Live detection system for in-operation low-voltage current transformer, and wiring connection apparatus

Abstract

A live detection system for an in-operation low-voltage current transformer, comprising: a primary standard current transformer, a primary current acquisition circuit, a secondary standard current transformer, a secondary current acquisition circuit, an isolated data conversion module, a programmable power supply, a programmable controller, a human-machine interaction unit and a microprocessor, which are capable of adjusting current values of test primary currents flowing through the low-voltage current transformer and the standard current transformers to achieve continuously adjustable test currents for full-range calibration. Further disclosed is a wiring connection apparatus, capable of rapid wiring while ensuring optimal contact pressure and engagement consistency for each wiring, thereby preventing overly tight or loose connection.

Description

A system for detecting a low-voltage current transformer under operation and a wiring connection device TECHNICAL FIELD

[0001] The present application relates to the technical field of power system monitoring, and in particular to a system for detecting a low-voltage current transformer under operation and a wiring connection device. BACKGROUND

[0002] There is a great demand for online detection technology for continuously or regularly automatically detecting the condition of equipment without affecting the operation of the equipment. For current transformers, there are relatively mature technologies such as oil gas analysis technology, partial discharge detection technology, dielectric loss and capacitance measurement technology, etc., but these are all projects for detecting insulation conditions, and there is no online detection method for the error of the current transformer. The error of the current transformer directly affects the measurement of electric quantity and the reliability of the action of the relay protection, and long-term inaccurate measurement and incorrect action of the relay protection will cause huge economic losses to power supply enterprises or power utilization enterprises, and even cause damage to power equipment and large-scale power outages.

[0003] The existing current transformer has a primary winding and a secondary winding, including a plurality of measurement windings and protection windings, the lead-out wires of the secondary windings are connected to a terminal box near the current transformer, and then connected to a remote load through wires. Generally, when detecting the error of the current transformer, the current transformer must be powered off, the original circuit is disconnected from the terminals S1, S2, S3, and S4 of the secondary windings, and a temporary lead is connected to the current transformer calibrator, and the secondary lead of the external standard transformer is also connected to the movable current transformer calibrator. The error of each winding of the current transformer is obtained by comparison.

[0004] According to JJG1189.3-2022 "Measuring Transformers Part 3: Electric Current Transformers", when calibrating the current transformer, the calibration points are 1%, 5%, 20%, 100%, and 120% of the rated current points, and when calibrating under the condition of power failure, the corresponding test current points can be linearly adjusted through the power frequency voltage regulating power supply and the current increasing power supply. However, under the condition of electrification, because the station area is in a working state, due to the load, the line itself has a real current, which is closely related to the current load, and in order to meet the current point of the calibration requirement, the device needs to provide an adjustable 1% to 120% rated current size to realize the error calibration under the whole current.

[0005] SUMMARY

[0006] In view of the problems in the prior art, the present application is proposed.

[0007] Therefore, the problem to be solved by the present application is how to adjust the current value of the test primary current flowing through the low-voltage current transformer and the standard current transformer to obtain a continuously adjustable test current of %~% and realize full-range calibration.

[0008] To solve the above technical problems, the present application provides the following technical solutions: a system for detecting a low-voltage current transformer under operation.

[0009] As a preferred scheme of the system for detecting a low-voltage current transformer under operation, the primary standard current transformer is connected to the primary current data acquisition, one end of the primary standard current transformer is connected to the primary current line, and the other end is connected to the interface position of the primary current acquisition circuit.

[0010] The primary current acquisition circuit converts the circuit signal input by the primary standard current transformer into a voltage signal.

[0011] The secondary standard current transformer is connected to the secondary current data acquisition of the to-be-detected transformer, one end of the secondary standard current transformer is connected to the secondary current line of the to-be-detected transformer, and the other end is connected to the interface position of the secondary current acquisition circuit.

[0012] The secondary current acquisition circuit converts the current signal input by the secondary standard current transformer into a voltage signal.

[0013] The isolation type data conversion module is electrically connected to the output of the primary current acquisition circuit and the secondary current acquisition circuit, and can isolate and convert the input signal.

[0014] The programmable controller is electrically connected to the isolation type data conversion module and can control different mode states and data communication of the system.

[0015] The microprocessor plays a role of digital signal processing analysis, and can realize error analysis, discrete Fourier processing, and electric energy conversion on the basis of different channel sampling data, and finally obtain a test result.

[0016] The input end of the program-controlled power supply is connected to the commercial power supply, the output end of the program-controlled power supply is connected to the primary standard current transformer, a voltage transformer is arranged at the output end of the program-controlled power supply, the voltage transformer sends a signal to the isolation type data conversion module after being filtered and amplified, and the drive protection module of the program-controlled power supply is electrically connected to the programmable controller.

[0017] As a preferred scheme of the system for detecting a low-voltage current transformer under operation, the primary standard current transformer and the secondary standard current transformer each contain a winding, and each winding includes an input winding, an output winding, and a feedback winding.

[0018] As a kind of preferred scheme of the low-voltage current transformer live detection system described in the application, wherein: the program-controlled power supply mainly includes circuit, rectifier circuit, DC intermediate circuit, inverter circuit, filter circuit, voltage detection circuit and drive protection circuit.

[0019] The application also solves the problem that when connecting the terminal, it is occasionally connected too tightly or too loosely, resulting in the connected wire being damaged or not tight, causing poor connection effect and possibly falling off, and therefore a wiring device capable of quickly wiring and ensuring that the force and degree of wiring each time reach the best effect is needed.

[0020] To solve the above technical problems, the application further provides the following technical solutions: a wiring connection device, comprising a fixed component, a movable component and an adjusting component.

[0021] As a kind of preferred scheme of the wiring connection device described in the application, wherein: the fixed component comprises a wiring box and a wiring screw, and the wiring screw is arranged inside the wiring box;

[0022] The movable component is arranged on the top of the fixed component and comprises a translation plate, a movable frame and a positioning piece, the translation plate is arranged on the top of the wiring box, the movable frame is arranged at both ends of the translation plate, and the positioning piece is arranged at the end of the movable frame; and

[0023] The adjusting component is arranged inside the movable component and comprises an adjusting waist round pipe, a rotating column, a reset column and a tight prevention ring, the adjusting waist round pipe penetrates through the translation plate, the rotating column is arranged at the bottom of the adjusting waist round pipe, the reset column is arranged at the top of the adjusting waist round pipe, and the tight prevention ring is sleeved outside the adjusting waist round pipe.

[0024] As a kind of preferred scheme of the wiring connection device described in the application, wherein: the wiring box is provided with a wire hole and a screw hole, the wire hole is arranged at the bottom of the side surface of the wiring box, the screw hole is arranged on the top of the wire hole and communicates with the bottom surface of the wiring box, and the wiring screw is matched with the screw hole.

[0025] As a kind of preferred scheme of the wiring connection device described in the application, wherein: the wiring box is further provided with a limiting horizontal groove and a positioning vertical groove, the limiting horizontal groove is arranged on the top of the side surface of the wiring box, the positioning vertical groove is arranged above and below the limiting horizontal groove, and the positioning vertical groove is opposite to the wire hole.

[0026] As a preferred scheme of the wiring connection device, the bottom of the translation plate is matched with the top of the wiring box, the translation plate is provided with a limiting horizontal hole and a limiting vertical hole, the limiting horizontal hole penetrates the side of the translation plate, the limiting horizontal hole is matched with the anti-tightening ring, and the limiting vertical hole penetrates the upper and lower surfaces of the translation plate, and the limiting vertical hole is matched with the adjusting waist round pipe.

[0027] As a preferred scheme of the wiring connection device, the movable frame is a half frame, one end of the top of the movable frame is fixedly connected with the side of the translation plate, one end of the bottom of the movable frame is provided with a limiting column, the limiting column is matched with the limiting horizontal groove, a positioning groove is arranged in the middle of the limiting column, the positioning member is matched with the positioning groove, the positioning member is provided with a positioning spring and a positioning cone, one end of the positioning spring is fixed to the bottom of the positioning groove, the other end of the positioning spring is fixed to the bottom of the positioning cone, one end of the positioning cone is matched with the positioning groove, and the other end of the positioning cone is matched with the positioning vertical groove.

[0028] As a preferred scheme of the wiring connection device, the adjusting waist round pipe is provided with a double-thread and an external thread, the double-thread is arranged inside the adjusting waist round pipe, the external thread is arranged outside the adjusting waist round pipe, and the adjusting waist round pipe is matched with the limiting vertical hole.

[0029] The rotating column is provided with a positioning column, a magnetic head and a mounting hole, the positioning column is symmetrically arranged on the side of the rotating column, the positioning column is matched with the double-thread, the magnetic head is arranged on the bottom of the rotating column, the magnetic head is matched with the wiring screw, and the mounting hole is arranged on the top of the rotating column.

[0030] As a preferred scheme of the wiring connection device, the reset column is provided with a mounting column, a reset spring and a pressing table, the mounting column is arranged on the bottom of the reset column, the mounting column is rotationally connected with the mounting hole, the pressing table is arranged on the top of the reset column, the reset spring is sleeved on the top of the reset column, the top of the reset spring is fixedly connected with the bottom of the pressing table, the bottom of the reset spring is fixedly connected with the top of the adjusting waist round pipe, the inner wall of the anti-tightening ring is provided with an internal thread, the internal thread is matched with the external thread, and the anti-tightening ring is matched with the limiting horizontal hole.

[0031] The device adopts a program-controlled power supply, can realize precision self-calibration for a clamp meter in a live detection device, can output a current signal of a certain size, can realize accurate calibration of the clamp meter by embedding the clamp meter in a coupling coil of the module, and can display results and user operation through the man-machine interface, and the interface system is installed with a test program, so that the user can use and observe the results.

[0032] Meanwhile, the voltage signal generated by the program-controlled power supply passes through a current booster to generate an adjusted current meeting the test requirements, and the adjusted current is connected in series with the low-voltage current transformer and the standard current transformer, so as to adjust the current value of the test primary current flowing through the low-voltage current transformer and the standard current transformer, obtain a continuously adjustable test current of %~%, and realize full-range calibration.

[0033] The application can also quickly connect wires and ensure that the force and degree of each connection are kept at the best effect, without being too tight or too loose. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort. Among them:

[0035] Fig. 1 is a structure diagram of the full-range live detection system of the low-voltage current transformer in operation.

[0036] Fig. 2 is a whole structure diagram of the wire connection device.

[0037] Fig. 3 is a structure diagram of the movable assembly of the wire connection device.

[0038] Fig. 4 is a structure diagram of the adjusting assembly of the wire connection device.

[0039] Fig. 5 is a sectional view of the adjusting waist pipe of the wire connection device. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0041] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the concept of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0042] Secondly, "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent of or mutually exclusive with other embodiments.

[0043] Embodiment 1

[0044] Referring to Fig. 1, a first embodiment of the present application provides a low-voltage current transformer live detection system.

[0045] Specifically, the primary standard current transformer is connected to the primary current data acquisition; one end of the primary standard current transformer is connected to the primary current line, and the other end is connected to the interface position of the primary current acquisition circuit;

[0046] The primary current acquisition circuit converts the circuit signal input by the primary standard current transformer into a voltage signal;

[0047] The secondary standard current transformer is connected to the secondary current data acquisition of the to-be-tested transformer; one end of the secondary standard current transformer is connected to the secondary current line of the to-be-tested transformer, and the other end is connected to the interface position of the secondary current acquisition circuit;

[0048] The secondary current acquisition circuit converts the current signal input by the secondary standard current transformer into a voltage signal;

[0049] The isolation type data conversion module is electrically connected to the output of the primary current acquisition circuit and the secondary current acquisition circuit, and converts and isolates the input signal;

[0050] The programmable controller is electrically connected to the isolation type data conversion module and can control different mode states and data communication of the system;

[0051] The programmable controller is the control core of the device.

[0052] The microprocessor plays a role in digital signal processing analysis, and realizes error analysis, discrete Fourier processing, and electric energy conversion for different channel sampling data, and finally obtains the test result;

[0053] The microprocessor is the core operation unit of the device.

[0054] The input end of the program-controlled power supply is connected to the commercial power supply, the output end of the program-controlled power supply is connected to the primary standard current transformer, the output end of the program-controlled power supply is provided with a voltage transformer, and after being filtered and amplified, it is sent to the isolation type data conversion module and AD converted, and the drive protection module of the program-controlled power supply is electrically connected to the programmable controller.

[0055] Specifically, the primary standard current transformer and the secondary standard current transformer contain three windings, including an input winding, an output winding, and a feedback winding.

[0056] Specifically, the program-controlled power supply mainly includes an EMI circuit, a rectifier circuit, a direct current intermediate circuit, an inverter circuit, a filter circuit, a voltage detection circuit, and a drive protection circuit.

[0057] EMI power filter is a kind of low-pass filter composed of inductance and capacitance, which allows DC or power frequency signal to pass through, and has a large attenuation effect on other signals with higher frequency; The rectifier circuit selects integrated chip, which can withstand large reverse voltage and work stably; The intermediate DC circuit adopts capacitor filtering and selects high-performance electrolytic capacitor; The inverter circuit adopts bridge inverter circuit and selects IGBT as power switch tube; The output filter circuit adopts LC filter; The voltage detection circuit is a voltage transformer installed at the output end of the phase-shifting circuit, which sends the filtered and amplified voltage signal to the isolation data conversion module AD conversion, and then the current output voltage value and phase value can be obtained through the operation of the programmable controller; The drive protection circuit is a current transformer installed at the output end of the filter circuit, and a voltage proportional to the detected primary current can be obtained at the secondary side of the current transformer; The secondary voltage is proportional to the output current, and the secondary voltage is transmitted to the isolation data conversion module and compared with the threshold voltage of the output current. When the threshold voltage is exceeded, the corresponding pin of the programmable controller is low, and the drive protection circuit outputs the overcurrent protection program to shut down the output signal.

[0058] The programmable power supply takes programmable controller and microprocessor as the core control circuit; Its working principle is as follows: EMI circuit is used to filter out high-frequency harmonics of external power grid, and reduce electromagnetic interference of power supply to external environment; The rectifier circuit converts 220V AC into DC; The intermediate DC link adopts capacitor filtering to reduce the ripple of DC voltage and obtain smooth DC voltage, which is sent to the inverter circuit; The inverter circuit adopts SPWM control technology to obtain AC output, and the sine AC output is obtained after filtering the harmonics by the filter circuit; The sampling circuit obtains the amplitude and phase of the input power, the voltage and current of the output signal, and the phase feedback signal; According to the error between the given signal and the feedback signal, the programmable controller calculates the required drive signal of the inverter circuit, and the drive signal passes through the drive circuit to obtain the switching signal of the switch tube, which controls the operation of the inverter circuit; The protection circuit provides necessary protection measures for the system.

[0059] The self-calibration connection mode of primary standard current transformer and secondary standard current transformer is as follows: the primary standard current transformer and the secondary standard current transformer are connected at the output end of the programmable power supply; The output current of the primary standard current transformer and the secondary standard current transformer can enter the isolation data conversion module through the corresponding current collection circuit; In this case, the isolation data conversion module can not only collect the output voltage of the primary standard current transformer and the secondary standard current transformer, but also collect the voltage signal fed back by the voltage transformer installed at the output end of the programmable power supply; Through calculation, the measurement error of the primary standard current transformer and the secondary standard current transformer can be obtained, and the compensation coefficient can be obtained by combining the error to replace the original coefficient.

[0060] Embodiment 2

[0061] Referring to Figs. 2-5, a second embodiment of the application is based on the previous embodiment.

[0062] Specifically, the fixed assembly 100 includes a terminal box 101 and terminal screws 102, and the terminal screws 102 are arranged inside the terminal box 101.

[0063] The fixed assembly 100 is used to fix the wires to be connected.

[0064] The movable assembly 200 is arranged on the top of the fixed assembly 100 and includes a translation plate 201, movable frames 202, and positioning members 203. The translation plate 201 is arranged on the top of the terminal box 101, the movable frames 202 are arranged on both ends of the translation plate 201, and the positioning members 203 are arranged on the ends of the movable frames 202.

[0065] The movable assembly 200 is used to position the components for assisting in tightening the screws.

[0066] The adjustment assembly 300 is arranged inside the movable assembly 200 and includes an adjustment waist pipe 301, a rotating column 302, a reset column 303, and a tight prevention ring 304. The adjustment waist pipe 301 penetrates through the translation plate 201, the rotating column 302 is arranged at the bottom of the adjustment waist pipe 301, the reset column 303 is arranged at the top of the adjustment waist pipe 301, and the tight prevention ring 304 is sleeved outside the adjustment waist pipe 301.

[0067] The adjustment assembly 300 is used to set the optimal position for pressing, avoid loose pressing, and maintain the optimal position so that each screw can be in the optimal position.

[0068] Specifically, the terminal box 101 is provided with a wire hole H1 and a screw hole H2. The wire hole H1 is arranged at the bottom of the side surface of the terminal box 101, and the screw hole H2 is arranged on the top of the wire hole H1 and is connected to the bottom surface of the terminal box 101. The terminal screw 102 is matched with the screw hole H2.

[0069] After the wire is peeled, it is inserted into the wire hole H1, and the terminal screw 102 is screwed into the screw hole H2 to press the wire.

[0070] Specifically, the terminal box 101 is further provided with a limiting horizontal groove K1 and a positioning vertical groove K2. The limiting horizontal groove K1 is arranged at the top of the side surface of the terminal box 101, and the positioning vertical groove K2 is arranged above and below the limiting horizontal groove K1. The positioning vertical groove K2 is opposite to the wire hole H1.

[0071] The translation plate 201 is used to fix the adjustment assembly 300 so that the adjustment assembly 300 is aligned with the terminal screw 102.

[0072] Specifically, the bottom of the translation plate 201 is matched with the top of the terminal box 101, the translation plate 201 is provided with a limiting horizontal hole H3 and a limiting vertical hole H4, the limiting horizontal hole H3 penetrates through the side of the translation plate 201, the limiting horizontal hole H3 is matched with the anti-tight ring 304, and the limiting vertical hole H4 penetrates through the upper and lower surfaces of the translation plate 201 and is matched with the adjusting waist pipe 301.

[0073] The cooperation between the movable frame 202, the limiting column 202a, the positioning member 203, the limiting horizontal groove K1 and the positioning vertical groove K2 enables the movable assembly 200 to be translated along the long end direction of the terminal box 101 and to be fixed relatively stably above the screw hole H2, so that the terminal screw 102 can be tightened conveniently and the movable assembly 200 is not locked.

[0074] Specifically, the movable frame 202 is a half frame, one end of the top of the movable frame 202 is fixedly connected with the side of the translation plate 201, one end of the bottom of the movable frame 202 is provided with the limiting column 202a, the limiting column 202a is matched with the limiting horizontal groove K1, the middle of the limiting column 202a is provided with the positioning groove K3, the positioning member 203 is matched with the positioning groove K3, the positioning member 203 is provided with the positioning spring 203a and the positioning cone 203b, one end of the positioning spring 203a is fixedly connected with the bottom of the positioning groove K3, the other end is fixedly connected with the bottom of the positioning cone 203b, one end of the positioning cone 203b is matched with the positioning groove K3, and the other end is matched with the positioning vertical groove K2.

[0075] When the terminal screw 102 is tightened, the positioning cone 203b is matched with the positioning groove K3, the center line of the movable assembly 200 is aligned with the screw hole H2, the force is directed to the screw hole H2, and the movable assembly 200 cannot be moved; when the position of the movable assembly 200 is adjusted, the force is directed to the long end of the terminal box 101, the positioning cone 203b is pushed back to the mounting hole H5, and the movable assembly 200 can be translated.

[0076] Specifically, the adjusting waist pipe 301 is provided with a double-thread L1 and an external thread L2, the double-thread L1 is arranged inside the adjusting waist pipe 301, the external thread L2 is arranged outside the adjusting waist pipe 301, and the adjusting waist pipe 301 is matched with the limiting vertical hole H4.

[0077] The double-thread L1 is used to cooperate with the rotating column 302 and prevent the rotating column 302 from being pushed downward due to too dense threads.

[0078] The top end of the double-thread L1 penetrates through the top surface of the adjusting waist pipe 301 and is used to install the rotating column 302, and the tail end of the double-thread L1 does not penetrate through the bottom surface of the adjusting waist pipe 301 and is used to avoid the rotating column 302 from being separated.

[0079] The rotating column 302 is provided with a positioning column 302a, a magnetic head 302b and a mounting hole H5. The positioning column 302a is symmetrically arranged on the side of the rotating column 302 and is matched with the double-thread L1. The magnetic head 302b is arranged on the bottom of the rotating column 302 and is matched with the wiring screw 102. The mounting hole H5 is arranged on the top of the rotating column 302.

[0080] When the rotating column 302 is pressed, the positioning column 302a moves in the double-thread L1 until the end of the double-thread L1.

[0081] Specifically, the reset column 303 is provided with a mounting column 303a, a reset spring 303b and a pressing table 303c. The mounting column 303a is arranged on the bottom of the reset column 303 and is rotationally connected with the mounting hole H5. The pressing table 303c is arranged on the top of the reset column 303. The reset spring 303b is sleeved on the top of the reset column 303. The top of the reset spring 303b is fixedly connected with the bottom of the pressing table 303c. The bottom of the reset spring 303b is fixedly connected with the top of the adjusting waist pipe 301. The inner wall of the anti-tight ring 304 is provided with an inner thread L3 matched with the outer thread L2. The anti-tight ring 304 is matched with the limiting horizontal hole H3.

[0082] When the pressing table 303c is stressed, it will move to the wiring box 101 and push the rotating column 302, so that the rotating column 302 rotates along the double-thread L1 and rotates into the screw hole H2, and the wiring screw 102 is rotated into the screw hole H2.

[0083] The anti-tight ring 304 is rotated to adjust the height of the adjusting waist pipe 301, so as to indirectly adjust the maximum distance of the magnetic head 302b rotating in, so that the wiring screw 102 can be rotated into the optimal position each time.

[0084] In use, first, the wiring screw 102 is adsorbed on the magnetic head 302b. Then, the movable assembly 200 is adjusted, the positioning cone 203b is clamped, and the wire in the movable assembly 200 falls on the top of the screw hole H2 of the tightening screw. Then, the anti-tight ring 304 is adjusted to position the specific screw hole H2. At this time, the pressing table 303c is pressed, the magnetic head 302b rotates the wiring screw 102 into the screw hole H2, the installation of the wiring screw 102 is observed, the anti-tight ring 304 is rotated to install the wiring screw 102 in the optimal position. As long as this one is adjusted, the following screws can be set in this way, so that the remaining screws can be installed in the optimal position, which can greatly reduce the degree of installing the screws by hand feeling, reduce the overall installation depth variance, and prolong the service life of the wiring box 101.

[0085] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is explained in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or substituted equivalently without departing from the spirit and scope of the technical solutions of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A low voltage current transformer live detection system while in operation, characterized by: Comprising, The primary standard current transformer is connected to the primary current data acquisition; one end of the primary standard current transformer is connected to the primary current line, and the other end is connected to the interface position of the primary current acquisition circuit; The primary current acquisition circuit converts the circuit signal input by the primary standard current transformer into a voltage signal; The secondary standard current transformer is connected to the secondary current data acquisition of the to-be-tested transformer; one end of the secondary standard current transformer is connected to the secondary current line of the to-be-tested transformer, and the other end is connected to the interface position of the secondary current acquisition circuit; The secondary current acquisition circuit converts the current signal input by the secondary standard current transformer into a voltage signal; The isolation type data conversion module is electrically connected with the output of the primary current acquisition circuit and the secondary current acquisition circuit, and can isolate and convert the input signal; The programmable controller is electrically connected with the isolation type data conversion module, and can control different mode states and data communication of the system; The microprocessor plays a role of digital signal processing analysis, and realizes error analysis, discrete Fourier processing, and electric energy conversion on the basis of different channel sampling data, so as to finally obtain a test result; The input of the program-controlled power supply is connected with the commercial power supply, the output of the program-controlled power supply is connected with the primary standard current transformer, a voltage transformer is arranged on the output of the program-controlled power supply, the voltage transformer is sent into the isolation type data conversion module after being filtered and amplified and AD converted, and the drive protection module of the program-controlled power supply is electrically connected with the programmable controller.

2. The system for detecting the in-service low-voltage current transformer under voltage according to claim 1, wherein: The primary standard current transformer and the secondary standard current transformer each contain three windings, including an input winding, an output winding, and a feedback winding.

3. The system for detecting the in-service low-voltage current transformer under voltage according to claim 1, wherein: The program-controlled power supply mainly includes an EMI circuit, a rectifier circuit, a direct-current intermediate circuit, an inverter circuit, a filter circuit, a voltage detection circuit, and a drive protection circuit.

4. A wiring connection device for connecting the current transformer and the data conversion module according to any one of claims 1 to 3, the wiring connection device comprising, a fixed assembly (100) including a wiring box (101) and a wiring screw (102), the wiring screw (102) being arranged inside the wiring box (101); a movable assembly (200) arranged on the top of the fixed assembly (100) and including a translation plate (201), a movable frame (202), and a positioning member (203), the translation plate (201) being arranged on the top of the wiring box (101), the movable frame (202) being arranged on both ends of the translation plate (201), and the positioning member (203) being arranged on the end of the movable frame (202); and The adjusting assembly (300) is arranged inside the movable assembly (200), and comprises an adjusting waist pipe (301), a rotating column (302), a reset column (303) and a anti-tight ring (304). The adjusting waist pipe (301) penetrates the translation plate (201). The rotating column (302) is arranged at the bottom of the adjusting waist pipe (301). The reset column (303) is arranged at the top of the adjusting waist pipe (301). The anti-tight ring (304) is sleeved outside the adjusting waist pipe (301).

5. The terminal connecting device of claim 4, wherein: The terminal box (101) is provided with a wire hole (H1) and a screw hole (H2). The wire hole (H1) is arranged at the bottom of the side of the terminal box (101). The screw hole (H2) is arranged at the top of the wire hole (H1) and communicates with the bottom surface of the terminal box (101). The terminal screw (102) is matched with the screw hole (H2).

6. The terminal connecting device of claim 5, wherein: The terminal box (101) is further provided with a limiting horizontal groove (K1) and a positioning vertical groove (K2). The limiting horizontal groove (K1) is arranged at the top of the side of the terminal box (101). The positioning vertical groove (K2) is arranged above and below the limiting horizontal groove (K1). The positioning vertical groove (K2) is opposite to the wire hole (H1).

7. The terminal connecting device of claim 6, wherein: The bottom of the translation plate (201) is matched with the top of the terminal box (101) on both sides. The translation plate (201) is provided with a limiting horizontal hole (H3) and a limiting vertical hole (H4). The limiting horizontal hole (H3) penetrates the side of the translation plate (201). The limiting horizontal hole (H3) is matched with the anti-tight ring (304). The limiting vertical hole (H4) penetrates the upper and lower surfaces of the translation plate (201). The limiting vertical hole (H4) is matched with the adjusting waist pipe (301).

8. The terminal connecting device of claim 7, wherein: The movable frame (202) is a half frame. One end of the top of the movable frame (202) is fixedly connected with the side of the translation plate (201). A limiting column (202a) is arranged at one end of the bottom of the movable frame (202). The limiting column (202a) is matched with the limiting horizontal groove (K1). A positioning groove (K3) is arranged in the middle of the limiting column (202a). The positioning member (203) is matched with the positioning groove (K3). The positioning member (203) is provided with a positioning spring (203a) and a positioning cone (203b). One end of the positioning spring (203a) is fixedly connected with the bottom of the positioning groove (K3). The other end of the positioning spring (203a) is fixedly connected with the bottom of the positioning cone (203b). One end of the positioning cone (203b) is matched with the positioning groove (K3). The other end of the positioning cone (203b) is matched with the positioning vertical groove (K2).

9. The terminal connecting device of claim 8, wherein: ​ The adjusting waist pipe (301) is provided with double thread (L1) and external thread (L2), the double thread (L1) is arranged inside the adjusting waist pipe (301), the external thread (L2) is arranged outside the adjusting waist pipe (301), the adjusting waist pipe (301) and the limiting vertical hole (H4) are matched; The rotating column (302) is provided with positioning column (302a), magnetic head (302b) and mounting hole (H5), the positioning column (302a) is symmetrically arranged on the side of the rotating column (302), the positioning column (302a) and the double thread (L1) are matched, the magnetic head (302b) is arranged at the bottom of the rotating column (302), the magnetic head (302b) and the wiring screw (102) are matched, and the mounting hole (H5) is arranged at the top of the rotating column (302).

10. The wiring connection device of claim 9, wherein: The reset column (303) is provided with mounting column (303a), reset spring (303b) and pressing table (303c), the mounting column (303a) is arranged at the bottom of the reset column (303), the mounting column (303a) and the mounting hole (H5) are rotatably connected, the pressing table (303c) is arranged at the top of the reset column (303), the reset spring (303b) is sleeved at the top of the reset column (303), the top of the reset spring (303b) and the bottom of the pressing table (303c) are fixedly connected, the bottom of the reset spring (303b) and the top of the adjusting waist pipe (301) are fixedly connected, the inner wall of the anti-tight ring (304) is provided with internal thread (L3), the internal thread (L3) and the external thread (L2) are matched, and the anti-tight ring (304) and the limiting horizontal hole (H3) are matched.

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