit calibration module includes: The first operator grounds the tap to be checked at the transformer terminal box with a grounding wire, and the second operator connects one end of the transformer secondary circuit calibration module to the terminal to be checked at the terminal box, and grounds the other end of the transformer secondary circuit calibration module.

5. The current transformer secondary circuit calibration method according to claim 4, characterized in that: Also includes: When the transformer secondary circuits are correctly wired, the transformer secondary circuit calibration module access circuit does not contain windings, and the external circuit to be connected is equivalent to a short circuit. The indicator light is on and the alarm electronic components are turned on.

6. The current transformer secondary circuit calibration method according to claim 5, characterized in that: Incorrect wiring conditions include: When the wiring is wrong, the external circuit to be connected is connected to a winding with a resistance greater than the third threshold, and the current of the response circuit does not reach the response value of the indicator light and the alarm electronic component, then the indicator light will not light up and the alarm electronic component will not sound.

7. The current transformer secondary circuit calibration method according to claim 6, characterized in that: Types of wiring errors include: Cable open circuit, reverse cable connection, and wrong connection of cables with different windings; When the cable is open or connected in reverse during calibration, the external circuit to be connected of the transformer secondary circuit calibration module is equivalent to an open circuit, the AC current and the detection light form a circuit that is not conductive, the detection light is not on, the photoresistor resistance in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound; When cables of different windings are connected incorrectly during calibration, the external waiting circuit of the transformer secondary circuit calibration module is equivalent to connecting one winding, the impedance of the internal winding of the transformer is greater than the third threshold, the circuit formed by the AC power supply and the detection light is not conductive, the detection light is not on, the resistance of the photoresistor in the electro-optical coupling module is greater than the first threshold, the alarm circuit is not conductive, the indicator light is not on, and the alarm electronic components do not sound.

8. A system using the current transformer secondary circuit calibration method according to any one of claims 1 to 7, characterized in that: include: A configuration module, used to obtain the transformer secondary circuit wiring information, and configure the transformer secondary circuit calibration module according to the transformer secondary circuit wiring information; A calibration module, used for calibrating the wiring condition of the secondary circuit calibration module; The correction module is used to identify the type of wiring error through the response of the secondary circuit calibration module in the case of wiring error, and perform corresponding correction on the wiring error type.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the current transformer secondary circuit calibration method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the current transformer secondary circuit calibration method according to any one of claims 1 to 7.

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