High-voltage live detection device and high-voltage equipment

Abstract

The invention discloses a high-voltage live detection device and high-voltage equipment, the high-voltage live detection device comprises a signal acquisition module, a signal amplification module, a signal filtering module, a signal processing module and a main control processing module, the signal amplification module amplifies an induction signal; the signal filtering module performs low-pass filtering on the amplified signal; the signal processing module performs offset processing on the filtered signal to obtain an analog signal; the master control processing module converts the analog signal into a digital signal, performs spectral analysis on the digital signal, extracts the amplitude of a target frequency signal, and compares the amplitude with a preset value to judge the live-line state; according to the technical scheme, the problems of erroneous recognition, missed judgment, inaccurate sampling and the like of an existing induction type device in a strong electromagnetic interference environment are effectively solved, and the practicability and the safety of the device in complex application scenes such as a transformer substation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage equipment, and in particular to a high-voltage live detection device and high-voltage equipment. Background Art

[0002] High-voltage live-current indicators are devices used to monitor and display whether high-voltage electrical equipment is live. They are widely used in high-voltage systems such as cable terminals, busbars, and power supply lines, particularly in high-voltage switchgear and substations. Their primary function is to detect the electric field or current signal near high-voltage conductors through a sensing device and visually display this status through indicator lights and LCD screens, assisting operators in determining the equipment's operating status and ensuring operational safety.

[0003] Existing high-voltage live-current display devices are roughly divided into two categories: contact and inductive. Contact devices acquire electrical signals by directly contacting live objects. However, due to the large insulation gaps they require, they carry the risk of single-phase grounding faults and partial discharge. They are also primarily used in indoor high-voltage switchgear and are not suitable for outdoor or high-humidity environments.

[0004] In contrast, inductive high-voltage live charge display devices, which detect the induced charge around the charged body in a non-contact manner, have the advantages of small size, easy installation, and high safety, and have gradually become mainstream. However, inductive devices face the following key technical issues in actual use:

[0005] 1. Significant electromagnetic interference: Due to the complex substation environment and dense interference sources, the signals collected by traditional devices are often mixed with a large amount of interference components other than the power frequency, which can easily lead to misjudgment of the live state;

[0006] 2. Limited signal processing capabilities: Traditional devices typically use simple signal amplification and comparison methods, making it difficult to distinguish valid signals from interference signals, and the display device is subject to the risk of misjudgment and missed judgments.

[0007] 3. Low sampling accuracy: Traditional analog signal paths are susceptible to noise, and the supporting circuits have limited accuracy, further limiting device performance. Summary of the Invention

[0008] The embodiments of the present invention provide a high-voltage live detection device and a high-voltage device to solve the above-mentioned technical problems.

[0009] A first aspect of an embodiment of the present invention provides a high-voltage live detection device, comprising:

[0010] A signal acquisition module, whose acquisition end is connected to the high-voltage electrical equipment and is used to acquire the induction signal generated during the operation of the high-voltage electrical equipment;

[0011] a signal amplifying module, whose input end is connected to the output end of the signal acquisition module and is used to amplify the sensing signal;

[0012] a signal filtering module, whose input end is connected to the output end of the signal amplifying module, and is used to perform low-pass filtering on the amplified signal;

[0013] a signal processing module, whose input end is connected to the output end of the signal filtering module, and is used to perform offset processing on the filtered signal to obtain an analog signal;

[0014] The main control processing module, whose input end is connected to the output end of the signal processing module, is used to convert the analog signal into a digital signal, extract the amplitude of the target frequency signal after performing spectrum analysis on the digital signal, and compare it with the preset value to determine the charged state.

[0015] Optionally, the high-voltage live display device further includes:

[0016] The status display module has an input end connected to the first output end of the main control processing module, and the main control processing module displays the power-on state or the power-off state through the status display module according to the judgment result.

[0017] Optionally, the high-voltage live display device further includes:

[0018] The unlocking execution module has an input end connected to the second output end of the main control processing module, and the main control processing module controls the unlocking execution module to execute a locking action or an unlocking action according to the judgment result.

[0019] Optionally, the signal acquisition module is an inductive sensor, which is used to acquire inductive signals from the high-voltage electrical equipment.

[0020] Optionally, the signal amplification module includes a surge protection module, a voltage stabilization module, an inductance module and a negative feedback amplification module;

[0021] One end of the surge protection module is the input end of the signal amplification module, the other end of the surge protection module is respectively connected to one end of the voltage stabilization module and the first end of the inductance module, the other end of the voltage stabilization module and the second end of the inductance module are commonly connected to the ground, the third end of the inductance module is connected to the first input end of the negative feedback amplification module, the fourth end of the inductance module and the second input end of the negative feedback amplification module are commonly connected to the ground, and the output end of the negative feedback amplification module is the output end of the signal amplification module.

[0022] Optionally, the signal filtering module includes a first-stage RC low-pass circuit, a second-stage RC low-pass circuit and an operational amplifier, the first end of the first-stage RC low-pass circuit is the input end of the signal filtering module, the second end of the first-stage RC low-pass circuit is connected to the first end of the second-stage RC low-pass circuit, the second end of the second-stage RC low-pass circuit is connected to the non-inverting input end of the operational amplifier, the output end of the operational amplifier is respectively connected to the inverting input end of the operational amplifier and the third end of the first-stage RC low-pass circuit, and the third end of the second-stage RC low-pass circuit is grounded.

[0023] Optionally, the signal processing module is an adder, a first input terminal of the adder receives the filtered signal, and a second input terminal of the adder receives an offset voltage;

[0024] The adder is used to superimpose the filtered signal and the offset voltage to offset the filtered signal into a positive voltage range.

[0025] Optionally, the main control processing module performs Fourier operation on the digital signal according to a preset sampling frequency to obtain amplitudes of multiple frequency signals, and obtains the amplitude of the target frequency signal from the amplitudes of the multiple frequency signals.

[0026] Optionally, the main control processing module determines that the target frequency signal is in a powered state when it detects that the amplitude thereof is greater than a preset value, and outputs a locking control signal to the unlocking execution module;

[0027] When the main control processing module detects that the amplitude of the target frequency signal is not greater than a preset value, it determines that the power is off and outputs an unlocking control signal to the unlocking execution module.

[0028] A second aspect of an embodiment of the present invention provides a high-voltage device, comprising the high-voltage live detection device and high-voltage electrical equipment described in the first aspect.

[0029] The technical effects of the embodiments of the present invention are as follows: by introducing a multi-level signal processing path and a spectrum analysis mechanism, the accuracy and anti-interference capability of high-voltage live state detection are significantly improved; first, the signal acquisition module collects the induction signals around the high-voltage equipment in a non-contact manner, avoiding the local discharge and insulation risks of traditional contact solutions; second, the signal amplification module and the signal filtering module effectively suppress the interference above the power frequency and pulse interference, thereby improving the purity of the signal; the signal processing module further performs offset correction on the signal to enhance the stability of the analog signal. Finally, the main control processing module performs spectrum analysis on the digitized signal, which can accurately extract the target frequency component and determine whether the equipment is in a live state by comparing it with a preset threshold, thereby effectively solving the problems of misidentification, missed identification and inaccurate sampling of existing induction devices in a strong electromagnetic interference environment, and improving the practicality and safety of the device in complex application scenarios such as substations. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 This is a first structural diagram of a high-voltage live detection device provided in Example 1 of the present invention;

[0032] Figure 2 This is a second structural diagram of a high-voltage live detection device provided in the first embodiment of the present invention;

[0033] Figure 3 This is a third structural diagram of a high-voltage live detection device provided in the first embodiment of the present invention;

[0034] Figure 4 This is a circuit diagram of an unlocking execution module of a high-voltage live detection device provided in Example 1 of the present invention;

[0035] Figure 5 This is a structural diagram of a signal amplification module of a high-voltage live detection device provided in Example 1 of the present invention;

[0036] Figure 6 This is a circuit diagram of a signal amplification module of a high-voltage live detection device provided in Example 1 of the present invention;

[0037] Figure 7 This is a structural diagram of a signal filtering module of a high-voltage live detection device provided in Example 1 of the present invention;

[0038] Figure 8 This is a circuit diagram of a signal filtering module of a high-voltage live detection device provided in Example 1 of the present invention;

[0039] Figure 9 This is a schematic diagram of the working process of a high-voltage live detection device provided in Example 1 of the present invention;

[0040] In the figure: 100, high-voltage electrical equipment; 101, signal acquisition module; 102, signal amplification module; 103, signal filtering module; 104, signal processing module; 105, main control processing module; 106, status display module; 107, unlocking execution module; 201, surge protection module; 202, voltage stabilization module; 203, inductor module; 204, negative feedback amplification module; 301, first-stage RC low-pass circuit; 302, second-stage RC low-pass circuit; 303, operational amplifier. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] It should be understood that the present invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0043] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, a first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part without departing from the teachings of the present invention.

[0044] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0045] In order to fully understand the present invention, detailed structures and steps will be provided in the following description to illustrate the technical solutions proposed by the present invention. Preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other implementations.

[0046] Example 1

[0047] This embodiment provides a high voltage live detection device, such as Figure 1 Shown, including:

[0048] The signal acquisition module 101 has an acquisition terminal connected to the high-voltage electrical equipment 100 and is used to acquire the induction signal generated during the operation of the high-voltage electrical equipment 100;

[0049] The signal amplification module 102 has an input end connected to the output end of the signal acquisition module 101 and is used to amplify the sensing signal;

[0050] A signal filtering module 103, whose input end is connected to the output end of the signal amplifying module 102, is used to perform low-pass filtering on the amplified signal;

[0051] The signal processing module 104 has an input end connected to the output end of the signal filtering module 103 and is used to perform offset processing on the filtered signal to obtain an analog signal;

[0052] The main control processing module 105 has its input end connected to the output end of the signal processing module 104 and is used to convert the analog signal into a digital signal, perform spectrum analysis on the digital signal, extract the amplitude of the target frequency signal, and compare it with the preset value to determine the charged state.

[0053] The signal acquisition module 101 is used to contactlessly sense the electric field or current signals generated by the high-voltage electrical equipment 100 during operation, generating a weak analog signal output. Possible structures for the signal acquisition module 101 include, but are not limited to, an inductive electric field sensor or voltage transformer, outputting a microampere current signal or a millivolt voltage signal. The module is installed near the high-voltage conductor and utilizes spatial electric or magnetic field coupling. The signal amplification module 102 amplifies the weak signal output by the signal acquisition module 101 to increase signal strength for subsequent processing. Possible structures for the signal amplification module 102 include, but are not limited to, a low-noise operational amplifier with surge and overvoltage protection devices at its input, such as a PTC thermistor, a TVS diode, or a common-mode inductor. The signal filtering module 103 filters the amplified signal to remove high-frequency noise and spurious signals. Possible structures for the signal filtering module 103 include, but are not limited to, an active low-pass filter circuit, such as an RC filter network. The signal processing module 104 performs bias processing on the filtered AC signal, shifting its overall voltage to a sampling voltage range (e.g., 0-3.3V) to accommodate the analog-to-digital converter of the main control processing module 105. Possible structures of the signal processing module 104 include, but are not limited to, a waveform offset circuit with an adder structure, or a DC bias superposition implemented by an operational amplifier; used to offset the original positive and negative voltage signals to a pure positive voltage range (e.g., a center offset of 1.5V). The main control processing module 105 performs analog-to-digital conversion on the analog signal, runs a Fourier algorithm to extract the amplitude of a preset target frequency, and compares it with a preset threshold value; it outputs a judgment result, indicating whether the current state is "powered" or "de-powered."

[0054] The working process of this embodiment is:

[0055] 1. Induction signal acquisition stage: When the high-voltage electrical equipment 100 is in operation, the power frequency electric field generated around its live conductor is sensed by the signal acquisition module 101 and a weak signal is output.

[0056] 2. Signal amplification and processing stage: After being protected by the protection circuit, the weak signal enters the signal amplification module 102 for voltage amplification to enhance the signal amplitude.

[0057] 3. Signal filtering stage: The amplified analog signal is input to the signal filtering module 104 to filter out high-frequency interference and retain only the target frequency and its harmonic components.

[0058] 4. Offset processing stage: A DC bias voltage is superimposed on the filtered AC signal to keep it within the voltage sampling range allowed by the ADC (e.g., 0V to 3V).

[0059] 5. Analog-to-digital conversion and FFT analysis stage: The main control processing module 105 receives the offset analog signal and performs AD sampling; runs the FFT spectrum conversion algorithm in the program to extract the amplitude of the preset frequency; compares the amplitude with the preset threshold value to determine whether it is charged.

[0060] 6. Status output stage: If the amplitude is greater than the threshold value, it is determined to be a powered state, the powered display is output, and the locking control can be activated; if it is less than the threshold value, it is determined to be a de-powered state, and the unlocked state is output.

[0061] The technical effect of this embodiment is that: by introducing a multi-level signal processing path and a spectrum analysis mechanism, the accuracy and anti-interference ability of high-voltage live state detection are significantly improved; first, the signal acquisition module collects the induction signal around the high-voltage equipment in a non-contact manner, avoiding the local discharge and insulation risks of traditional contact solutions; second, the signal amplification module and the signal filtering module effectively suppress the interference above the power frequency and pulse interference, thereby improving the purity of the signal; the signal processing module further performs offset correction on the signal to enhance the stability of the analog signal. Finally, the main control processing module performs spectrum analysis on the digitized signal, which can accurately extract the target frequency component and determine whether the equipment is in a live state by comparing it with the preset threshold, thereby effectively solving the problems of misidentification, missed judgment and inaccurate sampling of existing induction devices in strong electromagnetic interference environments, and improving the practicality and safety of the device in complex application scenarios such as substations.

[0062] As an implementation method, Figure 2 As shown, the high-voltage live display device also includes:

[0063] The status display module 106 has an input end connected to the first output end of the main control processing module 105 . The main control processing module 105 displays the power-on state or the power-off state through the status display module 106 according to the judgment result.

[0064] The status display module 106 is used to visually display the main control processing module 105's determination of the high-voltage equipment's energized state in real time, allowing maintenance personnel to intuitively understand whether the electrical equipment is currently energized or de-energized. Based on the determination signal output by the main control processing module 105, the status display module 106 controls the display device to indicate the "energized" or "de-energized" status. For example, when the 50Hz signal amplitude detected exceeds a preset threshold, the status display module 106 illuminates the "energized" indicator; otherwise, the "de-energized" indicator is illuminated. A buzzer or flashing indicator can be integrated to issue a warning when the "energized" state is detected, enhancing safety awareness. Possible configurations for the status display module 106 include, but are not limited to: an LED indicator module (red indicates energized, green indicates de-energized); an OLED or LCD display (capable of displaying the text "energized" or "de-energized"); a multi-color light-emitting diode (with bidirectional color switching to indicate status); and a buzzer / flash module (for audible and visual alarms, depending on the application scenario).

[0065] The technical effect of this embodiment is that the status display module 106 significantly improves the operation and maintenance personnel's intuitive identification ability of the high-voltage equipment operation status by outputting the energized or de-energized status determined by the main control processing module 105 in real time in a visual manner; by adopting multiple forms such as LED indication, LCD display or sound and light alarm, the status information is clearly, promptly and accurately conveyed, the safety and reliability of on-site operations are enhanced, and the safety hazards caused by misjudgment or delayed identification of the energized status are effectively reduced.

[0066] As an implementation method, Figure 3 As shown, the high-voltage live display device also includes:

[0067] The unlocking execution module 107 has an input terminal connected to the second output terminal of the main control processing module 105 . The main control processing module 105 controls the unlocking execution module 107 to execute a locking action or an unlocking action according to the judgment result.

[0068] The unlocking execution module 107 is used to lock or unlock the high-voltage electrical equipment 100 or its associated operating mechanisms based on the determination made by the main control processing module 105, ensuring operational safety and preventing misoperation. When the main control processing module 105 determines that the equipment is in a "powered state," it outputs a locking signal to the unlocking execution module 107, causing it to enter a locked state. By controlling relays, electronic switches, or electromagnetic actuators, the operating mechanisms are locked, prohibiting misoperations such as forced closing or plugging. When the main control processing module 105 determines that the equipment is in a "de-powered state," it outputs an unlocking signal. Upon receiving this signal, the unlocking execution module enters an unlocked state, removing physical interlocks or logical control restrictions, allowing personnel or systems to perform subsequent operations. The unlocking execution module 107 can be linked to devices such as switch mechanisms, motor drivers, and relays through normally open / normally closed contacts, digital signal lines, and drive currents, offering excellent versatility and scalability. The possible structures of the unlocking execution module 107 are: a control relay module; a MOS tube or transistor drive circuit; an electromagnetic locking mechanism control interface; and an electric actuator control module.

[0069] The technical effect of this embodiment is that the unlocking execution module realizes the locking or unlocking control of the operating mechanism by receiving the control signal output by the main control processing module 105, ensuring that the operation is allowed only when the device is in a power-off state, thereby effectively preventing the risk of electric shock and equipment damage caused by misoperation, and significantly improving the system's operational safety and intelligent interlocking capabilities.

[0070] As an example, Figure 4 As shown, the unlocking execution module 107 includes a resistor R7, a resistor R8, a transistor Q1, a diode D3 and a relay K1. The pin of the main control processing module 105 drives the relay K1 through the transistor Q1, outputting a set of normally open contacts and a set of normally closed contacts for the user to select and use for live locking control. KO1 is the control pin of the main control processing module 105, outputting a high level of 3.3V or a low level of 0V. Resistor R8 is a 10k ohm pull-down resistor. When power is first applied, the main control processing module 105 is not initialized, causing the control pin to be in a low level state, and relay K1 is stable and inactive. Resistor R7 is a 1k ohm current-limiting resistor, which limits the current flowing through the base of transistor Q1. Transistor Q1 is an NPN transistor, model MMBT2222A, which acts as a current amplifier. Relay K1 is model DSP1-5V, providing one set of normally open contacts and one set of normally closed contacts. Diode D3 is model 1N4148. When the relay K1 coil is closed, it forms a closed loop with the coil's reverse electromotive force to dissipate energy and protect the transistor Q1 circuit.

[0071] As an implementation manner, the signal acquisition module 101 is an inductive sensor, and the inductive sensor is used to acquire the inductive signal in the high-voltage electrical equipment 100 .

[0072] The inductive sensor is used to contactlessly collect changes in the electric or magnetic field generated by high-voltage electrical equipment 100 during operation. Using the principle of electromagnetic induction, these changes are converted into analog signals (such as voltage or current signals) to indicate whether the high-voltage equipment is energized. The inductive sensor can sense the energized state without direct contact with the high-voltage conductor, providing excellent electrical isolation and safety. Possible structures for the inductive sensor include, but are not limited to, electric field sensing structures, capacitive sensing structures, and current sensing coils.

[0073] The technical effect of this embodiment is that the inductive sensor collects the inductive signals around the high-voltage electrical equipment 100 in real time in a non-contact manner, thereby realizing safe and reliable detection of the energized state of the equipment; compared with the traditional contact sampling method, the sensor has higher insulation performance and better environmental adaptability, effectively avoiding the electrical safety risks brought by direct contact with high-voltage conductors, and improving the stability and operational safety of the detection system.

[0074] As an implementation method, Figure 5 As shown, the signal amplification module 102 includes a surge protection module 201, a voltage stabilization module 202, an inductance module 203 and a negative feedback amplification module 204; one end of the surge protection module 201 is the input end of the signal amplification module 102, the other end of the surge protection module 201 is respectively connected to one end of the voltage stabilization module 202 and the first end of the inductance module 203, the other end of the voltage stabilization module 202 and the second end of the inductance module 203 are commonly connected to the ground, the third end of the inductance module 203 is connected to the first input end of the negative feedback amplification module 204, the third end of the inductance module 203 and the second input end of the negative feedback amplification module 204 are commonly connected to the ground, and the output end of the negative feedback amplification module 204 is the output end of the signal amplification module 102.

[0075] Among them, the surge protection module 201 is used to protect the subsequent circuit from surge impacts, voltage spikes, electromagnetic pulse interference, etc. from the induction signal input end, ensuring the safe operation of the system; the possible structure of the surge protection module 201 is a PTC (positive temperature coefficient) thermistor, which quickly heats up and limits the current when a surge occurs; a small gas discharge tube or a transient suppression module. The voltage stabilization module 202 stabilizes the input signal voltage after surge suppression to ensure the stability of the input level, suppress low-amplitude high-frequency interference, and improve circuit stability; the possible structure of the voltage stabilization module 202 is a voltage regulator diode, a three-terminal voltage regulator, etc. The inductor module 203 is used to filter out common-mode interference and stray high-frequency signals, further improving the purity of the signal, and providing electromagnetic isolation function; the possible structure of the inductor module 203 is a common-mode suppression inductor (bifilar winding type). Negative feedback amplifier module 204 linearly amplifies the signal after protection and filtering in the previous stage, and uses negative feedback technology to control the amplification factor, improving amplification accuracy and stability. Negative feedback amplifier module 204 may be a non-inverting or inverting amplifier circuit composed of an operational amplifier 303. The operating process is as follows: the weak signal output by the sensor first enters the surge protection module 201 to protect against static shock and transient high voltage. The voltage regulator module 202 stabilizes the input voltage and removes overvoltage interference. The signal then passes through the inductor module 203 to filter out high-frequency noise and improve the signal-to-noise ratio. Finally, the signal is sent to the negative feedback amplifier module 204 for stable linear amplification, outputting a filtered voltage signal for subsequent filtering and AD sampling.

[0076] The technical effect of this embodiment is that by sequentially arranging a surge protection module, a voltage stabilization module, an inductance module, and a negative feedback amplification module, surge impacts and high-frequency interference at the input end can be effectively suppressed to ensure stable signal input; at the same time, a negative feedback amplification structure is used to amplify weak sensing signals with high precision, thereby improving signal amplitude and signal-to-noise ratio, and providing clear and stable signals for subsequent filtering and digital processing, thereby significantly enhancing anti-interference capability and signal detection accuracy.

[0077] As an example, Figure 6As shown, the surge protection module 201 is a positive temperature thermistor PTC1, the voltage stabilizing module 202 is a TVS tube (transient voltage suppression diode) D2, the inductor module 203 is a common mode suppression inductor L2, and the negative feedback amplifier module 204 includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C6 and a chip U10; one end of the positive temperature thermistor PTC1 is the input end of the signal amplification module 102, and the other end of the positive temperature thermistor PTC1 is connected to one end of the TVS tube D2 and the first end of the common mode suppression inductor L2 respectively. The third end of the common-mode suppression inductor L2 is connected to one end of the resistor R1, and the other end of the resistor R1 is respectively connected to one end of the capacitor C1, one end of the resistor R2, one end of the resistor R3, and one end of the capacitor C6. The other end of the resistor R2 is connected to the inverting input terminal of the chip U10. The fourth end of the common-mode suppression inductor L2, the other end of the capacitor C6, and the non-inverting input terminal of the chip U10 are commonly connected to the ground. The output terminal of the chip U10 is the output terminal of the signal amplification module 102.

[0078] The circuit structure operates as follows: sensor signal S1_IN is protected by components like positive temperature thermistor PTC1, TVS diode D2, and common-mode suppression inductor L2 before entering chip U10. After being amplified and converted to a voltage range of 0 to ±1.5V, it is connected to the next-level circuit. The positive temperature thermistor PTC1 prevents sensor-induced surge interference from damaging the circuit; TVS diode D2 prevents static electricity and overvoltage interference from damaging the circuit; common-mode suppression inductor L2 reduces common-mode interference of the input signal; resistor R2 is a current-limiting resistor, protecting the pins of chip U10 from overcurrent damage; capacitors C1 and C6 serve as bypass capacitors for the amplifier circuit, preventing self-oscillation. Resistors R1 (510 ohm resistor), R3 (47k ohm resistor), and chip U10 form a negative feedback amplifier circuit, amplifying the input signal before outputting it.

[0079] As an implementation method, Figure 7 As shown, the signal filtering module 103 includes a first-stage RC low-pass circuit 301, a second-stage RC low-pass circuit 302 and an operational amplifier 303. The first end of the first-stage RC low-pass circuit 301 is the input end of the signal filtering module 103, the second end of the first-stage RC low-pass circuit 301 is connected to the first end of the second-stage RC low-pass circuit 302, the second end of the second-stage RC low-pass circuit 302 is connected to the non-inverting input end of the operational amplifier 303, the output end of the operational amplifier 303 is respectively connected to the inverting input end of the operational amplifier 303 and the third end of the first-stage RC low-pass circuit 301, and the third end of the second-stage RC low-pass circuit 302 is grounded.

[0080] The first-stage RC low-pass circuit 301 performs a first-stage low-pass filtering on the input signal, attenuating interference components above the cutoff frequency. A possible structure for the first-stage RC low-pass circuit 301 is a resistor and a capacitor connected in series; this can form a simple RC filter, determining the initial filtering characteristics. The second-stage RC low-pass circuit 302 further fine-filters the signal after the first-stage filtering, improving high-frequency suppression and forming a second-order filtering system. A possible structure for the second-stage RC low-pass circuit 302 is a resistor and a capacitor connected in series; this forms a cascaded structure with the first-stage RC low-pass circuit 301. The operational amplifier 303, serving as the amplification core of the active filter, provides buffering and negative feedback, enhancing filter stability and suppressing signal attenuation. The working process is that the input end of the filter module receives an amplified analog signal containing the target frequency component and high-frequency interference; the signal first passes through the first-stage RC low-pass circuit 301 to preliminarily filter out high-frequency noise above the designed cutoff frequency (such as 1kHz); the signal is further transmitted to the second-stage RC low-pass circuit 302 to enhance the filtering and interference suppression effects; the operational amplifier 303 provides low output impedance and signal tracking to avoid signal distortion or slow response; its output is both stable and suitable for connection to the subsequent ADC module for sampling.

[0081] As an example, Figure 8 As shown, the first-stage RC low-pass circuit 301 includes resistor R5 and capacitor C2, while the second-stage RC low-pass circuit 302 includes resistor R6 and capacitor C3. The signal is input to chip U11, passing the low-frequency signal and filtering out high-frequency interference before entering the next stage of AD conversion. Resistor R5 is a 68k ohm resistor, and capacitor C2 is a 1.6nF capacitor, forming the first-stage RC low-pass circuit 301. Resistor R6 is a 140k ohm resistor, and capacitor C3 is a 1.6nF capacitor, forming the second-stage RC low-pass circuit 302. Chip U11 is an OP07 low-noise operational amplifier. These two RC stages form a second-order low-pass active filter circuit.

[0082] As an embodiment, the signal processing module 104 is an adder, the first input end of the adder receives the filtered signal, and the second input end of the adder receives the offset voltage; the adder is used to superimpose the filtered signal and the offset voltage to offset the filtered signal into the positive voltage range.

[0083] The adder's primary function is to superimpose the filtered AC signal with a constant offset voltage, shifting the signal, which originally contained positive and negative voltage waveforms, into the positive voltage range to meet the input requirements of the subsequent analog-to-digital converter (ADC). The filtered signal typically fluctuates around 0V, fluctuating within a ±1.5V range. This makes it difficult to directly connect to the ADC channels of most control chips. For example, the ADC input range of the STM32 series is typically 0 to 3V, preventing negative voltages from causing ADC sampling errors or hardware damage.

[0084] As an implementation manner, the main control processing module 105 performs Fourier operation on the digital signal according to a preset sampling frequency to obtain amplitudes of multiple frequency signals, and obtains the amplitude of the target frequency signal from the amplitudes of the multiple frequency signals.

[0085] Among them, after receiving the digital signal after analog-to-digital conversion, the main control processing module 105 first performs a fast Fourier transform (FFT) operation on the signal according to a preset sampling frequency (such as 2kHz), which can convert the time domain signal into the frequency domain, and then analyze the energy size (i.e., amplitude) corresponding to each frequency component in the signal. By performing the FFT operation, the main control processing module 105 can obtain the signal amplitude of multiple frequency points, such as 0Hz (DC component), 50Hz (power frequency signal), 100Hz, 150Hz and other harmonic components. Subsequently, the main control processing module 105 selects the amplitude data corresponding to the target frequency (e.g., 50Hz, corresponding to the power grid frequency in my country) from these frequency components for subsequent state discrimination. The amplitude of the target frequency signal reflects whether the device is in a live state. If the amplitude is higher than the set threshold value, it means that there is a significant power frequency electric field around the device and it is judged to be in a live state; otherwise, it is in a dead state. When the main control processing module 105 detects that the amplitude of the target frequency signal is greater than the preset value, it determines that it is in a powered state and outputs a locking control signal; when the main control processing module 105 detects that the amplitude of the target frequency signal is not greater than the preset value, it determines that it is in a de-powered state and outputs an unlocking control signal. The specific judgment logic is as follows:

[0086] 1. When the amplitude of the target frequency signal is detected to be greater than a preset value, it indicates the presence of a significant power frequency electric field or current induction signal around the device, indicating that the device is in operation or powered on. At this point, the main control processing module 105 determines that the device is "powered" and immediately outputs a "lockout control signal" to control a relay or other interlocking mechanism to prevent operator error and ensure operational safety.

[0087] 2. If the amplitude of the target frequency signal is detected to be less than or equal to the preset value, the power frequency signal is weak or has disappeared, indicating that the device is in a power outage, disconnected, or non-operating state. The main control processing module 105 then determines that the device is in a "no power state" and outputs an "unlock control signal" to release the interlock and allow subsequent operations.

[0088] In this embodiment, the main control processing module 105 adopts a 32-bit high-performance microcontroller (MCU) of model STM32F103RCT6, which has a built-in analog-to-digital converter (ADC) and powerful processing capabilities, and is suitable for real-time signal analysis and processing. Figure 9As shown, the main control chip connects the analog signal output by the signal processing module 104 to its ADC input channel and performs periodic sampling at a sampling frequency of 2kHz, converting the continuous analog signal into equally spaced digital sample values. Each sampling acquires 20 points, forming a complete data sampling sequence. Subsequently, the main control chip runs a built-in 20-point fast Fourier transform (FFT) algorithm to perform frequency domain analysis on the sampled digital signal, completing the transformation from the time domain to the frequency domain. The algorithm extracts the amplitude information of the following frequency components: DC component (0Hz), 50Hz, 100Hz, 150Hz, 200Hz, 250Hz, 300Hz, 350Hz, 400Hz, 450Hz, 500Hz, 550Hz, 600Hz, 650Hz, 700Hz, 750Hz, 800Hz, 850Hz, 900Hz, and 950Hz. The remaining frequency components are not involved in the calculation and output, thereby effectively filtering out high-frequency interference signals and non-target frequency band energy. Because the AC frequency of my country's power grid is 50Hz, the program specifically extracts and analyzes the amplitude corresponding to this frequency, using it as an effective basis for determining whether the device is energized. The main control program compares the extracted 50Hz frequency amplitude with the set energized threshold value and determines the current state based on the comparison result: if the 50Hz amplitude is greater than the threshold value, the device is determined to be energized, and the main control processing module 105 outputs a lock control signal; if the 50Hz amplitude is less than or equal to the threshold value, the device is determined to be de-energized, and the main control processing module 105 outputs an unlock control signal.

[0089] Through the above method, accurate judgment of the energized state of high-voltage equipment is achieved. At the same time, it has strong anti-interference ability and signal recognition selectivity, which significantly improves the safety and reliability of system operation.

[0090] Furthermore, the main control processing module 105 not only extracts the amplitude of the target frequency (e.g., 50Hz) signal but also combines the amplitude information of multiple harmonic components of the signal (e.g., 100Hz, 150Hz, 200Hz, etc.) to perform multi-frequency fusion analysis to improve the accuracy and anti-interference ability of the device's power-on status judgment. The main control processing module performs analog-to-digital conversion (ADC) on the filtered and offset analog signal at a sampling frequency of 2kHz, obtains 20 consecutive sampling points, and then runs a 20-point fast Fourier transform (FFT) algorithm to obtain amplitude information including the following frequencies: DC component (0Hz); fundamental frequency (50Hz); and various harmonic frequencies (100Hz, 150Hz, 200Hz, 250Hz, 300Hz, 350Hz, 400Hz, 450Hz, etc.).

[0091] To improve the robustness of the judgment, the amplitudes of the three frequency bands of 50Hz, 100Hz, and 150Hz are selected from the above frequencies and fused. The fusion method is weighted averaging or amplitude superposition. For example:

[0092] F_total=a1×|X1|+a2×|X2|+a3×|X3|;

[0093] Among them, |X1|, |X2|, |X3| are the amplitudes of the corresponding frequency components, and a1, a2, and a3 are preset weighting coefficients, satisfying a1>a2>a3 to ensure the dominance of the main frequency signal.

[0094] Compare the fused integrated amplitude F_total with the set threshold value F_threshold:

[0095] When F_total>F_threshold, the device is judged to be in a powered state; when F_total≤F_threshold, the device is judged to be in a de-powered state.

[0096] In addition, if the amplitude of a certain harmonic (such as 100Hz) is found to be abnormally high and exceeds the main frequency, an interference environment alarm may be triggered, reminding the user that there may be a risk of electromagnetic harmonic interference.

[0097] Through this multi-frequency fusion mechanism, even when the main frequency signal is weak or covered by interference, the system can still make auxiliary judgments based on harmonic information, thereby enhancing judgment accuracy and anti-interference performance. It is suitable for high-voltage equipment status detection in complex electromagnetic environments.

[0098] Example 2

[0099] The second embodiment provides a high-voltage device, including the high-voltage live detection device and high-voltage electrical equipment provided in the first embodiment.

[0100] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A high voltage live detection device, characterized in that: include: A signal acquisition module, whose acquisition end is connected to the high-voltage electrical equipment and is used to acquire the induction signal generated during the operation of the high-voltage electrical equipment; a signal amplifying module, whose input end is connected to the output end of the signal acquisition module and is used to amplify the sensing signal; a signal filtering module, whose input end is connected to the output end of the signal amplification module, and is used to perform low-pass filtering on the amplified signal; a signal processing module, whose input end is connected to the output end of the signal filtering module, and is used to perform offset processing on the filtered signal to obtain an analog signal; The main control processing module, whose input end is connected to the output end of the signal processing module, is used to convert the analog signal into a digital signal, extract the amplitude of the target frequency signal after performing spectrum analysis on the digital signal, and compare it with the preset value to determine the charged state.

2. The high voltage live detection device according to claim 1, characterized in that: The high-voltage charged display device further includes: The status display module has an input end connected to the first output end of the main control processing module, and the main control processing module displays the power-on state or the power-off state through the status display module according to the judgment result.

3. The high voltage live detection device according to claim 2, characterized in that: The high-voltage charged display device further includes: The unlocking execution module has an input end connected to the second output end of the main control processing module, and the main control processing module controls the unlocking execution module to execute a locking action or an unlocking action according to the judgment result.

4. The high voltage live detection device according to any one of claims 1 to 3, characterized in that: The signal acquisition module is an inductive sensor, which is used to acquire the inductive signal from the high-voltage electrical equipment.

5. The high voltage live detection device according to any one of claims 1 to 3, characterized in that: The signal amplification module includes a surge protection module, a voltage stabilization module, an inductance module and a negative feedback amplification module; One end of the surge protection module is the input end of the signal amplification module, the other end of the surge protection module is respectively connected to one end of the voltage stabilization module and the first end of the inductance module, the other end of the voltage stabilization module and the second end of the inductance module are commonly connected to the ground, the third end of the inductance module is connected to the first input end of the negative feedback amplification module, the fourth end of the inductance module and the second input end of the negative feedback amplification module are commonly connected to the ground, and the output end of the negative feedback amplification module is the output end of the signal amplification module.

6. The high voltage live detection device according to any one of claims 1 to 3, characterized in that: The signal filtering module includes a first-stage RC low-pass circuit, a second-stage RC low-pass circuit and an operational amplifier. The first end of the first-stage RC low-pass circuit is the input end of the signal filtering module, the second end of the first-stage RC low-pass circuit is connected to the first end of the second-stage RC low-pass circuit, the second end of the second-stage RC low-pass circuit is connected to the non-inverting input end of the operational amplifier, the output end of the operational amplifier is respectively connected to the inverting input end of the operational amplifier and the third end of the first-stage RC low-pass circuit, and the third end of the second-stage RC low-pass circuit is grounded.

7. The high voltage live detection device according to any one of claims 1 to 3, characterized in that: The signal processing module is an adder, a first input terminal of the adder receives the filtered signal, and a second input terminal of the adder receives the offset voltage; The adder is used to superimpose the filtered signal and the offset voltage to offset the filtered signal into a positive voltage range.

8. The high voltage live detection device according to claim 3, characterized in that: The main control processing module performs Fourier operation on the digital signal according to a preset sampling frequency to obtain amplitudes of multiple frequency signals, and obtains the amplitude of the target frequency signal from the amplitudes of the multiple frequency signals.

9. The high voltage live detection device according to claim 8, characterized in that: When the main control processing module detects that the amplitude of the target frequency signal is greater than a preset value, it determines that the signal is in a powered state and outputs a locking control signal to the unlocking execution module; When the main control processing module detects that the amplitude of the target frequency signal is not greater than a preset value, it determines that the power is off and outputs an unlocking control signal to the unlocking execution module.

10. A high-voltage device, characterized in that: It comprises at least one high-voltage live detection device according to any one of claims 1 to 9 and high-voltage electrical equipment.

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