Bus on-line and lightning arrester on-line monitoring device

Abstract

The utility model discloses a bus on-line and lightning arrester on-line monitoring device, which comprises a reference signal acquisition circuit and three three-phase voltage acquisition circuits, and the circuit structures of the reference signal acquisition circuit and the three three-phase voltage acquisition circuits are the same. The input end of the one-path reference signal acquisition circuit is connected with the bus on-line monitoring device and is used for acquiring reference voltage signals, and the input ends of the three-path three-phase voltage acquisition circuits are respectively connected with the lightning arrester on-line monitoring device and are used for acquiring three-phase voltage signals. According to the utility model, the measurement result is more stable and accurate, the requirement on a reference signal is lower, and hardware resources are utilized to the greatest extent.

Description

Technical Field

[0001] The utility model relates to arrester monitoring, in particular to an online busbar and arrester monitoring device. Background Art

[0002] Metal oxide (MOA) arresters are important overvoltage protection devices in power systems. As the arrester operates for a long time, its valve plate will deteriorate due to factors such as thermal damage, resonant overvoltage, and internal moisture, causing damage to the arrester or even explosion, and the protected equipment will lose protection.

[0003] The arrester online monitoring system can monitor the operating status of the arrester in real time, detect faults in time and remind the operating personnel to take measures to prevent the occurrence of faults.

[0004] The existing online monitoring system for lightning arresters collects reference signals and three-phase signals separately, and most of them are monitored in a one-to-nine manner. The disadvantages are: unstable measurement of resistive current and capacitance, large errors; high requirements for reference signals; no measurement of bus voltage; small number of cascaded bus online monitoring devices and lightning arrester online monitoring devices; and high cost. Utility Model Content

[0005] In order to solve the defects of the above-mentioned prior art, the utility model provides a busbar online and arrester online monitoring device. The measurement result of the utility model is more stable and accurate, the requirement for reference signal is lower, and the hardware resources are maximized.

[0006] To achieve the above technical objectives, the utility model adopts the following technical solutions: a bus online and lightning arrester online monitoring device, including 1 reference signal acquisition circuit and 3 three-phase voltage acquisition circuits, the circuit structure of the 1 reference signal acquisition circuit and the 3 three-phase voltage acquisition circuits are the same; the input end of the 1 reference signal acquisition circuit is connected to the bus online monitoring device for collecting reference voltage signals, and the input ends of the 3 three-phase voltage acquisition circuits are respectively connected to the lightning arrester online monitoring device for collecting three-phase voltage signals.

[0007] Furthermore, the one-way reference signal acquisition circuit and the three-way three-phase voltage acquisition circuits include a voltage transformer T, a first resistor R is connected in series on the secondary side of the voltage transformer T, a negative pole of the first resistor R is grounded, a positive pole is connected to pin 3 of the op amp chip U, pin 2 of the op amp chip U is connected to pin 1 of the op amp chip U, pin 4 of the op amp chip U is connected to a V-12V voltage, pin 5 of the op amp chip U is connected to a V+12V voltage, pin 1 of the op amp chip U is connected to a second resistor R, one way of the second resistor R is connected to ground through a capacitor C, and the other way outputs the collected signal.

[0008] Furthermore, the first resistor R and the second resistor R are chip resistors.

[0009] Furthermore, the operational amplifier chip U adopts a model of AD822A.

[0010] In summary, the utility model has achieved the following technical effects:

[0011] The measurement results of the utility model are more stable and accurate, because the same frequency sampling technology is designed, so the phases collected by the two devices are more stable and accurate;

[0012] The utility model has lower requirements on the reference signal, and the variable of the reference signal phase is offset when calculating the phase difference, and the reference signals of the two devices are the same at the same time;

[0013] The utility model is one-to-many, and one busbar online monitoring device can be connected to a maximum of 60 arrester online monitoring devices, thus maximizing the use of hardware resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a collection circuit provided by an embodiment of the utility model;

[0015] Figure 2 This is a cascade diagram. DETAILED DESCRIPTION

[0016] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0017] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0022] Example:

[0023] A bus online and arrester online monitoring device comprises a reference signal acquisition circuit and three three-phase voltage acquisition circuits, wherein the circuit structures of the reference signal acquisition circuit and the three three-phase voltage acquisition circuits are the same; the input end of the reference signal acquisition circuit is connected to the bus online monitoring device for collecting the reference voltage signal of the bus, and the input ends of the three three-phase voltage acquisition circuits are respectively connected to the arrester online monitoring device for collecting the three-phase voltage signals.

[0024] The 4 circuits all include a voltage transformer T, and a first resistor R is connected in series on the secondary side of the voltage transformer T. The negative pole of the first resistor R is grounded, and the positive pole is connected to pin 3 of the operational amplifier chip U. Pin 2 of the operational amplifier chip U is connected to pin 1 of the operational amplifier chip U. Pin 4 of the operational amplifier chip U is connected to a V-12V voltage, and pin 5 of the operational amplifier chip U is connected to a V+12V voltage. Pin 1 of the operational amplifier chip U is connected to a second resistor R. One path of the second resistor R is connected to ground through a capacitor C, and the other path outputs the collected signal.

[0025] The first resistor R and the second resistor R are chip resistors.

[0026] The operational amplifier chip U adopts the model AD822A.

[0027] Taking 1-channel reference signal acquisition circuit as an example, the reference signal acquisition circuit includes a voltage transformer T3, and a resistor R129 is connected in series on the secondary side of the voltage transformer T3. The negative pole of the resistor R129 is grounded, and the positive pole is connected to the 3rd pin of the operational amplifier chip U, the 2nd pin of the operational amplifier chip U is connected to the 1st pin of the operational amplifier chip U, the 4th pin of the operational amplifier chip U is connected to the V-12V voltage, the 5th pin of the operational amplifier chip U is connected to the V+12V voltage, and the 1st pin of the operational amplifier chip U is connected to the resistor R127. The resistor R127 is grounded through the capacitor C63 on one path, and the other path outputs the PT data ADC signal PT_SIGNAL after isolation and amplification.

[0028] The utility model ensures that the phases of the three phases and the reference phase collected by the 4-way collection circuit bus online monitoring device are at the same time as the phase collected by the arrester online monitoring device. The utility model sends a trigger collection instruction through 485 communication, and starts collecting at the same time after sending. After receiving the instruction, the arrester starts collecting and calculating the phase.

[0029] When the frequency of the reference signal fluctuates, if the sampling frequency of the acquisition device does not change accordingly, the calculated phase is an inaccurate value, so the sampling frequency of the acquisition device needs to be consistent with the frequency of the reference signal. The reference signal used by the bus online monitoring device and the arrester online monitoring device is the same signal, so their sampling frequencies must also be set to the same. The utility model bus online monitoring device collects the reference signal through a sampling circuit, calculates the frequency of the reference signal, and sends a synchronous sampling signal. When the synchronous sampling is triggered, the parameter is sent to the arrester online monitoring device to achieve same-frequency sampling and prevent inaccurate phase calculation.

[0030] The utility model sets up a 3-way three-phase voltage acquisition circuit, which can monitor the three-phase voltage signal, including voltage and multiple harmonic signals. The utility model is equipped with a total of 4 signal acquisition units, one of which acquires the reference signal and the other 3 acquire the three-phase voltage signal. After each trigger acquisition, the three-phase signal is collected at the same time, and the voltage, harmonics and phase of each phase are continuously calculated. The circuit schematic diagram is shown as follows Figure 1 shown.

[0031] If a busbar online monitoring device is only connected to one arrester online monitoring device, the cost will be very high. Currently, the market uses one-to-three or one-to-nine, which reduces some costs, but the number of arresters used in a substation is far more than 9, and the cost of the one-to-nine method is still very high. In order to reduce this part of the cost, the utility model can achieve one-to-sixty, which greatly reduces the cost. Figure 2The figure shows a schematic diagram of one-way cascade connection. The communication method between the busbar online monitoring device and the arrester online monitoring device of the utility model adopts 485 communication to ensure the reliability and timeliness of information. The characteristic of 485 communication equipment that multiple devices can be connected in parallel is used to realize a one-to-many mode. However, it cannot be connected in parallel infinitely. According to the communication distance limit, a maximum of 32 devices can be connected in parallel in the substation at the same time. At the same time, in order to ensure anti-interference and no bit errors, the utility model adopts a busbar online monitoring device with one 485 in parallel with 15 arrester online monitoring devices. The busbar online device is equipped with 4 485s that communicate with the arrester online monitoring device, so a busbar online monitoring device can connect up to 60 devices in total.

[0032] The reference signals of the busbar online monitoring device and the arrester online monitoring device are the same at the same time. According to the following formula, it can be seen that the variable of the reference signal phase is offset when calculating the phase difference.

[0033]

[0034] In addition, one output and one input can be set on the bus online monitoring device, and an input circuit that is exactly the same as the bus online monitoring device can be set on the arrester online monitoring device. The bus online monitoring device outputs an output signal, and the bus online monitoring device and the arrester online monitoring device receive the signal at the same time. Since the input circuits are exactly the same, the trigger signals received are almost at the same time, realizing synchronous sampling.

[0035] The above description is only a preferred implementation mode of the present invention, and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A busbar online and arrester online monitoring device, characterized in that: It includes 1 reference signal acquisition circuit and 3 three-phase voltage acquisition circuits, and the circuit structures of the 1 reference signal acquisition circuit and the 3 three-phase voltage acquisition circuits are the same; the input end of the 1 reference signal acquisition circuit is connected to the bus online monitoring device for collecting reference voltage signals, and the input ends of the 3 three-phase voltage acquisition circuits are respectively connected to the arrester online monitoring device for collecting three-phase voltage signals.

2. A busbar online and arrester online monitoring device according to claim 1, characterized in that: The one-way reference signal acquisition circuit and the three-way three-phase voltage acquisition circuits include a voltage transformer T, a first resistor R is connected in series on the secondary side of the voltage transformer T, a negative electrode of the first resistor R is grounded, a positive electrode is connected to pin 3 of the operational amplifier chip U, pin 2 of the operational amplifier chip U is connected to pin 1 of the operational amplifier chip U, pin 4 of the operational amplifier chip U is connected to a V-12V voltage, pin 5 of the operational amplifier chip U is connected to a V+12V voltage, pin 1 of the operational amplifier chip U is connected to a second resistor R, one way of the second resistor R is connected to ground through a capacitor C, and the other way outputs the collected signal.

3. A busbar online and arrester online monitoring device according to claim 2, characterized in that: The first resistor R and the second resistor R are chip resistors.

4. A busbar online and arrester online monitoring device according to claim 2, characterized in that: The operational amplifier chip U adopts the model AD822A.

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