Direct current system distributed capacitance searching device

Abstract

The utility model discloses a DC system distributed capacitance searching device, which relates to the technical field of substation safety and comprises a host, a finder and a mutual inductor. Wherein the signal output end of the host is connected with a bus of a direct current system to be detected, and the host is further in communication connection with the finder; the finder is connected with the mutual inductor; the host is used for injecting a target characteristic signal to a bus of the direct current system to be detected and sending the target characteristic signal to the finder; the mutual inductor is used for acquiring a detection characteristic signal of the target detection point location and sending the detection characteristic signal to the finder; the target detection point is a detection point on the DC system to be detected; and the finder is used for determining whether distributed capacitance exists in the target detection point based on the phase difference between the target characteristic signal and the detection characteristic signal. According to the utility model, the technical problem that point locations of distributed capacitors cannot be accurately positioned in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of transformer substation safety, in particular to a device and method for finding distributed capacitance of a DC system. Background Art

[0002] The DC system provides reliable DC power for control, signal, protection, automatic devices and emergency lighting in the substation. It also provides reliable operating power for operation. The reliability of the DC system plays a vital role in the safe operation of the substation and is the guarantee of the safe operation of the substation.

[0003] Distributed capacitance refers to a distributed parameter formed in a non-capacitive state. It is a capacitor with circuit distribution characteristics. The distributed capacitance of a DC system generally comes from microcomputer protection devices, insulation detection devices, cables, and filtering equipment. With the continuous expansion of the scale of substations in recent years, the distributed capacitance has also increased, causing protection misoperation and affecting the DC system grounding fault troubleshooting, which has a severe impact. However, the traditional search method for distributed capacitance in a DC system cannot accurately locate the distributed capacitance points. Utility Model Content

[0004] The purpose of the utility model is to provide a device and method for finding distributed capacitance of a DC system in order to solve at least one of the above technical problems.

[0005] In the first aspect, an embodiment of the utility model provides a device for searching for distributed capacitance in a DC system, comprising: a host, a finder and a mutual inductor; wherein the signal output end of the host is connected to the bus of the DC system to be detected, and the host is also communicatively connected to the finder; the finder is connected to the mutual inductor; the host is used to inject a target characteristic signal into the bus of the DC system to be detected, and send the target characteristic signal to the finder; the mutual inductor is used to obtain a detection characteristic signal of a target detection point, and send the detection characteristic signal to the finder; the target detection point is a detection point on the DC system to be detected; the finder is used to determine whether there is distributed capacitance at the target detection point based on the phase difference between the target characteristic signal and the detection characteristic signal.

[0006] Furthermore, the signal output terminal of the host is connected to the busbar of the DC system to be detected through a connecting line; the host is connected to the finder through wireless communication; and the finder is connected to the mutual inductor through a connecting line.

[0007] Furthermore, the host includes a first main control CPU module, a first display module, a characteristic signal module, a first communication module and a first power module; the finder includes a second main control CPU module, a second display module, a characteristic signal acquisition module, a second communication module and a second power module.

[0008] Furthermore, both the first communication module and the second communication module are WiFi modules.

[0009] Furthermore, the first main control CPU module and the second main control CPU module are both stm32 chips.

[0010] Furthermore, the characteristic signal module includes a signal generating circuit constructed with an AD9833 chip as the core, which is used to emit the target characteristic signal.

[0011] Furthermore, the characteristic signal acquisition module includes a two-stage operational amplifier circuit for performing signal tracking and signal amplification on the detection characteristic signal.

[0012] Furthermore, the mutual inductor comprises a clamp-on mutual inductor.

[0013] The utility model provides a device for finding distributed capacitance of a DC system. A host computer injects a characteristic signal into the DC system, and then a finder and a mutual inductor monitor and detect the characteristic signal of the DC system. Finally, by judging the phase difference between the detected characteristic signal and the injected characteristic signal, it is judged whether there is distributed capacitance in the DC system. The utility model can timely find and troubleshoot the distributed capacitance in the DC system of the substation, ensure the trouble-free operation of the DC system, improve the reliability of the DC system used in the substation, ensure the safe production of electric power, and alleviate the technical problem that the distributed capacitance point cannot be accurately located in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A schematic diagram of a DC system distributed capacitance search device provided by an embodiment of the utility model;

[0016] Figure 2 A schematic diagram of the hardware composition of a host provided by an embodiment of the utility model;

[0017] Figure 3A schematic diagram of the hardware composition of a finder provided in an embodiment of the utility model;

[0018] Figure 4 A partial circuit diagram of a power supply voltage stabilizing circuit of a first power supply module provided in an embodiment of the utility model;

[0019] Figure 5 A schematic diagram of a power supply circuit of a second power supply module provided in an embodiment of the utility model;

[0020] Figure 6 A circuit diagram of a first communication module and a second communication module provided in an embodiment of the utility model;

[0021] Figure 7 A circuit diagram of a first main control CPU module provided by an embodiment of the utility model;

[0022] Figure 8 A circuit diagram of a second main control CPU module provided by an embodiment of the utility model;

[0023] Fig. 9 A circuit diagram of a characteristic signal module provided by an embodiment of the utility model;

[0024] Fig.10 A circuit diagram of a characteristic signal acquisition module provided by an embodiment of the utility model;

[0025] Fig.11 A front view schematic diagram of a host provided by an embodiment of the utility model;

[0026] Fig.12 A schematic diagram of the back side of a host provided by an embodiment of the utility model;

[0027] Fig.13 A schematic diagram of the overall structure of a finder provided by an embodiment of the utility model;

[0028] Fig.14 A schematic diagram of the structure of a mutual inductor provided in an embodiment of the utility model;

[0029] Fig.15 A schematic diagram of the internal software operation flow of a device for finding distributed capacitance in a DC system provided by an embodiment of the utility model.

[0030] In the figure: 10, host, 11, first main control CPU module, 12, first display module, 13, characteristic signal module, 14, first communication module, 15, first power module, 16, operation indicator light, 17, characteristic signal access point, 18, signal indicator light, 19, switch, 110, power interface, 20, finder, 21, second main control CPU module, 22, second display module, 23, characteristic signal acquisition module, 24, second communication module, 25, second power module, 26, function key, 27, mutual inductor interface, 30, mutual inductor, 31, finder interface. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] Figure 1 Schematic diagram of a DC system distributed capacitance search device provided according to an embodiment of the utility model. Figure 1 As shown, it includes: a host 10, a finder 20 and a mutual inductor 30. Specifically, the signal output end of the host 10 is connected to the busbar of the DC system to be detected, and the host 10 is also connected to the finder 20 for communication; the finder 20 is connected to the mutual inductor 30.

[0033] Specifically, the host 10 is used to inject the target characteristic signal into the bus of the DC system to be detected, and send the target characteristic signal to the finder 20;

[0034] The mutual inductor 30 is used to obtain the detection characteristic signal of the target detection point and send the detection characteristic signal to the finder 20; wherein the target detection point is the detection point on the DC system to be detected;

[0035] The finder 20 is used to determine whether there is a distributed capacitance at the target detection point based on the phase difference between the target characteristic signal and the detection characteristic signal.

[0036] Specifically, the finder 20 compares the phases between the target characteristic signal and the detection characteristic signal, and determines that if the phase of the detection characteristic signal leads the phase of the target characteristic signal by 90°, then it determines that there is distributed capacitance at the target detection point, otherwise there is no distributed capacitance.

[0037] Preferably, in the embodiment of the utility model, the signal output end of the host 10 is connected to the bus of the DC system to be detected through a connecting line; the host 10 is connected to the finder 20 through wireless communication; the finder 20 is connected to the mutual inductor 30 through a connecting line.

[0038] Preferably, the host 10 and the finder 20 are connected via WiFi communication.

[0039] Figure 2 is a schematic diagram of the hardware composition of a host provided according to an embodiment of the utility model, Figure 3 Schematic diagram of the hardware composition of a finder provided according to an embodiment of the utility model. Figure 2 and Figure 3 As shown, the host 10 includes a first main control CPU module 11, a first display module 12, a characteristic signal module 13, a first communication module 14 and a first power supply module 15; the finder 20 includes a second main control CPU module 21, a second display module 22, a characteristic signal acquisition module 23, a second communication module 24 and a second power supply module 25.

[0040] Preferably, the first power module 15 is powered by a three-phase power supply, and the second power module 25 is powered by three AAA batteries, and both are provided with power supply voltage stabilizing circuits to ensure stable operation of other electronic circuit modules.

[0041] Figure 4 is a partial circuit diagram of a power supply voltage stabilizing circuit of a first power supply module provided according to an embodiment of the utility model, Figure 5 Schematic diagram of a power supply circuit of a second power supply module provided according to an embodiment of the utility model. Figure 4 As shown, the input of the first power supply module 15 is 24V, and a voltage-stabilized power supply circuit is designed through capacitors to output a reliable and stable 3.3V power supply.

[0042] Figure 6 1 is a circuit diagram of a first communication module and a second communication module provided according to an embodiment of the present utility model. Figure 6 As shown, the first communication module 14 and the second communication module 24 are both WiFi modules.

[0043] Preferably, the first main control CPU module 11 and the second main control CPU module 21 are both stm32 chips.

[0044] Figure 7 is a circuit diagram of a first main control CPU module provided according to an embodiment of the utility model, Figure 8 FIG. 1 is a circuit diagram of a second main control CPU module provided according to an embodiment of the utility model. Figure 7 and Figure 8As shown, the circuit of the first main control CPU module 11 uses stm32f407, 15M crystal oscillator, inductor, resistor and capacitor to form CPU and peripheral minimum circuit. The circuit of the second main control CPU module 21 uses stm32 chip, processes the data collected by the mutual inductor 30 and transmits it to the host 10 for judgment.

[0045] Fig. 9 1 is a circuit diagram of a characteristic signal module provided according to an embodiment of the utility model. Fig. 9 As shown, the characteristic signal module includes a signal generating circuit built with the AD9833 chip as the core, which is used to send out the target characteristic signal. Specifically, the characteristic signal module 13 communicates with the finder 20 through the WiFi module. The AD9833 chip is a programmable signal low-power generator chip with an operating voltage of 2.3-5.5V. It can generate a 0.1Hz-12.5MHz sine wave driven by an external 25MHz clock signal to send out a characteristic signal to find the distributed capacitance.

[0046] Fig.10 FIG. 1 is a circuit diagram of a characteristic signal acquisition module provided according to an embodiment of the utility model. Fig.10 As shown, the characteristic signal acquisition module 23 includes a secondary operational amplifier circuit for signal tracking and signal amplification of the detection characteristic signal. Specifically, the primary circuit realizes signal tracking, the secondary circuit realizes signal amplification, and communicates with the host 10 through the WiFi module to transmit the collected data to the host 10.

[0047] Preferably, the first display module 12 includes a 4.3-inch color industrial display screen, and the second display module 22 includes a 3-inch TFT color display screen with backlight.

[0048] Fig.11 is a front view of a host provided according to an embodiment of the utility model, Fig.12 1 is a schematic diagram of the back of a host provided according to an embodiment of the utility model. Fig.11 and Fig.12 As shown, a first display module 12 , an operation indicator light 16 , a characteristic signal access point 17 and a signal indicator light 18 are arranged on the front of the host 10 , and a switch 19 and a power interface 110 are arranged on the back of the host 10 .

[0049] Fig.13 is a schematic diagram of the overall structure of a finder provided according to an embodiment of the utility model, Fig.14 Schematic diagram of a transformer according to an embodiment of the present utility model. Fig.13 and Fig.14As shown, the finder 20 is a handheld device, a second display module 22 and function keys 26 are arranged on the panel, and a transformer interface 27 is arranged on the top; the transformer 30 includes a clamp-type transformer, and a finder interface 31 is arranged at the tail end of the transformer 30. The finder 20 and the transformer 30 are connected by connecting wires through the transformer interface 27 and the finder interface 31.

[0050] Fig.15 1 is a schematic diagram of the internal software operation flow of a DC system distributed capacitance search device provided according to an embodiment of the utility model. Fig.15 As shown, on the host 10, connect the characteristic signal access point 17 to the positive or negative pole of the circuit bus with a wire (only one side needs to be connected), click the "cast signal" touch key on the host 10, and the host 10 enters the "characteristic signal interface". After clicking the start touch key, the host 10 sends the characteristic signal to the bus, and sends the sending point characteristic signal data to the finder 20. At the same time, the signal indicator 18 on the host 10 starts flashing. Clicking stop will stop the host from sending the characteristic signal.

[0051] Connect the mutual inductor 30 to the finder 20, clamp the line to be detected with pliers, turn on the finder 20, press the function key 26, the finder 20 receives the information transmitted by the host 10 and the mutual inductor 30 and performs calculations, compares the phase of the host characteristic signal emission point and the phase of the detection point, if the detection point phase is 90° ahead of the host clamping point phase, it is determined that there is distributed capacitance at the detection point and displayed on the host screen, if not ahead, it is determined that there is no distributed capacitance.

[0052] From the above description, it can be seen that the DC system distributed capacitance search device provided by the embodiment of the utility model is specially used for searching the DC system distributed capacitance, solving the problem of no searching equipment for the DC system distributed capacitance; urgently searching and troubleshooting the DC system distributed capacitance, ensuring the trouble-free operation of the value flow system, improving the reliability of the station DC system, and ensuring safe production of electricity.

[0053] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0054] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A device for finding distributed capacitance of a DC system, characterized in that: include: A host, a finder and a mutual inductor; wherein the signal output terminal of the host is connected to the busbar of the DC system to be detected, and the host is also in communication connection with the finder; the finder is connected to the mutual inductor; The host is used to inject a target characteristic signal into the bus of the DC system to be detected, and send the target characteristic signal to the finder; The mutual inductor is used to obtain a detection characteristic signal of a target detection point and send the detection characteristic signal to the finder; the target detection point is a detection point on the DC system to be detected; The finder is used to determine whether there is distributed capacitance at the target detection point based on the phase difference between the target characteristic signal and the detection characteristic signal.

2. The device for finding distributed capacitance of a DC system according to claim 1, characterized in that: The signal output terminal of the host is connected to the busbar of the DC system to be detected through a connecting line; the host is connected to the finder through wireless communication; and the finder is connected to the mutual inductor through a connecting line.

3. The device for finding distributed capacitance of a DC system according to claim 1, characterized in that: The host comprises a first main control CPU module, a first display module, a characteristic signal module, a first communication module and a first power module; the finder comprises a second main control CPU module, a second display module, a characteristic signal acquisition module, a second communication module and a second power module.

4. The device for finding distributed capacitance of a DC system according to claim 3, characterized in that: The first communication module and the second communication module are both WiFi modules.

5. The device for finding distributed capacitance of a DC system according to claim 3, characterized in that: The first main control CPU module and the second main control CPU module are both stm32 chips.

6. The device for finding distributed capacitance of a DC system according to claim 3, characterized in that: The characteristic signal module includes a signal generating circuit built with an AD9833 chip as the core, which is used to emit the target characteristic signal.

7. The device for finding distributed capacitance of a DC system according to claim 3, characterized in that: The characteristic signal acquisition module includes a two-stage operational amplifier circuit, which is used to perform signal tracking and signal amplification on the detection characteristic signal.

8. The device for finding distributed capacitance of a DC system according to claim 1, characterized in that: The mutual inductor comprises a clamp-on mutual inductor.

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