High-isolation voltage-resistant direct current sensor, preparation method and application

Abstract

The invention discloses a high-isolation voltage-withstanding direct current sensor, a preparation method and application, and the sensor comprises a plurality of sampling resistors which are disposed on a PCB and convert a to-be-measured high voltage into a small current signal; the coil winding is arranged in the PCB, the coil winding comprises multiple turns of coils, the multiple turns of coils are formed by winding with the center penetrating hole in the PCB as the center, and the small current signals are amplified through the coil winding and detected by the magnetic ring penetrating through the center of the center penetrating hole in the PCB; and the current module is used for detecting the current output by the magnetic ring to obtain a required signal. High voltage is converted into small current signals, the mode that the coil winding and the magnetic ring are arranged on the PCB for induction is adopted, current amplification and detection are achieved, meanwhile, signal isolation of the high-voltage end and the low-voltage end is achieved, isolation of a power source does not need to be considered, only signal isolation is needed, isolation withstand voltage can be high enough, and the high-isolation withstand voltage requirement is met.

Description

Technical Field

[0001] The present application belongs to the field of high voltage detection technology, and specifically relates to a high isolation and withstand voltage DC sensor, a preparation method and an application, which is suitable for detecting situations where the DC input voltage is tens of thousands of volts and the isolation withstand voltage is required to be above AC40KV. Background Art

[0002] There are three main technologies used in existing high-voltage and high-isolation sensors: the first is a voltage sensor based on the Hall principle, the second is a modulation and demodulation voltage sensor based on digital isolation, and the third is a magnetic modulation voltage sensor based on a coreless planar transformer.

[0003] Among the above three technologies, the voltage sensor based on the Hall principle has low cost, but has disadvantages such as high power consumption, large temperature drift, and low voltage resistance. Its isolation voltage resistance is generally around AC10KV. The modulation and demodulation voltage sensor based on digital isolation has the advantages of high accuracy and low temperature drift, but it needs to consider power isolation, and the cost is relatively high. In addition, transformer isolation is used, and the maximum isolation voltage resistance is around AC18.5KV. The magnetic modulation voltage sensor based on the coreless planar transformer has the advantages of high accuracy and low temperature drift, but it also needs to consider voltage isolation, and the cost is relatively high. In addition, planar transformer isolation is used, and the maximum isolation voltage resistance is AC20KV.

[0004] Therefore, the isolation withstand voltage performance of existing technologies is limited and cannot meet higher isolation withstand voltage requirements, such as AC40KV isolation withstand voltage requirements. Summary of the invention

[0005] In order to solve the problem that the isolation and voltage resistance performance of existing voltage sensors is limited and cannot meet higher isolation and voltage resistance requirements, the present application proposes a high isolation and voltage resistance DC sensor, a preparation method and an application. The present application converts high voltage into a small current signal and adopts the built-in coil winding and magnetic ring induction method on the PCB board to realize current amplification and detection. At the same time, the built-in coil winding and magnetic ring on the PCB board realize signal isolation between the high voltage end and the low voltage end, and there is no need to consider the isolation of the power supply. That is, the present application adopts a passive input method for isolation, and only requires signal isolation. The isolation and voltage resistance can be high enough to meet the high isolation and voltage resistance requirements.

[0006] This application is implemented through the following technical solutions:

[0007] A high isolation and withstand voltage DC sensor, the high isolation and withstand voltage DC sensor comprising:

[0008] A plurality of sampling resistors are arranged on the PCB board, and the plurality of sampling resistors convert the high voltage to be measured into a small current signal;

[0009] A coil winding built into the PCB board, the coil winding comprising a plurality of turns of coil, and the plurality of turns of coil are wound around a through hole on the PCB board as a center, the small current signal is amplified by the coil winding and detected by a magnetic ring passing through the center of the through hole on the PCB board;

[0010] And, a current module, wherein the current module detects the current output by the magnetic ring to obtain a required signal.

[0011] In some implementations, the number of the sampling resistors is determined according to the high voltage to be measured and the expected value of the small current signal.

[0012] In some implementations, the number of turns of the coil winding is determined according to the amplification factor of the small current signal.

[0013] In some implementations, the current module uses a leakage current principle or a fluxgate principle to perform current detection.

[0014] In some embodiments, the PCB board is a multi-layer board, and the coil winding is formed by winding the PCB in the multi-layer board.

[0015] In some embodiments, the magnetic ring is located at the center of the through hole of the PCB board, and there is an insulation distance that meets the requirements between the magnetic ring and the PCB board.

[0016] In some embodiments, the magnetic ring is an open magnetic ring with an insulating ceramic sheath disposed outside.

[0017] In some embodiments, the sensor is integrally potted with a potting compound.

[0018] In a second aspect, the present application proposes a method for preparing the above-mentioned high isolation withstand voltage DC sensor, the preparation method comprising:

[0019] The PCB board is prepared by using a multilayer board, a through hole that meets the insulation requirements is prepared on the PCB board as a through hole, and a wire is wound in the multilayer board with the through hole as the center to form a multi-turn coil winding;

[0020] Arranging a plurality of sampling resistors on the PCB board, wherein the plurality of sampling resistors are connected in series with two ends of the coil winding to form a signal loop;

[0021] The magnetic ring is passed through the center of the through hole, and the output end of the magnetic ring is connected to the input end signal of the current module, and the output end of the current module serves as the signal output end of the sensor;

[0022] The sensor is potted as a whole.

[0023] In a third aspect, the present application proposes a high voltage detection device, which uses the above-mentioned high isolation withstand voltage DC sensor to detect high voltages of 10,000 volts and requiring an isolation withstand voltage of more than AC40KV.

[0024] Compared with the prior art, this application has the following advantages and beneficial effects:

[0025] The present application proposes a high isolation and withstand voltage DC sensor, preparation method and application, which realizes current amplification and detection by converting high voltage into a small current signal and adopting the built-in coil winding and magnetic ring induction method on the PCB board. At the same time, the built-in coil winding and magnetic ring on the PCB board realize signal isolation between the high voltage end and the low voltage end, and there is no need to consider the isolation of the power supply. That is, the present application adopts a passive input method for isolation, and the isolation withstand voltage can be high enough to meet the high isolation withstand voltage requirements of more than AC40KV.

[0026] A high-isolation withstand-voltage DC sensor, preparation method and application proposed in the present application can save the area of ​​the PCB board and realize winding with a sufficient number of turns within a limited area by performing PCB winding in a multilayer board for coil winding;

[0027] The present application proposes a high isolation and withstand voltage DC sensor, preparation method and application, which achieves high isolation strength between the magnetic ring and the PCB board by ensuring the isolation strength between the magnetic ring and the PCB board. For example, the diameter size of the through hole of the PCB board is set to ensure that there is a sufficient insulation distance between the magnetic ring and the PCB board, and an insulating ceramic sheath is set on the outside of the magnetic ring, thereby meeting the high isolation and withstand voltage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0029] Figure 1 This is a schematic diagram of a DC sensor according to an embodiment of the present application;

[0030] Figure 2 This is a schematic diagram of the DC sensor structure of an embodiment of the present application;

[0031] Figure 3 A schematic diagram of a DC sensor model according to an embodiment of the present application;

[0032] Figure 4 This is a flow chart of the preparation method of an embodiment of the present application.

[0033] Reference numerals and corresponding component names:

[0034] 1-PCB board, 2-sampling resistor, 3-coil winding, 4-through hole, 5-magnetic ring, 6-current module. DETAILED DESCRIPTION

[0035] Hereinafter, the term "include" or "may include" used in various embodiments of the present application indicates the presence of the invented function, operation or element, and does not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present application, the terms "include", "have" and their cognates are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items.

[0036] In various embodiments of the present application, the expression "or" or "at least one of A or / and B" includes any combination or all combinations of the words listed at the same time. For example, the expression "A or B" or "at least one of A or / and B" may include A, may include B, or may include both A and B.

[0037] The expressions (such as "first", "second", etc.) used in the various embodiments of the present application may modify the various constituent elements in the various embodiments, but may not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used for the purpose of distinguishing one element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of the present application, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0038] It should be noted that if it is described that one component element is “connected” to another component element, the first component element may be directly connected to the second component element, and a third component element may be “connected” between the first component element and the second component element. Conversely, when one component element is “directly connected” to another component element, it can be understood that there is no third component element between the first component element and the second component element.

[0039] The terms used in the various embodiments of the application are only used to describe the purpose of specific embodiments and are not intended to limit the various embodiments of the application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise limited, all terms used here (including technical terms and scientific terms) have the same meaning as the meanings commonly understood by ordinary technicians in the field of the various embodiments of the application. The terms (such as the terms defined in the dictionary generally used) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in the various embodiments of the application.

[0040] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with examples and drawings. The illustrative implementation scheme of the present application and its description are only used to explain the present application and are not intended to limit the present application.

[0041] Example:

[0042] The existing voltage sensors based on the Hall principle are low in cost, but have disadvantages such as high power consumption, large temperature drift, and low voltage resistance. The isolation voltage resistance is generally around AC10KV. The modulation and demodulation voltage sensor based on digital isolation has the advantages of high precision and low temperature drift, but it is necessary to consider power supply isolation, which is relatively expensive. In addition, transformer isolation is used, and the maximum isolation voltage resistance is around AC18.5KV. The magnetic modulation voltage sensor based on the coreless planar transformer has the advantages of high precision and low temperature drift, but it is also necessary to consider voltage isolation, which is relatively expensive. In addition, planar transformer isolation is used, and the maximum isolation voltage resistance is around AC20KV. Therefore, the isolation and voltage resistance performance of the existing high-voltage isolation sensors are limited, and cannot meet the high isolation and voltage resistance requirements of AC40KV. In view of this, this embodiment proposes a high isolation and voltage resistance DC sensor, such as Figure 1 As shown, the high isolation withstand voltage DC sensor proposed in this embodiment converts a high voltage of 10,000 volts into a small current signal through a number of sampling resistors. The small current signal is amplified by the multi-turn coil winding on the PCB board, and is detected by the through-core magnetic ring induction. Finally, the fluxgate detection principle is used for detection, and the required signal is output. This embodiment only realizes signal isolation between the high-voltage end and the low-voltage end through the built-in coil winding and magnetic ring on the PCB board, and does not need to consider the isolation of the power supply. That is, this embodiment uses a passive input method for isolation, and the withstand voltage isolation can be high enough to meet the isolation and withstand voltage requirements of more than AC40KV.

[0043] like Figure 2-Figure 3 As shown, the high isolation withstand voltage DC sensor proposed in this embodiment specifically includes:

[0044] A plurality of sampling resistors 2 are arranged on the PCB board 1, wherein the plurality of sampling resistors 2 convert the high voltage to be measured into a small current signal. It should be noted that the number of sampling resistors 2 is set or selected according to actual needs, and is usually determined by the high voltage to be measured and the small current signal. The small current signal is defined as a current signal less than or equal to 1 mA.

[0045] The coil winding 3 built into the PCB board 1 includes a multi-turn coil, which is wound around the through hole 4 on the PCB board 1. The small current signal is amplified by the coil winding and detected by the magnetic ring 5 passing through the center of the through hole on the PCB board 1. Several sampling resistors are connected in series with both ends of the multi-turn coil winding to form a loop. The open end receives the high voltage to be measured. The sampling resistor converts the high voltage to be measured into a small current signal. The small current signal flows through the multi-turn coil winding for signal amplification. It should be noted that the number of turns of the coil winding 3 is related to the current amplification factor. For example, the high voltage is converted into a 1mA current signal (i.e., a small current signal) through several series-connected sampling resistors. If a 5A DC signal is to be obtained, the number of turns of the coil winding 3 needs to be 5000 turns.

[0046] And, a current module 6, which uses a leakage current principle or a fluxgate principle to detect the current output by the magnetic ring to obtain a required signal.

[0047] This embodiment converts high voltage into a small current signal, and adopts the built-in coil winding and magnetic ring induction method on the PCB board to realize current amplification and detection. At the same time, the built-in coil winding and magnetic ring on the PCB board realize signal isolation between the high voltage end and the low voltage end, and there is no need to consider the isolation of the power supply. That is, this embodiment adopts a passive input method for isolation, and the isolation withstand voltage can be high enough to meet the high isolation withstand voltage requirements of more than AC40KV.

[0048] In an optional implementation, the PCB board 1 is a multilayer board, and the coil winding is formed by winding the PCB in the multilayer board, which can save the area of ​​the PCB board 1 and achieve a sufficient number of turns of winding within a limited area. Furthermore, the surface of the PCB board 1 is insulated. Among them, the PCB winding is a copper wire wound with multiple turns to form a winding. In addition, the winding inside the PCB can achieve physical insulation through the surface PCB medium. The insulation capacity can be further improved by potting glue and other methods to meet the high isolation and withstand voltage requirements.

[0049] In an optional embodiment, the magnetic ring 5 is located at the center of the through hole 4 of the PCB board 1, and a sufficient insulation distance is maintained between the magnetic ring 5 and the PCB board 1 to ensure isolation strength, that is, the diameter of the through hole 4 of the PCB board 1 is set according to the magnetic ring 5 and the insulation distance between the magnetic ring 5 and the PCB board 1.

[0050] In an optional implementation, an insulating ceramic sheath is provided outside the magnetic ring 5 to enhance insulation protection and further improve insulation strength.

[0051] In an optional implementation manner, the sensor is integrally potted with potting glue to further improve the insulation strength.

[0052] In an optional implementation manner, the magnetic ring 5 may be, but is not limited to, an open magnetic ring. In another optional implementation manner, a closed magnetic ring may also be used.

[0053] The fluxgate detection principle adopted by the current module is based on the fluxgate effect. When the magnetic induction intensity reaches saturation, the magnetic permeability of the magnetic medium will change, resulting in a change in the magnetic flux. This change is similar to a "gate". Through this "gate", the corresponding magnetic flux is modulated and generates an induced electromotive force. By using this phenomenon, the magnetic field generated by the current can be measured, thereby indirectly measuring the current. It should be noted that the current module in this embodiment can use an existing current detection device, which will not be described in detail here.

[0054] The high isolation and withstand voltage DC sensor proposed in this embodiment adopts a voltage-to-current through-core detection structure, and its withstand voltage index exceeds that of existing voltage sensors, meeting the requirements of high isolation and withstand voltage AC40KV and above.

[0055] This embodiment also proposes a method for preparing a high isolation and withstand voltage DC sensor, such as Figure 4 As shown, the preparation method proposed in this embodiment specifically includes:

[0056] A PCB board 1 is prepared by using a multilayer board, a through hole with a preset size is prepared on the PCB board as a through hole 4, and a multi-turn coil winding 3 is formed by winding around the through hole 4 as the center of the circle in the multilayer board; it should be noted that the number of turns of the coil winding is related to the amplification factor of the small current signal, that is, the number of turns of the coil winding can be determined according to the amplification factor of the small current. The diameter of the through hole is determined by the size of the magnetic ring and the insulation distance between the magnetic ring and the PCB board, that is, the diameter of the through hole needs to meet the requirement of having a sufficient insulation distance between the magnetic ring and the PCB board.

[0057] A plurality of sampling resistors 2 are arranged on the PCB board 1 and are connected in series with both ends of the multi-turn coil winding 3 to form a signal loop; it should be noted that the number of sampling resistors is mainly determined according to the expected values ​​of the high voltage and small current signals to be measured.

[0058] The magnetic ring 5 passes through the center of the through hole 4, and the output end of the magnetic ring 5 is connected to the input end signal of the current module, and the output end of the current module serves as the signal output end of the sensor.

[0059] Finally, the sensor is potted as a whole (for example, potting is performed by using potting glue), thereby completing the preparation of the entire sensor.

[0060] This embodiment also provides a high voltage detection device, which uses the above-mentioned high isolation withstand voltage DC sensor to detect high voltages of 10,000 volts and requiring an isolation withstand voltage of more than AC40KV.

[0061] This embodiment also proposes a high voltage detection method, which uses the above-mentioned high isolation withstand voltage DC sensor to detect a high voltage of 10,000 volts and requiring an isolation withstand voltage of more than AC40KV. The specific detection method includes:

[0062] The 10,000-volt high voltage is converted into a low current signal through the sampling resistor 2 of the sensor;

[0063] The small current signal is amplified by the coil winding 3 and is sensed and output by the magnetic ring 5 passing through the through hole 4 of the PCB board 1;

[0064] The current module 6 detects the output current induced by the magnetic ring 5 and outputs the required signal.

[0065] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A high isolation withstand voltage DC sensor, characterized in that: The high isolation and withstand voltage DC sensor comprises: A plurality of sampling resistors are arranged on the PCB board, and the plurality of sampling resistors convert the high voltage to be measured into a small current signal; A coil winding built into the PCB board, the coil winding comprising a plurality of turns of coil, and the plurality of turns of coil are wound around a through hole on the PCB board as a center, the small current signal is amplified by the coil winding and detected by a magnetic ring passing through the center of the through hole on the PCB board; And, a current module, wherein the current module detects the current output by the magnetic ring to obtain a required signal.

2. A high isolation withstand voltage DC sensor according to claim 1, characterized in that: The number of the sampling resistors is determined according to the high voltage to be measured and the expected value of the small current signal.

3. A high isolation withstand voltage DC sensor according to claim 1, characterized in that: The number of turns of the coil winding is determined according to the amplification factor of the small current signal.

4. The high isolation withstand voltage DC sensor according to claim 1, characterized in that: The current module uses leakage current principle or fluxgate principle to perform current detection.

5. A high isolation withstand voltage DC sensor according to any one of claims 1 to 4, characterized in that: The PCB board is a multi-layer board, and the coil winding is formed by winding the PCB in the multi-layer board.

6. A high isolation withstand voltage DC sensor according to any one of claims 1 to 4, characterized in that: The magnetic ring is located at the center of the through hole of the PCB board, and there is an insulation distance that meets the requirements between the magnetic ring and the PCB board.

7. A high isolation withstand voltage DC sensor according to any one of claims 1 to 4, characterized in that: The magnetic ring is an open type magnetic ring, and an insulating ceramic sheath is arranged outside.

8. A high isolation withstand voltage DC sensor according to any one of claims 1 to 4, characterized in that: The sensor is integrally potted with potting glue.

9. A method for preparing a high isolation withstand voltage DC sensor according to any one of claims 1 to 8, characterized in that: The preparation method comprises: The PCB board is prepared by using a multilayer board, a through hole that meets the insulation requirements is prepared on the PCB board as a through hole, and a wire is wound in the multilayer board with the through hole as the center to form a multi-turn coil winding; Arranging a plurality of sampling resistors on the PCB board, wherein the plurality of sampling resistors are connected in series with two ends of the coil winding to form a signal loop; The magnetic ring is passed through the center of the through hole, and the output end of the magnetic ring is connected to the input end signal of the current module, and the output end of the current module serves as the signal output end of the sensor; The sensor is potted as a whole.

10. A high voltage detection device, characterized in that: The high voltage detection device uses the high isolation withstand voltage DC sensor described in any one of claims 1 to 8 to detect high voltages of 10,000 volts and requiring an isolation withstand voltage of more than AC40KV.

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