Accuracy evaluation device for Rogowski coil calibrator
The accuracy evaluation device, consisting of a primary current generator, a standard current transformer, and a coaxial shunt, solves the problems of high cost, complex operation, and long time required for Rogowski coil calibrators, achieving high precision and rapid calibration results.
Patent Information
- Application Number
- CN202422930477.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-11-29
AI Technical Summary
Existing Rogowski coil calibration methods are costly, complex to operate, and time-consuming, and their reliance on external equipment increases the difficulty of equipment management and maintenance.
An accuracy evaluation device consisting of a primary current generator, a standard current transformer, and a coaxial shunt is used. An alternating magnetic flux is generated by a standard current transformer, and the secondary current is converted into a voltage signal by the coaxial shunt and input to the Rogowski coil calibrator, which simplifies the calibration process.
It reduces equipment costs and operational complexity, improves the output accuracy and signal integrity of the Rogowski coil calibrator, simplifies the calibration process, and ensures the speed and reliability of calibration.
Smart Images
Figure CN223624409U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of Rogowski coils, and more particularly to an accuracy evaluation device for a Rogowski coil calibrator. Background Technology
[0002] In existing technologies, the following are commonly used: Figure 2 The dual-standard power supply calibration structure shown uses two interconnected standard current sources, L1 and L2, as standards for calibration. The specific connection method is as follows:
[0003] The current output terminal S of the standard current source L1 01 S X1 Connect to the standard sampling unit terminals S1 and S2 of the calibrator. The current output terminal S of the standard current source L2. 02 S X2 The voltage signal is connected to the terminals K1 and K2 of the sampled unit under test on the calibrator via a current-to-voltage converter. This means that a voltage signal is input to the terminals K1 and K2 of the sampled unit under test via the current-to-voltage converter. The signal is also grounded as required.
[0004] Adjust the standard current source to output current signals I1 and I2 with corresponding amplitude and phase (L1 outputs I1, L2 outputs I2). I1 and I2 should be consistent with the product specifications. Observe and record the readings of the calibrator. Analyze and evaluate the accuracy of the Rogowski coil calibrator based on the readings of the calibrator.
[0005] The main problems with this testing method include:
[0006] High cost: Using two interconnected standard current sources as reference devices for calibration results in high equipment costs. Complex operation: Precise adjustment of the outputs of the two standard current sources is required, making operation complex. Long time cycle: The entire calibration process is time-consuming, impacting work efficiency. Dependence on external equipment: Reliance on external standard current sources increases the difficulty of equipment management and maintenance. Utility Model Content
[0007] To address the aforementioned technical problems and improve the output accuracy of the Rogowski coil calibrator during calibration, this invention proposes an accuracy evaluation device for the Rogowski coil calibrator, comprising:
[0008] A primary current generator is used to generate the current to be measured.
[0009] A standard current transformer is electrically connected to the output of a primary current generator to generate an alternating magnetic flux through the measured current and induce a secondary current based on the alternating magnetic flux.
[0010] The coaxial shunt has its input end connected to the output of a standard current transformer and its output end connected to a Rogowski coil calibrator. It is used to convert the secondary current into a voltage signal and input it into the Rogowski coil calibrator.
[0011] The Rogowski coil calibrator is connected to the output of a standard current transformer and is used to analyze the secondary current output by the standard current transformer and the voltage signal input by the coaxial shunt.
[0012] Furthermore, the standard current transformer includes: a primary side and a secondary side; wherein:
[0013] The primary side is electrically connected to the output terminal of the primary current generator; the primary side is used to generate alternating magnetic flux through the measured current; the secondary side generates secondary current through electromagnetic induction under the action of the alternating magnetic flux.
[0014] Furthermore, the primary side includes: a primary coil;
[0015] The output terminal of the primary current generator outputs the measured current to the primary coil; the primary coil generates alternating magnetic flux through the measured current.
[0016] Furthermore, both the input and output terminals of the coaxial shunt include positive and negative terminals.
[0017] Furthermore, the secondary side includes: a secondary coil, and a positive terminal S1 disposed at the positive end of the secondary coil and a negative terminal S2 disposed at the negative end of the secondary coil;
[0018] The secondary coil is connected to the positive terminal of the Rogowski coil calibrator via the positive terminal S1 and to the negative terminal of the coaxial shunt input via the negative terminal S2; the negative terminal of the Rogowski coil calibrator is connected to the positive terminal of the coaxial shunt input.
[0019] The secondary coil induces a secondary current based on the alternating magnetic flux generated by the primary coil and inputs it to the coaxial shunt and the Rogowski coil calibrator.
[0020] Furthermore, the Rogowski coil calibrator includes:
[0021] The standard signal input terminal is used to receive the secondary current induced by the secondary coil and input it to the coaxial shunt; the positive terminal K1 of the standard signal input terminal is connected to the positive terminal S1, and the negative terminal K2 is connected to the positive terminal of the coaxial shunt input terminal; the negative terminal of the coaxial shunt input terminal is connected to the negative terminal S2.
[0022] The measured signal input terminal is used to connect the voltage signal output by the coaxial shunt; the positive terminal V1 of the measured signal input terminal is connected to the positive terminal of the coaxial shunt output terminal, and the negative terminal V2 is connected to the negative terminal of the coaxial shunt output terminal.
[0023] Furthermore, the accuracy assessment device also includes:
[0024] An evaluator connected to the output of the Rogowski coil calibrator is used to receive the analysis results from the Rogowski coil calibrator and evaluate the accuracy of the Rogowski coil calibrator based on the analysis results.
[0025] Furthermore, the primary current generator includes:
[0026] A voltage regulator and a current booster; the input terminal of the voltage regulator is connected to a power source, and the output terminal is connected to the input terminal of the current booster; the voltage regulator is used to adjust the voltage input to the current booster; the output terminal of the current booster is used to output the measured current to the primary coil; the measured current output by the current booster increases with the increase of the voltage regulator's output voltage.
[0027] Compared with the prior art, the present invention has at least the following beneficial effects:
[0028] (1) In this utility model, the standard current transformer is electrically connected to the output terminal of the primary current generator and is used to generate alternating magnetic flux through the measured current and induce a secondary current based on the alternating magnetic flux; the coaxial shunt is connected to the output of the standard current transformer at its input terminal and to the Rogowski coil calibrator at its output terminal, and is used to convert the secondary current into a voltage signal and input it into the Rogowski coil calibrator; the Rogowski coil calibrator is connected to the output of the standard current transformer and is used to analyze the secondary current output by the standard current transformer and the voltage signal input by the coaxial shunt. That is, this utility model can achieve verification through one standard current transformer, avoiding the use of two standard current sources, reducing equipment cost and operational complexity;
[0029] (2) Using a coaxial shunt can directly convert the secondary current signal of a standard current transformer into a voltage signal, which simplifies the calibration process. At the same time, since the coaxial shunt is equivalent to a pure resistor, the current signal will not produce an angle difference after being transformed by the coaxial shunt, thereby improving the output accuracy of the Rogowski coil calibrator.
[0030] (3) By simultaneously inputting the secondary current signal of the standard current transformer into the standard signal input terminal and the coaxial shunt of the calibrator, the integrity and accuracy of the signal are ensured. Attached Figure Description
[0031] Figure 1 This is a structural diagram of an accuracy evaluation device for a Rogowski coil calibrator.
[0032] Figure 2 This is a diagram illustrating the calibration structure for a dual-standard power supply used in existing technology.
[0033] In the picture:
[0034] 11. Voltage regulator; 12. Current booster; 2. Standard current transformer; 21. Primary coil; 22. Secondary coil; 23. Iron core; 3. Rogowski coil calibrator; 4. Coaxial shunt. Detailed Implementation
[0035] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.
[0036] To solve the above-mentioned technical problems and improve the output accuracy of the Rogowski coil calibrator during calibration, such as... Figure 1 As shown, this utility model proposes an accuracy evaluation device for a Rogowski coil calibrator, comprising:
[0037] A primary current generator is used to generate the current to be measured.
[0038] The primary current generator includes:
[0039] A voltage regulator 11 and a current booster 12 are provided. The input terminal of the voltage regulator 11 is connected to a power source, and the output terminal is connected to the input terminal of the current booster 12. The voltage regulator 11 is used to adjust the voltage input to the current booster 12. The output terminal of the current booster 12 is used to output the measured current to the primary coil 21. The measured current output by the current booster 12 increases with the increase of the voltage regulator output voltage.
[0040] The standard current transformer 2 is electrically connected to the output terminal of the primary current generator and is used to generate alternating magnetic flux through the measured current and induce a secondary current based on the alternating magnetic flux.
[0041] In this embodiment, the accuracy class of the standard current transformer 2 is 0.01S.
[0042] The standard current transformer 2 includes: a primary side and a secondary side, and an iron core 23 disposed between the primary side and the secondary side; wherein:
[0043] The primary side is electrically connected to the output terminal of the primary current generator; the primary side is used to generate alternating magnetic flux through the measured current; the secondary side generates secondary current through electromagnetic induction under the action of the alternating magnetic flux.
[0044] The primary side includes: a primary coil 21;
[0045] The output terminal of the primary current generator outputs the measured current to the primary coil 21; the primary coil 21 generates alternating magnetic flux through the measured current.
[0046] The coaxial shunt 4 has a positive terminal and a negative terminal at both its input and output.
[0047] The secondary side includes: a secondary coil 22, and a positive terminal S1 disposed at the positive end of the secondary coil 22 and a negative terminal S2 disposed at the negative end of the secondary coil 22.
[0048] The coaxial shunt 4 has its input end connected to the output of the standard current transformer 2 and its output end connected to the Rogowski coil calibrator 3, which is used to convert the secondary current into a voltage signal and input it into the Rogowski coil calibrator 3.
[0049] In this embodiment, the accuracy class of the coaxial shunt 4 is 0.005.
[0050] The Rogowski coil calibrator 3 is connected to the output of the standard current transformer 2 and is used to analyze the secondary current output by the standard current transformer 2 and the voltage signal input by the coaxial shunt 4.
[0051] The secondary coil 22 is connected to the positive terminal of the Rogowski coil calibrator 3 via the positive terminal S1 and to the negative terminal of the coaxial shunt 4 via the negative terminal S2; the negative terminal of the Rogowski coil calibrator is connected to the positive terminal of the coaxial shunt.
[0052] The secondary coil 22 induces a secondary current based on the alternating magnetic flux generated by the primary coil 21 and inputs it into the coaxial shunt 4 and the Rogowski coil calibrator 3.
[0053] The Rogowski coil calibrator 3 includes:
[0054] The standard signal input terminal is used to receive the secondary current induced by the secondary coil 22 and input it to the coaxial shunt 4; the positive terminal K1 of the standard signal input terminal is connected to the positive terminal S1, and the negative terminal K2 is connected to the positive terminal of the input terminal of the coaxial shunt 4; the negative terminal of the input terminal of the coaxial shunt 4 is connected to the negative terminal S2.
[0055] In other words, a loop is formed between the standard current transformer 2, the Rogowski coil calibrator 3, and the coaxial shunt 4: positive terminal S1 > positive terminal K1 of the standard signal input > negative terminal K2 of the standard signal input > positive terminal of the input of the coaxial shunt 4 > negative terminal of the input of the coaxial shunt 4 -> negative terminal S2. Through this loop, both the Rogowski coil calibrator 3 and the coaxial shunt 4 can be connected to the secondary current induced by the secondary coil 22.
[0056] The input terminal for the measured signal is used to connect the voltage signal output by the coaxial shunt 4; the positive terminal V1 of the input terminal for the measured signal is connected to the positive terminal + of the output terminal of the coaxial shunt 4, and the negative terminal V2 is connected to the negative terminal - of the output terminal of the coaxial shunt 4.
[0057] In the prior art, Rogowski coil calibrators are used to calibrate standard signals ( Figure 2 I1 in the middle and the measured signal ( Figure 2 The amplitude and phase of the voltage signal output by the current-to-voltage converter are compared to obtain the ratio difference and phase difference. In this embodiment, the secondary current collected by the standard current transformer 2 is sent to the standard signal input terminal of the Rogowski coil calibrator 3. The secondary current signal is simultaneously converted into a voltage signal by the coaxial shunt 4 and sent to the measured signal input terminal of the Rogowski coil calibrator 3. The Rogowski coil calibrator 3 calculates the ratio difference and phase difference using the secondary current output by the standard current transformer 2 and the voltage signal input by the coaxial shunt 4.
[0058] It needs to be explained that the coaxial shunt 4 is essentially a precision resistive element. When current flows through it, a corresponding voltage drop is generated, which is proportional to the current flowing through it. Because it is purely resistive, it theoretically does not introduce any phase delay or distortion, meaning that the phase of the current signal remains unchanged after passing through the coaxial shunt 4. This embodiment utilizes this to eliminate the influence of phase error during the calibration process of the Rogowski coil calibrator 3. Specifically, when using the coaxial shunt 4 instead of a traditional current-to-voltage converter, it is essentially replacing an unknown element with an element of known characteristics (the coaxial shunt 4). Since the phase error of the coaxial shunt 4 is extremely small, almost negligible, it can be assumed that it has no effect on the phase. Therefore, when the output voltage of the coaxial shunt 4 is compared with the secondary current of the standard current transformer 2, any observed phase difference can be attributed to the error of the Rogowski coil calibrator 3 itself. In other words, if the Rogowski coil calibrator 3 is found to show a certain phase difference or ratio difference, it can be concluded that this is a deviation inherent in the instrument itself, rather than a true property of the object under test.
[0059] The advantage of this calibration structure lies in its significant simplification of the calibration process, while also providing higher accuracy and stability. This approach not only allows for rapid and efficient evaluation of the Rogowski coil calibrator 3's performance but also ensures its reliability and consistency during the calibration process.
[0060] The accuracy assessment device further includes:
[0061] An evaluator connected to the output of the Rogowski coil calibrator 3 is used to receive the analysis results from the Rogowski coil calibrator 3 and evaluate the accuracy of the Rogowski coil calibrator 3 based on the analysis results.
[0062] It should be noted that if either the ratio difference or the phase difference exceeds the preset tolerance range, the evaluator will consider the Rogowski coil calibrator to be inaccurate. The preset tolerance range is typically set according to industry standards or the requirements of the specific application.
[0063] In this invention, a standard current transformer is electrically connected to the output of a primary current generator to generate an alternating magnetic flux through the measured current and induce a secondary current based on the alternating magnetic flux. A coaxial shunt is connected to the output of the standard current transformer at its input and to a Rogowski coil calibrator at its output, converting the secondary current into a voltage signal and inputting it into the Rogowski coil calibrator. The Rogowski coil calibrator is connected to the output of the standard current transformer to analyze the secondary current output by the standard current transformer and the voltage signal input by the coaxial shunt. This invention allows for calibration using only one standard current transformer, avoiding the need for two standard current sources and reducing equipment costs and operational complexity.
[0064] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0065] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0066] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0067] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
Claims
1. An accuracy evaluation device for a Rogowski coil calibrator, characterized in that, include: A primary current generator is used to generate the current to be measured. A standard current transformer is electrically connected to the output of a primary current generator to generate an alternating magnetic flux through the measured current and induce a secondary current based on the alternating magnetic flux. The coaxial shunt has its input end connected to the output of a standard current transformer and its output end connected to a Rogowski coil calibrator. It is used to convert the secondary current into a voltage signal and input it into the Rogowski coil calibrator. The Rogowski coil calibrator is connected to the output of a standard current transformer and is used to analyze the secondary current output by the standard current transformer and the voltage signal input by the coaxial shunt.
2. The accuracy evaluation device for a Rogowski coil calibrator according to claim 1, characterized in that, The standard current transformer includes: a primary side and a secondary side; wherein: The primary side is electrically connected to the output terminal of the primary current generator; the primary side is used to generate alternating magnetic flux through the measured current; the secondary side generates secondary current through electromagnetic induction under the action of the alternating magnetic flux.
3. The accuracy evaluation device for a Rogowski coil calibrator according to claim 2, characterized in that, The primary side includes: a primary coil; The output terminal of the primary current generator outputs the measured current to the primary coil; the primary coil generates alternating magnetic flux through the measured current.
4. The accuracy evaluation device for a Rogowski coil calibrator according to claim 3, characterized in that, The input and output terminals of the coaxial shunt both include positive and negative terminals.
5. The accuracy evaluation device for a Rogowski coil calibrator according to claim 4, characterized in that, The secondary side includes: a secondary coil, and a positive terminal S1 disposed at the positive end of the secondary coil and a negative terminal S2 disposed at the negative end of the secondary coil; The secondary coil is connected to the positive terminal of the Rogowski coil calibrator via the positive terminal S1 and to the negative terminal of the coaxial shunt input via the negative terminal S2; the negative terminal of the Rogowski coil calibrator is connected to the positive terminal of the coaxial shunt input. The secondary coil induces a secondary current based on the alternating magnetic flux generated by the primary coil and inputs it to the coaxial shunt and the Rogowski coil calibrator.
6. The accuracy evaluation device for a Rogowski coil calibrator according to claim 5, characterized in that, The Rogowski coil calibrator includes: The standard signal input terminal is used to receive the secondary current induced by the secondary coil and input it to the coaxial shunt; the positive terminal K1 of the standard signal input terminal is connected to the positive terminal S1, and the negative terminal K2 is connected to the positive terminal of the coaxial shunt input terminal; the negative terminal of the coaxial shunt input terminal is connected to the negative terminal S2. The measured signal input terminal is used to connect the voltage signal output by the coaxial shunt; the positive terminal V1 of the measured signal input terminal is connected to the positive terminal of the coaxial shunt output terminal, and the negative terminal V2 is connected to the negative terminal of the coaxial shunt output terminal.
7. The accuracy evaluation device for a Rogowski coil calibrator according to claim 1, characterized in that, The accuracy assessment device further includes: An evaluator connected to the output of the Rogowski coil calibrator is used to receive the analysis results from the Rogowski coil calibrator and evaluate the accuracy of the Rogowski coil calibrator based on the analysis results.
8. The accuracy evaluation device for a Rogowski coil calibrator according to claim 6, characterized in that, The primary current generator includes: A voltage regulator and a current booster; the input terminal of the voltage regulator is connected to a power source, and the output terminal is connected to the input terminal of the current booster; the voltage regulator is used to adjust the voltage input to the current booster; the output terminal of the current booster is used to output the measured current to the primary coil; the measured current output by the current booster increases with the increase of the voltage regulator's output voltage.