A relay protection export pressure plate monitoring device

Abstract

The present invention discloses a monitoring device for a relay protection outlet pressure plate, comprising: a signal sending device for monitoring the negative voltage amplitude to ensure the safe operation of relay protection operation and maintenance, and a signal receiving device for monitoring the received negative voltage amplitude and the injection signal strength to ensure the safe operation of relay protection operation and maintenance. The present invention solves the problem that the existing relay protection operation and maintenance methods have hidden defects resulting in frequent occurrence of protection refusal and misoperation accidents through a monitoring device for a relay protection outlet pressure plate, and ensures the safe operation of relay protection operation and maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection operation and maintenance, and in particular to a relay protection outlet pressure plate monitoring device. Background Art

[0002] The deployment and retraction of outlet pressure plates is an effective means of relay protection operation and maintenance. However, in actual operation, hidden defects such as false deployment due to abnormal aging of the pressure plate structure and incorrect or missed deployment due to improper operation and maintenance often lead to protection failure and misoperation accidents, seriously threatening the safe and reliable operation of the power grid. Implementing online monitoring and intelligent alarms for the relay protection outlet circuit can eliminate major safety hazards in power grid operation caused by false, incorrect, or missed deployment of pressure plates, reduce the workload of operation and maintenance personnel, and improve the quality and efficiency of operation and inspection management.

[0003] The circuit where the relay protection outlet pressure plate is located is a DC secondary circuit. During normal operation, there is no DC current. Defects such as false tripping, erroneous tripping, or missed tripping of the relay protection outlet pressure plate are very hidden and difficult for operators to detect during routine inspections. To solve these problems, online monitoring of the outlet pressure plate's energized state or electrical conductivity is necessary. Existing non-electrical quantity monitoring methods such as integrated pressure plates, wired sensors, radio frequency sensors, robot image recognition, dual pressure plates, and micro switch sensors can only monitor the pressure plate's position, but cannot monitor the outlet pressure plate's energized state. They are unable to identify hidden faults such as broken backplane terminals of spring-type pressure plates, detached connecting bolts and terminals, and false connections of continuous-piece pressure plates, where the pressure plate appears to be engaged but is actually disconnected.

[0004] Therefore, in order to ensure the safe operation of relay protection operation and maintenance, and to solve the technical problems that the existing relay protection operation and maintenance methods have hidden defects that lead to frequent protection refusal and false operation accidents, it is urgent to construct a relay protection outlet pressure plate monitoring device. Summary of the Invention

[0005] The present invention provides a relay protection outlet pressure plate monitoring device, which is used to solve the problem that the existing relay protection operation and maintenance method has hidden defects that lead to frequent protection refusal and malfunction accidents.

[0006] The present invention provides a relay protection outlet pressure plate monitoring device, which includes a signal sending device and a signal receiving device connected to each other;

[0007] The signal sending device is used to monitor the negative voltage amplitude to ensure the safe operation of the relay protection operation and maintenance;

[0008] The signal receiving device is used to monitor the received negative voltage amplitude and the injection signal strength to ensure the safe operation of the relay protection operation and maintenance;

[0009] The signal sending device includes a power voltage monitoring module, a power conversion module, a signal output channel and an MCU micro control unit that are interconnected;

[0010] The power voltage monitoring module is used to monitor the negative voltage amplitude;

[0011] The power conversion module is used to convert the power voltage;

[0012] The signal output channel is used to ensure the safe operation of relay protection operation and maintenance;

[0013] The MCU micro control unit is used to regulate the signal sending device.

[0014] Optionally, the signal output channel includes a first control relay, a signal source, and a first resistor connected in sequence;

[0015] The first control relay is used to combine the signal source and the resistor to ensure the safe operation of relay protection operation and maintenance;

[0016] The signal source is used to combine the first control relay and the resistor to ensure the safe operation of relay protection operation and maintenance;

[0017] The first resistor is used to combine the signal source and the first control relay to ensure the safe operation of relay protection operation and maintenance.

[0018] Optionally, the signal receiving device includes a master control unit and a plurality of detection modules connected in sequence;

[0019] The master control unit is used to monitor the received negative voltage amplitude to ensure the safe operation of relay protection operation and maintenance;

[0020] The detection module is used to measure the intensity of the received injection signal to ensure the safe operation of relay protection operation and maintenance.

[0021] Optionally, the master control unit is electrically connected to the detection module through an RS485 communication interface.

[0022] Optionally, the master control unit is contact-mounted on the pressure plate.

[0023] Optionally, the master control unit is also used to supply power to the detection module and receive information on whether the detection module is allowed to be put into use, and to obtain the connection status between the master control unit and the pressure plate.

[0024] Optionally, the master control unit is an RT1062 embedded processor of NXP.

[0025] Optionally, the detection module includes an MCU micro-control sub-unit, as well as a monitoring channel, a detection and delivery long-term connection line, and an on-board indicator light, which are respectively connected to the MCU micro-control sub-unit;

[0026] The monitoring channel is used to obtain the injection signal and measure the intensity of the injection signal;

[0027] The MCU micro-control sub-unit is used to regulate the detection module;

[0028] The detection and delivery long-term connection line is used to detect whether the detection module is allowed to be used for delivery in the long term;

[0029] The on-board indicator light is used to indicate the connection status between the MCU micro-control sub-unit and the monitoring channel.

[0030] Optionally, the monitoring channel includes a second control relay, a second resistor, and a circuit amplifier that are connected to each other;

[0031] The second control relay is used to combine the second resistor and the circuit amplifier to obtain and measure the injection signal;

[0032] The second resistor is used to combine the second control relay and the circuit amplifier to obtain and measure the injection signal;

[0033] The circuit amplifier is used to combine the second control relay and the second resistor to obtain and measure the injection signal.

[0034] It can be seen from the above technical solutions that the present invention has the following advantages:

[0035] A monitoring device for a relay protection export pressure plate according to the present invention, the relay protection export pressure plate monitoring device includes a signal sending device and a signal receiving device that are connected to each other. The signal sending device is used to monitor the negative voltage amplitude to ensure the safe operation of relay protection operation and maintenance. The signal receiving device is used to monitor the received negative voltage amplitude and the injection signal intensity to ensure the safe operation of relay protection operation and maintenance.

[0036] The relay protection operation and maintenance are monitored through the signal sending device and the signal receiving device to ensure the safe operation of the relay protection operation and maintenance. Through a relay protection export pressure plate monitoring device, the safety of the relay protection operation and maintenance is improved, and the technical problem that the existing relay protection operation and maintenance methods have hidden defects resulting in frequent occurrence of protection refusal and misoperation accidents is solved, ensuring the safe operation of the relay protection operation and maintenance. Description of the Drawings

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings;

[0038] Figure 1 It is a structural block diagram of an embodiment of a relay protection outlet pressure plate monitoring device of the present invention;

[0039] Figure 2 It is a schematic circuit diagram of an on-line monitoring technology for relay protection outlet pressure plates of the present invention;

[0040] Figure 3 It is a structural block diagram of a signal sending device in a relay protection outlet pressure plate monitoring device of the present invention;

[0041] Figure 4 It is a structural block diagram of a signal receiving device in a relay protection outlet pressure plate monitoring device of the present invention;

[0042] Figure 5 It is a structural block diagram of a detection module in a signal receiving device of the present invention;

[0043] Figure 6 It is a wiring schematic diagram of the sampling line of the detection module in a signal receiving device of the present invention;

[0044] Figure 7 It is a front view of the installation of a signal sending device of the present invention;

[0045] Figure 8 It is a structural diagram of a signal receiving device of the present invention;

[0046] Figure 9 It is a rear view of a signal receiving device of the present invention. Detailed implementation manners

[0047] The following will clearly and completely describe the technical solutions of the present application in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0048] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] Unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application.

[0050] See also Figure 1 , Figure 1 101 is a signal sending device, and 102 is a signal receiving device; the signal sending device 101 and the signal receiving device 102 are connected to each other;

[0051] The signal sending device 101 is used to monitor the negative voltage amplitude to ensure the safe operation of the relay protection operation and maintenance;

[0052] The signal receiving device 102 is used to monitor the received negative voltage amplitude and the injection signal strength to ensure the safe operation of the relay protection operation and maintenance.

[0053] Specifically, see Figure 2 , Figure 2 This is a schematic diagram of the circuit principle for online monitoring of the relay protection outlet pressure plate. This method essentially reflects the pressure plate's engagement and disengagement status by testing the continuity of the tripping and closing circuit. In theory, the continuity of the tripping circuit (pressure plate position, holding relay, coil, and protection outlet relay) can also be evaluated online by monitoring changes in the strength of the received signal.

[0054] In different states of the circuit breaker, the tripping circuit and the closing circuit are quite different:

[0055] 1) Circuit breaker closed state;

[0056] A. When the normally open contact of the trip circuit DL is closed, the detection module can receive the AC signal sent by the bus negative signal source. The signal path is:

[0057] Negative bus signal source → normally open contact of DL closed → TBJ → upper terminal of the pressure plate → pressure plate connection piece → lower terminal of the pressure plate. The total path impedance is about 200 ohms.

[0058] B. The normally closed contact of DL in the closing circuit is open, and the detection module cannot receive the AC signal sent by the negative bus signal source, so the online monitoring of the closing pressure plate status cannot be carried out.

[0059] 2) Circuit breaker in the open state;

[0060] A. The normally open contact of DL in the tripping circuit is open, and the detection module cannot receive the AC signal sent by the negative bus signal source, so the online monitoring of the tripping outlet pressure plate status cannot be carried out.

[0061] B. The normally closed contact of DL in the closing circuit is closed, and the detection module can receive the AC signal sent by the negative bus signal source. The signal path is:

[0062] Negative bus signal source → normally closed contact of DL closed → HBJ → upper terminal of the pressure plate → pressure plate connection piece → lower terminal of the pressure plate. The total path impedance is about 200 ohms.

[0063] The following situations need to be considered emphatically in the design of this scheme:

[0064] 1) The original structure of the secondary circuit remains unchanged and no transformation is required;

[0065] 2) It does not cause DC grounding of the secondary circuit and does not trigger the grounding alarm of the insulation monitoring device;

[0066] 3) The insulation level of the secondary circuit is not affected and the AC intrusion alarm of the insulation monitoring device is not triggered;

[0067] 4) The signal sending device and the receiving device have the function of automatically locking the voltage monitoring. When the voltage is abnormal, they should be able to automatically withdraw;

[0068] 5) The hardware structures between the receiving modules are independent of each other;

[0069] 6) When the device is damaged or there is an internal short circuit, it does not cause DC circuit grounding;

[0070] 7) The connection between the pressure plate lead-out wire and the pressure plate terminal needs to be isolated from DC to avoid grounding caused by the lead-out wire;

[0071] 8) There are two grounding points together with the DC monitoring device for a long time, and the circuit risk is large.

[0072] Specifically, please refer to Figure 3 , Figure 3It is a structural block diagram of a signal sending device in a relay protection outlet pressure plate monitoring device of the present invention; among them, 301 is a power supply voltage monitoring module, 302 is a power conversion module, 303 is a signal output channel, and 304 is an MCU micro-control unit; the power supply voltage monitoring module 301, the power conversion module 302, the signal output channel 303 and the MCU micro-control unit 304 are connected to each other;

[0073] The power supply voltage monitoring module 301 is used to monitor the negative voltage amplitude;

[0074] The power conversion module 302 is used to convert the power supply voltage;

[0075] The signal output channel 303 is used to ensure the safe operation of relay protection operation and maintenance;

[0076] The MCU micro-control unit 304 is used to regulate the signal sending device.

[0077] Specifically, as shown in Table 1, Table 1 is the basic specification of the signal sending device.

[0078] Table 1

[0079]

[0080]

[0081] Specifically, the signal generating device 101 is powered by direct current and monitors the negative voltage amplitude. When the negative voltage amplitude is normal, the signal output channel 303 is opened to inject a small AC signal. If it exceeds the set detection limit, the signal output channel 303 is closed until the voltage value returns to the safe voltage range.

[0082] Specifically, the signal output channel 303 includes a first control relay, a signal source, and a first resistor connected in sequence;

[0083] The first control relay is used to combine the signal source and the resistor to ensure the safe operation of relay protection operation and maintenance;

[0084] The signal source is used to combine the first control relay and the resistor to ensure the safe operation of relay protection operation and maintenance;

[0085] The first resistor is used to combine the signal source and the first control relay to ensure the safe operation of relay protection operation and maintenance.

[0086] Specifically, please refer to Figure 4 , Figure 4It is a structural block diagram of a signal receiving device in a relay protection export pressure plate monitoring device of the present invention; the signal receiving device 102 includes a master control unit and a plurality of detection modules connected in sequence;

[0087] The master control unit is used to monitor the received negative voltage amplitude to ensure the safe operation of relay protection operation and maintenance;

[0088] The detection module is used to measure the intensity of the received injection signal to ensure the safe operation of relay protection operation and maintenance.

[0089] Specifically, as shown in Table 2, Table 2 is the basic specification of the signal receiving and transmitting device.

[0090] Table 2

[0091]

[0092]

[0093] Specifically, the master control unit is electrically connected to the detection module through an RS485 communication interface.

[0094] Specifically, the master control unit is contact-mounted on the pressure plate.

[0095] Specifically, the master control unit is also used to supply power to the detection module and receive information on whether the detection module is allowed to be put into use, and to obtain the connection status between the master control unit and the pressure plate.

[0096] Specifically, the master control unit is an RT1062 embedded processor of NXP; as shown in Table 3, Table 3 is the hardware specification table of the master control unit.

[0097] Table 3

[0098] Parameter Specification Quantity Power Input 110 / 220V AC / DC 1 Power Output 5V DC (Internal Bus) 1 Main Frequency Cortex-M7 Core, 500M / SDRAM On-board 1MB / SPI Flash On-board 8MB / Watchdog On-board Independent Hardware Watchdog 1 Serial Port 1-way RS485 Internal Bus, 2-way External 3 Network Interface 100M 1 Output 1 For Internal Use, with Opto-isolation (Reserved) 1 Input 1 For Internal Use, with Opto-isolation (Reserved) 1 PCB Plug Interface 6-pin Ribbon Cable, 2 pins for Signal and Power Left Empty ≥18 Board Fixer Fixed by 4 M3 Screws 1

[0099] Specifically, please refer to Figure 5 , Figure 5 It is a structural block diagram of a detection module in a signal receiving device of the present invention; among them, 501 is a monitoring channel, 502 is an MCU micro-control sub-unit, 503 is an on-board indicator light, and 504 is a long-term connection for detection and release; the MCU micro-control sub-unit 502 is respectively connected to the monitoring channel 501, the long-term connection 504 for detection and release, and the on-board indicator light 503;

[0100] The monitoring channel 501 is used to obtain the injection signal and measure the intensity of the injection signal;

[0101] The MCU micro-control sub-unit 502 is used to regulate the detection module;

[0102] The on-board indicator light 503 is used to prompt the connection status between the MCU micro-control sub-unit and the monitoring channel;

[0103] The detection release long-term connection line 504 is used to detect whether the detection module is allowed to be released and used for a long time.

[0104] Please refer to Figure 6 , Figure 6 which is a wiring schematic diagram of the sampling line of the detection module in a signal receiving device of the present invention; after the sampling line of the detection module is reversely blocked by a diode and the DC component is blocked by the Y1 safety capacitor, it is connected to the lower terminal of the pressure plate, and the DC component is blocked by a capacitor at the contact with the pressure plate. For the continuous pressure plate, a nut sleeve with a tail wire (external PVC plastic sleeve) is used, and for the plug-in pressure plate, an accessory with strong adsorption ability is used, and the accessory contacts the metal part of the pressure plate with a spring.

[0105] Specifically, the monitoring channel 501 includes a second control relay, a second resistor, and a circuit amplifier connected to each other;

[0106] The second control relay is used to combine the second resistor and the circuit amplifier to obtain and measure the injected signal;

[0107] The second resistor is used to combine the second control relay and the circuit amplifier to obtain and measure the injected signal;

[0108] The circuit amplifier is used to combine the second control relay and the second resistor to obtain and measure the injected signal.

[0109] Specifically, please refer to Figure 7 , Figure 7 which is a front installation schematic diagram of a signal sending device of the present invention; the size of the signal sending device is 150mm×120mm×50mm (tentative), and it can be installed on one side rail in the switch cabinet or configured with an independent rail. The power supply uses the DC control loop power supply.

[0110] Specifically, please refer to Figure 8 , Figure 8 which is a structural schematic diagram of a signal receiving device of the present invention; the signal receiving device is a 1U high 19-inch standard chassis, and the mechanical dimensions (width×height×depth) are 438mm×44.4mm×305mm. One signal acquisition device is installed on each side of the protection device panel.

[0111] Specifically, please refer to Figure 9 , Figure 9Schematic diagram of the back side of a signal receiving device of the present invention; the signal receiving device adopts a back-side wiring method, with the power supply and communication ports both located on the back side of the device, and the operating status indicator light located on the front side of the device. The structure of the back panel of the device is as Figure 9 shown.

[0112] Specifically, the present invention monitors the on-off state of the outlet pressure plate in real time through the bus negative signal injection method. A low-frequency current signal is artificially injected between the bus and the ground, and a sampling resistor connected to the ground is connected to the lower end of the pressure plate, that is, the connection end with the contact. By sampling the amplitude of the low-frequency current signal at both ends of this resistor, it is possible to determine whether the pressure plate is conducting, so as to timely detect hidden defects such as the fracture of the backplane terminal of the pressure plate, the detachment of the connecting bolt and the terminal post, and the loose connection of the patch-type pressure plate.

[0113] A relay protection outlet pressure plate monitoring device of the present invention, the relay protection outlet pressure plate monitoring device includes a signal sending device and a signal receiving device connected to each other. The signal sending device is used to monitor the negative voltage amplitude to ensure the safe operation of relay protection operation and maintenance. The signal receiving device is used to monitor the received negative voltage amplitude and the injection signal strength to ensure the safe operation of relay protection operation and maintenance.

[0114] Through the signal sending device and the signal receiving device, the relay protection operation and maintenance are monitored to ensure the safe operation of the relay protection operation and maintenance. Through a relay protection outlet pressure plate monitoring device, the safety of the relay protection operation and maintenance is improved, and the technical problem that the existing relay protection operation and maintenance methods have hidden defects resulting in frequent protection refusal and misoperation accidents is solved, ensuring the safe operation of the relay protection operation and maintenance.

[0115] It should be understood that in this application, "at least one (item)" means one or more, and "multiple" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item) of the following" or its similar expression means any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A relay protection outlet pressure plate monitoring device, characterized in that, The relay protection outlet pressure plate monitoring device includes a signal sending device and a signal receiving device connected to each other, which is used to judge whether the outlet pressure plate is conducting; The signal receiving device is used to monitor the intensity of the injected signal received at one end of the outlet pressure plate away from the negative bus; The signal sending device includes a power voltage monitoring module, a power conversion module, a signal output channel and an MCU micro-control unit connected to each other; The power voltage monitoring module is used to monitor the negative voltage amplitude; The power conversion module is used to convert the power voltage; The signal output channel is used to inject a low-frequency current signal into the negative bus when the negative voltage amplitude is normal, and the signal output channel is closed when the negative voltage amplitude exceeds the set detection limit until the negative voltage amplitude returns to the safe voltage range; The MCU micro-control unit is used to control the signal sending device; 2. The relay protection outlet pressure plate monitoring device according to claim 1, characterized in that, The signal output channel includes a first control relay, a signal source, a first resistor and a grounding capacitor connected in sequence. The signal source injects the low-frequency current signal into the negative bus through the first control relay and is grounded through the first resistor and the grounding capacitor; 3. The relay protection export pressure plate monitoring device according to claim 1, characterized in that, The signal receiving device includes a master control unit and a plurality of detection modules connected in sequence; The plurality of detection modules are used to measure the intensity of the injected signals received by each of the outlet pressure plates respectively; 4. The relay protection export pressure plate monitoring device according to claim 3, wherein, The master control unit is electrically connected to the detection module through an RS485 communication interface; 5. The relay protection export pressure plate monitoring device according to claim 3, wherein The master control unit is also used to supply power to the detection module and receive information on whether the detection module is allowed to be put into use; 6. The relay protection export pressure plate monitoring device according to claim 3, characterized in that, The master control unit is an RT1062 embedded processor of NXP; 7. The relay protection export pressure plate monitoring device according to claim 3, characterized in that, The detection module includes an MCU micro-control sub-unit, and a monitoring channel, a detection and release long-term connection line and an on-board indicator light respectively connected to the MCU micro-control sub-unit; The monitoring channel is used to obtain the injected signal and measure the intensity of the injected signal; The MCU micro-control sub-unit is used to control the detection module; The detection and release long-term connection line is used to detect whether the detection module is allowed to be put into use for a long time; The on-board indicator light is used to prompt the connection status between the MCU micro-control sub-unit and the monitoring channel; 8. The relay protection export pressure plate monitoring device according to claim 7, characterized in that, The monitoring channel includes a second control relay, a second resistor and a circuit amplifier connected in sequence, and is used to obtain and measure the injected signal.

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