Multi-path current transformer self-identification device and method
The multi-channel current transformer self-identification device automatically recognizes the change ratio of the current transformer, which solves the problem that the corresponding relationship cannot be automatically identified and recorded in the prior art, and realizes efficient and accurate switching of the current transformer.
Patent Information
- Application Number
- CN202510550636.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2025-07-11
AI Technical Summary
The prior art cannot automatically identify the ratio of the current transformer, and the corresponding relationship between the switching switch and the current transformer is prone to errors, resulting in inefficiency and increased errors.
A multi-channel current transformer self-identification device is adopted, including a current generation source, a control and verification device (MCU, sampling module and multiple switch). By controlling the current generation source, the target current is output, the sampling module measures the current value, the MCU calculates the change ratio, and records the corresponding relationship between the switch and the current transformer.
It realizes automatic identification of the change ratio of the current transformer and records the corresponding relationship between the switch switch, avoids errors and errors, and improves efficiency and accuracy.
Smart Images
Figure CN120294658A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrical testing, and particularly relates to a multi-channel current transformer self-identification device and method. Background Art
[0002] In the power system and industrial fields, there are many products that require current transformers. For example, smart meters for electric energy metering, photovoltaic inverters for the new energy field, charging piles, etc. In the smart meter industry, manufacturers usually sell different current transformers together with meters according to different current ranges to facilitate customers. To ensure product quality, manufacturers will conduct a series of tests before selling meters, including signal calibration. Different customer requirements result in a variety of current transformers equipped with products. When debugging and inspecting products with different signals, it is necessary to continuously switch among current transformers with different transformation ratios. Currently, there are two existing methods for switching current transformers.
[0003] The first method is the traditional manual replacement of current transformers, which is inefficient and not suitable for frequent replacement of current transformers. The second method is to install a switch quantity output module for current transformer switching. When replacing the position of the current transformer or newly connecting a new current transformer, it is necessary to re-record the relationship between the current transformer and the switch quantity output port. These two methods cannot automatically identify the transformation ratio of the replaced current transformer, and the second method cannot dynamically record the corresponding relationship between the switching switch and the transformation ratio of the replaced current transformer, making it easy to make mistakes in the corresponding relationship between the switching switch and the transformation ratio of the current transformer it can switch. Summary of the Invention
[0004] The purpose of the present invention is to overcome the defects existing in the prior art and provide a multi-channel current transformer self-identification device and method that can automatically identify the transformation ratio of the current transformer and can adaptively record the corresponding relationship between the switching switch and the transformation ratio of the current transformer it can switch.
[0005] To achieve the above purpose, the first aspect of the present invention provides a multi-channel current transformer self-identification device, including a current generating source and a control and verification device; The control and verification device includes an MCU, a sampling module, and a multi-channel switch. The MCU is communicatively connected to the current generating source, the MCU is electrically connected to the sampling module, the sampling module is electrically connected to the multi-channel switch respectively, the control ends of the multi-channel switch are electrically connected to the MCU respectively, and each switch is used to be electrically connected to the secondary side circuit of a current transformer to be identified; The current generating source is used to access the primary side circuit of the current transformer to be identified and output a target current; The sampling module is used to sample the electrical signal in the secondary side circuit of the current transformer to be identified, determine the current value in the secondary side circuit of the current transformer to be identified and transmit it to the MCU; The MCU is used to control the current generating source to be connected to the primary side circuits of multiple current transformers to be identified in sequence, and output a target current; control the closing or opening of the multi-way switch; and determine the transformation ratio of each current transformer to be identified according to the ratio between the value of the target current input in the primary side circuit of each current transformer to be identified and the value of the current measured in the secondary side circuit.
[0006] Furthermore, the multi-way current transformer self-identification device further includes a plurality of relays. The output end of the current generating source is respectively connected to the common ends of the plurality of relays. The normally open contact ends of each relay are respectively used to be connected to the primary side circuit of a current transformer to be identified, and the control end of each relay is connected to the MCU.
[0007] Furthermore, the multi-way current transformer self-identification device further includes an electronic switch array. The output end of the current generating source is connected to the common end of the electronic switch array. Each channel port of the electronic switch array is used to be connected to the primary side circuit of a current transformer to be identified, and the control end of the electronic switch array is connected to the MCU.
[0008] Furthermore, the MCU is specifically used to control the current generating source to be connected to the primary side circuit of the target current transformer among the multiple current transformers to be identified, and control the current generating source to output a target current to the primary side circuit of the target current transformer; control the switch connected to the secondary side circuit of the target current transformer to close; sample the electrical signal in the secondary side circuit of the target current transformer through the sampling module to measure the value of the current in the secondary side circuit of the target current transformer; determine the transformation ratio of the target current transformer according to the ratio between the value of the target current and the value of the current in the secondary side circuit of the target current transformer; record the corresponding relationship between the transformation ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; repeat the above steps until the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto is recorded.
[0009] Furthermore, when the MCU controls the current generating source to output a target current to the primary side circuit of the target current transformer, it is specifically used to send an output signal instruction to the current generating source, and the output signal instruction includes current value information, so that the current generating source outputs a target current with a corresponding current value according to the current value information; when receiving the response message returned by the current generating source, it is determined that the current generating source outputs a target current to the primary side circuit of the target current transformer.
[0010] A second aspect of the present invention provides a multi-way current transformer self-identification method, which is applicable to the multi-way current transformer self-identification device according to any item of the first aspect, and includes: Control the current generating source to access the primary side circuit of the target current transformer among multiple current transformers to be identified, and control the current generating source to output a target current to the primary side circuit of the target current transformer; Control the switch connected to the secondary side circuit of the target current transformer to close; Sample the electrical signal in the secondary side circuit of the target current transformer through a sampling module to measure the current value in the secondary side circuit of the target current transformer; Determine the transformation ratio of the target current transformer according to the ratio between the value of the target current and the current value in the secondary side circuit of the target current transformer; Record the corresponding relationship between the transformation ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; Repeat the above steps until the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto is recorded.
[0011] Further, controlling the current generating source to access the primary side circuit of the target current transformer among multiple current transformers to be identified includes: Output a control signal to the control terminal of the relay connected to the primary side circuit of the target current transformer to make the normally open contact of the relay close.
[0012] Further, the controlling the current generating source to output a target current to the primary side circuit of the target current transformer includes: Send an output signal instruction to the current generating source, where the output signal instruction contains current value information, so that the current generating source outputs a target current with a corresponding current value according to the current value information; When receiving the response message returned by the current generating source, determine that the current generating source outputs a target current to the primary side circuit of the target current transformer.
[0013] Further, the controlling the current generating source to output a target current to the primary side circuit of the target current transformer includes: Control the current generating source to output a target current with a magnitude linearly changing according to a time sequence to the primary side circuit of the target current transformer in a time-sharing manner; The determining the transformation ratio of the target current transformer according to the value of the target current and the current value in the secondary side circuit of the target current transformer includes: Select a measured current value that linearly changes in the same way and has a corresponding time sequence as the target current from the current values measured in the secondary side circuit of the target current transformer by the sampling module in a time-sharing manner; Determine the transformation ratio of the target current transformer according to the ratio between the measured current value and the value of the target current at the corresponding time sequence values of both.
[0014] Furthermore, the controlling the current generating source to output a target current whose magnitude varies linearly according to a time sequence to the primary side loop of the target current transformer in a time-sharing manner comprises: According to the numerical values in the first sequence, the current generating source is controlled to output the target current of corresponding magnitude to the primary side circuit of the target current transformer in a time-sharing manner, and the numerical values in the first sequence change linearly; The step of selecting a measured current value having the same linear change as the target current and corresponding to the time sequence from the current value in the secondary side loop of the target current transformer measured by the sampling module in time division includes: The current values in the secondary side circuit of the target current transformer measured by the sampling module in time division are organized into a second sequence according to a time sequence; Determining a subsequence in the second sequence that has the same linear variation as that in the first sequence; The step of determining the transformation ratio of the target current transformer according to the ratio between the measured current value and the target current value, which have corresponding time sequences, comprises: According to the position of any value in the subsequence in the second sequence, the target value corresponding to the position in the first sequence is selected; The ratio between the target value and any one of the values is used as the transformation ratio of the target current transformer.
[0015] The advantages and beneficial effects of the present invention are that the transformation ratio of the current transformer connected to the switching switch can be automatically identified, and the corresponding relationship between the transformation ratio of the switching switch and the current transformer connected to it can be recorded, so as to achieve the effect of adaptively recording the corresponding relationship between the transformation ratio of the switching switch and the switchable current transformer, thereby avoiding the problem of error in the transformation ratio of the current transformer switchable by the switching switch after replacing the current transformer. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of a multi-channel current transformer self-identification device of the present invention; Figure 2 It is a multi-channel current transformer identification flow chart; Figure 3 It is a flow chart of the multi-channel current transformer identification method of the present invention; In the figure: 11, current source; 10, control and verification device; 101, MCU; 102, sampling module; (1, 2, ..., i) are switches; (21, 22, ..., 2i) are current transformers to be identified. DETAILED DESCRIPTION
[0017] The following further describes the specific implementation manners of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.
[0018] According to Figure 1 As shown, the multi-channel current transformer self-identification device of the present invention includes a current generating source 11 and a control and verification device 10; the control and verification device includes an MCU 101, a sampling module 102, and multi-channel switches (1, 2,..., i). The MCU 101 is communicatively connected to the current generating source 11, the MCU 101 is electrically connected to the sampling module 102, the sampling module 101 is electrically connected to the multi-channel switches (1, 2,..., i) respectively, the control ends of the multi-channel switches (1, 2,..., i) are electrically connected to the MCU 101 respectively, and each switch is used to be electrically connected to the secondary side circuit of a current transformer to be identified; the current generating source 11 is used to access the primary side circuit of the current transformer to be identified (21, 22,..., 2i) and output a target current; the sampling module 102 is used to sample the electrical signal in the secondary side circuit of the current transformer to be identified, determine the current value in the secondary side circuit of the current transformer to be identified and transmit it to the MCU 101; the MCU 101 is used to control the current generating source 11 to access the primary side circuits of multiple current transformers to be identified (21, 22,..., 2i) in sequence and output a target current; control the multi-channel switches (1, 2,..., i) to be closed or opened; determine the transformation ratio of each current transformer to be identified according to the ratio between the value of the target current input in the primary side circuit of each current transformer to be identified and the current value measured in the secondary side circuit.
[0019] Exemplarily, starting from the self-identification process, the MCU 101 controls the current generator 11 to access the primary side circuit of the current transformer 21 to be identified, and sends an output signal instruction to the current generator 11. The instruction contains information indicating that the current generator 11 outputs a current with a target magnitude (e.g., 20 A). The current generator 11 outputs a target current of 20 A. At the same time, the MCU 101 controls the switch 1 connected to the current transformer 21 to close. After a short delay, the current in the secondary side circuit of the current transformer 21 tends to be stable. The sampling module 102 samples the electrical signal in the secondary side circuit of the current transformer 21, measures the current value in the secondary side circuit of the current transformer 21, obtains a measurement result (e.g., 0.5 A), and transmits the measurement result to the MCU 101. The MCU 101 determines the turns ratio of the current transformer 21 to be 20 A / 0.5 A = 40:1 based on the current value of 20 A of the target current input to the primary side circuit of the current transformer 21 and the measurement result of the current value of 0.5 A in the secondary side circuit of the current transformer 21. The MCU 101 records the corresponding relationship between the switching switch 1 and the turns ratio of 40:1 of the current transformer 21 for subsequent operation using the current transformer 21 in the device. At the same time, the MCU 101 controls the switching switch 1 to open.
[0020] And so on, the MCU 101 sequentially controls the current generator 11 to access the primary side circuits of the current transformers 22 to 2i to be identified. Each time the current generator 11 outputs a target current to a current transformer to be identified, it controls the switching switch connected to the current transformer to be identified to close, so as to measure the current value in the secondary side circuit of the current transformer to be identified through the sampling module 102, calculate the turns ratio of the current transformer to be identified, and record the corresponding relationship between its turns ratio and the switching switch connected to it until the identification of each current transformer connected to the switching switch is completed.
[0021] Controlling the current generator to sequentially access the primary side circuits of multiple current transformers to be identified, rather than directly connecting the primary side circuits of all current transformers to be identified to the current generator, is to avoid the situation where current transformers with unclosed secondary side circuit switches are idling. If there is current input to the primary side circuit of a current transformer but the secondary side circuit is open, it will cause the magnetic flux in the iron core to saturate sharply, the hysteresis loss and eddy current loss in the iron core to increase sharply, and the iron core to heat severely. Moreover, when the secondary side of a current transformer with an unclosed switch is open, there is still current passing through its primary side, which will generate magnetic field coupling interference to other current transformers being measured, resulting in distorted sampling data and increased error in turns ratio calculation.
[0022] The present invention can automatically identify the transformation ratio of the current transformer connected to the change-over switch and record the corresponding relationship between the change-over switch and the transformation ratio of the current transformer it connects to, achieving the effect of adaptively recording the corresponding relationship between the change-over switch and the transformation ratio of the switchable current transformer, and avoiding the problem of incorrect transformation ratio of the switchable current transformer after replacing the current transformer.
[0023] One type of multi-channel current transformer identification is as Figure 2 shown: Step 201: The MCU sends an output signal instruction to the current source through communication.
[0024] Step 202: Determine whether the current source has received the output signal instruction. The determination method is: whether the MCU has received the message of the answer start signal from the current source.
[0025] Step 203: Control one switch to close.
[0026] Step 204: Delay to sample the electrical signal data of this path and save the current value. The MCU calculates the transformation ratio of the current transformer and records the corresponding relationship between this switch and the transformation ratio of the current transformer.
[0027] Step 205: Open the switch opened in Step 203.
[0028] Step 206: Determine whether the switch is the last switch. If the switch is the last one, the determination of the transformation ratio of the current transformer corresponding to each switch is completed; if the switch is not the last switch, return to Step 203 to continue the next round of switch closing, data acquisition, transformation ratio calculation and recording.
[0029] To achieve high-voltage electrical isolation and improve the safety when the current source outputs high-voltage current, a preferred implementation of the present invention further provides that the multi-channel current transformer self-identification device further includes a plurality of relays. The output end of the current source is respectively connected to the common end of the plurality of relays. The normally open contact end of each relay is respectively used to connect to the primary side circuit of a current transformer to be identified, and the control end of each relay is connected to the MCU.
[0030] To be applicable to the scenario of frequent switching and solve the deficiencies of the relay solution in terms of efficiency, lifespan and flexibility, a preferred implementation of the present invention further provides that the multi-channel current transformer self-identification device further includes an electronic switch array. The output end of the current source is connected to the common end of the electronic switch array. Each channel port of the electronic switch array is used to connect to the primary side circuit of a current transformer to be identified, and the control end of the electronic switch array is connected to the MCU.
[0031] To flexibly implement the process of current transformer identification, the implementation scheme of the present invention further provides that the MCU is specifically configured to control the current generating source to access the primary side circuit of the target current transformer among multiple current transformers to be identified, and control the current generating source to output a target current to the primary side circuit of the target current transformer; control the switch connected to the secondary side circuit of the target current transformer to close; sample the electrical signal in the secondary side circuit of the target current transformer through the sampling module to measure the current value in the secondary side circuit of the target current transformer; determine the transformation ratio of the target current transformer according to the ratio between the value of the target current and the current value in the secondary side circuit of the target current transformer; record the corresponding relationship between the transformation ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; repeat the above steps until the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto is recorded.
[0032] To flexibly control the current generating source to output a target current, a preferred implementation scheme of the present invention is that when the MCU controls the current generating source to output a target current to the primary side circuit of the target current transformer, it is specifically configured to send an output signal instruction to the current generating source, and the output signal instruction includes current value information, so that the current generating source outputs a target current corresponding to the current value according to the current value information; when receiving the response message returned by the current generating source, it is determined that the current generating source outputs a target current to the primary side circuit of the target current transformer.
[0033] To select current data within the range of the current transformer for transformation ratio calculation and improve the measurement accuracy of the transformation ratio of the current transformer, a preferred implementation scheme of the present invention is that when the MCU controls the current generating source to output a target current to the primary side circuit of the target current transformer, it is specifically configured to control the current generating source to output a target current whose magnitude changes linearly according to the time sequence to the primary side circuit of the target current transformer in a time-sharing manner.
[0034] When the MCU determines the transformation ratio of the target current transformer according to the value of the target current and the current value in the secondary side circuit of the target current transformer, it is specifically configured to select the measured current value that changes linearly in the same time sequence as the target current and corresponds to the time sequence from the current values measured in the secondary side circuit of the target current transformer in a time-sharing manner by the sampling module; determine the transformation ratio of the target current transformer according to the ratio between the measured current value and the value of the target current at the corresponding time sequence.
[0035] In order to optimize the process of selecting current data within the range of a current transformer for ratio calculation and improve the measurement accuracy of the current transformer ratio, a preferred implementation of the present invention is that when the MCU controls the current generating source to output a target current with a magnitude that changes linearly according to a time sequence to the primary side circuit of the target current transformer, it is specifically used to control the current generating source to output the corresponding target current to the primary side circuit of the target current transformer in sequence according to the values in the first sequence, and the values in the first sequence change linearly.
[0036] When the MCU selects a measured current value that changes linearly in the same way and has a corresponding time sequence from the current values measured by the sampling module in the secondary side circuit of the target current transformer in sequence, it is specifically used to form the current values measured by the sampling module in the secondary side circuit of the target current transformer in sequence into a second sequence; determine a subsequence in the second sequence that changes linearly in the same way as the first sequence.
[0037] When the MCU determines the ratio of the current transformer according to the ratio between the values corresponding to the time sequences of the measured current value and the target current value, it is specifically used to select a target value corresponding to the position in the first sequence according to the position of any value in the subsequence in the second sequence; use the ratio between the target value and any value as the ratio of the target current transformer.
[0038] A second aspect of the present invention provides a method for self-identifying multiple current transformers, which is applicable to the device for self-identifying multiple current transformers in the above embodiment, and includes: S301. Control the current generating source to be connected to the primary side circuit of the target current transformer among multiple current transformers to be identified, and control the current generating source to output a target current to the primary side circuit of the target current transformer.
[0039] S302. Control the switch connected to the secondary side circuit of the target current transformer to be closed.
[0040] S303. Sample the electrical signal in the secondary side circuit of the target current transformer through the sampling module to measure the current value in the secondary side circuit of the target current transformer.
[0041] S304. Determine the ratio of the target current transformer according to the ratio between the value of the target current and the current value in the secondary side circuit of the target current transformer.
[0042] S305. Record the corresponding relationship between the ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; S306. Repeat the above steps until the corresponding relationship between the ratio of each current transformer to be identified and the switch connected to it is recorded.
[0043] In order to achieve high-voltage electrical isolation and improve the safety when the current generating source outputs high-voltage current, a preferred embodiment of the present invention is to control the current generating source to access the primary side circuit of the target current transformer among multiple current transformers to be identified, including: outputting a control signal to the control end of the relay connected to the primary side circuit of the target current transformer so that the normally open contact of the relay closes.
[0044] In order to flexibly control the current generating source to output a target current, a preferred embodiment of the present invention is to control the current generating source to output a target current to the primary side circuit of the target current transformer, including: sending an output signal instruction to the current generating source, where the output signal instruction contains current value information, so that the current generating source outputs a target current corresponding to the current value according to the current value information; when receiving the response message returned by the current generating source, determine that the current generating source outputs a target current to the primary side circuit of the target current transformer.
[0045] In order to select current data within the range of the current transformer for ratio calculation and improve the measurement accuracy of the ratio of the current transformer, a preferred embodiment of the present invention is to control the current generating source to output a target current to the primary side circuit of the target current transformer, including: controlling the current generating source to output a target current whose magnitude changes linearly in time sequence to the primary side circuit of the target current transformer in a time-sharing manner.
[0046] Determine the ratio of the target current transformer according to the value of the target current and the current value in the secondary side circuit of the target current transformer, including: select the measured current value that changes linearly in the same way and has a corresponding time sequence as the target current from the current values measured by the sampling module in the secondary side circuit of the target current transformer in a time-sharing manner; determine the ratio of the target current transformer according to the ratio between the corresponding values of the measured current value and the target current value in terms of time sequence.
[0047] The range of the current transformer refers to the linear range in which it can accurately transfer current. Within this range, the ratio of the primary side current to the secondary side current, that is, the ratio, remains constant. If it exceeds the range (such as when the primary side current is too large), the iron core of the current transformer will be magnetically saturated, resulting in the ratio deviating from the nominal value, and the secondary side current will no longer be proportional to the primary side current, showing non-linearity. By controlling the current generating source to output a target current with a linear change to the primary side of the current transformer (for example, gradually increasing the current gear output by the current generating source in stages), and observing whether the response of the secondary side current changes linearly, it can be judged whether the current transformer is operating in the linear region. When calculating the ratio at different times, any data in the linear region can be selected for the ratio calculation of the current transformer, but it should be noted that the primary side data and the secondary side data need to correspond to each other, which can be determined by whether the primary side data and the secondary side data correspond in time sequence, because the secondary side current is the response to the primary side current, and the time when the secondary side current data is generated is almost synchronous with the current input on the primary side.
[0048] In order to optimize the process of selecting current data within the range of the current transformer for ratio calculation and improve the measurement accuracy of the current transformer ratio, a preferred implementation scheme of the present invention is to control the current generating source to output a target current whose magnitude changes linearly according to a time sequence to the primary side loop of the target current transformer in a time-sharing manner, including: controlling the current generating source to output a target current of corresponding magnitude to the primary side loop of the target current transformer in a time-sharing manner according to the numerical value in the first sequence, and the numerical value in the first sequence changes linearly.
[0049] From the current values in the secondary side circuit of the target current transformer measured by the sampling module in a time-sharing manner, the measured current values that have the same linear change as the target current and have corresponding time sequence are selected, including: the current values in the secondary side circuit of the target current transformer measured by the sampling module in a time-sharing manner are organized into a second sequence according to the time sequence; and a subsequence in the second sequence that has the same linear change as that in the first sequence is determined.
[0050] The transformation ratio of the target current transformer is determined according to the ratio between the values corresponding to the time series of the measured current value and the target current value, including: selecting the target value corresponding to the position in the first sequence according to the position of any value in the subsequence in the second sequence; and taking the ratio between the target value and any value as the transformation ratio of the target current transformer.
[0051] The controlled current source outputs a current with values in a linearly varying sequence in time segments. For example, the linearly varying sequence is 50, 40, 30, 20, 10. The controlled current source outputs a 50 A current in the starting time segment (within 1 - 5 s), and the current on the secondary side of the target current transformer is measured to be 4.1 A. The controlled current source outputs a 40 A current in the second time segment (within 5 - 10 s), and the current on the secondary side of the target current transformer is measured to be 4.0 A. The controlled current source outputs a 30 A current in the third time segment (within 10 - 15 s), and the current on the secondary side of the target current transformer is measured to be 3.0 A. The controlled current source outputs a 20 A current in the fourth time segment (within 15 - 20 s), and the current on the secondary side of the target current transformer is measured to be 2.0 A. The controlled current source outputs a 10 A current in the fourth time segment (within 20 - 25 s), and the current on the secondary side of the target current transformer is measured to be 1.0 A. The second sequence composed of the measured current values in the secondary side loop is 4.1, 4.0, 3.0, 2.0, 1.0. Relative to the first sequence 50, 40, 30, 20, 10 of the primary side input current values, only the subsequence 4.0, 3.0, 2.0, 1.0 in the second sequence also varies linearly. Therefore, it shows that the primary side current values 40, 30, 20, 10 and the secondary side current values 4.0, 3.0, 2.0, 1.0 are within the range of the target current transformer. Select any value in the subsequence 4.0, 3.0, 2.0, 1.0, for example 4.0, whose position in the second sequence is the second. Select the value 40 which is in the corresponding position (also the second) in the first sequence as the target value. Take the ratio 10:1 of 40 to 4.0 as the turns ratio of the target current transformer.
[0052] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.
Claims
1. A multi-channel current transformer self-identification device, characterized in that It includes a current generating source and a control verification device; The control verification device includes an MCU, a sampling module, and a multiplexer switch. The MCU is communicatively connected to the current generating source, the MCU is electrically connected to the sampling module, the sampling module is electrically connected to the multiplexer switch respectively, the control ends of the multiplexer switch are electrically connected to the MCU respectively, and each switch is respectively used for being electrically connected to the secondary side circuit of a current transformer to be identified; The current generating source is used for accessing the primary side circuit of the current transformer to be identified and outputting a target current; The sampling module is used for sampling the electrical signal in the secondary side circuit of the current transformer to be identified, determining the current value in the secondary side circuit of the current transformer to be identified and transmitting it to the MCU; The MCU is used for controlling the current generating source to access the primary side circuits of multiple current transformers to be identified in sequence and outputting a target current; controlling the multiplexer switch to be closed or opened; determining the transformation ratio of each current transformer to be identified according to the ratio between the value of the target current input in the primary side circuit of each current transformer to be identified and the current value measured in the secondary side circuit, and recording the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto.
2. The multi-channel current transformer self-identification device according to claim 1, characterized in that The multi-channel current transformer self-identification device further includes a plurality of relays. The output end of the current generating source is respectively connected to the common ends of the plurality of relays. The normally open contact ends of each relay are respectively used for being connected to the primary side circuit of a current transformer to be identified, and the control ends of each relay are connected to the MCU.
3. The multi-channel current transformer self-identification device according to claim 1, characterized in that, The multi-channel current transformer self-identification device further includes an electronic switch array. The output end of the current generating source is connected to the common end of the electronic switch array. Each channel port of the electronic switch array is used for being connected to the primary side circuit of a current transformer to be identified, and the control end of the electronic switch array is connected to the MCU.
4. The multi-channel current transformer self-identification device according to claim 1, characterized in that, Specifically, the MCU is used for controlling the current generating source to access the primary side circuit of the target current transformer among the multiple current transformers to be identified, and controlling the current generating source to output a target current to the primary side circuit of the target current transformer; controlling the switch connected to the secondary side circuit of the target current transformer to be closed; sampling the electrical signal in the secondary side circuit of the target current transformer through the sampling module and measuring the current value in the secondary side circuit of the target current transformer; determining the transformation ratio of the target current transformer according to the ratio between the value of the target current and the current value in the secondary side circuit of the target current transformer; recording the corresponding relationship between the transformation ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; repeating the above steps until the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto is recorded.
5. The multi-channel current transformer self-identification device according to claim 4, characterized in that, When the MCU controls the current generating source to output a target current to the primary side circuit of the target current transformer, it is specifically used to send an output signal instruction to the current generating source, and the output signal instruction includes current value information, so that the current generating source outputs a target current with a corresponding current value according to the current value information; when receiving the response message returned by the current generating source, it is determined that the current generating source outputs a target current to the primary side circuit of the target current transformer.
6. A method for self-identifying a multi-channel current transformer, applicable to the multi-channel current transformer self-identifying device according to any one of claims 1-5, characterized in that, Including: Controlling the current generating source to be connected to the primary side circuit of the target current transformer among multiple current transformers to be identified, and controlling the current generating source to output a target current to the primary side circuit of the target current transformer; Controlling the switch connected to the secondary side circuit of the target current transformer to close; Sampling the electrical signal in the secondary side circuit of the target current transformer through a sampling module to measure the current value in the secondary side circuit of the target current transformer; Determining the transformation ratio of the target current transformer according to the ratio between the value of the target current and the current value in the secondary side circuit of the target current transformer; Recording the corresponding relationship between the transformation ratio of the target current transformer and the switch connected to the secondary side circuit of the target current transformer; Repeating the above steps until the corresponding relationship between the transformation ratio of each current transformer to be identified and the switch connected thereto is recorded.
7. The multi-channel current transformer self-identification method according to claim 6, characterized in that, Controlling the current generating source to be connected to the primary side circuit of the target current transformer among multiple current transformers to be identified includes: Outputting a control signal to the control terminal of the relay connected to the primary side circuit of the target current transformer to make the normally open contact of the relay close.
8. The multi-channel current transformer self-identification method according to claim 6, wherein The controlling the current generating source to output a target current to the primary side circuit of the target current transformer includes: Sending an output signal instruction to the current generating source, and the output signal instruction includes current value information, so that the current generating source outputs a target current with a corresponding current value according to the current value information; When receiving the response message returned by the current generating source, it is determined that the current generating source outputs a target current to the primary side circuit of the target current transformer.
9. The multi-channel current transformer self-identification method according to claim 6, characterized in that, The controlling the current generating source to output a target current to the primary side circuit of the target current transformer includes: Controlling the current generating source to output a target current with a magnitude linearly changing according to the time sequence to the primary side circuit of the target current transformer in a time-sharing manner; The determining the transformation ratio of the target current transformer according to the value of the target current and the current value in the secondary side circuit of the target current transformer includes: Selecting a measured current value that linearly changes in the same way as the target current and has a corresponding time sequence from the current values measured in the secondary side circuit of the target current transformer by the sampling module in a time-sharing manner; Determining the transformation ratio of the target current transformer according to the ratio between the measured current value and the value of the target current at the corresponding time sequences of both.
10. The multi-channel current transformer self-identification method according to claim 9, characterized in that The controlling the current generating source to output a target current with a magnitude linearly changing according to the time sequence to the primary side circuit of the target current transformer in a time-sharing manner includes: Control the current generating source to output target currents of corresponding magnitudes to the primary side circuit of the target current transformer in sequence at different times according to the values in the first sequence, and the values in the first sequence change linearly; Among the current values measured by the sampling module at different times in the secondary side circuit of the target current transformer, select the measured current values that change linearly in the same way and have corresponding time sequences as the target current, including: Form a second sequence according to the time sequence of the current values measured by the sampling module at different times in the secondary side circuit of the target current transformer; Determine the subsequence in the second sequence that changes linearly in the same way as the first sequence; Determine the transformation ratio of the target current transformer according to the ratio between the measured current value and the value of the target current at the corresponding time sequences of both, including: Select the target value corresponding to the position in the first sequence according to the position of any value in the subsequence in the second sequence; Use the ratio between the target value and the any value as the transformation ratio of the target current transformer.