Multi-Terminal Current Conversion Test Apparatus

Abstract

The multi-terminal current conversion test device of the present invention comprises: a primary side measurement value input unit that receives a current to be measured by a current sensor to be tested; a secondary side measurement value input unit that receives a sensor measurement value output as a result of the current sensor to be tested measuring the current; a primary side A / D converter that converts the value of the current measured by the primary side measurement value input unit into a first digital value; a secondary side A / D converter that converts the sensor measurement value input to the secondary side measurement value input unit into a second digital value; and a comparative analysis unit that evaluates the performance of the current sensor to be tested by comparing the first digital value and the second digital value. The above secondary side measurement value input unit is equipped with at least two individual terminal terminals, and each of the terminal terminals can be connected in parallel with each other.

Description

Technology Field

[0001] The present invention relates to a current conversion test device equipped with a sensor input terminal having a high-precision multi-terminal function for testing the performance of a current sensor. Background Technology

[0003] Figure 1 illustrates the configuration of a typical full digital substation.

[0004] Digital substations equipped with station bus-based substation automation systems composed of upper-level operating devices and intelligent electronic devices based on the IEC 61850 international standard are becoming more widespread. Recently, there has been a trend toward conducting demonstration studies on process bus-based full digital substations that include a machine unit that converts analog voltage and current signals transmitted via copper wires into digital voltage and current signals, as shown in Fig. 1.

[0005] Figure 2 is a conceptual diagram of a merging unit.

[0006] Figure 3 illustrates the principle of a Rogowski coil type current sensor.

[0007] As shown in Fig. 2, the merging unit, a key component of a full digital substation, performs the role of converting the secondary analog input of a conventional iron-core type CT (Current Transformer) / VT (Voltage Transformer) or LPIT (Low Power Instrument Transformer) into a Sampled Value digital signal based on IEC 61850-9.

[0008] It is common to use a Rogowski coil type current sensor as the input for the merging unit. As shown in FIG. 3, the current sensor using a Rogowski coil measures current by sensing the voltage induced by winding a coil around an air core (42), so it has the advantage of being able to be designed to be compact and lightweight, and has a significantly wide current measurement range because there is no saturation phenomenon. Although an integrator (43) is required to measure current, the Rogowski coil type current sensor is mainly used because integration calculations can be performed in the merging unit.

[0010] Figure 4 illustrates the configuration of a typical Rogowski coil type current conversion test device.

[0011] Figure 5 shows photographs illustrating terminal connectors by type.

[0012] To test the conversion performance of such current sensors, a test is performed by comparing the primary side current value with the secondary side output of the current sensor using a current conversion test device configured as shown in Fig. 4.

[0013] The current conversion test device (10) of FIG. 4 generally has a single terminal selected from BNC, SMA, RJ45, etc. of FIG. 5 at the secondary side voltage input section (21), and if it does not match the terminal of the secondary side voltage output of the Rogowski coil (40), a separate terminal module (a type of adapter) (29) is added to perform the current conversion test.

[0014] The secondary voltage of the urban current conversion test device consists of components as shown in Equation 1 below.

[0015] [ Mathematical formula 1 ]

[0016] Vp = Vs + Vt + Vi

[0017] Here, Vp: test device terminal voltage, Vs: sensor secondary side voltage, Vt: terminal terminal voltage, Vi: voltage input section voltage

[0018] Therefore, it can be seen that the device measuring and testing Vs requires calibration for Vt and Vi. For example, calibration according to the following mathematical formula 2 is required.

[0019] [ Mathematical formula 2 ]

[0020] Vs(RJ45) - Vt(RJ45 to BNC) - Vi(BNC to Tester)

[0021] When performing a current conversion test by adding a terminal module in this way, there are limitations in accurately measuring the secondary voltage output value of the Rogowski coil due to the voltage drop caused by the resistance of the terminal module (adapter). To compensate for this, it may be necessary to perform calibration work for the voltage drop or purchase additional modules or equipment suitable for the terminal, which consumes time and money.

[0022] In particular, when using RJ45 for the secondary output of an LPIT (Low Power Instrument Transformer), there is no specific standard, and the pin numbers used may vary depending on the design of the system or device (i.e., may vary by manufacturer), making it difficult to match / calibrate the terminals.

[0023] As examined above, accurately measuring the secondary analog conversion output of current sensors is very important in various industrial fields. However, there is a problem in that currently used test devices cannot measure various types of current sensors. Prior art literature

[0025] Republic of Korea Public Notice No. 10-2002-0032151 The problem to be solved

[0026] The present invention aims to provide a multi-terminal current conversion test device capable of preventing interference with result measurement caused by a voltage drop due to the resistance of a terminal port connected to a current sensor under test. means of solving the problem

[0028] A multi-terminal current conversion test device according to one aspect of the present invention comprises: a primary side measurement value input unit that receives a current to be measured by a current sensor to be tested; a secondary side measurement value input unit that receives a sensor measurement value output by the current sensor to be tested as a result of measuring the current; a primary side A / D converter that converts the value of the current measured by the primary side measurement value input unit into a first digital value; a secondary side A / D converter that converts the sensor measurement value input by the secondary side measurement value input unit into a second digital value; and a comparative analysis unit that evaluates the performance of the current sensor to be tested by comparing the first digital value and the second digital value.

[0029] The above secondary side measurement value input unit is equipped with at least two individual terminal terminals, and each of the terminal terminals can be connected in parallel with each other.

[0030] Here, the comparison analysis unit may include an input voltage drop calibration unit that adjusts the voltage drop caused by the impedance component added at the secondary side measurement value input unit.

[0031] Here, the secondary side measurement value input unit or the comparative analysis unit may further include a terminal-specific deviation correction unit that corrects the influence of the deviation of the impedance component added according to one of the terminal terminals selected to be connected to the current sensor under test.

[0032] Here, the terminal terminals include one or more of an M12 terminal and an RJ45 terminal, and the secondary measurement value input unit may include a pin number selection unit that specifies the pin number of the M12 terminal or the RJ45 terminal used by the output terminal of the product of the current sensor under test.

[0033] Here, the secondary side measurement value input unit or the comparison analysis unit may further include a pin selection deviation correction unit that corrects the influence of the deviation of the impedance component added according to the pin designated by the pin number selection unit.

[0034] Here, the current sensor under test may be a Rogowski coil type current sensor.

[0035] Here, an integrator presence / absence specification unit may be further included to specify whether the current sensor under test is equipped with an integrator. Effects of the invention

[0037] Implementing a multi-terminal current conversion test device according to the concept of the present invention with the above-described configuration offers the advantage of accurately testing the performance of various types of current sensors. In other words, it can simultaneously improve the convenience of the tester and the accuracy of the test during the testing process. Such a current conversion test device equipped with high-precision multi-terminal functions can be applied to various industrial fields where current sensors are used, such as electrical, electronic, automotive, aerospace, energy, medical, and telecommunications industries.

[0038] In addition, other features and advantages of the present invention may be newly identified through the embodiments of the present invention. Brief explanation of the drawing

[0040] Figure 1 is a configuration diagram of a typical full digital substation. Figure 2 is a conceptual diagram of a merging unit. Figure 3 is a conceptual diagram illustrating the principle of a Rogowski coil type current sensor. FIG. 4 is a block diagram illustrating the configuration of a typical Rogowski coil type current conversion test device. Figure 5 shows photographs illustrating terminal terminals by type. FIG. 6 is a block diagram illustrating an embodiment of a current conversion test device having a high-precision multi-terminal function according to the concept of the present invention. Specific details for implementing the invention

[0041] In describing the present invention, terms such as first, second, etc. may be used to describe various components, but the components may not be limited by the terms. The terms are intended solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0042] When it is mentioned that a component is connected to or coupled with another component, it can be understood that it may be directly connected to or coupled with that other component, or that there may be other components in between.

[0043] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions may include plural expressions unless the context clearly indicates otherwise.

[0044] In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0045] In addition, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

[0047] The present invention provides a current conversion test device having a multi-terminal function without using a conventional terminal port module (adapter) that generates a voltage drop that interferes with accurate result measurement.

[0049] FIG. 6 is a block diagram illustrating an embodiment of a current conversion test device having a high-precision multi-terminal function according to the concept of the present invention.

[0050] A multi-terminal current conversion test device (100) comprises: a primary side measurement value input unit (110) that receives a current to be measured by a current sensor (40) to be tested; a secondary side measurement value input unit (120) that receives a sensor measurement value output as a result of the current being measured by the current sensor (40); a primary side A / D converter (130) that converts the value of the current measured by the primary side measurement value input unit (110) into a first digital value; a secondary side A / D converter (140) that converts the sensor measurement value input by the secondary side measurement value input unit (120) into a second digital value; and a comparative analysis unit (160, 170) that evaluates the performance of the current sensor to be tested by comparing the first digital value and the second digital value.

[0051] The above secondary side measurement value input unit (120) is equipped with at least two individual terminal terminals, and each of the terminal terminals has a sensor connection terminal hardware structure in which they are connected in parallel with each other.

[0052] For example, the secondary side measurement value input unit (120) may be equipped with all of the terminal terminals shown in FIG. 5 (or counterpart terminals that can be coupled to the shown terminal terminals). At this time, each terminal may be connected to the secondary side A / D converter (140), and as a result, each terminal has a parallel connection relationship with each other.

[0053] The above comparison analysis unit (160, 170) may include a comparison operation unit (160) that compares the first digital value and the second digital value; and a result output unit (170) that determines and outputs the performance of the test subject current sensor (40) according to the degree of similarity compared by the comparison operation unit (160).

[0054] The secondary voltage of the urban current conversion test device (100) is composed of components such as those in Equation 3 below.

[0055] [ Mathematical formula 3 ]

[0056] Vp = Vs + Vi

[0057] Here, Vp: test device terminal voltage, Vs: sensor secondary voltage, Vi: voltage drop at the voltage input

[0058] Therefore, it can be seen that the device measuring and testing Vs requires only calibration for Vi. For example, calibration according to the following mathematical formula 4 is required.

[0059] [ Mathematical formula 4 ]

[0060] Vs(RJ45) - Vi(RJ45 to Tester)

[0061] Depending on the implementation for performing the calibration described above, the comparison analysis unit (160, 170) may further include an input voltage drop calibration unit (not shown) that adjusts the voltage drop caused by the impedance component added at the secondary side measurement value input unit.

[0062] In addition to the above input voltage drop calibration unit, depending on the implementation, the secondary side measurement value input unit (120) or the comparison analysis unit may further include a terminal-specific deviation correction unit that corrects the influence of the deviation of the impedance component added according to one of the terminal terminals selected to be connected to the test target current sensor.

[0063] For example, the terminal-specific deviation correction unit added to the secondary side measurement value input unit (120) may be composed of tuning impedance elements added to the path of each terminal to equalize the impedance components added by all terminals (HW correction).

[0064] In this case, separate hardware is required, but it has the advantage of simplifying the calibration process as much as possible.

[0065] In this case, it is easy to implement that the voltage drop determined by the input voltage drop calibration unit is the lowest value of the voltage drops caused by each terminal.

[0067] For example, the terminal-specific deviation correction unit added to the comparison analysis unit can correct the deviation by providing a difference value between the voltage drop caused by impedance components, such as contact resistance added by the connected terminal, and the voltage drop determined by the input voltage drop calibration unit (SW correction). In this case, for example, the voltage drop determined by the input voltage drop calibration unit may be the average value of the voltage drops caused by each terminal.

[0068] In this case, there is the advantage that no separate hardware is required, but the comparison analysis unit must be able to recognize which of the terminal terminals is connected to the current sensor under test.

[0070] As examined above, a current conversion test device having a multi-terminal port according to the concept of the present invention can accurately measure various types of current sensors. That is, as shown in FIG. 6, it is equipped with various types of terminal ports individually, including various types of ports such as BNC, SMA, and RJ45, and can respond to the various requirements of current sensor manufacturers (or users). In the case of M12 or RJ45 ports, pins as shown in Table 1 below are provided.

[0071]

[0072] In particular, for M12 or RJ45 inputs, the port can be configured according to the user's needs by controlling the pin number input section with the following additional configuration.

[0073] The RJ45 port has 8 pins, and the secondary voltage of the Rogowski coil type current sensor is transmitted to pins 1 and 2 of the RJ45 port according to the standard.

[0074] However, when using RJ45 for the secondary output of an LPIT (Low Power Instrument Transformer), it should be taken into account that there is no specific standard and the pin numbers used may vary depending on the design of the system or device (i.e., may vary by manufacturer).

[0075] Therefore, the test device must be able to distinguish the pins of the RJ45 port to which the current sensor to be tested is connected, and the pin number selection unit (190) performs this role.

[0076] In this case, the terminal terminals may include one or more of an M12 terminal and an RJ45 terminal, and accordingly, the secondary measurement value input unit (120) may be provided with a pin number (port) selection unit (190) that specifies the pin number of the M12 terminal or RJ45 terminal used by the output terminal of the product of the current sensor under test. For example, the tester (user) may manually input two pin numbers connected to the current sensor under test to the pin number selection unit (190).

[0077] Additionally, the secondary side measurement value input unit (120) or the comparison analysis unit may further include a pin selection deviation correction unit that corrects the influence of the deviation of the impedance component added according to the pin designated by the pin number selection unit (190).

[0078] The above pin selection deviation correction unit may be implemented as tuning impedance elements (HW correction) added to the path of the port according to each pin number when added to the secondary side measurement value input unit (120), similar to the input voltage drop calibration unit described above, or as a method (SW correction) that provides the difference value between the voltage drop caused by impedance components such as contact resistance added by the connected pin number port and the voltage drop determined by the input voltage drop calibration unit when added to the comparison analysis unit.

[0079] A multi-terminal current conversion test device according to the concept of the present invention is particularly suitable when the current sensor to be tested is a Rogowski coil type current sensor as shown in FIG. 3.

[0080] However, depending on the product, the Rogowski coil type current sensor may or may not include the integrator shown in Fig. 3.

[0081] The improved multi-terminal current conversion test device, taking into account the circumstances described above, may further include an integrator presence / absence specification unit for specifying whether the current sensor (40) under test is equipped with an integrator. For example, regarding the integrator presence / absence specification unit, a test performer (user) may manually input whether the integrator is included or not.

[0083] Those skilled in the art to which the present invention pertains should understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features, and therefore the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims set forth below rather than by the detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0085] 100 : Multi-terminal current conversion test device 40: Current sensor under test 110 : Primary side measurement value input section 120 : Secondary side measurement value input section 130 : Primary side A / D converter 140 : Secondary side A / D converter 160 : Comparison operation unit 170 : Result Output Section

Claims

Claim 1 A primary side measurement value input unit that receives a current to be measured by a current sensor under test; a secondary side measurement value input unit that receives a sensor measurement value output by the current sensor under test as a result of measuring the current; a primary side A / D converter that converts the measured current value input to the primary side measurement value input unit into a first digital value; and a secondary side A / D converter that converts the sensor measurement value input to the secondary side measurement value input unit into a second digital value. A multi-terminal current conversion test device comprising a comparison analysis unit that evaluates the performance of the current sensor under test by comparing the first digital value and the second digital value, wherein the secondary side measurement value input unit comprises at least two individual terminal terminals, each of which is connected in parallel with each other, and the terminal terminals include one or more of an M12 terminal and an RJ45 terminal, and the secondary side measurement value input unit comprises a pin number selection unit that designates the pin number of the M12 terminal or RJ45 terminal used by the output terminal of the corresponding product of the current sensor under test, and the secondary side measurement value input unit or the comparison analysis unit further comprises a pin selection deviation correction unit that corrects the influence of the deviation of the impedance component added according to the pin designated by the pin number selection unit. Claim 2 A multi-terminal current conversion test device according to claim 1, wherein the comparison analysis unit comprises an input voltage drop calibration unit that adjusts the voltage drop caused by an impedance component added at the secondary side measurement value input unit. Claim 3 In paragraph 2, the multi-terminal current conversion test device further comprises a terminal-specific deviation correction unit that corrects the influence of a deviation in an impedance component added according to one of the terminal terminals selected to be connected to the current sensor under test, wherein the secondary side measurement value input unit or the comparison analysis unit further comprises a terminal-specific deviation correction unit. Claim 4 delete Claim 5 delete Claim 6 In claim 1, the current sensor subject to test is a multi-terminal current conversion test device that is a Rogowski coil type current sensor. Claim 7 A multi-terminal current conversion test device according to claim 1, further comprising an integrator presence / absence designation unit for specifying whether the current sensor under test is equipped with an integrator.

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