CN111090072A

CN111090072A - CT loop wireless automatic checking device and checking method

Info

Publication number: CN111090072A
Application number: CN202010210811.XA
Authority: CN
Inventors: 邹学灿
Original assignee: Beijing Ruichuang Xinzhi Technology Co ltd
Current assignee: Beijing Ruichuang Xinzhi Technology Co ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2020-05-01
Anticipated expiration: 2040-03-24
Also published as: CN111090072B

Abstract

The invention provides a CT loop wireless automatic checking device and a checking method. The CT loop wireless automatic checking device is divided into a signal generating device and a signal measuring device, wherein the signal generating device can automatically generate the amplitude and the phase of primary current and reference voltage according to the electrical parameters of a detected primary loop, and automatically judge whether the current CT loop is correct or not according to the CT vector measuring result returned by the signal measuring device; the signal measuring equipment can receive the virtual voltage sent by the signal generating equipment in a wireless mode, accurately measure the CT vector and wirelessly feed back the CT vector measuring result to the signal generating equipment. The wireless automatic checking device for the CT loop can simply, safely and automatically judge the transformation ratio error and the polarity error in the CT loop, and overcomes the technical defects that the testing loop in the prior art has overhigh voltage, a primary circuit or a secondary circuit needs to be changed in the testing process, and the safety risk brought by using a long cable is high.

Description

CT loop wireless automatic checking device and checking method

Technical Field

The invention relates to the technical field of power industry, in particular to the technical field of secondary system testing in a transformer substation, and particularly relates to a CT circuit checking device and a checking method.

Background

The secondary system in the transformer substation is large in scale, the protection configuration and the CT loop are complex, problems of reverse CT polarity connection, wrong transformation ratio connection and the like often occur in the test, and adverse effects are brought to the debugging progress and the quality.

In field debugging of a secondary system of a transformer substation, measures such as checking wiring, testing loop resistance and point CT polarity are usually adopted to ensure the correctness of a loop, but the methods are indirect testing methods, and a final testing conclusion can be obtained only by mutually verifying a plurality of testing results. And the problems of correct CT transformation ratio, grounding of a cable or shunt generation of a parasitic loop and the like cannot be reliably detected.

Often, the line under test will not only have one CT device, but may have a variety of inductive or capacitive devices, such as: series reactance or shunt reactor, or shunt capacitor, but also combinations of these devices are possible. In such a complex situation, it is difficult for the technician to see the correct vector value of the CT at a glance, and careful calculation is required according to the parameters of different devices to obtain what the correct vector value of the CT should be.

Therefore, in actual operation, the accuracy of the measured loop is often determined by applying a current to the primary device, measuring the magnitude and phase of the current on the secondary side of the device, and comparing whether the measured value and the theoretical value are consistent, as shown in fig. 1.

As can be seen from fig. 1, the current CT loop checking apparatus only outputs a large current, cannot output a voltage, and cannot output a high voltage (if the large current and the high voltage are output simultaneously, a very large output power is required (for example, a current voltage of 100A and 110kV is output, and a current power P =100 × 110=11000kVA is required, such a device is very large and belongs to a large device), so that the secondary side of the device can only see the phase relationship between the current amplitude and each phase current, and cannot see the phase relationship between the current and the voltage. The purpose of measuring the vector is to measure the phase relationship between the current and the voltage after one current is passed, and to determine whether the polarity of the CT loop is correct. The method is to measure the phase difference between the measured current vector and a certain fixed voltage vector as a reference. Therefore, the current CT loop checking apparatus cannot completely complete the testing of the current vector.

In some cases, although the correctness of the polarity can be judged by the difference current calculated by the differential protection device, for example, two currents with the same polarity, the difference current should be 0, and if the difference current is not 0, it is judged that there is a CT polarity which is misconnected, the method has the following disadvantages:

1. although it is known that there must be one CT polarity error in the two CTs, it is not clear which CT polarity error is specific, and further verification by other methods is required;

2. even if the difference stream is 0, the CT polarity cannot be determined to be correct, because there is a possibility that both CT polarities are wrong;

3. because the sampling precision of the protection device is 5%, if the secondary side current is below 10mA, only 1% of the rated current 1A is far less than the minimum accurate measurement current, the sampling accuracy of the protection device is greatly influenced, and the applied primary current needs to be increased to improve the accuracy of current measurement. When the primary loop impedance is larger, it is very difficult to increase the primary current output by the large current generator;

4. this method cannot determine the CT loop polarity for which no difference current calculation is performed, such as the breaker protection CT.

An improved CT loop verification apparatus is shown in fig. 2. It can independently produce primary current and primary voltage respectively, has solved the problem that current vector measurement needs voltage as the measuring reference, has also solved the too big problem of output function that exports high voltage and heavy current simultaneously and lead to, but it also has obvious shortcoming:

since the tester outputs high voltage and large current to be applied to the primary sides of the CT and PT at the same time, the whole test loop is in a high voltage environment, as shown by the dashed line box in fig. 2. At this moment, high voltage causes very big injury to tester device and tester, so, can isolate the PT return circuit during actual test, also be exactly primary voltage return circuit and primary current return circuit, guarantee that high voltage can not influence primary current return circuit, tester device and tester. The isolation point is typically chosen at the junction of the PT and the primary line, as shown by the cross in fig. 2. And because no switch or knife switch is used as an isolation point between the PT and the primary circuit, a primary lead must be dismantled, and the dismantling work is time-consuming, labor-consuming and unsafe, which is also the root reason why the equipment cannot be widely applied on site.

There is also currently a test method in which a voltage is applied directly to the secondary side of the PT, as shown in fig. 3. It requires an actual voltage of around 60V to be applied in the test loop and the PT secondary side loop to be disconnected to complete the test. This method has the following disadvantages:

firstly, the voltage in the test loop is about 60V, which is higher than the human body safety voltage of 36V, so that potential safety hazards exist; secondly, the method of changing the tested loop increases the hidden danger of site accidents, and the accident that the loop is forgotten to be changed after the test is finished in the actual working site; thirdly, the distance from the calibration device of the primary equipment site to the protection and automation device of the secondary equipment chamber is far, various primary high-voltage equipment exists, and great safety risk exists when the primary high-voltage equipment is connected through a wire. Therefore, many application units are relatively abstaining from such a method and cannot be widely used on the spot.

Disclosure of Invention

Aiming at the problems in the prior art, the wireless automatic checking device for the CT loop provided by the invention can simply, safely and automatically judge the transformation ratio error and the polarity error in the CT loop.

In order to solve the technical problems, the invention provides the following technical scheme:

unlike the prior art which completes the test by applying current and voltage on the primary sides of CT and PT, the present invention completes the test by applying current on the primary side of CT and virtually generating the voltage data on the secondary side of PT (as shown in fig. 4), and the specific technique includes the following aspects:

in a first aspect, the present invention provides a wireless automatic calibration apparatus for CT loop, comprising: the signal generating device and the signal measuring device are two parts. The signal generating equipment is positioned at a primary equipment site and used for generating CT primary current and applying the CT primary current to a primary loop to be detected; the signal measuring device is located in the secondary device chamber and used for measuring the CT secondary current vector.

The signal generating apparatus, characterized by comprising: the device comprises a man-machine interface unit, a master control unit, a primary current signal unit, a current power amplifier unit, a reference voltage signal unit and a wireless communication unit.

The human-computer interface unit is used for setting technical parameters of the CT circuit wireless automatic checking device, inputting electrical parameters of a primary circuit to be tested and current environmental parameters, and displaying the current working state of the CT circuit wireless automatic checking device in real time, wherein the working state comprises a test result, a communication state, and real-time output voltage and current.

The total control unit is used for controlling the running state of the whole CT loop wireless automatic checking device, and comprises the following steps: automatically calculating the output minimum current according to the electrical parameters of the tested loop, wherein the current is determined by the total impedance of the tested loop and the measurement precision of the signal measurement equipment; automatically calculating the amplitude and the phase of the output reference voltage according to the electrical parameters of the tested loop, wherein the amplitude and the phase are determined by the electrical parameters of the tested loop; controlling the normal work of the current power amplification unit and the wireless communication unit; and the master control unit is also used for automatically judging whether the current CT secondary circuit is correct or not according to the CT vector measurement result returned by the signal measurement equipment.

And the primary current signal unit generates an actual current signal according to the current data calculated by the master control unit.

The current power amplifier unit is used for amplifying the current signal generated by the primary current signal unit to a set size and then applying the amplified current signal to the primary side of the CT.

And the reference voltage signal unit generates a reference voltage signal according to the voltage data calculated by the master control unit.

The wireless communication unit is used for transmitting the voltage signal generated by the reference voltage signal unit to the signal measuring equipment in the secondary equipment chamber in a wireless mode, and is used for sending CT vector measurement data returned by the signal measuring equipment to the master control unit.

The signal measuring apparatus, characterized by comprising: CT vector measurement terminal unit and wireless communication unit.

The CT vector measurement terminal unit is used for measuring CT secondary current and generating CT vector measurement data according to the reference voltage wirelessly transmitted by the signal generating equipment.

The wireless communication unit is used for receiving reference voltage data transmitted by signal generation equipment in a primary equipment site in a wireless mode on one hand, and is used for sending CT vector measurement data generated by the CT vector measurement terminal unit to the signal generation equipment on the other hand.

The main control unit not only automatically generates the amplitude and the phase of the primary current and the reference voltage to be applied, but also automatically calculates the theoretical amplitude and the polarity of the current at the secondary side of the CT in the tested loop.

And the master control unit automatically judges whether the current CT secondary circuit is correct or not according to the theoretical amplitude and polarity of the CT secondary side current in the measured circuit calculated and the received CT vector measurement result returned by the signal measurement equipment.

The reference voltage transmitted to the signal measuring equipment by the signal generating equipment is a virtual voltage data message and is transmitted in a wireless mode, and the specific wireless technology can be WIFI, GPRS, LORA and 5G.

The receiving and dispatching power of the wireless communication module is controlled by the master control unit, under the condition that the requirement of wireless transmitting power of equipment of a transformer substation or a power plant is met, the receiving and dispatching power is automatically calculated and adjusted according to the distance between a primary equipment field and a secondary equipment chamber and the shielding condition, the minimum transmitting power is adopted under the condition that reliable communication is ensured, and the electromagnetic radiation interference to other electronic equipment is reduced to the minimum.

In a second aspect, the present invention further provides a testing method for CT loop verification using a CT loop wireless automatic verification apparatus, the method including:

connecting the CT loop wireless automatic checking device and a tested line into a closed loop through a ground network, and applying a current signal generated by a signal generating device to the primary side of the CT;

inputting the electrical parameters of the tested loop from the man-machine interface unit: the method comprises the steps of CT transformation ratio, whether capacitive or inductive equipment exists in a circuit, the number of the capacitive or inductive equipment in the circuit and electrical parameters of each equipment, and whether shielding exists or not, wherein the distance between a primary equipment field and a secondary equipment chamber is required to be input; the master control unit not only automatically generates the amplitude and phase of the primary current and the reference voltage to be applied according to the input parameters, but also automatically calculates the theoretical amplitude and polarity of the current on the secondary side of the CT in the tested loop, and also automatically calculates the minimum power transmitted wirelessly;

the main control unit automatically controls the primary current signal unit and the current power amplification unit to output specified current to be applied to the primary side of the CT, and the reference voltage signal unit and the wireless communication unit are automatically controlled to output specified reference voltage to be wirelessly sent to the signal measuring equipment;

and measuring the secondary current of the CT by using the CT vector measurement terminal unit, and generating CT vector measurement data according to the reference voltage wirelessly transmitted by the signal generating equipment. Then the data is sent to a master control unit in the signal generating equipment through a wireless communication unit in the signal measuring equipment;

and the master control unit automatically judges whether the current CT secondary circuit is correct or not according to the theoretical amplitude and polarity of the CT secondary side current in the measured circuit calculated and the received CT vector measurement data returned by the signal measurement equipment.

In a third aspect, the present invention provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the CT loop automatic verification method when executing the program.

In a fourth aspect, the present invention provides a computer readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the CT loop automatic verification method.

As can be seen from the above description, the automatic CT loop verification apparatus and the automatic CT loop verification method provided by the embodiments of the present invention have the following advantages:

1. the testing process is fully automatic, the primary current and the reference voltage can be automatically set according to the electrical parameters of the tested loop, the theoretical amplitude and the polarity of the current of the secondary side of the CT in the tested loop can be automatically calculated, the testing result of the CT loop can be automatically judged, the technical capability requirement on testing personnel is reduced, and the standardized testing is realized.

2. The voltage data of the virtually generated PT secondary side is used as the reference voltage of the measured current vector, the whole test loop does not have any high voltage, a primary circuit and a secondary circuit do not need to be disconnected, and the test loop is very safe and convenient.

3. The reference voltage is transmitted to the CT vector measurement terminal unit of the protection cell in a wireless mode to complete the current vector measurement, so that the trouble of cable elongation is eliminated, and the safety risk caused by long cables in actual test is avoided.

4. The CT polarity is judged according to the measured current phase, and the limitation that the CT polarity is judged by depending on the calculated difference current in the prior art is eliminated.

5. Because the output reference voltage is only a virtual voltage data message and is not the actual voltage quantity, the output power of the CT loop checking device is reduced, the weight and the volume of equipment are reduced, and the field carrying is convenient.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts:

FIG. 1 is a diagram of a current vector measurement method performed by a conventional CT circuit calibration device

FIG. 2 is a diagram of a method for measuring a current vector by the improved CT circuit checking device 1

FIG. 3 is a diagram of a method for measuring a current vector by the improved CT circuit checking device 2

FIG. 4 is a connection diagram of functional modules of the wireless automatic checking device for CT circuit of the present invention

FIG. 5 is a schematic structural diagram of a signal generating device according to an embodiment of the present invention;

FIG. 6 is a schematic flow chart illustrating a CT loop checking method according to an embodiment of the present invention;

FIG. 7 is a diagram of a circuit to be tested according to an embodiment of the present invention;

FIG. 8 is a schematic flow chart illustrating a CT loop verification method according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of an electronic device in an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to solve the problem that the current CT circuit checking device cannot completely complete current vector testing, the embodiment of the invention provides a CT circuit wireless automatic checking device and provides a corresponding testing method.

The embodiment of the invention provides a schematic structural diagram of a signal generating device of a CT loop wireless automatic checking device, and the schematic structural diagram is shown in FIG. 5.

In an embodiment, the signal generating device comprises: CPU chip, memory cell (SD storage card and DDR memory), man-machine interface unit (touch-sensitive screen), sampling module, power amplifier module and communication unit (wireless communication module), wherein:

the CPU chip is used for running a software program of a test system and controlling respective input data and output data of the CPU chip in cooperation with the current output unit, the current regulating unit, the voltage output unit, the voltage regulating unit and the voltage phase regulating unit;

the memory cell includes: the SD memory card and the DDR memory card are used for storing programs and configuration files in the CPU, the voltage output unit, the voltage regulating unit and the voltage phase regulating unit;

the human-computer interface unit is a touch screen and is used for setting technical parameters of the CT circuit wireless automatic checking device, inputting electrical parameters of a primary circuit to be tested and displaying the current working state of the CT circuit wireless automatic checking device in real time, wherein the working state comprises a testing result, a communication state, real-time output voltage, real-time output current and the like.

The communication unit is used for communicating with an external device.

In an embodiment, the communication unit is configured to communicate with an external device, and includes:

the signal measurement device is used for wirelessly transmitting the voltage signal generated by the reference voltage signal unit to the signal measurement device located in the secondary device cell, and transmitting CT vector measurement data returned by the signal measurement device to the master control unit;

and the plurality of CT loop wireless automatic checking devices carry out synchronous operation in a wireless transmission mode.

The power amplification unit is used for amplifying the current signal output by the CPU;

the sampling unit is used for sampling, tracking and calibrating the reference voltage and the output current in real time; on one hand, the CT loop wireless automatic checking device needs to obtain accurate amplitude and phase of output current and voltage; on the other hand, the device must track and calibrate the output current and voltage in real time according to the set current and voltage output state and synchronization requirements, so as to achieve the purpose of accurate output.

The embodiment of the present invention further provides a test method for CT verification by using a CT loop wireless automatic verification apparatus, referring to fig. 6, the method includes:

step 100: the CT loop wireless automatic checking device and the tested line are connected into a closed loop through a ground network, and a current signal generated by the signal generating equipment is applied to the primary side of the CT.

Step 200: the electric parameters of the loop to be tested are input from a human-computer interface unit in the CT loop wireless automatic checking device, the master control unit automatically generates the amplitude and the phase of the primary current and the reference voltage which need to be applied according to the input parameters, and the theoretical amplitude and the polarity of the current of the secondary side of the CT in the loop to be tested are automatically calculated.

Step 300: a signal generating device in the CT loop wireless automatic checking device outputs specified current to be applied to the primary side of the CT, and outputs specified reference voltage to be wirelessly sent to a signal measuring device.

Step 400: and measuring the secondary current of the CT by using the CT vector measurement terminal unit, and generating CT vector measurement data according to the reference voltage wirelessly transmitted by the signal generating equipment. This data is then transmitted via the wireless communication unit in the signal measuring device to the overall control unit in the signal generating device.

Step 500: and the master control unit automatically judges whether the current CT secondary circuit is correct or not according to the theoretical amplitude and polarity of the current on the secondary side of the CT in the tested circuit calculated and the received CT vector measurement data returned by the signal measurement equipment.

In order to further explain the scheme, the invention provides a specific application example of the CT verification method by taking the fourth string of equipment of a 500kV transformer substation as an example.

In the initial case: as shown in fig. 7, the 500kV fourth string 5041 switch, 5042 switch, 5043 switch, line 1 and line 2 of a certain substation are all in a maintenance state. In order to ensure that the current does not affect other equipment when the current flows once, a 5041 switch is disconnected from the I bus, a 5043 switch is disconnected from the II bus, and a line 1 and a line 2 are also disconnected from the fourth string, as shown by a fork in FIG. 7.

The number and function of each CT is shown in fig. 7, and the transformation ratio of each CT is 2500/1.

The implementation method of the specific application example includes the following contents, and refer to fig. 8.

S0: and connecting the CT loop wireless automatic checking device with the primary loop to be tested.

A5041 switch is selected to be a primary current application point close to the I bus side, namely, a current output end of the wireless automatic checking device of the CT loop is connected, and the current output end is shown by an arrow on the left side of the figure 7. The 5043 switch is selected to be the primary current drain near the il bus side, as shown by the right ground point in fig. 7. The test current forms a closed loop together with the earth screen through the fourth string of equipment, and the current direction flows from the I bus to the II bus, as shown by the primary current direction identified in fig. 7.

S1: and automatically generating the amplitude and the phase of the primary current and the reference voltage to be applied, and automatically calculating the theoretical amplitude and the theoretical polarity direction of the secondary side current of each CT.

Because the transformation ratios of the CT in the tested loop are 2500/1, the CT is calculated according to the reliable measured value of the current of the secondary side of the CT being 40mA, the amplitude of the applied primary current is 100A, and the phase is selected to be 0 degree; according to the difference of the positions and functions of the various CTs shown in fig. 7, it is calculated that the polarities of the various CTs should be in the positive direction or the negative direction as shown in fig. 7. Such as: the CT421 is used as the pilot differential protection 1 of the line 1, and the polarity direction should be directed to the line 1, so that the current direction should have a positive polarity; if CT441 is used as I bus differential protection 2, the polarity direction should be directed to I bus, so that the current direction should exhibit reverse polarity. The amplitude of the applied reference voltage is selected to be 60V (data message), the phase is adjusted according to the parameters of the tested loop, and the phase of the reference voltage is selected to be 0 degree because the whole testing loop does not have inductance and capacitance elements.

S2: a signal generating device in the CT loop wireless automatic checking device outputs specified current to be applied to the primary side of the CT, and outputs specified reference voltage to be wirelessly sent to a signal measuring device.

S3: and measuring the secondary current of the CT by using the CT vector measurement terminal unit, and generating CT vector measurement data according to the reference voltage wirelessly transmitted by the signal generating equipment. This data is then transmitted via the wireless communication unit in the signal measuring device to the overall control unit in the signal generating device.

S4: and the master control unit automatically judges whether the current CT secondary circuit is correct or not according to the theoretical amplitude and polarity of the current on the secondary side of the CT in the tested circuit calculated and the received CT vector measurement data returned by the signal measurement equipment.

The judgment result is as follows: (only a few items with errors in the test results are selected for illustration, and the description is omitted for the sake of accuracy)

If the measured phase of the phase a of CT421 is 180 °, it is determined that the CT polarity is wrong. The reason is that: CT421 is positive, and the phase of the a-phase current and the reference voltage should be 0 °;

for the C phase of CT441, if the measured amplitude is 81mA, the selection of CT transformation ratio is judged to be wrong. The reason is that: c441 is 2500/1 CT, the primary 100A current and the secondary current should be 40 mA.

From the above test results, the wireless automatic checking device for the CT loop and the test method thereof provided by the invention can accurately judge the transformation ratio error and the polarity error of the primary CT.

It should be noted that the working frequency band of the wireless communication module in this specific application example strictly complies with the requirements of the wireless communication frequency bands of the country and the transformer substation, the transceiving power also strictly complies with the requirements of the transformer substation for electromagnetic compatibility, and no interference is caused to other electronic devices of the transformer substation.

Based on the same inventive concept, the embodiment of the present application further provides a wireless automatic checking apparatus for a CT loop, which can be used to implement the methods described in the above embodiments, such as the following embodiments. As used hereinafter, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. While the system described in the embodiments below is preferably implemented in software, implementations in hardware, or a combination of software and hardware are also possible and contemplated.

An embodiment of the present application further provides a specific implementation manner of an electronic device capable of implementing all steps in the CT loop verification method in the foregoing embodiment, and referring to fig. 9, the electronic device specifically includes the following contents:

a processor (processor) 1201, a memory (memory) 1202, a communication interface 1203, and a bus 1204;

the processor 1201, the memory 1202 and the communication interface 1203 complete communication with each other through the bus 1204; the communication interface 1203 is used for implementing information transmission among the server-side device, the measurement device, the CT and the related devices.

The processor 1201 is configured to call the computer program in the memory 1202, and the processor executes the computer program to implement all the steps in the CT loop checking method in the above-described embodiment, for example, the processor executes the computer program to implement the following steps, as shown in fig. 6.

As can be seen from the above description, the electronic device in the embodiment of the present application provides the reference voltage required for measuring the current vector, and provides the unit capable of adjusting the amplitude of the reference voltage and adjusting the phase of the reference voltage, so that the transformation ratio error and the polarity error of the primary CT can be accurately determined, and the technical defect that the transformation ratio error can only be detected by the amplitude of the CT loop checking apparatus in the prior art is overcome.

An embodiment of the present application further provides a computer-readable storage medium capable of implementing all the steps in the wireless automatic CT loop checking method in the foregoing embodiment, where the computer-readable storage medium stores a computer program, and the computer program, when executed by a processor, implements all the steps of the wireless automatic CT loop checking method in the foregoing embodiment, for example, when the processor executes the computer program, the following steps are implemented, as shown in fig. 6.

As can be seen from the above description, the computer-readable storage medium in the embodiment of the present application provides the reference voltage required for measuring the current vector, and provides the unit capable of adjusting the amplitude of the reference voltage and adjusting the phase of the reference voltage, so that the transformation ratio error and the polarity error of the primary CT can be accurately determined, and the technical defect that the transformation ratio error can only be detected by the amplitude of the CT loop checking apparatus in the prior art is overcome.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the hardware + program class embodiment, since it is substantially similar to the method embodiment, the description is simple, and the relevant points can be referred to the partial description of the method embodiment.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

Although the present application provides method steps as in an embodiment or a flowchart, more or fewer steps may be included based on conventional or non-inventive labor. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. When an actual apparatus or client product executes, it may execute sequentially or in parallel (e.g., in the context of parallel processors or multi-threaded processing) according to the embodiments or methods shown in the figures.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The principle and the implementation mode of the invention are explained by applying specific embodiments in the invention, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A wireless automatic checking device of CT loop is characterized by comprising: a signal generating device and a signal measuring device, wherein:

the signal generating equipment is positioned at a primary equipment site and used for generating CT primary current and applying the CT primary current to a primary loop to be detected;

the signal measuring equipment is positioned in the secondary equipment chamber and used for measuring the CT secondary current vector.

2. The wireless automatic checking apparatus for CT loop according to claim 1, wherein said signal generating device comprises: man-machine interface unit, total control unit, current signal unit, current power amplifier unit, reference voltage signal unit, wireless communication unit, wherein:

the human-computer interface unit is used for setting technical parameters of the CT circuit wireless automatic checking device, inputting electrical parameters of a primary circuit to be tested, inputting current environmental parameters and displaying the current working state of the CT circuit wireless automatic checking device in real time, wherein the working state comprises a test result, a communication state and real-time output voltage and current;

the total control unit is used for controlling the operation of the whole CT loop wireless automatic checking device, and comprises the following steps:

generating a minimum current according to the total impedance of the tested loop and the measurement precision of the signal measurement equipment;

generating the amplitude and the phase of a reference voltage signal according to the number of capacitive or inductive devices of a tested loop and electrical parameters of the capacitive or inductive devices;

automatically judging whether the current CT secondary circuit is correct or not according to the CT vector measurement result returned by the signal measurement equipment;

controlling the normal work of the current power amplification unit and the wireless communication unit;

the primary current signal unit generates an actual current signal according to the current data calculated by the master control unit;

the current power amplifier unit is used for amplifying the current signal generated by the primary current signal unit to a set size and then applying the amplified current signal to the primary side of the CT;

the reference voltage signal unit generates a reference voltage signal according to the voltage data calculated by the master control unit;

3. The wireless automatic checking apparatus for CT loop according to claim 1, wherein said signal measuring device comprises: CT vector measurement terminal unit and wireless communication unit;

the CT vector measurement terminal unit is used for measuring CT secondary current and generating CT vector measurement data according to the reference voltage wirelessly transmitted by the signal generating equipment;

4. The wireless automatic checking device of the CT loop according to claim 1, wherein the transceiving power of the wireless communication module is controlled by the master control unit;

and automatically calculating and adjusting according to the distance between the primary equipment field and the secondary equipment cell and the shielding condition between the primary equipment field and the secondary equipment cell, and adopting the minimum transmitting power under the condition of ensuring reliable communication.

5. A wireless automatic checking method of CT loop is characterized in that,

applying a current signal generated by the signal generating device to the primary side of the CT; inputting the electrical parameters of the tested loop from the man-machine interface unit: the method comprises the steps of CT transformation ratio, whether capacitive or inductive equipment exists in a circuit, the number of the capacitive or inductive equipment in the circuit, electrical parameters of each equipment, the distance between a primary equipment field and a secondary equipment cell, and whether shielding exists between the primary equipment field and the secondary equipment cell; the master control unit not only automatically generates the amplitude and phase of the primary current and the reference voltage to be applied according to the input parameters, but also automatically calculates the theoretical amplitude and polarity of the current on the secondary side of the CT in the tested loop, and also automatically calculates the minimum power transmitted wirelessly;

a CT vector measuring terminal unit in the signal measuring equipment measures a CT secondary current vector;

and the master control unit automatically judges whether the current CT secondary circuit is correct or not according to the theoretical amplitude and polarity of the current on the secondary side of the CT in the tested circuit calculated and the received CT vector measurement result returned by the signal measurement equipment.

6. The wireless automatic checking method for the CT loop according to claim 5, wherein the reference voltage transmitted by the signal generating device to the signal measuring device is a virtual voltage data packet and is transmitted wirelessly, and the specific wireless technology may be any one of WIFI, GPRS, LORA, or 5G.

7. The wireless automatic checking method for the CT loop according to claim 5, wherein when the wireless automatic checking device for the CT loop is used for checking the CT loop, the current signal generated by the signal generating device is applied to the primary side of the CT, and the CT secondary current vector is measured by using the CT vector measuring terminal unit in the signal measuring device; and after the test is finished, directly reading a test result from a human-computer interface of the signal generating equipment.

8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the wireless automatic checking method for CT loops according to any one of claims 5 to 7 when executing the program.

9. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method for wireless automatic verification of a CT loop according to any one of claims 5 to 7.