Voltage reduction circuit and high-voltage direct-current voltage reduction system

Abstract

The utility model discloses a voltage reduction circuit and a high-voltage direct-current voltage reduction system, and relates to the technical field of electronic information. According to the scheme, a plurality of first resistors larger than a first preset resistance threshold value and a second resistor smaller than a second preset resistance threshold value are connected in series between the positive electrode and the negative electrode of a high-voltage direct-current power supply; a plurality of high-resistance resistors are connected in series with a low-resistance resistor, so that a common multimeter or oscilloscope can test the voltage at the two ends of a second resistor in a voltage division mode, and the output voltage of the high-voltage direct-current power supply is determined according to the voltage at the two ends of the second resistor and the resistance ratio of each first resistor to the second resistor. And whether the voltage output by the high-voltage direct-current power supply is stable or not can be judged according to the real-time acquired voltage values at the two ends of the second resistor.

Description

Technical Field

[0001] This utility model relates to the field of electronic information technology, and in particular to a voltage reduction circuit and a high-voltage DC voltage reduction system. Background Technology

[0002] With the development of technology, high voltage direct current (HVDC) circuits are widely used in fields such as renewable energy grid connection, ultra-long-distance power transmission, and cross-border power grid interconnection because they are more efficient, have lower losses, better stability, and are easier to smooth out the fluctuations of renewable energy during long-distance power transmission. However, in actual use, in order to verify whether the voltage of the HVDC circuit is stable, it is necessary to use high voltage testing instruments for measurement, but the cost of high voltage testing instruments is too high. Utility Model Content

[0003] The purpose of this invention is to provide a voltage reduction circuit and a high-voltage DC voltage reduction system. This solution connects several first resistors with a first preset resistance threshold and a second resistor with a second preset resistance threshold in series between the positive and negative terminals of a high-voltage DC power supply. In other words, several high-resistance resistors are connected in series with a low-resistance resistor. Then, by voltage division, a common multimeter or oscilloscope can test the voltage across the second resistor. The output voltage of the high-voltage DC power supply is determined by the voltage across the second resistor and the resistance ratio of each first resistor to the second resistor. Furthermore, the stability of the output voltage of the high-voltage DC power supply can be determined by the real-time acquisition of the voltage across the second resistor.

[0004] To solve the above-mentioned technical problems, this utility model provides a pressure reduction circuit, including: a plurality of first resistors and a second resistor, wherein the resistance value of the first resistors is greater than a first preset resistance threshold, the resistance value of the second resistor is less than a second preset resistance threshold, and the first preset resistance threshold is greater than the second preset resistance threshold.

[0005] Each of the first resistors is connected in series with the first common terminal connected to the positive terminal of the high voltage DC power supply, and the second common terminal is connected to the first terminal of the second resistor and the positive terminal of the voltage acquisition of the multimeter or oscilloscope, respectively.

[0006] The second end of the second resistor is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope.

[0007] Optional, also includes:

[0008] A plurality of switching devices are connected in parallel with each of the first resistors in a one-to-one correspondence. The control terminal is connected to the controller and is used to turn the device on or off according to the control of the controller.

[0009] Optional, also includes:

[0010] An autotransformer, wherein the first end of the primary winding of the autotransformer is connected to the positive terminal of the high-voltage DC power supply, the second end of the primary winding of the autotransformer is connected to the negative terminal of the high-voltage DC power supply, the first end of the secondary winding of the autotransformer is connected to the positive terminal of the voltage acquisition of a multimeter or an oscilloscope, the second end of the secondary winding of the autotransformer is connected to the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, and the control terminal of the secondary winding of the autotransformer is connected to a controller for changing the number of turns of the secondary winding of the autotransformer based on the control of the controller.

[0011] Optional, also includes:

[0012] A buck DC-DC converter, wherein the positive input terminal of the buck DC-DC converter is connected to the positive terminal of the high-voltage DC power supply, the negative input terminal is connected to the negative terminal of the high-voltage DC power supply, the positive output terminal is connected to the positive voltage acquisition terminal of the multimeter or the oscilloscope, the negative output terminal is connected to the negative voltage acquisition terminal of the multimeter or the oscilloscope, and the control terminal is connected to a controller for changing the duty cycle of the internal switching transistors of the buck DC-DC converter based on the control of the controller.

[0013] Optional, also includes:

[0014] A voltage comparison module, wherein the first input terminal of the voltage comparison module is connected to the second terminal of the second resistor, the second input terminal is connected to a preset reference voltage, and the output terminal is connected to the controller, for comparing the magnitude of the voltage across the second resistor with the preset reference voltage;

[0015] The main switch has its first end connected to the positive terminal of the high-voltage DC power supply, its second end connected to the first common terminal of each of the first resistors, and its control end connected to the controller. It is used to disconnect when the voltage across the second resistor is greater than the preset reference voltage.

[0016] Optional, also includes:

[0017] A signal isolation module, wherein the input terminal of the signal isolation module is connected to the output terminal of the voltage comparison module;

[0018] A signal amplifier, the input of which is connected to the output of the signal isolation module, and the output of which is connected to the controller.

[0019] Optional, also includes:

[0020] The first filter capacitor has its first end connected to the second common terminal of each of the first resistors and the positive voltage acquisition terminal of the multimeter or the oscilloscope, and its second end connected to the negative terminal of the high voltage DC power supply and the negative voltage acquisition terminal of the multimeter or the oscilloscope.

[0021] The first Zener diode has its cathode connected to the second common terminal of each of the first resistors and the positive voltage acquisition terminal of the multimeter or the oscilloscope, and its anode connected to the negative terminal of the high voltage DC power supply and the negative voltage acquisition terminal of the multimeter or the oscilloscope.

[0022] Optional components also include: a second filter capacitor, a first current-limiting resistor, a second current-limiting resistor, and a clamping module;

[0023] The first terminal of the second filter capacitor is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the second terminal is grounded.

[0024] The first end of the first current-limiting resistor is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, and the second end is grounded.

[0025] The first end of the clamping module is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the second end is connected to the first end of the second current limiting resistor.

[0026] The second terminal of the second current-limiting resistor is grounded.

[0027] Optionally, the clamping module includes: a second Zener diode and a third Zener diode;

[0028] The cathode of the second Zener diode is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the anode is connected to the anode of the third Zener diode.

[0029] The cathode of the third Zener diode is connected to the first end of the second current-limiting resistor.

[0030] To solve the above-mentioned technical problems, this utility model also provides a high-voltage DC voltage reduction system, including: a shell made of insulating material, a multimeter or oscilloscope, a high-voltage DC power supply, and a voltage reduction circuit as described above. The voltage reduction circuit is disposed inside the shell and is connected to the positive voltage acquisition terminal of the multimeter or oscilloscope, the negative voltage acquisition terminal of the multimeter or oscilloscope, the positive terminal of the high-voltage DC power supply, and the negative terminal of the high-voltage DC power supply, respectively.

[0031] The purpose of this invention is to provide a voltage reduction circuit and a high-voltage DC voltage reduction system. This solution connects several first resistors with a first preset resistance threshold and a second resistor with a second preset resistance threshold in series between the positive and negative terminals of a high-voltage DC power supply. In other words, several high-resistance resistors are connected in series with a low-resistance resistor. Then, by voltage division, a common multimeter or oscilloscope can test the voltage across the second resistor. The output voltage of the high-voltage DC power supply is determined by the voltage across the second resistor and the resistance ratio of each first resistor to the second resistor. Furthermore, the stability of the output voltage of the high-voltage DC power supply can be determined by the real-time acquisition of the voltage across the second resistor. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 A schematic diagram of a pressure reducing circuit provided by this utility model;

[0034] Figure 2 A schematic diagram of another pressure reduction circuit provided by this utility model;

[0035] Figure 3 This is a schematic diagram showing the positions of a pressure-reducing circuit and an insulating shell provided by this utility model. Detailed Implementation

[0036] The core of this utility model is to provide a voltage reduction circuit and a high-voltage DC voltage reduction system. This solution connects several first resistors with a first preset resistance threshold and a second resistor with a second preset resistance threshold in series between the positive and negative terminals of the high-voltage DC power supply. That is, several high-resistance resistors are connected in series with a low-resistance resistor. Then, by voltage division, a common multimeter or oscilloscope can test the voltage across the second resistor. The output voltage of the high-voltage DC power supply is determined by the voltage across the second resistor and the resistance ratio of each first resistor to the second resistor. Furthermore, the stability of the output voltage of the high-voltage DC power supply can be determined by the real-time acquisition of the voltage across the second resistor.

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0038] Please refer to Figure 1 , Figure 1 This utility model provides a structural schematic diagram of a pressure reducing circuit. The pressure reducing circuit includes: several first resistors 1 and one second resistor 2. The resistance value of the first resistors 1 is greater than a first preset resistance threshold, and the resistance value of the second resistor 2 is less than a second preset resistance threshold. The first preset resistance threshold is greater than the second preset resistance threshold.

[0039] Each of the first resistors 1 is connected in series with the first common terminal connected to the positive terminal of the high voltage DC power supply, and the second common terminal is connected to the first terminal of the second resistor 2 and the positive terminal of the voltage acquisition of the multimeter or oscilloscope respectively.

[0040] The second end of the second resistor 2 is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition device of a multimeter or oscilloscope.

[0041] In this invention, considering that existing technologies require specialized high-voltage testing instruments to verify the stability of a high-voltage DC circuit, but these instruments are too expensive, this solution aims to enable the use of ordinary multimeters or oscilloscopes to detect the voltage of the high-voltage DC circuit and thus verify its stability. Therefore, this solution includes several first resistors 1 and one second resistor 2, where the first resistors 1 are high-resistance resistors and the second resistors 2 are low-resistance resistors. This solution allows for voltage division, enabling ordinary multimeters or oscilloscopes to directly acquire the voltage across the second resistor 2. The output voltage of the high-voltage DC power supply can be determined based on the resistance ratio of each first resistor 1 to the second resistor 2, and the stability of the high-voltage DC power supply output voltage can be judged by the real-time acquisition of the voltage across the second resistor 2.

[0042] This embodiment provides a voltage reduction circuit. This solution connects several first resistors 1 with a first preset resistance threshold and a second resistor 2 with a second preset resistance threshold in series between the positive and negative terminals of a high-voltage DC power supply. In other words, several high-resistance resistors are connected in series with a low-resistance resistor. Then, by voltage division, a common multimeter or oscilloscope can test the voltage across the second resistor 2. The output voltage of the high-voltage DC power supply is determined by the voltage across the second resistor 2 and the resistance ratio of each first resistor 1 to the second resistor 2. Furthermore, the stability of the output voltage of the high-voltage DC power supply can be determined by the real-time acquisition of the voltage value across the second resistor 2.

[0043] Based on the above embodiments:

[0044] As an optional embodiment, it also includes:

[0045] Several switching devices are connected in parallel to each of the first resistors 1. The control terminal is connected to the controller and is used to turn the device on or off according to the controller's control.

[0046] In this invention, considering that different multimeters or oscilloscopes have different voltage measurement ranges, several switching devices are added to allow for flexible connection to different multimeters or oscilloscopes. Each switching device is connected in parallel with the corresponding first resistor 1. The controller can select to turn on or off any number of switching devices according to the voltage measurement range of the multimeter or oscilloscope to be connected, so that the multimeter or oscilloscope can measure the voltage across the second resistor 2, thereby improving the applicability of the solution.

[0047] It should be noted that, as Figure 2 As shown, the number of first resistors 1 can be 15, as long as the voltage across the second resistor 2 meets the voltage acquisition requirements of a multimeter or oscilloscope. This application does not impose any special limitation on the number of first resistors 1. For example, when the number of first resistors 1 is 15, the resistance of the first resistor 1 is 100MΩ, and the resistance of the second resistor 2 is 300KΩ, the output voltage of the high-voltage DC power supply, after being divided by each of the first resistors 1 and the second resistor 2, has an attenuation ratio of 1:5KV. When the output voltage of the high-voltage DC power supply is 100000V, the voltage across the second resistor 2 is 20V.

[0048] As an optional embodiment, it also includes:

[0049] An autotransformer has its primary winding connected to the positive terminal of a high-voltage DC power supply, and its secondary winding connected to the negative terminal of a high-voltage DC power supply. The primary winding's first terminal is connected to the positive terminal of a multimeter or oscilloscope, and its secondary winding's second terminal is connected to the negative terminal. The secondary winding's control terminal is connected to a controller, allowing for control-based changes in the number of turns in the secondary winding.

[0050] In this invention, considering that existing technologies require specialized high-voltage testing instruments to verify the stability of high-voltage DC circuit voltage, but these instruments are too expensive, this solution aims to enable ordinary multimeters or oscilloscopes to detect the voltage of the high-voltage DC circuit and verify its stability. Therefore, this solution also includes an autotransformer. The primary winding voltage of the autotransformer is the output voltage of the high-voltage DC power supply, and the secondary winding voltage is the actual voltage acquired by the multimeter or oscilloscope. Furthermore, the autotransformer can adjust the number of turns in its secondary winding according to the controller's control, thereby changing the turns ratio between the primary and secondary windings and flexibly adjusting the secondary winding voltage to meet the acquisition requirements of the multimeter or oscilloscope. This allows ordinary multimeters or oscilloscopes to test the voltage across the second resistor 2, and the stability of the high-voltage DC power supply output voltage can be determined by the real-time voltage value acquired across the second resistor 2.

[0051] As an optional embodiment, it also includes:

[0052] A buck DC-DC converter has its positive input terminal connected to the positive terminal of a high-voltage DC power supply, its negative input terminal connected to the negative terminal of the high-voltage DC power supply, its positive output terminal connected to the positive terminal of a multimeter or oscilloscope for voltage acquisition, its negative output terminal connected to the negative terminal of a multimeter or oscilloscope for voltage acquisition, and its control terminal connected to a controller for changing the duty cycle of the internal switching transistors of the buck DC-DC converter based on the controller's control.

[0053] In this invention, considering that existing technologies require specialized high-voltage testing instruments to verify the stability of high-voltage DC circuit voltages, but these instruments are too expensive, this solution aims to enable ordinary multimeters or oscilloscopes to detect the voltage of high-voltage DC circuits and thus verify their stability. Therefore, this solution includes a step-down DC-DC converter. This converter reduces the voltage output from the high-voltage DC power supply to a preset value, successfully meeting the voltage acquisition requirements of the multimeter or oscilloscope. Furthermore, the step-down converter can adjust the duty cycle of its internal switching transistors based on controller control to flexibly adjust the voltage value after step-down output. This solution considers the different voltage measurement ranges of various multimeters or oscilloscopes; therefore, by adding a step-down DC-DC converter, the practicality of the solution is improved.

[0054] As an optional embodiment, it also includes:

[0055] The voltage comparison module has its first input terminal connected to the second terminal of the second resistor 2, the second input terminal connected to a preset reference voltage, and its output terminal connected to the controller. It is used to compare the voltage across the second resistor 2 with the preset reference voltage.

[0056] The main switch has its first terminal connected to the positive terminal of the high-voltage DC power supply, its second terminal connected to the first common terminal of each of the first resistors 1, and its control terminal connected to the controller. It is used to disconnect when the voltage across the second resistor 2 is greater than the preset reference voltage.

[0057] This invention also includes a voltage comparison module and a main switch. The voltage comparison module compares the voltage across the second resistor 2 with a preset reference voltage. The comparison result determines whether the resistance values ​​of the first resistor 1 and the second resistor 2 are set appropriately. For example, if the voltage across the second resistor 2 is greater than the preset reference voltage, it indicates that the resistance values ​​of the first resistor 1 and the second resistor 2 are not set appropriately. In this case, the main switch needs to be turned off so that the user or operator can promptly detect any abnormalities in the voltage reduction circuit and adjust the resistance values ​​of the first resistor 1 and the second resistor 2 to ensure that the voltage across the second resistor 2 after adjustment is not greater than the preset reference voltage. This allows the user or operator to measure the voltage of the circuit containing the high-voltage DC power supply using only a common multimeter or oscilloscope.

[0058] It should be noted that in practical applications, the voltage comparison module can be a comparator, an operational amplifier circuit, or other devices with voltage comparison functions.

[0059] As an optional embodiment, it also includes:

[0060] The signal isolation module has its input terminal connected to the output terminal of the voltage comparison module.

[0061] The signal amplifier's input is connected to the output of the signal isolation module, and its output is connected to the controller.

[0062] In this invention, considering that the voltage comparison module needs to transmit the comparison result between the voltage across the second resistor 2 and the preset reference voltage to the controller in the form of a signal so that the controller can accurately control whether the main switch is closed based on the comparison result, and because the signal is easily interfered with by environmental factors during transmission, thus affecting the accuracy of the signal transmission, this solution adds a signal isolation module and a signal amplifier to ensure that the voltage comparison signal can be transmitted stably. The signal isolation module isolates the signal transmitted by the voltage comparison module from the actual high-voltage DC circuit, and the signal amplifier amplifies the signal output by the voltage comparison module, thereby improving the anti-interference capability of the signal and ensuring that the signal can be transmitted stably to the controller, thus improving the stability of the solution.

[0063] It should be noted that because the input and output of an optocoupler are isolated from each other, and the electrical signal transmission is unidirectional, it has good electrical insulation and anti-interference capabilities. Therefore, optocouplers are used as signal isolation modules in practical applications to greatly improve the stability of signal transmission.

[0064] As an optional embodiment, it also includes:

[0065] The first filter capacitor C1 has its first end connected to the second common terminal of each first resistor 1 and the positive terminal of the voltage acquisition of a multimeter or oscilloscope, and its second end connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope.

[0066] The first Zener diode Z1 has its cathode connected to the second common terminal of each of the first resistors 1 and the positive terminal of the voltage acquisition of a multimeter or oscilloscope, and its anode connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope.

[0067] In this invention, considering that the power transmission in the circuit where the high-voltage DC power supply is located may be affected by environmental factors, leading to instability during power transmission, a first filter capacitor C1 is added to filter out interference in the power output of the high-voltage DC power supply, thereby improving the stability of the power transmission process.

[0068] It should be noted that, in practical applications, to improve the safety of the voltage reduction circuit, a protection module can also be set in the voltage reduction circuit. For example, the first terminal of the protection module is connected to the positive terminal of the high-voltage DC power supply, and the second terminal is connected to the first common terminal of each of the first resistors 1. This module is used to disconnect the circuit when the voltage value of the circuit containing the high-voltage DC power supply exceeds a preset voltage threshold or the current value of the circuit containing the high-voltage DC power supply exceeds a preset current threshold. That is, when an overvoltage or overcurrent occurs in the circuit, the circuit is disconnected in time to protect the electronic components, the high-voltage DC power supply, and the downstream load in the voltage reduction circuit. The protection module can be a fuse, circuit breaker, or other circuit element that can provide protection; this application does not impose any specific limitations on this.

[0069] As an optional embodiment, it also includes: a second filter capacitor C2, a first current-limiting resistor R1, a second current-limiting resistor R2, and a clamping module;

[0070] The first terminal of the second filter capacitor C2 is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope, and the second terminal is grounded.

[0071] The first terminal of the first current-limiting resistor R1 is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope, and the second terminal is grounded.

[0072] The first terminal of the clamping module is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope, respectively, and the second terminal is connected to the first terminal of the second current limiting resistor R2.

[0073] The second terminal of the second current-limiting resistor R2 is grounded.

[0074] In this invention, considering that ordinary multimeters or oscilloscopes need to ensure that the voltage of the circuit being tested is stable within a preset range when performing voltage detection, this solution adds a clamping module to clamp the voltage of the circuit containing the high-voltage DC power supply within the preset voltage range. This satisfies the testing requirements of ordinary multimeters or oscilloscopes while ensuring the safety of the voltage reduction circuit. Furthermore, considering that excessive current in the circuit containing the high-voltage DC power supply can affect the safety of the entire voltage reduction circuit and may even burn out components, this solution adds a first current-limiting resistor R1 and a second current-limiting resistor R2. These resistors reduce the current value in the circuit containing the high-voltage DC power supply. Additionally, considering that the power transmission in the circuit containing the high-voltage DC power supply may be affected by environmental factors, leading to instability during power transmission, this solution adds a second filter capacitor C2. This capacitor filters out interference during power transmission, improving the stability of the power transmission process.

[0075] As an optional embodiment, the clamping module includes: a second Zener diode Z2 and a third Zener diode Z3;

[0076] The cathode of the second Zener diode Z2 is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of a multimeter or oscilloscope, respectively, and the anode is connected to the anode of the third Zener diode Z3.

[0077] The cathode of the third Zener diode Z3 is connected to the first end of the second current-limiting resistor R2.

[0078] In this invention, considering that the reverse connection of two Zener diodes can clamp the voltage, and that the clamping module composed of two Zener diodes is small in size and low in cost, this solution uses the reverse-connected second Zener diode Z2 and third Zener diode Z3 as the clamping module to clamp the voltage of the circuit where the high-voltage DC power supply is located within the preset voltage range. This can meet the testing requirements of ordinary multimeters or oscilloscopes, and also ensure the safety of the voltage reduction circuit.

[0079] This utility model also provides an embodiment of a high-voltage DC voltage reduction system, including: a shell made of insulating material, a multimeter or oscilloscope, a high-voltage DC power supply, and a voltage reduction circuit as described above. The voltage reduction circuit is disposed inside the shell and is connected to the positive and negative terminals of the multimeter or oscilloscope, the positive terminal and the negative terminal of the high-voltage DC power supply, respectively.

[0080] The high-voltage DC voltage reduction system provided in this embodiment corresponds to the voltage reduction circuit described above, and therefore has the same beneficial effects as the voltage reduction circuit described above. Therefore, for the embodiment of the high-voltage DC voltage reduction system, please refer to the description of the embodiment of the voltage reduction circuit, which will not be repeated here.

[0081] It should be noted that the insulating material constituting the casing can be epoxy resin or other materials with insulating properties, and the voltage reduction circuit is built into the casing. The casing needs to have pre-reserved positive and negative input terminals for connecting to the high-voltage DC power supply, as well as pre-reserved positive and negative test terminals for connecting to a multimeter or oscilloscope. Figure 3 As shown, Figure 3 The attenuation plate resistor in the circuit is a voltage reduction circuit.

[0082] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage reduction circuit, characterized in that, include: A plurality of first resistors and a second resistor, wherein the resistance value of the first resistors is greater than a first preset resistance value threshold, the resistance value of the second resistor is less than a second preset resistance value threshold, and the first preset resistance value threshold is greater than the second preset resistance value threshold. Each of the first resistors is connected in series with the first common terminal connected to the positive terminal of the high voltage DC power supply, and the second common terminal is connected to the first terminal of the second resistor and the positive terminal of the voltage acquisition of the multimeter or oscilloscope, respectively. The second end of the second resistor is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope.

2. The voltage reduction circuit as described in claim 1, characterized in that, Also includes: A plurality of switching devices are connected in parallel with each of the first resistors in a one-to-one correspondence. The control terminal is connected to the controller and is used to turn the device on or off according to the control of the controller.

3. The voltage reduction circuit as described in claim 1, characterized in that, Also includes: An autotransformer, wherein the first end of the primary winding of the autotransformer is connected to the positive terminal of the high-voltage DC power supply, the second end of the primary winding of the autotransformer is connected to the negative terminal of the high-voltage DC power supply, the first end of the secondary winding of the autotransformer is connected to the positive terminal of the voltage acquisition of a multimeter or an oscilloscope, the second end of the secondary winding of the autotransformer is connected to the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, and the control terminal of the secondary winding of the autotransformer is connected to a controller for changing the number of turns of the secondary winding of the autotransformer based on the control of the controller.

4. The voltage reduction circuit as described in claim 1, characterized in that, Also includes: A buck DC-DC converter, wherein the positive input terminal of the buck DC-DC converter is connected to the positive terminal of the high-voltage DC power supply, the negative input terminal is connected to the negative terminal of the high-voltage DC power supply, the positive output terminal is connected to the positive voltage acquisition terminal of the multimeter or the oscilloscope, the negative output terminal is connected to the negative voltage acquisition terminal of the multimeter or the oscilloscope, and the control terminal is connected to a controller for changing the duty cycle of the internal switching transistors of the buck DC-DC converter based on the control of the controller.

5. The voltage reduction circuit as described in claim 1, characterized in that, Also includes: A voltage comparison module, wherein the first input terminal of the voltage comparison module is connected to the second terminal of the second resistor, the second input terminal is connected to a preset reference voltage, and the output terminal is connected to the controller, for comparing the magnitude of the voltage across the second resistor with the preset reference voltage; The main switch has its first end connected to the positive terminal of the high-voltage DC power supply, its second end connected to the first common terminal of each of the first resistors, and its control end connected to the controller. It is used to disconnect when the voltage across the second resistor is greater than the preset reference voltage.

6. The voltage reduction circuit as described in claim 5, characterized in that, Also includes: A signal isolation module, wherein the input terminal of the signal isolation module is connected to the output terminal of the voltage comparison module; A signal amplifier, the input of which is connected to the output of the signal isolation module, and the output of which is connected to the controller.

7. The voltage reduction circuit as described in claim 1, characterized in that, Also includes: The first filter capacitor has its first end connected to the second common terminal of each of the first resistors and the positive voltage acquisition terminal of the multimeter or the oscilloscope, and its second end connected to the negative terminal of the high voltage DC power supply and the negative voltage acquisition terminal of the multimeter or the oscilloscope. The first Zener diode has its cathode connected to the second common terminal of each of the first resistors and the positive voltage acquisition terminal of the multimeter or the oscilloscope, and its anode connected to the negative terminal of the high voltage DC power supply and the negative voltage acquisition terminal of the multimeter or the oscilloscope.

8. The voltage reduction circuit according to any one of claims 1 to 7, characterized in that, Also includes: Second filter capacitor, first current limiting resistor, second current limiting resistor, clamping module; The first terminal of the second filter capacitor is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the second terminal is grounded. The first end of the first current-limiting resistor is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, and the second end is grounded. The first end of the clamping module is connected to the negative terminal of the high voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the second end is connected to the first end of the second current limiting resistor. The second terminal of the second current-limiting resistor is grounded.

9. The voltage reduction circuit as described in claim 8, characterized in that, The clamping module includes: a second Zener diode and a third Zener diode; The cathode of the second Zener diode is connected to the negative terminal of the high-voltage DC power supply and the negative terminal of the voltage acquisition of the multimeter or the oscilloscope, respectively, and the anode is connected to the anode of the third Zener diode. The cathode of the third Zener diode is connected to the first end of the second current-limiting resistor.

10. A high-voltage direct current voltage reduction system, characterized in that, include: The device comprises an outer casing made of insulating material, a multimeter or oscilloscope, a high-voltage DC power supply, and a voltage reduction circuit as described in any one of claims 1 to 9, wherein the voltage reduction circuit is disposed within the outer casing and is connected to the positive voltage acquisition terminal, the negative voltage acquisition terminal, the positive terminal, and the negative terminal of the high-voltage DC power supply, respectively.

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