Lightning arrester monitoring system
Through the combination of current sensors, protection circuits, signal conditioning circuits and comparator circuits in the lightning arrester monitoring system, the problem of high cost and high power consumption in the existing technology is solved, and low power consumption and efficient lightning strike event judgment is achieved.
Patent Information
- Application Number
- CN202421669937.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-15
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-07-15
AI Technical Summary
The existing online lightning arrester monitoring system has high cost and high power consumption when processing high-frequency signals, so it is impossible to accurately predict lightning strike events, resulting in wasted system resources.
The primary current sensor, protection circuit, signal conditioning circuit, reference voltage circuit, comparator circuit and control circuit are used to judge lightning strike events through signal conversion, filtering and comparison, reducing system power consumption and improving judgment accuracy.
It realizes low-cost and efficient lightning strike event judgment, reduces system power consumption and improves judgment accuracy.
Smart Images
Figure CN223296058U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of arrester online monitoring, in particular to a arrester monitoring system. Background Art
[0002] Metal oxide lightning arresters (hereinafter referred to as arresters) are one of the main devices that ensure the safe and stable operation of power grid systems. They can use their excellent nonlinear volt-ampere characteristics to significantly reduce the overvoltage flowing into the power grid system, ensuring the stable operation of power equipment. However, lightning arresters are usually placed in open-air environments. During operation, they are exposed to power frequency voltage and harsh environments for a long time. The lightning arrester valve plates will age or become damp, resulting in a decrease in the lightning arrester's protection capability. In severe cases, it will cause large-scale power outages in the power grid. By performing real-time online monitoring of the lightning arrester's full current, resistive current, number of lightning strikes, and lightning strike time, the health status of the lightning arrester can be evaluated in a timely manner, potential faults of the lightning arrester can be discovered, and important data basis can be provided for condition-based maintenance. Among them, effective monitoring of the lightning current signal of the lightning arrester for counting the number of lightning strikes and the time of lightning strikes is particularly important.
[0003] When the arrester is in a lightning strike state, the current flowing through the arrester grounding wire (hereinafter referred to as the arrester lightning strike current) can reach tens of amperes to tens of kiloamperes, or even higher. Usually, a primary current sensor such as a Rogowski coil or an electromagnetic mutual inductor is used to convert the arrester lightning strike current into a secondary weak current signal, such as Figure 1 shown.
[0004] The existing technology has different ways of processing and utilizing secondary weak current signals. To effectively monitor the secondary weak current signals of lightning arrester lightning current, the existing technology adopts the following methods:
[0005] The secondary weak current signal of the lightning current enters the A / D analog-to-digital conversion circuit through the protection circuit and signal conditioning circuit, and is converted from an analog signal to a digital signal, and then collected and processed by the CPU central processing unit. The signal conditioning circuit includes but is not limited to rectification, filtering, proportional amplification, following and other circuits. The processing process is as follows Figure 2 shown.
[0006] The signal waveform collected and processed by the CPU central processing unit corresponds to the primary side lightning arrester lightning current waveform (original waveform). The lightning arrester lightning current waveform is as follows: Figure 3 As shown; the CPU then performs further processing, including calculating the instantaneous current value, comparing it with the preset lower limit current, and determining whether a lightning strike has occurred.
[0007] Since lightning current signals are high-frequency signals, the A / D sampling in the existing technology requires high-speed sampling, which is extremely costly to implement. Since lightning events are random and cannot be accurately predicted, the full-channel circuits in the existing technology, including the CPU central processing unit, are in a high-frequency operation state for a long time, resulting in high system power consumption.
[0008] Based on this, the utility model proposes a new online monitoring system for lightning arresters. Utility Model Content
[0009] In view of the above technical problems, the utility model provides a lightning arrester monitoring system.
[0010] The technical solution of the utility model to solve the above technical problems is as follows:
[0011] A lightning arrester monitoring system includes a primary current sensor, a protection circuit, a signal conditioning circuit, a reference voltage circuit, a comparator circuit and a control circuit;
[0012] The primary current sensor is used to collect the current signal on the lightning arrester grounding wire in real time, convert the current signal into a secondary weak current signal and output it to the protection circuit;
[0013] The protection circuit is used to protect the control circuit from damage caused by overvoltage when the lightning arrester is activated by overvoltage;
[0014] The signal conditioning circuit is used to perform signal conversion and signal filtering on the signal output by the primary current sensor, and provide the comparator circuit with a voltage signal that meets its input voltage requirement;
[0015] The reference voltage circuit provides a stable reference voltage to the comparator circuit for comparison with the signal output by the signal conditioning circuit;
[0016] The comparator circuit is used to compare the signal output by the signal conditioning circuit with the reference voltage and output a comparison result;
[0017] The control circuit is used to receive the comparison result output by the comparator circuit and make a decision based on the comparison result.
[0018] Compared with the prior art, the present invention has the following technical effects:
[0019] When the lightning arrester is turned on due to overvoltage, a large current flows through the lightning arrester. The primary current sensor converts the current on the lightning arrester grounding wire into a secondary weak current signal. The protection circuit protects the subsequent circuit from possible damage caused by overvoltage. The signal conditioning circuit converts and filters the signal output by the primary current sensor to provide the comparator circuit with a correct signal that meets its input voltage requirements; the reference voltage circuit provides a stable reference voltage to the comparator circuit, which is compared with the signal output by the signal conditioning circuit; the comparator circuit compares the signal output by the signal conditioning circuit with the reference voltage and outputs the comparison result; the controller circuit obtains the comparison result and can directly determine whether a lightning strike has occurred based on the high and low level signals output by the comparator.
[0020] On the basis of the above technical solution, the following improvements can be made to the above technical solution:
[0021] Furthermore, the control circuit is also used to receive a control command and send it to the reference voltage circuit through a signal control line; the reference voltage circuit adjusts the output reference voltage value.
[0022] The beneficial effect of adopting the above further technical solution is that the CPU central processing unit is used to adjust the comparator reference voltage output value, which has low cost and low power consumption, and the lower limit value of the lightning current signal action can be dynamically set.
[0023] Furthermore, the primary current sensor is a Rogowski coil sensor or an electromagnetic mutual inductor.
[0024] The beneficial effect of adopting the above further technical solution is that the Rogowski coil sensor is a ring coil uniformly wound on a non-ferromagnetic material, which can measure current signals, especially large current signals, and output corresponding voltage signals through hardware integration.
[0025] Furthermore, the protection circuit adopts a varistor or a TVS (Transient Voltage Suppressor) transient suppression tube or a parallel connection of the two.
[0026] The beneficial effect of adopting the above further technical solution is that when the voltage across any one of the varistor or TVS transient suppressor tube or the parallel structure of the two exceeds a certain threshold, the varistor or TVS transient suppressor tube breaks down, clamping the voltage within a certain safety range, preventing high-voltage shock from damaging subsequent circuits; the varistor or TVS transient suppressor tube or the two are connected in parallel to reduce the voltage amplitude input to the subsequent circuit.
[0027] Furthermore, the signal conditioning circuit includes a signal conversion circuit and a filtering circuit.
[0028] The beneficial effects of adopting the above-mentioned further technical solution are as follows: since the signal output by the primary current sensor is weak, it needs to be amplified by an amplifier; a low-pass filter is used to filter out high-frequency noise to improve signal quality; and since the output of the Rogowski coil is a differential signal, it needs to be restored to an actual current signal by an integration circuit. The integration circuit can be a self-integrating Rogowski coil, an external passive RC integration circuit, or an active integration circuit.
[0029] Furthermore, the comparator circuit adopts a voltage comparator.
[0030] Furthermore, the control circuit adopts a CPU central processing unit.
[0031] Furthermore, the reference voltage circuit is a DA conversion circuit (digital-to-analog conversion circuit). BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 This is a schematic diagram of the lightning current conversion of the lightning arrester;
[0033] Figure 2 It is a schematic diagram of the processing process in the prior art;
[0034] Figure 3 The waveform of lightning current of the arrester in the prior art is shown below:
[0035] Figure 4 This is a schematic diagram of the processing process of a lightning arrester monitoring system of the utility model;
[0036] Figure 5 This is a schematic diagram of the high and low level signals output by the comparator in the present invention. DETAILED DESCRIPTION
[0037] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0038] Reference Figure 4-Figure 5 , a lightning arrester monitoring system, including a primary current sensor, a protection circuit, a signal conditioning circuit, a reference voltage circuit, a comparator circuit and a control circuit;
[0039] The primary current sensor is used to collect the current signal on the lightning arrester grounding wire in real time, convert the current signal into a secondary weak current signal and output it to the protection circuit;
[0040] The protection circuit is used to protect all circuits from damage caused by overvoltage;
[0041] The signal conditioning circuit is used to perform signal conversion and signal filtering on the signal output by the primary current sensor, and provide the comparator circuit with a voltage signal that meets its input voltage requirement;
[0042] The reference voltage circuit provides a stable reference voltage to the comparator circuit for comparison with the signal output by the signal conditioning circuit;
[0043] The comparator circuit is used to compare the signal output by the signal conditioning circuit with the reference voltage and output a comparison result;
[0044] The control circuit is used to receive the comparison result output by the comparator circuit and make a decision based on the comparison result.
[0045] In this embodiment, the primary current sensor is a Rogowski coil sensor or an electromagnetic mutual inductor. A Rogowski coil sensor is a toroidal coil uniformly wound around a non-ferromagnetic material. It can measure current signals, especially high current signals, and output a corresponding voltage signal through hardware integration.
[0046] In this embodiment, the protection circuit is used to protect subsequent circuits from damage caused by high voltage and transient overvoltage generated by lightning strikes, thereby protecting the control circuit of the subsequent circuits. Specifically, the protection circuit uses a varistor or a TVS transient suppressor, or both in parallel.
[0047] In this embodiment, the signal conditioning circuit is used to convert and filter the signal output by the primary current sensor, providing a voltage signal that meets the comparator circuit's input voltage requirements. Specifically, the signal conditioning circuit may include a signal conversion circuit and a filtering circuit. The signal conditioning circuit first converts the signal output by the primary current sensor into a voltage signal that meets the comparator circuit's input voltage requirements; then, it filters the signal output by the primary current sensor to remove external interference signals and ensure signal accuracy.
[0048] Comparator circuits all have an input voltage range. Usually, the signal output by a primary current sensor does not necessarily meet this range. At the same time, the signal output by a primary current sensor is not necessarily a voltage signal, but may also be a current signal. Therefore, it is necessary to convert the signal or current signal that does not meet the voltage range into a signal that meets the comparator input voltage requirements.
[0049] In this embodiment, the reference voltage circuit provides a stable reference voltage for the comparator circuit for comparison with the signal output by the signal conditioning circuit, and the reference voltage value can be adjusted as needed. Specifically, the reference voltage circuit is a DA converter circuit or a digitally controllable power supply.
[0050] In this embodiment, the comparator circuit is a voltage comparator, which is used to compare the signal output by the signal conditioning circuit with a reference voltage and transmit the comparison result to the control circuit.
[0051] In this embodiment, the control circuit utilizes a CPU (central processing unit) to receive the comparison results output by the comparator circuit and perform corresponding processing based on the signals. Based on the high and low level signals output by the comparator, the CPU can directly determine whether a lightning strike has occurred. The CPU is also configured to receive and parse control commands and adjustment values, re-encode them, and transmit them via a signal control line to the registers of the reference voltage circuit. The registers of the reference voltage circuit automatically adjust the output reference voltage value based on the received encoded values to accommodate different monitoring requirements.
[0052] When the lightning arrester is turned on due to overvoltage, a large current flows through the lightning arrester. The primary current sensor converts the current on the lightning arrester grounding wire into a secondary weak current signal. The protection circuit protects the subsequent circuit from possible damage caused by overvoltage. The signal conditioning circuit conditions the signal output by the primary current sensor. The reference voltage circuit provides a stable reference voltage for the comparator circuit, which is compared with the signal output by the signal conditioning circuit. The comparator circuit compares the signal output by the signal conditioning circuit with the reference voltage and outputs high and low level signals. The controller circuit obtains the comparison result, and the CPU central processing unit can directly determine whether a lightning strike has occurred based on the high and low level signals output by the comparator.
[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A lightning arrester monitoring system, characterized in that: It includes a primary current sensor, a protection circuit, a signal conditioning circuit, a reference voltage circuit, a comparator circuit and a control circuit; The primary current sensor is used to collect the current signal on the lightning arrester grounding wire in real time, convert the current signal into a secondary weak current signal and output it to the protection circuit; The protection circuit is used to protect all circuits from damage caused by overvoltage; The signal conditioning circuit is used to perform signal conversion and signal filtering on the signal output by the primary current sensor, and provide the comparator circuit with a voltage signal that meets its input voltage requirement; The reference voltage circuit provides a stable reference voltage for the comparator circuit for comparison with the signal output by the signal conditioning circuit; the reference voltage circuit is a DA conversion circuit; The comparator circuit is used to compare the signal output by the signal conditioning circuit with the reference voltage and output a comparison result; The control circuit is used to receive the comparison result output by the comparator circuit and make a decision based on the comparison result; The control circuit adopts a CPU central processing unit; The control circuit is further configured to receive a control command and send the command to the reference voltage circuit via a signal control line; the reference voltage circuit adjusts the output reference voltage value.
2. A lightning arrester monitoring system according to claim 1, characterized in that: The primary current sensor is a Rogowski coil sensor or an electromagnetic mutual inductor.
3. A lightning arrester monitoring system according to claim 1, characterized in that: The protection circuit adopts a varistor or a TVS transient suppression tube or a parallel connection of the two.
4. A lightning arrester monitoring system according to claim 1, characterized in that: The signal conditioning circuit includes a signal conversion circuit and a filtering circuit.
5. The lightning arrester monitoring system according to claim 1, characterized in that: The comparator circuit adopts a voltage comparator.