Wide-range current transformer and electronic equipment

Abstract

The utility model provides a wide-range current transformer and electronic equipment, and belongs to the technical field of current measuring and monitoring equipment. The wide-range current transformer comprises a self-coupling voltage regulator, a current transformer body and a temperature measuring device, the input end of the self-coupling voltage regulator is used for being connected with an external power source, and the output end of the self-coupling voltage regulator is connected with the input end of the current transformer body; the temperature measuring device is connected to the input end of the current transformer in parallel and used for detecting the working temperature of the current transformer. By adopting the wide-range current transformer and the electronic equipment, the influence of large current and high temperature environment on the normal work of the current transformer in the related technology can be solved, and the accuracy and applicability of current measurement are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of current measurement and monitoring equipment, and particularly relates to a wide-range current transformer and an electronic device. Background Art

[0002] Traditional current transformers are common sensors widely used in power systems. They are used to measure and monitor current to ensure the normal operation of the power system.

[0003] In the related art, the working principle of traditional current transformers is based on Faraday's law, and current is induced through a coil wound around an iron core. When current passes through the cable or device under test, the generated magnetic field will pass through the iron core of the current transformer, thereby inducing a proportional current.

[0004] However, when the current reaches a certain range, such as a large current of several thousand amperes or higher, the magnetic circuit of traditional current transformers will saturate, resulting in distorted output signals. Moreover, temperature conditions also affect the performance of traditional current transformers. Since traditional current transformers use an iron core as the induction element, the magnetic permeability of the iron core decreases with the increase in temperature. This means that in a high-temperature environment, the sensitivity and accuracy of traditional current transformers will be affected, resulting in unstable or incorrect output signals. Summary of the Utility Model

[0005] The embodiments of the utility model provide a wide-range current transformer, which can solve the influence of large current and high-temperature environment on the normal operation of the current transformer in the related art, and improve the accuracy and applicability of current measurement. The technical solution is as follows:

[0006] In a first aspect, the embodiments of the utility model provide a wide-range current transformer, including: an autotransformer, a current transformer, and a temperature measurement device.

[0007] The input end of the autotransformer is used to connect to an external power supply, and the output end of the autotransformer is connected to the input end of the current transformer.

[0008] The temperature measurement device is connected in parallel to the input end of the current transformer and is used to detect the operating temperature of the current transformer.

[0009] Optionally, the temperature measurement device includes a resistor-capacitor voltage division circuit and an electronic thermometer. The input end of the resistor-capacitor voltage division circuit is connected to the output end of the autotransformer, the output end of the resistor-capacitor voltage division circuit is connected to the electronic thermometer, and the resistor-capacitor voltage division circuit is used to divide the output voltage of the current transformer.

[0010] Optionally, the temperature measurement device further includes a rectifier filter circuit. The input end of the rectifier filter circuit is connected to the output end of the resistor-capacitor voltage division circuit, and the output end of the rectifier filter circuit is connected to the electronic thermometer. The rectifier filter circuit is used to convert the AC voltage into a DC voltage.

[0011] Optionally, the temperature measurement device further includes a three-terminal integrated voltage regulator circuit. The input end of the three-terminal integrated voltage regulator circuit is connected to the output end of the rectifier filter circuit, and the output end of the three-terminal integrated voltage regulator circuit is connected to the electronic thermometer.

[0012] Optionally, the rectifier filter circuit includes a bridge rectifier circuit and a filter capacitor. The input end of the bridge rectifier circuit is connected to the output end of the resistor-capacitor voltage division circuit, and the filter capacitor is disposed between the bridge rectifier circuit and the input end of the three-terminal integrated voltage regulator circuit.

[0013] Optionally, the rectifier filter circuit further includes a load resistor, and the load resistor is disposed between the filter capacitor and the input end of the three-terminal integrated voltage regulator circuit.

[0014] Optionally, a heat sink is provided on the three-terminal integrated voltage regulator circuit.

[0015] Optionally, the operating temperature range of the electronic thermometer is -50 to 200 °C.

[0016] Optionally, the electronic thermometer is a TEP11 type electronic thermometer.

[0017] In a second aspect, the present invention provides an electronic device, including the wide-range current transformer described in the first aspect above.

[0018] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0019] By using the wide-range current transformer provided by the embodiment of the present invention, a variac is provided before the input end of the current transformer 2 to pre-step down the voltage of the power supply end to be measured, reducing the voltage entering the input end of the current transformer, thereby reducing the corresponding input current, and thus improving the overall range of the current transformer. At the same time, by connecting a temperature measurement device in parallel in the current transformer circuit, while using the input current for power supply, the temperature of the current transformer and the surrounding environment is measured by the temperature measurement device, which is convenient for the tester to master the working environment temperature of the current transformer, avoiding obtaining incorrect current detection information due to overheating, and being able to reduce the influence of large current and high temperature environment on the normal operation of the current transformer in the related art, and improving the accuracy and applicability of current measurement. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 is a schematic structural diagram of a wide-range current transformer provided by an embodiment of the present invention;

[0022] Figure 2 is a schematic structural diagram of a resistor-capacitor voltage-dividing circuit provided by an embodiment of the present invention;

[0023] Figure 3 is a schematic structural diagram of a rectifier-filtering circuit provided by an embodiment of the present invention;

[0024] Figure 4 is a structural block diagram of a temperature measurement device provided by an embodiment of the present invention.

[0025] In the figure:

[0026] 1 - autotransformer; 2 - current transformer; 3 - temperature measurement device; 31 - resistor-capacitor voltage-dividing circuit; 32 - electronic thermometer; 33 - rectifier-filtering circuit; 34 - three-terminal integrated voltage regulator circuit; 331 - bridge rectifier circuit; 332 - filter capacitor; 333 - load resistor. Specific Embodiments

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail with reference to the accompanying drawings.

[0028] Figure 1 is a schematic structural diagram of a wide-range current transformer provided by an embodiment of the present invention; Figure 2 is a schematic structural diagram of a resistor-capacitor voltage-dividing circuit provided by an embodiment of the present invention; Figure 3 is a schematic structural diagram of a rectifier-filtering circuit provided by an embodiment of the present invention; Figure 4 is a structural block diagram of a temperature measurement device provided by an embodiment of the present invention. As Figures 1 to 4 shown, an embodiment of the present invention provides a wide-range current transformer, including an autotransformer 1, a current transformer 2, and a temperature measurement device 3. Among them, the input end of the autotransformer 1 is used to connect to an external power supply, and the output end of the autotransformer 1 is connected to the input end of the current transformer 2. The temperature measurement device 3 is connected in parallel to the input end of the current transformer 2 and is used to detect the operating temperature of the current transformer 2.

[0029] In the embodiment of the present utility model, compared with the traditional current transformer, an autotransformer 1 is added at the front end of the current transformer 2 for measuring the current of an external power supply, and a temperature measuring device 3 is connected in parallel in the circuit. The autotransformer includes a winding, where the primary and secondary windings are on the same line, and voltage conversion is achieved through self-coupling. In practical applications, the power supply to be measured is connected to the two input terminals 1a and 1b of the autotransformer 1 through the external ports 1A and 1B. For example, a power supply with a conventional standard voltage of 220V is connected. The winding of the autotransformer 1 adopted in this solution has more than 400 turns, and the turns ratio of the current transformer 2 is 50:1. After the voltage of the 220V power supply to be measured, 220v, is stepped down by the autotransformer 1, the voltage output from the two output terminals 1c and 1d of the autotransformer 1 to the primary side input terminal of the current transformer 2 is 0.44V. After passing through the current transformer 2, the voltage is further reduced to 0.0088V. Correspondingly, the current passing through the secondary side output terminals 2a and 2b of the current transformer 2 will also decrease accordingly. For example, the output value of this solution is 0.044A. At this time, the current transformer 2 can meet the requirements of current detection outside the detection range. At the same time, by connecting the temperature measuring device 3 in parallel in front of the input terminal of the current transformer 2, the two output terminals 1c and 1d of the autotransformer 1 can supply power to the power-consuming circuit inside the temperature measuring device 3. The temperature measuring device 3 is arranged on one side of the secondary side of the current transformer 2, and the temperature measuring device 3 is used to measure the temperature of the current transformer 2 and the surrounding environment, ensuring that it is within the normal working temperature range, which is convenient for the tester to judge the measurement accuracy of the current transformer 2.

[0030] By using the wide-range current transformer provided by the embodiment of the present utility model, an autotransformer 1 is arranged before the input terminal of the current transformer 2 to perform pre-step-down processing on the voltage of the power supply to be measured, reducing the voltage entering the input terminal of the current transformer 2, thereby reducing the corresponding input current, and thus improving the overall range of the current transformer 2. At the same time, by connecting the temperature measuring device 3 in parallel in the current transformer circuit, while using the connected current for power supply, the temperature measuring device 3 is used to measure the temperature of the current transformer 2 and the surrounding environment, which is convenient for the tester to master the working environment temperature of the current transformer 2, avoiding obtaining incorrect current detection information due to overheating, and being able to reduce the influence of large current and high temperature environment on the normal operation of the current transformer in the related art, improving the accuracy and applicability of current measurement.

[0031] Optionally, the temperature measuring device 4 includes a resistor-capacitor voltage dividing circuit 31 and an electronic thermometer 32. The input terminal of the resistor-capacitor voltage dividing circuit 31 is connected to the output terminal of the autotransformer 1, and the output terminal of the resistor-capacitor voltage dividing circuit 31 is connected to the electronic thermometer 32. The resistor-capacitor voltage dividing circuit 31 is used to divide the output voltage of the current transformer 2. Exemplarily, in the embodiment of the present utility model, asFigure 2 As shown, the U1 side is the input end of the resistor-capacitor voltage-dividing circuit 31, and U0 is the output end of the resistor-capacitor voltage-dividing circuit 31. The resistor-capacitor voltage-dividing circuit 31 realizes the voltage division output of 12V generated by the secondary side of the current transformer 2 by selecting commonly used resistors and capacitors. This circuit includes two series-connected voltage-dividing resistors R1 and R2 and series-connected voltage-dividing capacitors C1 and C2. At the same time, the voltage-dividing resistors and capacitors satisfy the relationship of R1C1 = R2C2. The resistance value of the voltage-dividing resistor R1 is 3.8 kΩ, the resistance value of R2 is 0.8 kΩ, the capacitance of the voltage-dividing capacitor C1 is 480 pF, and the capacitance of C2 is 1800 pF. This design ensures the working stability of the temperature measurement device 4.

[0032] Optionally, the temperature measurement device 4 further includes a rectifier-filtering circuit 33. The input end of the rectifier-filtering circuit 33 is connected to the output end of the resistor-capacitor voltage-dividing circuit 31, and the output end of the rectifier-filtering circuit 33 is connected to the electronic thermometer 32. The rectifier-filtering circuit 33 is used to convert the alternating voltage into a direct current voltage. Exemplarily, in the embodiment of the present invention, as Figure 3 shown, the U1 side is the input end of the rectifier-filtering circuit 33, and U0 is the output end of the rectifier-filtering circuit 33. The rectifier-filtering circuit 33 includes a bridge rectifier circuit 331, a filter capacitor 332, and a load resistor 333. The filter capacitor 332 is arranged between the bridge rectifier circuit 331 and the input end of the three-terminal integrated voltage regulator circuit 34, and the load resistor 333 is arranged between the filter capacitor 332 and the input end of the three-terminal integrated voltage regulator circuit 34. The bridge rectifier circuit 331 converts the alternating voltage passing through the resistor-capacitor voltage-dividing circuit 31 into a direct current voltage, and the filter capacitor 332 smooths the direct current voltage to reduce the fluctuation of the output voltage. In actual use, the load resistor 333 can be further connected to the output end of the rectifier-filtering circuit 33 to improve the stability of the circuit.

[0033] Optionally, the temperature measurement device 4 further includes a three-terminal integrated voltage regulator circuit 34. The input end of the three-terminal integrated voltage regulator circuit 34 is connected to the output end of the rectifier-filtering circuit 33, and the output end of the three-terminal integrated voltage regulator circuit 34 is connected to the electronic thermometer 32. Exemplarily, in the embodiment of the present invention, as Figure 4 shown, the voltage regulator circuit uses a three-terminal integrated voltage regulator circuit 34 to supply power to the temperature measurement device 4. The input end of the three-terminal integrated voltage regulator circuit 34, such as 7805, is connected to the rectifier-filtering circuit 33, and the output end is connected to the electronic thermometer 32. In order to avoid the voltage regulator circuit being affected by reverse voltage, a conducting diode can be connected in series in the middle. Further, in actual use, a heat sink can be added to 7805 to ensure that it does not overheat and burn out within its normal operating temperature range, and at the same time, it can further reduce the impact on the operation of the current transformer 2.

[0034] Optionally, the electronic thermometer 32 is a TEP11 type electronic thermometer. Exemplarily, in the embodiment of the present invention, the electronic thermometer 32 with the model number TEP11 is adopted. By virtue of its compact structure, it is beneficial to the assembly and production of the entire wide-range current transformer. At the same time, it is ensured that the operating temperature range of the electronic thermometer 32 is -50 to 200 °C, and the normal display of the test temperature can be guaranteed even under extreme temperature conditions on site.

[0035] The embodiment of the present invention also provides an electronic device, including the wide-range current transformer as Figures 1 to 4 shown. This wide-range current transformer is applicable to various industrial fields, including various positions that require large current measurement and detection in frequency converters, generators, power systems, etc. It can accurately measure large currents outside the temperature conditions and current ranges, and provide reliable operating temperature data to promote the stable operation of power equipment and systems. The overall structure is compact and the design is cost-effective, with the advantages of being easy to install and maintain, and is suitable for use in various environments.

[0036] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the specification and claims of the patent application of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. The terms such as "comprising" or "including" mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0037] The above are only optional embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wide range current transformer, characterized in that: include: An autovoltage regulator (1), a current transformer (2) and a temperature measuring device (3), The input end of the autovoltage regulator (1) is used to connect to an external power supply, and the output end of the autovoltage regulator (1) is connected to the input end of the current transformer (2); The temperature measuring device (3) is connected in parallel to the input end of the current transformer (2) and is used to detect the operating temperature of the current transformer (2).

2. The wide-range current transformer according to claim 1, characterized in that: The temperature measuring device (3) comprises a resistor-capacitor voltage divider circuit (31) and an electronic thermometer (32); the input end of the resistor-capacitor voltage divider circuit (31) is connected to the output end of the autovoltage regulator (1); the output end of the resistor-capacitor voltage divider circuit (31) is connected to the electronic thermometer (32); and the resistor-capacitor voltage divider circuit (31) is used to divide the output voltage of the current transformer (2).

3. The wide-range current transformer according to claim 2, characterized in that: The temperature measuring device (3) further comprises a rectifier and filter circuit (33), wherein an input end of the rectifier and filter circuit (33) is connected to an output end of the resistor and capacitor voltage divider circuit (31), and an output end of the rectifier and filter circuit (33) is connected to the electronic thermometer (32), and the rectifier and filter circuit (33) is used to convert an alternating current voltage into a direct current voltage.

4. The wide-range current transformer according to claim 3, characterized in that: The temperature measuring device (3) further comprises a three-terminal integrated voltage stabilizing circuit (34), the input end of the three-terminal integrated voltage stabilizing circuit (34) being connected to the output end of the rectifier filter circuit (33), and the output end of the three-terminal integrated voltage stabilizing circuit (34) being connected to the electronic thermometer (32).

5. The wide-range current transformer according to claim 4, characterized in that: The rectification and filtering circuit (33) comprises a bridge rectification circuit (331) and a filtering capacitor (332); the input end of the bridge rectification circuit (331) is connected to the output end of the resistor-capacitor voltage divider circuit (31); and the filtering capacitor (332) is arranged between the bridge rectification circuit (331) and the input end of the three-terminal integrated voltage stabilization circuit (34).

6. The wide-range current transformer according to claim 5, characterized in that: The rectification and filtering circuit (33) further comprises a load resistor (333), wherein the load resistor (333) is arranged between the filtering capacitor (332) and the input end of the three-terminal integrated voltage stabilization circuit (34).

7. The wide-range current transformer according to claim 4, characterized in that: The three-terminal integrated voltage stabilizing circuit (34) is provided with a heat sink.

8. The wide-range current transformer according to claim 2, characterized in that: The working temperature range of the electronic thermometer (32) is -50 to 200°C.

9. The wide-range current transformer according to claim 2, characterized in that: The electronic thermometer (32) is a TEP11 type electronic thermometer.

10. An electronic device, characterized in that: It comprises the wide-range current transformer as claimed in any one of claims 1 to 9.

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