DC voltage and current superposition impulse voltage test loop with protection device

Abstract

The utility model discloses a DC voltage and current superposition impulse voltage test loop with a protection device, and belongs to the technical field of electrical equipment. Comprising an impulse voltage source, a direct current source, an isolation device, a test object, a direct current voltage source, a blocking capacitor and a protection resistor. The impulse voltage source is connected with one end of the blocking capacitor, and the other end of the blocking capacitor is connected with the test object; the other end of the blocking capacitor is connected with one end of the protective resistor; the other end of the protective resistor is connected with a direct-current voltage source; the direct current source is connected with the test object through the isolation device; the isolation device comprises an isolation switch and a grounding switch. The isolating switch comprises a first insulator, a moving contact, a static contact, a switch base and a second insulator; and the moving contact is connected with the static contact. According to the utility model, multiple protection mechanisms are introduced, extra-high voltage grade equipment is tested, a reliable guarantee basis is provided for long-term live operation of an extra-high voltage electric appliance test object, and the risk of power grid operation is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical equipment, and particularly relates to a DC voltage, current superimposed impulse voltage test circuit with a protection device. Background Art

[0002] With the continuous expansion of the UHV AC transmission project and UHV DC transmission project of power grid companies, as an important part of power grid construction, intelligent substations put forward more stringent requirements for the safe, reliable and efficient operation of electrical equipment. Intelligent substations adopt advanced communication technologies, automation technologies and intelligent devices, realizing real-time monitoring, automatic regulation and intelligent control of the power grid, and significantly improving the operation efficiency and safety of the power grid.

[0003] Although the annual accident rate and failure rate of electrical equipment show a downward trend, the actual operation conditions and type test data indicate that many accidents or failures still stem from the instability of equipment reliability. Equipment reliability not only concerns the safe and stable operation of the power grid, but also directly affects the economic benefits and social reputation of power companies. Therefore, when selecting electrical equipment, power companies tend to choose products that have been verified by long-term grid operation and have good reliability and stability.

[0004] However, for new products of many manufacturers, especially products at the UHV level, due to their technical complexity and risk, it is difficult to directly obtain the opportunity of grid operation. This poses a great challenge for power companies when selecting these products, resulting in the long-term reliability of the equipment not being fully verified before it is put into operation, thus increasing the risk of power grid operation. Content of the Utility Model

[0005] Aiming at the problem in the prior art that for equipment at the UHV level, its long-term reliability cannot be fully verified before it is put into operation, thus increasing the risk of power grid operation. The utility model provides a DC voltage, current superimposed impulse voltage test circuit with a protection device, which tests equipment at the UHV level by introducing multiple protection mechanisms, provides a reliable guarantee basis for the long-term live operation of UHV electrical test samples, and reduces the risk of power grid operation.

[0006] In order to achieve the above object, the utility model provides the following technical solutions.

[0007] A DC voltage, current superposition impulse voltage test circuit with a protection device, comprising an impulse voltage source, a DC current source, an isolation device, a test sample, a DC voltage source, a DC-blocking capacitor and a protection resistor; the impulse voltage source is connected to one end of the DC-blocking capacitor, and the other end of the DC-blocking capacitor is connected to the test sample; the other end of the DC-blocking capacitor is connected to one end of the protection resistor; the other end of the protection resistor is connected to the DC voltage source; the DC current source is connected to the test sample through the isolation device; the isolation device includes a disconnecting switch and an earthing switch; the disconnecting switch includes a first insulator, a moving contact, a static contact, a switch base and a second insulator; the moving contact is connected to the static contact; the upper end of the first insulator is connected to the moving contact, and the lower end of the first insulator is connected to one end of the switch base; the upper end of the second insulator is connected to the static contact, and the lower end of the second insulator is connected to the other end of the switch base; the earthing switch includes a knife-switch mechanism and a knife-switch; the knife-switch mechanism is arranged below the switch base, and the knife-switch is installed in the upper-end area of the switch base.

[0008] Preferably, it further includes a universal voltage divider; the universal voltage divider is arranged between the test sample and the protection resistor.

[0009] Preferably, the DC current source includes a rectifying device, a voltage regulator, a generator and a motor; one end of the rectifying device is connected to the test sample, the other end of the current rectifying device is connected to one end of the voltage regulator, the other end of the voltage regulator is connected to the generator, and the generator is connected to the motor.

[0010] Preferably, an insulating drive rod is arranged between the generator and the motor.

[0011] Preferably, the disconnecting switch further includes a first wiring board and a second wiring board; the first wiring board is connected to the moving contact; the second wiring board is connected to the static contact.

[0012] Preferably, the first wiring board serves as one side of the isolation device, and the second wiring board serves as the other side of the isolation device.

[0013] Preferably, the isolation device further includes a vertical connecting rod and an operating mechanism box; the lower end of the vertical connecting rod is installed on the upper surface of the operating mechanism box, and the upper end of the vertical connecting rod is connected to the switch base; the operating mechanism box is located on the side of the knife-switch mechanism.

[0014] Preferably, the isolation device further includes a knife-switch connecting rod; the knife-switch connecting rod is installed in the upper-end area of the switch base; one end of the knife-switch connecting rod is connected to the knife-switch, and the other end of the knife-switch connecting rod is connected to the knife-switch mechanism.

[0015] Preferably, the impulse voltage source includes an impulse voltage generator and a weak-damping voltage divider.

[0016] Preferably, the DC voltage source includes a DC voltage generator, a grounding circuit, and a resistor divider.

[0017] Compared with the prior art, the present utility model has the following beneficial effects:

[0018] Through the design of the DC-blocking capacitor and the protection resistor, the present utility model effectively isolates the DC voltage and the impulse voltage, avoids the mutual influence and damage between voltage sources, and improves the safety of the test process. The DC-blocking capacitor has little influence on the superimposed voltage waveform and good impulse conduction ability, ensuring the accuracy of the test results. At the same time, the optimized design of the protection resistor also improves the stability and reliability of the test. Therefore, the present utility model is applicable to the testing of test specimens with different voltage levels and current levels, and has strong adaptability and flexibility. In addition, the test circuit design in the present utility model is simple and clear, and the operation is easy to perform, reducing the operation difficulty and working intensity of the test personnel. Therefore, the present utility model provides a reliable guarantee basis for the long-term live operation of UHV electrical test specimens. By simulating the voltage and current conditions in the actual operation environment, the performance and reliability of the test specimens can be evaluated more accurately. Through strict testing and evaluation, UHV electrical equipment with excellent performance and high reliability can be selected, thereby reducing the failure rate and risk in the power grid operation caused by equipment damage or failure. Description of the Drawings

[0019] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present utility model in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to assist in the understanding of the present utility model, rather than specifically limiting the shapes and proportional dimensions of the components of the present utility model. In the drawings:

[0020] Figure 1 is a schematic diagram of a DC voltage, current superimposed impulse voltage test circuit with a protection device according to the present utility model;

[0021] Figure 2 is a structural schematic diagram of a DC current source in a DC voltage, current superimposed impulse voltage test circuit with a protection device according to the present utility model;

[0022] Figure 3 is a structural schematic diagram of an isolation device in a DC voltage, current superimposed impulse voltage test circuit with a protection device according to the present utility model.

[0023] In the figure: 101 is an impulse voltage source; 102 is a DC current source; 103 is an isolation device; 104 is a test specimen; 105 is a general voltage divider; 106 is a DC voltage source; 107 is a DC-blocking capacitor; 108 is a protective resistor; 201 is a rectifying device; 202 is a voltage regulator; 203 is a generator; 204 is a motor; 1 is a first terminal block; 2 is a second terminal block; 3 is a first insulator; 4 is a moving contact; 5 is a static contact; 6 is a switch base; 7 is a vertical connecting rod; 8 is an earthing switch mechanism; 9 is an operating mechanism box; 10 is a second insulator; 11 is an earthing switch connecting rod; 12 is an earthing switch. Detailed implementation manners

[0024] In order to enable those skilled in the art of the present technology to better understand the technical solutions in the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0025] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present utility model. The terms used in the description of the present utility model in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] Aiming at the problem that in the prior art, the long-term reliability of ultra-high voltage grade equipment cannot be fully verified before it is put into operation, thus increasing the risk of power grid operation. The present utility model provides a DC voltage, current and impulse voltage superposition test circuit with a protection device.

[0028] As Figure 1As shown in the figure, a DC voltage, current superimposed impulse voltage test circuit with a protection device of the present utility model includes an impulse voltage source 101, a DC current source 102, an isolation device 103, a test sample 104, a general voltage divider 105, a DC voltage source 106, a DC-blocking capacitor 107, and a protection resistor 108.

[0029] The impulse voltage source 101, the test sample 104, and the DC voltage source 106 are connected in parallel. The test sample 104 is also connected to the DC current source 102, and an isolation device 103 is provided between the DC current source 102 and the test sample 104.

[0030] A general voltage divider 105 is also connected in parallel between the test sample 104 and the DC voltage source 106, and a protection resistor 108 is provided between the general voltage divider 105 and the DC voltage source 106.

[0031] A DC-blocking capacitor 107 is provided between the impulse voltage source 101 and the test sample 104.

[0032] One end of the DC-blocking capacitor 107 is connected to the impulse voltage source 101 through a copper wire. The other end of the DC-blocking capacitor 107 is connected to one end of the test sample 104, the high-voltage end of the general voltage divider 105, and one end of the protection resistor 108. The other end of the protection resistor 108 is connected to the DC voltage source 106. The DC current source 102 is connected in parallel across the two ends of the test sample 104 through the isolation device 103.

[0033] The impulse voltage source 101 includes an impulse voltage generator and a weakly damped voltage divider connected in parallel.

[0034] The DC voltage source 106 includes a DC voltage generator, a grounding circuit, and a resistance voltage divider. After the DC voltage generator is connected in series with the protection resistor 108, it is connected in parallel with the grounding circuit and the resistance voltage divider.

[0035] The high-voltage end of the impulse voltage generator is connected to one end of the DC-blocking capacitor 107 and one end of the weakly damped voltage divider at the same time. The other end of the DC-blocking capacitor 107 is connected to one end of the test sample 104 and one end of the protection resistor 108 at the same time. The other end of the protection resistor 108 is connected to the resistance voltage divider of the impulse voltage source 101. The DC current source 102 is connected in parallel across the two ends of the test sample 104 through the isolation device 103.

[0036] The general voltage divider 105 is connected in parallel with the test sample 104.

[0037] The voltage of the weakly damped voltage divider, the voltage of the general voltage divider 105, and the voltage of the resistance voltage divider are measured by a multi-channel measuring instrument.

[0038] The impulse voltage generator includes a charging capacitor, an impulse voltage generator protection resistor, and a charging resistor. One end of the charging capacitor is connected to one end of the sphere gap trigger device of the impulse voltage generator. The other end of the sphere gap trigger device of the impulse voltage generator is connected to one end of the impulse voltage generator protection resistor and one end of the charging resistor. The other end of the charging resistor is connected to one end of the DC-blocking capacitor 107 and one end of the underdamped voltage divider. The other end of the impulse voltage generator protection resistor is connected to the other end of the charging capacitor and then connected to the other end of the underdamped voltage divider.

[0039] The underdamped voltage divider includes a damping resistor, a high-voltage arm capacitor, and a low-voltage arm capacitor. One end of the damping resistor is connected to the other end of the charging resistor and one end of the DC-blocking capacitor 107. The other end of the damping resistor is connected to one end of the high-voltage arm capacitor. The other end of the high-voltage arm capacitor is connected to one end of the low-voltage arm capacitor. The other end of the low-voltage arm capacitor is connected to the other end of the impulse voltage generator protection resistor and the low-voltage end of the test sample 104.

[0040] The DC voltage generator includes a transformer, two capacitors, a transformer protection resistor, two silicon stacks, and an equipment protection resistor. The high-voltage end of the equipment protection resistor is connected to the high-voltage end of the grounding circuit. The other end of the equipment protection resistor is connected to one end of the first capacitor and the high-voltage end of the first silicon stack. The other end of the first capacitor is connected to the high-voltage end of the second silicon stack and one end of the transformer protection resistor. The other end of the transformer protection resistor is connected in series with one end of the transformer. The other end of the transformer is connected in series with one end of the second capacitor. The other end of the second capacitor is connected to the low-voltage ends of the two silicon stacks.

[0041] The grounding circuit includes a discharge resistor and a grounding switch connected in series. The resistor voltage divider includes a high-voltage arm resistor and a low-voltage arm resistor connected in series. The high-voltage end of the discharge resistor is connected to the high-voltage end of the protection resistor 108, the high-voltage end of the high-voltage arm resistor, and the high-voltage end of the equipment protection resistor. The low-voltage end of the discharge resistor is connected to one end of the grounding switch. The other end of the grounding switch is connected to the low-voltage end of the low-voltage arm resistor, the low-voltage ends of the two silicon stacks, and the other end of the second capacitor.

[0042] The general-purpose voltage divider 105 includes a high-voltage arm resistor, a low-voltage arm resistor, a high-voltage arm capacitor, a low-voltage arm capacitor, and a digital voltmeter. The high-voltage arm resistor and the high-voltage arm capacitor are connected in parallel to form the high-voltage arm. The low-voltage arm resistor, the low-voltage arm capacitor, and the digital voltmeter are connected in parallel to form the low-voltage arm. The high-voltage end after the high-voltage arm and the low-voltage arm are connected in series is connected to one end of the test sample 104. The low-voltage end after the high-voltage arm and the low-voltage arm are connected in series is grounded; The multi-channel measuring instrument is specifically used to measure the voltage between the high-voltage arm resistor and the low-voltage arm resistor, the voltage across the low-voltage arm capacitor, the voltage of the digital voltmeter, the voltage between the high-voltage arm capacitor and the low-voltage arm capacitor, and the voltage between the high-voltage arm resistor and the low-voltage arm resistor.

[0043] Such asFigure 2 As shown in the figure, the DC current source 102 includes a rectifying device 201, a voltage regulator 202, a generator 203, and a motor 204.

[0044] One end of the rectifying device 201 is connected to the test sample 104, the other end of the current loading device 201 is connected to one end of the voltage regulator 202, the other end of the voltage regulator 202 is connected to the generator 203, and the generator 203 is also connected to the motor 204.

[0045] The motor 204 drives the generator 203 to operate through an insulating transmission rod. Then, the alternating current is rectified into direct current through the voltage regulator 202 and the rectifying device 201, and is connected to one end of the isolation device 103 through a copper busbar. The other end of the isolation device 103 is connected to both ends of the test sample 104.

[0046] As Figure 3 shown, the isolation device 103 includes a disconnector switch and an earthing switch for earthing one side of the disconnector switch.

[0047] The disconnector switch includes a first terminal board 1, a second terminal board 2, a first insulator 3, a moving contact 4, a static contact 5, a switch base 6, a vertical connecting rod 7, an operating mechanism box 9, and a second insulator 10.

[0048] The first terminal board 1 serves as one side of the isolation device 103, the second terminal board 2 serves as the other side of the isolation device 103. The first terminal board 1 is connected to the moving contact 4, the second terminal board 2 is connected to the static contact 5, the upper end of the first insulator 3 is connected to the moving contact 4, the upper end of the second insulator 10 is connected to the static contact 5, the lower ends of the first insulator 3 and the second insulator 10 are fixedly connected to the switch base 6, the lower end of the vertical connecting rod 7 is installed on the upper surface of the operating mechanism box 9, and the vertical connecting rod 7 can drive the moving contact 4 to contact or disconnect from the static contact 5 under the control of the operating mechanism box 9.

[0049] The earthing switch includes an earthing knife mechanism 8, an earthing knife connecting rod 11, and an earthing knife 12. The earthing knife mechanism 8 is arranged at the lower part of the switch base 6 and is located on the side of the operating mechanism box 9. The earthing knife connecting rod 11 and the earthing knife 12 are assembled at the upper end of the switch base 6. One end of the earthing knife connecting rod 11 is connected to the earthing knife 12, and the other end of the earthing knife connecting rod 11 is connected to the static contact 5. During use, the earthing knife mechanism 8 can drive the earthing knife connecting rod 11, and further drive the earthing knife 12 to contact or disconnect from the static contact 5.

[0050] The earthing knife mechanism 8 is earthed and is operated through the operating mechanism box 9.

[0051] In this utility model, by adding an isolation device 103, a DC-blocking capacitor 107, and a protection resistor 108 to the DC voltage superimposed impulse voltage test circuit, when the test sample 104 operates with zero load and live outdoors for a long time, the disconnector in the isolation device 103 is disconnected and the grounding knife is closed to isolate and protect the DC current source 102. When it is necessary to operate with high load and live, closing the disconnector and separating the grounding knife can meet the requirements of the test circuit, improving work efficiency and protecting the equipment, so as not to affect the test progress due to equipment damage, providing a reliable guarantee for the long-term live operation of UHV electrical test samples.

[0052] In summary, in this utility model, an impulse voltage source 101 is used as the device for generating impulse voltage. By connecting one end of the DC-blocking capacitor 107, it ensures that the impulse voltage can be accurately and stably applied to the test sample 104. The other end of the DC-blocking capacitor 107 is connected to the test sample 107, and its main function is to isolate the DC voltage and prevent the DC voltage from having an adverse effect on the impulse voltage source 101. In addition, the design of the DC-blocking capacitor 107 also takes into account its advantages such as small influence on the superimposed voltage waveform and good impulse conduction ability, ensuring the accuracy of the test results. The protection resistor 108 is located between the other end of the DC-blocking capacitor 107 and the DC voltage source 106, and its main function is to reduce the influence of the impulse voltage on the DC voltage generator and protect the DC voltage source 106 from being damaged by the impulse voltage. The DC voltage source 106 is connected to the test sample 104 through the protection resistor 108 to provide a stable DC voltage for the test sample 104. The cooperation of the DC voltage source 106 and the protection resistor 108 ensures the stable application of the DC voltage and avoids the interference of the DC voltage on the impulse voltage source 101.

[0053] The DC current source 102 is connected to the test sample 104 through the isolation device 103 to provide a DC current for the test sample 104. The design of the isolation device 103 ensures the stable application of the DC current and avoids the influence of the DC current on other parts of the test circuit. The test sample 104 is a key part of the test circuit and is used to test its performance under the superimposed action of DC voltage, current, and impulse voltage. Through this test circuit, the insulation performance and voltage withstand capacity of the test sample 104 can be comprehensively evaluated.

[0054] Upon reading the above description, many embodiments and many applications other than the provided examples will be obvious to those skilled in the art. Therefore, the scope of this teaching should not be determined with reference to the above description, but should be determined with reference to the full scope of the foregoing claims and the equivalents thereof. For the sake of completeness, all articles and references, including the disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to abandon such subject matter, nor should the applicant be regarded as not considering such subject matter as part of the disclosed utility model subject matter.

[0055] The above content is a further detailed description of the present utility model. It cannot be determined that the specific implementation manner of the present utility model is limited thereto. For those of ordinary skill in the technical field to which the present utility model pertains, without departing from the concept of the present utility model, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope determined by the claims submitted for the present utility model.

Claims

1. A DC voltage, current superposition impulse voltage test circuit with a protection device, characterized in that, It includes an impulse voltage source (101), a DC current source (102), an isolating device (103), a test specimen (104), a DC voltage source (106), a DC-blocking capacitor (107), and a protective resistor (108); The impulse voltage source (101) is connected to one end of the DC-blocking capacitor (107), and the other end of the DC-blocking capacitor (107) is connected to the test specimen (104); The other end of the DC-blocking capacitor (107) is connected to one end of the protective resistor (108); The other end of the protective resistor (108) is connected to the DC voltage source (106); The DC current source (102) is connected to the test specimen (104) through the isolating device (103); The isolating device (103) includes a disconnector and an earthing switch; The disconnector includes a first insulator (3), a moving contact (4), a static contact (5), a switch base (6), and a second insulator (10); The moving contact (4) is connected to the static contact (5); The upper end of the first insulator (3) is connected to the moving contact (4), and the lower end of the first insulator (3) is connected to one end of the switch base (6); The upper end of the second insulator (10) is connected to the static contact (5), and the lower end of the second insulator (10) is connected to the other end of the switch base (6); The earthing switch includes a knife-switch mechanism (8) and a knife (12); The knife-switch mechanism (8) is arranged at the lower part of the switch base (6), and the knife (12) is installed in the upper-end area of the switch base (6).

2. The DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, wherein It also includes a universal voltage divider (105); The universal voltage divider (105) is arranged between the test specimen (104) and the protective resistor (108).

3. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The DC current source (102) includes a rectifying device (201), a voltage regulator (202), a generator (203), and a motor (204); One end of the rectifying device (201) is connected to the test specimen (104), the other end of the current rectifying device (201) is connected to one end of the voltage regulator (202), the other end of the voltage regulator (202) is connected to the generator (203), and the generator (203) is connected to the motor (204).

4. A DC voltage, current, and superimposed impulse voltage test circuit with a protection device according to claim 3, characterized in that An insulating drive rod is arranged between the generator (203) and the motor (204).

5. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The disconnector also includes a first terminal board (1) and a second terminal board (2); The first terminal board (1) is connected to the moving contact (4); The second terminal board (2) is connected to the static contact (5).

6. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 5, characterized in that, The first terminal board (1) serves as one side of the isolating device (103), and the second terminal board (2) serves as the other side of the isolating device (103).

7. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The isolating device (103) also includes a vertical connecting rod (7) and an operating mechanism box (9); The lower end of the vertical connecting rod (7) is installed on the upper surface of the operating mechanism box (9), and the upper end of the vertical connecting rod (7) is connected to the switch base (6); The operating mechanism box (9) is located on the side of the knife-switch mechanism (8).

8. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The isolating device (103) also includes a knife connecting rod (11); The knife connecting rod (11) is installed in the upper-end area of the switch base (6); One end of the grounding knife connecting rod (11) is connected to the grounding knife (12), and the other end of the grounding knife connecting rod (11) is connected to the grounding knife mechanism (8).

9. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The impulse voltage source (101) includes an impulse voltage generator and a weakly damped voltage divider.

10. A DC voltage, current superposition impulse voltage test circuit with a protection device according to claim 1, characterized in that, The DC voltage source (106) includes a DC voltage generator, a grounding circuit, and a resistive voltage divider.

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