Non-intrusive relay protection device outlet hard pressure plate status monitoring device and method

Abstract

This application discloses a non-intrusive relay protection device outlet hard pressure plate state monitoring device, relating to the field of state monitoring. The device includes a signal generating module and a pressure plate monitoring module. The signal generating module is connected to the lower terminal of the outlet hard pressure plate, the signal generating module is used to generate a reference square wave signal, and the pressure plate monitoring module is connected to the signal generating module. The pressure plate monitoring module is used to receive and analyze the pressure plate state signal to obtain output signal parameters. The pressure plate monitoring module is also used to analyze the output signal parameters to determine the switching state of the outlet hard pressure plate in the relay protection circuit. This application can effectively solve the problem that the existing technology has difficulty in accurately monitoring the switching state of the outlet hard pressure plate in real time through low-cost design.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of status monitoring, and in particular to a non-invasive device and method for monitoring the status of an outlet hard pressure plate. Background Art

[0002] The outlet pressure plate serves as the link between the relay protection device and the circuit breaker trip circuit or other actuators (such as signaling devices). When the relay protection device detects a fault and generates an actuation signal, this actuation signal is transmitted to the circuit breaker trip coil or other related actuators only when the outlet pressure plate is engaged, causing the circuit breaker to trip or trigger a corresponding signal. During maintenance, calibration, or commissioning of the relay protection device, the outlet pressure plate must be disconnected to avoid disrupting the normal operation of external equipment. Therefore, status monitoring of the outlet pressure plate is necessary to ensure that its status meets the varying requirements of current power system operation and maintenance.

[0003] Existing solutions for monitoring the status of hard platens involve installing image acquisition equipment to capture and analyze images of the platens and then identifying their status based on the images. While this method can monitor the status of the platens, it is prohibitively expensive. Furthermore, dirt or damage on the platen surface can lead to errors in the monitoring results, impacting the operation and maintenance of the power system. Furthermore, the image recognition and processing algorithms are computationally intensive, and the image acquisition equipment needs to capture images of the platens at high frequencies, resulting in a large amount of image data. These factors can lead to delays in image acquisition and analysis, impacting the real-time nature of hard platen status monitoring. Summary of the Invention

[0004] The embodiments of the present application provide a non-invasive relay protection device outlet hard pressure plate status monitoring device and method, which are used to solve the problem that the existing technology is difficult to accurately monitor the outlet hard pressure plate's insertion and withdrawal status in real time through low-cost design.

[0005] In the first aspect, a non-invasive relay protection device outlet hard pressure plate state monitoring device is provided, which is applied to the outlet hard pressure plate in the relay protection circuit. The device includes a signal generating module and a pressure plate monitoring module. The signal generating module is connected to the lower terminal of the outlet hard pressure plate. The signal generating module is used to generate a reference square wave signal. The reference square wave signal is converted into a pressure plate state signal based on the state change of the outlet hard pressure plate. The pressure plate monitoring module is connected to the signal generating module. The pressure plate monitoring module is used to receive and parse the pressure plate state signal to obtain output signal parameters. The pressure plate monitoring module is also used to obtain the potential state of the outlet hard pressure plate according to the output signal parameters, and to feedback the switching state of the outlet hard pressure plate in the relay protection circuit according to the potential state.

[0006] Optionally, the pressure plate monitoring module includes an element protection unit, an analog-to-digital converter, a microcontroller and a first relay connected in series in sequence, the element protection unit is connected to the signal generating module, the element protection unit protects the pressure plate monitoring module, the analog-to-digital converter is used to receive the pressure plate status signal, and transmit the pressure plate status signal to the microcontroller after analog-to-digital conversion, the microcontroller is used to parse the pressure plate status signal after analog-to-digital conversion, obtain output signal parameters, and obtain the potential state of the outlet hard pressure plate based on the output signal parameters. The first relay feeds back the potential state output by the microcontroller through the on-off state of the built-in passive switch contact.

[0007] Optionally, the component protection unit includes a second resistor, a third resistor, a fourth resistor, a voltage regulator diode, a voltage comparator, an optocoupler, a transistor and a second relay, one end of the second resistor and the third resistor are both connected to the in-phase end of the voltage comparator, the other end of the second resistor is connected to the signal generating module, the other end of the third resistor is grounded, the anode of the voltage regulator diode is connected to the inverting end of the voltage comparator, the cathode of the voltage regulator diode is grounded, the output end of the voltage comparator is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the anode of the optocoupler, the cathode of the optocoupler is grounded, the emitter of the optocoupler is connected to the base of the transistor, the collector of the transistor is connected to one end of the second relay, the emitter of the transistor is grounded, the other end of the second relay is connected to the analog-to-digital converter, and the collector of the optocoupler, the voltage comparator and the second relay are all connected to the power supply.

[0008] Optionally, the signal generating module includes an inductive capacitor assembly and a square wave generating source, the inductive capacitor assembly is fixedly connected to the lower terminal of the outlet hard pressure plate, when the lower terminal of the outlet hard pressure plate is in a non-floating state, the inductive plate in the inductive capacitor assembly and the lower terminal form an equivalent capacitor, the built-in resistor in the inductive capacitor assembly and the equivalent capacitor form an RC circuit, the square wave generating source is connected to the inductive capacitor assembly and is used to generate a reference square wave signal, the reference square wave signal is converted into a pressure plate status signal after passing through the RC circuit, and the pressure plate monitoring module is connected to the inductive capacitor assembly and receives the pressure plate status signal.

[0009] Optionally, the inductive capacitor assembly includes a metal adapter and a capacitive sensor, the inductive plate is embedded in one end of the capacitive sensor, one side of the inductive plate is attached to the inside of the capacitive sensor and is connected to the built-in resistor inside the capacitive sensor, the other side of the inductive plate is completely covered with high-voltage resistant insulating material, one end of the metal adapter is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter is fixedly attached to the side of the high-voltage resistant insulating material away from the inductive plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the lower terminal of the outlet hard pressure plate forms an equivalent capacitor with the inductive plate via the metal adapter, and the equivalent capacitor and the built-in resistor form an RC circuit.

[0010] In a second aspect, the present application provides a non-invasive method for monitoring the status of an outlet hard pressure plate, which is applied to any device described in the first aspect, and is characterized in that the method comprises the following steps:

[0011] The signal generating module continuously outputs a reference square wave signal, and based on the state change of the outlet hard pressure plate, the signal generating module is used to convert the reference square wave signal to obtain a pressure plate state signal;

[0012] Utilizing the pressure plate monitoring module to analyze the pressure plate status signal to obtain output signal parameters;

[0013] Analyzing the output signal parameters by the pressure plate monitoring module to obtain the potential state of the outlet hard pressure plate;

[0014] If the potential state is a floating state, the outlet hard pressure plate is fed back to indicate that it is in an exit state in the circuit of the relay protection device;

[0015] If the potential state is a non-floating state, the outlet hard pressure plate is fed back to the relay protection device circuit to be in an engaged state.

[0016] Optionally, the utilizing the pressure plate monitoring module to analyze the pressure plate status signal to obtain output signal parameters comprises the following steps:

[0017] Performing analog-to-digital conversion on the pressure plate state signal by the analog-to-digital converter to obtain a pressure plate state conversion signal;

[0018] The microcontroller uses a filtering algorithm to perform denoising on the pressure plate state conversion signal to obtain a pressure plate state low-noise signal;

[0019] Correcting the platen state low-noise signal using a baseline correction algorithm, and performing de-jitter processing on the corrected platen state low-noise signal to obtain a platen state standard signal;

[0020] Calculating the voltage change rate of the pressure plate state standard signal by the microcontroller, and extracting the charge and discharge interval and the high and low level interval of the pressure plate state standard signal according to the voltage change rate;

[0021] Extracting the edge time of the pressure plate state standard signal according to the charge and discharge interval, and calculating the rise time and fall time of the pressure plate state standard signal according to the edge time;

[0022] Calculating an average voltage of the pressure plate state standard signal within the high and low level intervals, and calculating a signal amplitude of the pressure plate state standard signal based on the average voltage;

[0023] Calculating the signal slope of the pressure plate state standard signal by combining the rise time, the fall time and the state signal amplitude;

[0024] The rise time, fall time, signal amplitude and signal slope are integrated to obtain output signal parameters.

[0025] Optionally, performing analog-to-digital conversion on the pressure plate state signal by the analog-to-digital converter to obtain a pressure plate state conversion signal comprises the following steps:

[0026] Sampling the platen status signal by an analog-to-digital converter using preset sampling parameters to obtain a signal sampling value;

[0027] Locking the signal sampling value by using a sample-and-hold circuit in the analog-to-digital converter, and mapping the locked signal sampling value into a discrete signal value;

[0028] Information encoding is performed on the discrete signal value, and a pressure plate state conversion signal is obtained according to the information encoding result.

[0029] Optionally, analyzing the potential state of the outlet hard pressure plate based on the output signal parameters includes the following steps:

[0030] Calculating the parameter similarity between the output signal parameters and the preset theoretical signal parameters using a similarity calculation formula;

[0031] Determining whether the pressure plate state standard signal has charge and discharge characteristics based on the parameter similarity;

[0032] If the pressure plate state standard signal does not have a charge-discharge feature, determining that the potential state is a floating state;

[0033] If the pressure plate state standard signal has a charge-discharge feature, it is determined that the pressure plate state is a non-floating state.

[0034] Optionally, the method further comprises the following steps:

[0035] Calculating the actual capacitance between the inductive capacitor assembly and the outlet hard pressure plate according to the output signal parameters, and calculating the capacitance difference between the actual capacitance and the pre-calculated theoretical capacitance;

[0036] If the capacitance difference is greater than a preset difference threshold, it is determined that there is a capacitance component abnormality in the sensing capacitance component;

[0037] If the capacitance difference is less than or equal to the preset difference threshold, it is determined that there is no capacitance component abnormality in the sensing capacitance component.

[0038] The beneficial effects of this application are:

[0039] In the relay protection circuit, when the outlet hard pressure plate is in the exit state, its lower terminal is not connected to any circuit and is in a floating state. If the outlet hard pressure plate is in the engaged state, the lower terminal of the outlet hard pressure plate is connected to the circuit and is in a non-floating state. Based on this principle, the lower terminal of the outlet hard pressure plate is connected to the signal generation module, and the signal generation module is used to generate a reference square wave signal. The reference square wave signal is converted into a pressure plate state signal by the signal generation module. Since the conversion result of the reference square wave signal is based on the state of the outlet hard pressure plate, the pressure plate state signal can be received and analyzed by the pressure plate monitoring module to obtain the output signal parameters. The output signal parameters are analyzed by the pressure plate monitoring module to obtain the potential state of the outlet hard pressure plate, that is, whether the outlet hard pressure plate is in a floating state. Based on whether the outlet hard pressure plate is in a floating state, the switching state of the outlet hard pressure plate in the relay protection circuit can be determined, thereby realizing real-time and accurate monitoring of the state of the outlet hard pressure plate, ensuring that the state of the outlet hard pressure plate meets the different requirements of the current power system operation and maintenance, thereby ensuring the normal operation of the power system.

[0040] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of an outlet hard plate status monitoring device provided in an embodiment of the present application;

[0042] Figure 2 A circuit diagram of a relay protection circuit provided in an embodiment of the present application;

[0043] Figure 3 A schematic diagram of a second relay response and software processing flow provided in an embodiment of the present application;

[0044] Figure 4 A circuit diagram of a component protection unit provided in an embodiment of the present application;

[0045] Figure 5A circuit diagram of another component protection unit provided in an embodiment of the present application;

[0046] Figure 6 A schematic diagram of the structure of a planar capacitor provided in an embodiment of the present application;

[0047] Figure 7 A schematic structural diagram of a cylindrical capacitor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0049] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0050] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their 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 at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0051] Figure 1 The present application discloses a non-intrusive relay protection device for monitoring the state of a hard pressure plate at an outlet, referring to Figure 1, applied to the outlet hard pressure plate in the relay protection circuit, characterized in that the device includes a signal generating module and a pressure plate monitoring module, the signal generating module is connected to the lower terminal of the outlet hard pressure plate, the signal generating module is used to generate a reference square wave signal, and the reference square wave signal is converted into a pressure plate state signal based on the state change of the outlet hard pressure plate, the pressure plate monitoring module is connected to the signal generating module, the pressure plate monitoring module is used to receive and parse the pressure plate state signal to obtain the output signal parameters, and the pressure plate monitoring module is also used to obtain the potential state of the outlet hard pressure plate according to the output signal parameters, and feedback the switching state of the outlet hard pressure plate in the relay protection circuit according to the potential state.

[0052] In this embodiment, referring to Figure 2 The relay protection circuit includes a closing position relay, a tripping output contact, an output hard pressure plate, a tripping auxiliary contact and a tripping coil. One end of the closing position relay is connected to the positive pole of the power supply, one end of the tripping output contact is connected to the positive pole of the power supply, the other end of the tripping output contact is connected to the lower terminal of the output hard pressure plate, the other end of the closing position relay and the upper terminal of the output hard pressure plate are both connected to one end of the tripping auxiliary contact, the other end of the tripping auxiliary contact is connected to one end of the tripping coil, and the other end of the tripping coil is connected to the negative pole of the power supply.

[0053] The trip auxiliary contact is used to reflect the operating status of the circuit breaker. When the circuit breaker is in the closed position, the normally open contact of the trip auxiliary contact is closed and the normally closed contact is open. When the circuit breaker is in the open position, the normally open contact is open and the normally closed contact is closed. The trip auxiliary contact is primarily used in control circuits to ensure that the circuit breaker's operating instructions accurately reflect its actual status. The trip coil is an electromagnet assembly inside the circuit breaker. When the coil is energized, it generates magnetic force, driving the mechanical mechanism to open the circuit breaker. The trip output contact is the logic control contact output by the relay protection device. When the relay protection device determines that a system fault has occurred, the relay protection device issues a trip command through the trip output contact, and the circuit breaker operates according to the command. The state of the trip output contact directly affects the operation of the circuit breaker and is critical to protecting equipment and personal safety.

[0054] The output pressure plate serves as the connection between the relay protection device and the circuit breaker trip circuit or other actuators (such as signaling devices). It isolates the protection device's internal logic from the external actuator circuit. When the relay protection device detects a fault and generates an action signal, this action signal is transmitted to the circuit breaker trip coil or other related actuator only when the output pressure plate is engaged, causing the circuit breaker to trip or trigger a corresponding signal. During maintenance, verification, or commissioning of the relay protection device, the output pressure plate conveniently disconnects the protection device's output signal from the external actuator circuit. This allows technicians to inspect and test the various functions and logic within the relay protection device without affecting the normal operation of external equipment (for example, preventing the circuit breaker from tripping).

[0055] The closing position relay is used to detect the closing position of the circuit breaker to ensure the accuracy and reliability of the circuit breaker operation. By monitoring the output signal of the closing position relay, the status of the circuit breaker can be grasped in real time, thereby ensuring the transmission and execution of high-precision opening and closing instructions, avoiding equipment failure or personal injury due to misoperation or other reasons.

[0056] The outlet pressure plate status monitoring device includes a signal generating module and a pressure plate monitoring module. The signal generating module is connected to the outlet pressure plate's lower terminal. The pressure plate monitoring module monitors the outlet pressure plate's potential through the signal generating module to monitor the plate's switching status in the relay protection circuit. Specifically, the signal generating module is connected to the pressure plate monitoring module and contains an inductive capacitor assembly and a square wave generator. The square wave generator continuously outputs a reference square wave signal. When the outlet pressure plate's lower terminal is not floating, meaning the outlet pressure plate is switched on in the relay protection circuit, the inductive capacitor assembly forms an equivalent capacitor with the lower terminal. Because the inductive capacitor assembly contains a built-in resistor, an RC circuit (resistance-capacitance circuit) is formed between the built-in resistor and the equivalent capacitor. This RC circuit provides filtering, timing and delay, waveform shaping, and signal amplification and attenuation. Furthermore, because the RC circuit consists of a capacitor and a resistor, when the power source charges the capacitor through the resistor, the resistor limits the current, while the capacitor stores the charge. When the capacitor discharges through the resistor, the stored charge is gradually released through the resistor. According to this principle, if a square wave of a certain frequency is applied to an RC circuit, a waveform exhibiting a charge-discharge process can be obtained after the square wave passes through the RC circuit. Conversely, if a square wave of the same frequency is applied to an ordinary non-RC circuit, a square wave waveform without a charge-discharge process is obtained. Therefore, a reference square wave signal is generated using a signal generation module. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor, and the equivalent capacitor forms an RC circuit with the built-in resistor in the inductive capacitor component. The reference square wave signal is converted into a pressure plate status signal through the RC circuit. The pressure plate status signal is sampled and analyzed using the pressure plate monitoring module. It can be found that the pressure plate status signal has charge-discharge characteristics. Conversely, when the lower terminal of the outlet hard pressure plate is in a floating state, the inductive capacitor component and the lower terminal of the outlet hard pressure plate do not form an equivalent capacitor, so there is no RC circuit. When the same reference square wave signal is input, the final pressure plate status signal does not have charge-discharge characteristics. According to the above principle, the pressure plate monitoring module can be used to perform characteristic analysis on the pressure plate status signal output from the signal generating module, and determine whether the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor based on whether the pressure plate status signal has charging and discharging characteristics, thereby determining the potential state of the lower terminal. If the potential state is a floating state, the monitoring result fed back by the pressure plate monitoring module is that the outlet hard pressure plate is in the exit state in the relay protection device circuit. If the potential state is a non-floating state, the monitoring result fed back by the pressure plate monitoring module is that the outlet hard pressure plate is in the input state in the relay protection device circuit, thereby achieving accurate monitoring of the outlet hard pressure plate status.

[0057] The outlet pressure plate status monitoring device allows real-time monitoring of the outlet pressure plate's status without changing the relay protection circuit. This prevents malfunctions in the device from tripping or closing the relay protection circuit, potentially impacting the entire power system. Furthermore, the device is low-cost and easy to install, making it suitable for widespread use in power systems.

[0058] In one embodiment, the pressure plate monitoring module includes an element protection unit, an analog-to-digital converter, a microcontroller and a first relay connected in series in sequence. The element protection unit is connected to the signal generating module. The element protection unit protects the pressure plate monitoring module. The analog-to-digital converter is used to receive the pressure plate status signal and transmit the pressure plate status signal to the microcontroller after analog-to-digital conversion. The microcontroller is used to analyze the pressure plate status signal after analog-to-digital conversion to obtain output signal parameters, and obtain the potential state of the outlet hard pressure plate based on the output signal parameters. The first relay feeds back the potential state output by the microcontroller through the on-off state of the built-in passive switch contact.

[0059] In this embodiment, the platen monitoring module includes a component protection unit, an analog-to-digital converter, a microcontroller, and a first relay. One end of the component protection unit is connected to the signal generation module, the other end of the component protection unit is connected to one end of the analog-to-digital converter, the other end of the analog-to-digital converter is connected to one end of the microcontroller, and the other end of the microcontroller is connected to the first relay. The primary function of the analog-to-digital converter (ADC) is to convert the continuous platen status signal into a discrete platen status transition signal through three steps: sampling, quantization, and encoding. This allows the microcontroller to subsequently extract, store, and transmit parameters from the platen status transition signal. The microcontroller can perform sliding average filtering on the pressure plate status signal to eliminate noise interference and calculate the parameters such as the rise time, fall time, signal amplitude and signal slope of the pressure plate status signal. These parameters can be used to determine whether the pressure plate status signal has the basis of charge and discharge characteristics. According to whether the pressure plate status signal has the charge and discharge characteristics, it can be determined whether the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor, thereby determining the potential state of the lower terminal. If the potential state is a floating state, the monitoring result fed back by the pressure plate monitoring module is that the outlet hard pressure plate is in the exit state in the relay protection device circuit. If the potential state is a non-floating state, the monitoring result fed back by the pressure plate monitoring module is that the outlet hard pressure plate is in the input state in the relay protection device circuit. Reference Figure 3The relay can quickly switch the state of the circuit upon receiving an electrical signal, thus realizing the on-off control of the circuit. Its working principle is based on electromagnetic induction. When current passes through the coil of the relay, a magnetic field is generated, which attracts the iron core to move the contacts, thereby realizing the on-off control of the circuit. The first relay can receive the judgment result of the on / off state from the microcontroller, and control the closing state of its internal passive switch contacts according to the on / off state. That is, when the outlet hard pressure plate is in the on state, the passive switch contact of the first relay is closed, and when the outlet hard pressure plate is in the off state, the passive switch contact of the first relay is opened. The closed state of the passive switch contact of the first relay can reflect the on / off state of the outlet hard pressure plate.

[0060] By using the above method, the switching status of the outlet hard pressure plate can be monitored in real time, and the final monitoring results can also be intuitively displayed through the status of the first relay, so that the power system staff can directly obtain the switching status of the outlet hard pressure plate based on the closed state of the passive switch contact, which is convenient for the subsequent power operations. In addition, since the present invention uses relay hard contact output, it can be easily connected to other systems without restriction. In addition, the present invention is a non-invasive sensing solution. Even if there is any abnormality in the outlet hard pressure plate status monitoring device, it will not affect the existing tripping circuit, ensuring the stable operation of the relay protection device.

[0061] In one embodiment, referring to Figure 4 The component protection unit includes a second resistor R2, a third resistor R3, a fourth resistor R4, a voltage regulator diode D1, a voltage comparator U1, an optocoupler U2A, a transistor Q1 and a second relay. One end of the second resistor R2 and the third resistor R3 are both connected to the non-inverting end of the voltage comparator U1, the other end of the second resistor R2 is connected to the signal generating module, the other end of the third resistor R3 is grounded, the anode of the voltage regulator diode D1 is connected to the inverting end of the voltage comparator U1, the cathode of the voltage regulator diode D1 is grounded, the output end of the voltage comparator U1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the anode of the optocoupler U2A, the cathode of the optocoupler U2A is grounded, the emitter of the optocoupler U2A is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to one end of the second relay, the emitter of the transistor Q1 is grounded, the other end of the second relay is connected to the analog-to-digital converter, the collector of the optocoupler U2A, the voltage comparator U1 and the second relay are all connected to the power supply VCC.

[0062] In this embodiment, the component protection unit includes a second resistor R2, a third resistor R3, a fourth resistor R4, a Zener diode D1, a voltage comparator U1, an optocoupler U2A, a transistor Q1, and a second relay. One end of the second resistor R2 and the third resistor R3 are both connected to the non-inverting end of the voltage comparator U1, the other end of the second resistor R2 is connected to the signal generating module, the other end of the third resistor R3 is grounded, the anode of the Zener diode D1 is connected to the inverting end of the voltage comparator U1, the cathode of the Zener diode D1 is grounded, the output end of the voltage comparator U1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the anode of the optocoupler U2A, the cathode of the optocoupler U2A is grounded, the emitter of the optocoupler U2A is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to one end of the second relay, the emitter of the transistor Q1 is grounded, the other end of the second relay is connected to the analog-to-digital converter, and the collector of the optocoupler U2A, the voltage comparator U1, and the second relay are all connected to the power supply VCC.

[0063] The second resistor R2 and the third resistor R3 act together as a voltage divider. If the equivalent capacitor experiences a component anomaly, such as damage to the high-voltage insulating material that makes up the equivalent capacitor, resulting in an excessive voltage at the pressure plate monitoring module, the voltage divider proportionally divides the voltage, limiting the current and preventing damage to the pressure plate monitoring module's components due to excessive current. The voltage comparator U1 primarily compares the two input voltages. When the input voltage exceeds a preset voltage threshold within the comparator, a trigger signal is generated. This trigger signal drives the optocoupler U2A, which converts the electrical signal at the input (i.e., the trigger signal) into an optical signal. This optical signal is then transmitted to the output and converted back into an electrical signal, achieving electrical isolation between the input and output, isolating the pressure plate monitoring module from the high voltage and thus protecting the pressure plate monitoring module. Furthermore, the Zener diode D1 provides a reference voltage for the comparator U1, enabling comparison with the input voltage at the non-inverting terminal. The reference voltage is equivalent to the preset voltage threshold. The collector of transistor Q1 is connected to one end of the second relay coil. When the voltage exceeds a preset threshold, transistor Q1 turns on, energizing the second relay coil and disconnecting the contacts, severing the physical connection between the pressure plate monitoring module and the high voltage, preventing the high voltage from continuing to be transmitted to the protection pressure plate monitoring module. In addition, due to the inductance inside the second relay, when the second relay coil is de-energized, a reverse electromotive force is generated due to the presence of inductance. The voltage of this reverse electromotive force may be very high, exceeding the withstand voltage value of transistor Q1, causing transistor Q1 to break down. Therefore, to prevent transistor Q1 from breaking down, a freewheeling diode can be connected in parallel across the relay coil. The anode of the freewheeling diode is connected to the collector of transistor Q1, and the cathode of the freewheeling diode is connected to the power supply VCC. The function of the freewheeling diode is to provide a low-impedance path, allowing this reverse current to flow back through the diode instead of through transistor Q1.

[0064] Although the probability of abnormal conditions such as damage to the high-voltage insulating material that constitutes the equivalent capacitor is small, once the high-voltage insulating material is damaged and the outlet hard pressure plate is in the engaged state, a short circuit may occur between the originally isolated capacitive sensor and the metal adapter, causing abnormal current flow, which may damage components such as the analog-to-digital converter and microcontroller in the pressure plate monitoring module. Therefore, a component protection module is required to protect components such as the analog-to-digital converter and microcontroller.

[0065] This application also provides another embodiment, referring to Figure 5The component protection unit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a reference voltage circuit, a second voltage comparator U2, a second transistor T1A, a diode D2 and a third relay. One end of the fifth resistor R5 and the sixth resistor R6 are both connected to the non-inverting end of the second voltage comparator U2, the other end of the fifth resistor R5 is connected to the signal generating module, the other end of the sixth resistor R6 is grounded, the reverse end of the second voltage comparator U2 is connected to the reference voltage circuit, the output end of the second voltage comparator U2 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to the base of the second transistor T1A, and the collector of the second transistor T1A is connected. An electrode is connected to one end of the third relay, an emitter of the second transistor T1A is grounded, one end of the eighth resistor R8 is connected between the seventh resistor R7 and the second transistor T1A, the other end of the eighth resistor R8 is grounded, an anode of the diode D2 is connected between the second transistor T1A and the third relay, a cathode of the diode D2 is connected between the third relay and the power supply VCC1, one end of the long arm contact of the third relay is connected to the analog-to-digital converter, the other end of the long arm contact of the third relay is connected between the fifth resistor R5 and the sixth resistor R6, the second voltage comparator U2 and the third relay are both connected to the power supply VCC1, and the reference voltage circuit is connected to the power supply VCC2.

[0066] In this embodiment, the component protection unit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a reference voltage circuit, a second voltage comparator U2, a second transistor T1A, a diode D2 and a third relay. One end of the fifth resistor R5 and the sixth resistor R6 are both connected to the in-phase terminal of the second voltage comparator U2, the other end of the fifth resistor R5 is connected to the signal generating module, the other end of the sixth resistor R6 is grounded, the reverse end of the second voltage comparator U2 is connected to the reference voltage circuit, the output end of the second voltage comparator U2 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to the base of the second transistor T1A, and the second transistor T1A is connected to the in-phase terminal of the second transistor T1A. The collector of A is connected to one end of the third relay, the emitter of the second transistor T1A is grounded, one end of the eighth resistor R8 is connected between the seventh resistor R7 and the second transistor T1A, the other end of the eighth resistor R8 is grounded, the anode of the diode D2 is connected between the second transistor T1A and the third relay, the cathode of the diode D2 is connected between the third relay and the power supply VCC1, one end of the long arm contact of the third relay is connected to the analog-to-digital converter, the other end of the long arm contact of the third relay is connected between the fifth resistor R5 and the sixth resistor R6, the second voltage comparator U2 and the third relay are both connected to the power supply VCC1, and the reference voltage circuit is connected to the power supply VCC2.

[0067] The main principle behind the component protection unit's ability to provide component protection is that the third relay is a normally closed solid-state relay driven by the second voltage comparator U2 and the second transistor T1A. When the input voltage at the non-inverting terminal of the voltage comparator is normal (i.e., the input voltage is less than or equal to the reference voltage provided by the reference voltage circuit connected to the inverting terminal), the input voltage simultaneously passes through the third relay to the analog-to-digital converter (ADC). When the input voltage at the non-inverting terminal is excessive (i.e., greater than the reference voltage), the second transistor T1A energizes and the third relay disconnects, providing protection. Specifically, the fifth resistor R5 and the sixth resistor R6 act as a voltage divider. If the equivalent resistor experiences abnormalities such as damage or aging of the high-voltage insulation material, the voltage input to the pressure plate monitoring module may be excessive, potentially damaging the components of the pressure plate monitoring module. Therefore, a voltage divider is required to proportionally divide the voltage and limit the current to prevent damage to the components of the pressure plate monitoring module caused by excessive current. The main function of the second voltage comparator U2 is to compare the size of the input voltage. When the input voltage exceeds the voltage threshold preset in the voltage comparator U1, a trigger signal is issued. The trigger signal can turn on the third relay, energize the third relay coil, disconnect the contacts, cut off the physical connection between the pressure plate monitoring module and the high voltage, and prevent the high voltage from continuing to be transmitted to the protection pressure plate monitoring module. The voltage threshold value depends on the size of the reference voltage provided by the reference voltage circuit connected to the inverting end of the second voltage comparator U2. The reference voltage circuit can be constructed by connecting a reference voltage source chip, a ninth resistor, and a tenth resistor. Specifically, one end of the ninth resistor is connected to one end of the reference voltage source chip, the other end of the ninth resistor is connected to one end of the tenth resistor, and the other end of the reference voltage source chip and the other end of the tenth resistor are both connected to ground. In addition, the reference voltage circuit is also constructed by connecting a junction field effect transistor and a resistor. Furthermore, to ensure the third relay's coil quickly reaches the required current and reduce electrical delay, a seventh resistor R7, an eighth resistor R8, and a second transistor T1A are connected between the third relay and the second voltage comparator U2. These resistors form a driver circuit that shortens the rise and fall times of the third relay's coil current. When the input voltage exceeds the reference voltage, the third relay quickly responds, severing the physical connection between the pressure plate monitoring module and the input voltage, thereby protecting the module. In the driver circuit, the seventh resistor R7 primarily functions as a current limiter. By adjusting its resistance, it ensures that the second transistor T1A operates in a saturated conduction or fully cutoff state, preventing overheating or insufficient drive due to excessive base current. When the base of the second transistor T1A is inactive (i.e., when the input voltage is less than or equal to the voltage threshold), the eighth resistor R8 pulls the base potential down to a low level, preventing leakage current from causing the second transistor T1A to erroneously turn on, thereby enhancing the driver circuit's anti-interference capabilities and stability.The second transistor T1A acts as an electronic switch, controlling the on / off state of the third relay coil via a base signal. When the input is high, the second transistor T1A conducts, energizing the third relay coil and closing the contacts. When the input is low, the second transistor T1A turns off, de-energizing the third relay coil and releasing the contacts. Finally, diode D2, connected in parallel with the third relay, dissipates the reverse electromotive force generated when the relay coil is de-energized, preventing breakdown of the second transistor T1A. Diode D2 can be a freewheeling diode.

[0068] Although the probability of abnormal conditions such as damage to the high-voltage insulating material that constitutes the equivalent capacitor is small, once the high-voltage insulating material is damaged, it may damage components such as the analog-to-digital converter and the microcontroller in the pressure plate monitoring module. Therefore, a component protection module is required to protect components such as the analog-to-digital converter and the microcontroller.

[0069] In one embodiment, the signal generating module includes an inductive capacitor component and a square wave generating source. The inductive capacitor component is fixedly connected to the lower terminal of the outlet hard pressure plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the inductive plate in the inductive capacitor component and the lower terminal form an equivalent capacitor, and the built-in resistor in the inductive capacitor component and the equivalent capacitor form an RC circuit. The square wave generating source is connected to the inductive capacitor component and is used to generate a reference square wave signal. The reference square wave signal is converted into a pressure plate status signal after passing through the RC circuit. The pressure plate monitoring module is connected to the inductive capacitor component and receives the pressure plate status signal.

[0070] In this embodiment, the signal generating module includes an inductive capacitor component and a square wave generating source. The inductive capacitor component is fixedly connected to the lower terminal of the outlet hard pressure plate, the square wave generating source is connected to the inductive capacitor component, and the inductive capacitor component is connected to the pressure plate monitoring module. The inductive capacitor component includes a metal adapter, a high-voltage resistant insulating material, an inductive plate, a capacitive sensor and a built-in resistor. Among them, the equivalent capacitor constructed by the metal adapter, the high-voltage resistant insulating material, the inductive plate, the capacitive sensor and the lower terminal includes types such as planar capacitors and cylindrical capacitors. When the lower terminal of the outlet hard pressure plate is in a non-floating state, that is, the outlet hard pressure plate is in the engaged state in the relay protection circuit, the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor. Since there is a built-in resistor in the inductive capacitor component, an RC circuit can be formed between the built-in resistor and the equivalent capacitor. Whether the RC circuit can be formed is the key to judging the in-and-out state of the outlet hard pressure plate.

[0071] The built-in resistor is not only a key component in forming the RC circuit, but also an important component in the charge and discharge speed after the RC circuit is formed. It is used to control the charge and discharge speed in the process of the square wave generator outputting the pressure plate status signal to ensure that the charge and discharge speed is not too small or too large. This is because a too small charge and discharge speed will lead to slow charging and discharging, which may cause the subsequent generation and analysis of the pressure plate status signal to be prolonged, thereby affecting the real-time monitoring of the export hard pressure plate status. In addition, the built-in resistor can also be used to limit the current, thereby protecting the signal generation module and preventing damage to the components of the protection signal generation module. The square wave generator refers to an electronic device that can generate square wave signals. The reason for using a square wave generator is that the square wave input signal is a periodic signal with steep rising and falling edges, which is quite different from the characteristics of the pressure plate status signal with charge and discharge characteristics. This makes the subsequent analysis of whether the pressure plate status signal has charge and discharge characteristics more accurate, thereby ensuring the accuracy of the export hard pressure plate status monitoring results.

[0072] In one embodiment, the inductive capacitor assembly includes a metal adapter and a capacitive sensor, the inductive plate is embedded in one end of the capacitive sensor, one side of the inductive plate is attached to the inside of the capacitive sensor and is connected to the built-in resistor inside the capacitive sensor, and the other side of the inductive plate is completely covered with high-voltage resistant insulating material. One end of the metal adapter is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter is fixedly attached to the side of the high-voltage resistant insulating material away from the inductive plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the lower terminal of the outlet hard pressure plate forms an equivalent capacitor with the inductive plate via the metal adapter, and the equivalent capacitor and the built-in resistor form an RC circuit.

[0073] In this embodiment, the inductive capacitor assembly includes a metal adapter, a high-voltage insulating material, an inductive plate, a capacitive sensor, and a built-in resistor. One side of the inductive plate is attached to the interior of the capacitive sensor and connected to the built-in resistor inside the capacitive sensor. The other side of the inductive plate is completely covered with a high-voltage insulating material. One end of the metal adapter is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter is fixedly attached to the side of the high-voltage insulating material away from the inductive plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, that is, the outlet hard pressure plate is in the engaged state in the relay protection circuit, the inductive capacitor assembly and the lower terminal of the outlet hard pressure plate form an equivalent capacitor. Since there is a built-in resistor in the inductive capacitor assembly, an RC circuit can be formed between the built-in resistor and the equivalent capacitor. In addition, equivalent capacitors include planar capacitors and cylindrical capacitors.

[0074] Reference Figure 6, the circular sensing plate is embedded in one end of the capacitive sensor. A layer of high-voltage insulating material is adhered to one side of the circular sensing plate outside the capacitive sensor. The high-voltage insulating material can be mica, silicone rubber, etc. The high-voltage insulating material completely covers the circular sensing plate, that is, the high-voltage insulating material can completely isolate the circular sensing plate from the metal adapter nut (one form of metal adapter). One end of the metal adapter nut is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter nut is fixedly fitted to the side of the high-voltage insulating material away from the circular sensing plate. The other end of the metal adapter nut can be coated with conductive glue, epoxy resin or other materials to fix it to the high-voltage insulating material. Figure 6 As shown in the figure, when the sensor is tightly pressed against the high-voltage (1000V) insulating material and the metal adapter nut, and the sensor is threadedly connected to the lower terminal of the outlet hard pressure plate through the metal adapter nut, a circular planar capacitor (equivalent capacitance) can be formed between the circular sensing plate inside the sensor and the nut of the metal adapter nut. At this time, the calculation formula for the equivalent capacitance is C=εA / d, where C represents capacitance, ε represents dielectric constant, A represents the overlapping area of the circular sensing plate cross-section and the metal adapter nut cross-section mapped perpendicularly to the same plane, and d represents the distance between the circular sensing plate and the metal adapter nut.

[0075] Reference Figure 7 The hollow cylindrical sensing plate is completely embedded in one end of the capacitive sensor, forming an open cylindrical cavity at one end of the capacitive sensor. The surface of the sensing plate in the cavity is completely covered with a layer of high-voltage resistant insulating material. When one end of the metal transfer nut column is tightly inserted into the cavity, the hollow cylindrical sensing plate and the metal transfer nut column (another form of metal adapter) are completely isolated. The other end of the metal transfer nut column can be threadedly connected to the lower terminal of the outlet hard pressure plate. Figure 7 As shown in the figure, when a capacitive sensor embedded with a hollow cylindrical sensing plate, high-voltage insulating material, and a metal transfer nut standoff is connected to the lower terminal of the outlet hard pressure plate via the metal transfer nut standoff, a cylindrical capacitor (equivalent capacitance) is formed between the hollow cylindrical sensing plate and the metal transfer nut standoff. The equivalent capacitance is calculated as C = 2πεL / ln(RB / RA), where C represents capacitance, ε represents the dielectric constant, L represents the length of the hollow cylindrical sensing plate, and RA and RB represent the maximum cross-sectional radius of the metal transfer nut standoff and the maximum cross-sectional radius of the hollow cylindrical sensing plate, respectively. To facilitate sensor mounting and avoid obstructing existing wires, tubing, or labels on the hard pressure plate, the metal transfer nut (standoff) can be screwed directly onto the terminal stud on the hard pressure plate.

[0076] The present application also discloses a non-invasive export hard plate state monitoring method, which is applied to the export hard plate state monitoring device described in any one of the above embodiments. The export hard plate state monitoring device includes a signal generating module and a plate monitoring module. The signal generating module includes an inductive capacitor component and a square wave generating source. The capacitor component includes a metal adapter and a capacitive sensor. The plate monitoring module component protection unit, an analog-to-digital converter, a microcontroller and a first relay. The component protection unit includes a second resistor R2, a third resistor R3, a fourth resistor R4, a voltage regulator diode D1, a voltage comparator U1, an optical Coupler U2A, transistor Q1 and the second relay, the lower terminal of the outlet hard pressure plate is threadedly connected to one end of the metal adapter, the sensing plate is embedded in one end of the capacitive sensor, and the side of the sensing plate that fits inside the capacitive sensor is connected to the built-in resistor inside the capacitive sensor. The other side of the sensing plate is completely covered with high-voltage resistant insulating material, one end of the metal adapter is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter is fixedly fitted to the side of the high-voltage resistant insulating material away from the sensing plate. The capacitive sensor is connected to one end of the square wave generator, and the other end of the square wave generator is grounded. One end of the second resistor R2 and the third resistor R3 are both connected to the non-inverting terminal of the voltage comparator U1, the other end of the second resistor R2 is connected between the capacitive sensor and the square wave generator, the other end of the third resistor R3 is grounded, the anode of the Zener diode D1 is connected to the inverting terminal of the voltage comparator U1, the cathode of the Zener diode D1 is grounded, the output end of the voltage comparator U1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the anode of the optocoupler U2A, the cathode of the optocoupler U2A is grounded, the emitter of the optocoupler U2A is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to one end of the second relay, the emitter of the transistor Q1 is grounded, the other end of the second relay is connected to one end of the analog-to-digital converter (ADC), the collector of the optocoupler U2A, the voltage comparator U1 and the second relay are all connected to the power supply VCC, the other end of the analog-to-digital converter is connected to one end of the microcontroller (MCU), and the other end of the microcontroller is connected to the first relay.

[0077] The method comprises the following steps:

[0078] The signal generating module continuously outputs a reference square wave signal, and based on the state change of the outlet hard pressure plate, the signal generating module is used to convert the reference square wave signal to obtain a pressure plate state signal;

[0079] Use the pressure plate monitoring module to analyze the pressure plate status signal and obtain the output signal parameters;

[0080] The output signal parameters are analyzed by the pressure plate monitoring module to obtain the potential state of the outlet hard pressure plate;

[0081] If the potential state is floating, the feedback outlet hard pressure plate is in the exit state in the relay protection device circuit;

[0082] If the potential state is non-floating state, the feedback outlet hard pressure plate is in the engaged state in the relay protection device circuit.

[0083] In this embodiment, a square wave generator in the control signal generation module inputs a reference square wave signal into the circuit formed by the inductive capacitor component and the built-in resistor. The reference square wave signal is a square wave with a certain frequency. Signal conversion refers to the charging and discharging process and the non-charging and discharging process performed by the reference square wave signal input into the circuit. When the outlet hard pressure plate is in the engaged state in the relay protection device circuit, the inductive capacitor component is connected to the lower terminal of the outlet hard pressure plate, forming an equivalent capacitor. The equivalent capacitor is connected to the built-in resistor to form an RC circuit. Therefore, when the input reference square wave signal jumps from a low level to a high level, that is, at the rising edge, the equivalent capacitor begins to charge. As charging progresses, the voltage across the equivalent capacitor gradually increases, while the voltage across the built-in resistor gradually decreases. The charging current decreases as the capacitor voltage increases. Ultimately, when the voltage across the equivalent capacitor equals the power supply voltage, charging ends. The charging process can be measured by the time constant τ: τ = RC, where R is the resistance value of the built-in resistor and C is the capacitance value of the equivalent capacitor. When the reference square wave signal transitions from a high level to a low level, that is, on the falling edge, the equivalent capacitor begins to discharge. At this point, the equivalent capacitor acts as a voltage source. During the discharge process, the voltage across the capacitor gradually decreases, and the discharge current also decreases. Discharge ends when the voltage across the capacitor drops to 0V. When the equivalent capacitor is connected to the relay protection device circuit and the reference square wave signal is input to the equivalent capacitor, the equivalent capacitor undergoes the aforementioned charging and discharging process, generating a pressure plate status signal with charging and discharging characteristics.

[0084] When the outlet hard pressure plate is in the exit state in the relay protection device circuit, the lower terminal of the outlet hard pressure plate is not connected to the relay protection device circuit. Therefore, the inductive capacitor component and the lower terminal of the outlet hard pressure plate do not form an equivalent capacitance. Without an equivalent capacitance, an RC circuit cannot be formed. When the same reference square wave signal is input into the circuit without capacitance, the above-mentioned charging and discharging process will not occur due to the lack of equivalent capacitance. That is, the output pressure plate status signal does not have charging and discharging characteristics. Based on the above principle, an analog-to-digital converter and a microcontroller are used to sample and analyze whether the pressure plate status signal has charging and discharging characteristics. Based on whether the pressure plate status signal has charging and discharging characteristics, the switching state of the outlet hard pressure plate in the relay protection device circuit can be determined.

[0085] First, set the sampling rate of the analog-to-digital converter (ADC). This sampling rate must be greater than or equal to twice the initial frequency. Next, set the appropriate ADC bit count (12 bits is recommended) and the trigger mode for the ADC. Edge triggering (rising / falling) or pulse width triggering can be used to ensure synchronization with the reference square wave signal. The ADC is then used for sampling, capturing the instantaneous voltage value of the analog signal at discrete time points to obtain a signal sample value. To maintain the stability of the signal sample value during subsequent processing, a sample-and-hold circuit (also known as a sample-and-hold amplifier) locks the signal sample value. Once locked, the signal sample value is mapped to discrete signal values. After the quantization step, the analog signal is converted to a digital signal, allowing for efficient processing and storage in digital systems. Finally, the discrete signal values are encoded, typically in binary format. The encoding step converts the quantized analog signal value into a digital form that a microcontroller can understand and process for further processing and analysis.

[0086] A filtering algorithm is used to denoise the pressure plate state transition signal, generating a low-noise pressure plate state signal. Common filtering algorithms include Kalman filtering, sliding average filtering, and median filtering to reduce the impact of random errors. The low-noise pressure plate state signal is then corrected using a baseline correction algorithm. Common baseline correction algorithms include sliding window averaging, moving median filtering, and high-pass filtering (IIR). When the tripping outlet contact is activated (i.e., briefly closed), the lower terminal of the outlet hard pressure plate is short-circuited to +110V. At this time, regardless of whether the outlet pressure plate is in the engaged or disengaged state, the lower terminal is not floating, causing the pressure plate to be judged as engaged. This can lead to misjudgment. However, due to the short tripping time, debouncing can be achieved through software or hardware debouncing. For example, in software debouncing, delay debouncing introduces a delay to wait for the jitter to disappear. This method is simple to implement and can be directly implemented using delay code written in languages such as C / C++ or Python.

[0087] For each sampling point in the standard platen status signal, the voltage change between it and the previous sampling point and the corresponding time change (i.e., the sampling interval) are calculated. The voltage change rate of the standard platen status signal is calculated by dividing the voltage change by the time change. Based on the voltage change rate, the high and low level regions and the charge and discharge intervals of the platen status signal are determined. Output signal parameters such as the rise time, fall time, signal amplitude, and signal slope are then calculated to determine whether the platen status signal exhibits charge and discharge characteristics. Based on these output signal parameters, it is possible to accurately determine whether the platen status signal exhibits charge and discharge characteristics, thereby determining the potential state of the outlet hard platen.

[0088] If the pressure plate status signal has charging and discharging characteristics, it means that the inductive capacitor component forms an RC circuit, that is, the inductive plate in the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor, and the necessary condition for the two to form an equivalent capacitor is that the lower terminal of the outlet hard pressure plate is connected to the relay protection circuit and the lower terminal is in a stable potential state, that is, a non-floating state. On the contrary, if the pressure plate status signal does not have charging and discharging characteristics, it means that the inductive capacitor component does not form an RC circuit, that is, the inductive plate in the inductive capacitor component and the lower terminal of the outlet hard pressure plate do not form an equivalent capacitor, and further indicates that the lower terminal of the outlet hard pressure plate is not connected to any circuit, that is, a floating state. When the lower terminal is in a non-floating state, it means that the upper terminal and the lower terminal of the outlet hard pressure plate are connected, that is, the outlet hard pressure plate is in the engaged state in the relay protection circuit. When the lower terminal is in a floating state, it means that the upper terminal and the lower terminal of the outlet hard pressure plate are not connected, that is, the outlet hard pressure plate is in the exit state in the relay protection circuit. Through the above method, real-time monitoring of the switching status of the outlet hard pressure plate can be achieved without affecting the relay protection circuit. At the same time, the monitoring principle is simple, easy and stable to implement, and no calibration is required when used on site. The outlet hard pressure plate status monitoring device is easy to install and can be directly screwed onto the terminal screw under the pressure plate without blocking the existing wires, sleeves or labels on the terminal. In addition, the present invention is small in size, simpler to install and maintain, and can be replaced at any time when a fault occurs.

[0089] In one embodiment, using the platen monitoring module to analyze the platen status signal and obtain the output signal parameters includes the following steps:

[0090] Performing analog-to-digital conversion on the pressure plate state signal through an analog-to-digital converter to obtain a pressure plate state conversion signal;

[0091] The pressure plate state conversion signal is de-noised by using a microcontroller and a filtering algorithm to obtain a pressure plate state low-noise signal;

[0092] The low-noise signal of the platen state is corrected using a baseline correction algorithm, and the corrected low-noise signal of the platen state is de-jittered to obtain a standard signal of the platen state;

[0093] The voltage change rate of the pressure plate state standard signal is calculated by the microcontroller, and the charge and discharge interval and the high and low level interval of the pressure plate state standard signal are extracted according to the voltage change rate;

[0094] Extract the edge time of the pressure plate state standard signal according to the charge and discharge interval, and calculate the rise time and fall time of the pressure plate state standard signal according to the edge time;

[0095] Calculate the average voltage of the pressure plate state standard signal within the high and low level intervals, and calculate the signal amplitude of the pressure plate state standard signal based on the average voltage;

[0096] The signal slope of the platen state standard signal is calculated by combining the rise time, fall time and state signal amplitude;

[0097] The output signal parameters are obtained by integrating the rise time, fall time, signal amplitude and signal slope.

[0098] In this embodiment, the sampling rate of the analog-to-digital converter (ADC) is first set. The set sampling rate must be greater than or equal to twice the initial frequency. Next, the appropriate ADC bit count (which can be set to 12 bits) and the trigger mode of the ADC are set. Edge triggering (rising / falling edge) or pulse width triggering can be used to ensure synchronization of the acquisition with the reference square wave signal. The ADC is then used for sampling, capturing the instantaneous voltage value of the analog signal at discrete time points to obtain a signal sample value. To maintain the stability of the signal sample value during subsequent processing, a sample-and-hold circuit locks the signal sample value. The sample-and-hold circuit, also known as a sample-and-hold amplifier, maintains the signal sample value unchanged during the sampling process. After locking, the signal sample value is mapped to discrete signal values. After the quantization step, the analog signal is converted to a digital signal, which enables efficient processing and storage in digital systems. Finally, the discrete signal value is encoded, typically in binary format. The encoding step converts the quantized analog signal value into a digital form that can be understood and processed by a microcontroller for further processing and analysis.

[0099] The pressure plate state transition signal is denoised using a filtering algorithm to obtain a low-noise pressure plate state signal. Commonly used filtering algorithms include Kalman filtering, sliding average algorithm, and median filtering. Taking the sliding average algorithm as an example, the sliding average is to weight the signal data at a certain moment in the pressure plate state transition signal with the signal data at surrounding moments. It can well handle the relationship between signal data in a short period of time and reduce the impact of random errors.

[0100] The platen state low-noise signal is then corrected using a baseline correction algorithm. Common baseline correction algorithms include sliding window averaging, moving median filtering, and high-pass filtering (IIR). Taking the sliding window averaging method as an example, the sliding window size is first determined. Starting from the starting point of the platen state low-noise signal, each sampling point is processed one by one. The processing steps include: adding the signal data of the current sampling point to the sliding window. When the sliding window reaches the set size, the earliest signal data added to the sliding window is removed, and the sum of all signal data in the sliding window is updated. After traversing all sampling points, the mean of all signal data in the current sliding window is calculated to obtain a baseline estimate. The baseline estimate is subtracted from each signal data in the uncorrected platen state low-noise signal to obtain the corrected platen state low-noise signal.

[0101] When the tripping outlet contact is activated (i.e. briefly closed), the lower terminal of the outlet hard pressure plate is short-circuited and connected to the +110V potential. At this time, regardless of whether the outlet pressure plate is in the engaged or disengaged state, the lower terminal is in a non-floating state, which causes the pressure plate to be judged as being in the engaged state, thereby creating the possibility of misjudgment. However, since the tripping action time is short, debouncing can be performed through software debouncing, hardware debouncing, and other methods. Taking the delayed debouncing in software debouncing as an example, a certain delay is introduced to wait for the jitter to disappear. This method is simple to implement and can be directly implemented by writing delay code in languages such as C / C++ or Python.

[0102] For each sampling point in the standard platen status signal, the voltage change between it and the previous sampling point and the corresponding time change (i.e., the sampling interval) are calculated. The voltage change rate of the standard platen status signal is obtained by dividing the voltage change by the time change. All voltage change rates are traversed. When the voltage change rate changes from a positive value to a negative value, it indicates that the discharge interval has been reached. When the voltage change rate changes from a negative value to a positive value, it indicates that the charge interval has been reached. Therefore, the charge and discharge interval can be determined based on the positive and negative values of the voltage change rate. Then, the high and low level intervals are determined based on the voltage value of each sampling point in the standard platen status signal. That is, if the voltage value is greater than the preset voltage threshold, the current interval is determined to be a high level interval. When the voltage value is less than or equal to the preset voltage threshold, the current interval is determined to be a low level interval.

[0103] The high- and low-level intervals include a high-level interval and a low-level interval. Within the high-level interval, the transient data on the rising / falling edges is removed, and the voltage values of the stable segments are retained. For example, the voltage data of the middle portion (which can be 70%) of the high-level interval can be retained. The average of the voltage values within the stable segment is calculated to obtain the high voltage average value Va. Similarly, within the low-level interval, the voltage values of the stable segment are also retained, and its low voltage average value Vd is calculated. The high voltage average value is subtracted from the low voltage average value to obtain the signal amplitude Vf of the pressure plate state standard signal. The charge and discharge intervals include the charge interval and the discharge interval. Within the charge interval, find the time point T1 when the voltage value first exceeds Vd+0.1Vf, and find the time point T2 when the voltage value first reaches Vd+0.9Vf. Subtract T2 from T1 to obtain the rise time of the pressure plate state standard signal. Within the discharge interval, find time T3, when the voltage first falls below Va - 0.1 Vf, and time T4, when the voltage first reaches Va - 0.9 Vf. Subtract T3 from T4 to obtain the fall time of the pressure plate status standard signal. Here, edge time refers to time T1, time T2, time T3, and time T4.

[0104] Signal slope refers to the rate of voltage change during the rising or falling process, including rising slope and falling slope. The calculation formula for rising slope is , is the signal amplitude, It refers to the rise time of the standard signal of the pressure plate state. The calculation formula of the falling slope is , Refers to the fall time of the standard pressure plate status signal. The rise time, fall time, signal amplitude, and signal slope are integrated to obtain the output signal parameters. Based on the output signal parameters, it is possible to accurately determine whether the pressure plate status signal has charge and discharge characteristics, thereby determining the switching status of the outlet hard pressure plate.

[0105] In one embodiment, performing analog-to-digital conversion on the pressure plate state signal by an analog-to-digital converter to obtain a pressure plate state conversion signal includes the following steps:

[0106] The pressure plate state signal is sampled by an analog-to-digital converter using preset sampling parameters to obtain a signal sampling value;

[0107] The sample-and-hold circuit in the analog-to-digital converter is used to lock the signal sampling value, and the locked signal sampling value is mapped into a discrete signal value;

[0108] The discrete signal value is encoded, and the pressure plate state conversion signal is obtained according to the information encoding result.

[0109] In this embodiment, the sampling parameters include sampling rate, ADC bit number, and trigger mode. The sampling rate of the analog-to-digital converter (ADC) is first set based on the Nyquist criterion and the initial frequency of the reference square wave signal. That is, the set sampling rate needs to be greater than or equal to twice the initial frequency. The ADC bit number is set based on the resolution requirement. The higher the resolution requirement, the higher the ADC bit number. Generally, it can be set to 2 to 16 bits. The trigger mode of the analog-to-digital converter can affect the sampling efficiency and the accuracy of the sampling results. The trigger mode can control the ADC to start sampling only under specific conditions, avoiding unnecessary sampling operations. At the same time, by setting an appropriate trigger mode, the analog-to-digital converter can be controlled to sample when the signal is stable, reducing noise interference caused by signal fluctuations, thereby improving the accuracy of the sampled data. Generally, edge triggering (rising edge / falling edge) or pulse width triggering can be used to ensure that the acquisition is synchronized with the reference square wave signal.

[0110] Next, an analog-to-digital converter performs sampling, capturing the instantaneous voltage value of the analog signal at discrete time points. The signal sample value is the instantaneous voltage value. Furthermore, to maintain the stability of the signal sample value during subsequent processing, a sample-and-hold circuit (also known as a sample-and-hold amplifier) locks the signal sample value. During the sampling phase, the switch (typically an analog switch) in the sample-and-hold circuit is on, allowing the input analog signal to pass through the switch and enter the hold capacitor. After the sampling phase ends, the switch in the sample-and-hold circuit opens, isolating the hold capacitor from the input signal and entering the hold phase. Therefore, even if the instantaneous voltage value obtained by the next sampling is different, it will not affect the previous sampling result, providing sufficient conversion time for the analog-to-digital converter to perform subsequent analog-to-digital conversion steps. After locking, the signal sample value is mapped to discrete signal values. This is the quantization step in the analog-to-digital conversion process. This divides the continuous analog signal amplitude into several discrete levels, each corresponding to a digital value. Through quantization, the analog signal is converted into a digital signal, enabling efficient signal processing and storage in digital systems.

[0111] Finally, the discrete signal values obtained from the quantization step are encoded, typically in binary format. This encoded discrete signal value serves as the platen state transition signal, completing the analog-to-digital conversion. The encoding step converts the quantized analog signal values into a digital form that the microcontroller can understand and process for further processing and analysis.

[0112] In one embodiment, analyzing the potential state of the outlet hard pressure plate based on the output signal parameters includes the following steps:

[0113] Calculate the parameter similarity between the output signal parameters and the preset theoretical signal parameters using the similarity calculation formula;

[0114] Judging whether the standard signal of the platen state has charge and discharge characteristics based on parameter similarity;

[0115] If the standard signal of the pressure plate state does not have the charge and discharge characteristics, the potential state is determined to be a floating state;

[0116] If the pressure plate state standard signal has charge and discharge characteristics, it is determined that the pressure plate state is a non-floating state.

[0117] In this embodiment, the preset theoretical signal parameters are calculated based on the circuit principle of the RC circuit. The parameters required to calculate the theoretical signal parameters include the resistance value of the built-in resistor, the capacitance value of the equivalent capacitor, the amplitude of the reference square wave signal, the frequency and the duty cycle, etc., which are all obtained in advance. The theoretical rise time, theoretical fall time, theoretical signal amplitude and theoretical signal slope are calculated based on the above parameters. The theoretical rise time and theoretical fall time are 2.2 , The time constant is obtained by multiplying the resistance of the built-in resistor by the capacitance of the equivalent capacitor. The capacitance of the equivalent capacitor is calculated according to the capacitance formula. The equivalent capacitance calculation formula is C=εA / d, where C represents capacitance, ε represents dielectric constant, A represents the overlapping area of the circular sensing plate cross section and the metal adapter nut cross section perpendicularly mapped to the same plane, and d represents the distance between the circular sensing plate and the metal adapter nut. The theoretical signal amplitude is calculated based on the theoretical rise time, theoretical fall time, and the amplitude of the reference square wave signal. The theoretical signal amplitude calculation formula is as follows:

[0118]

[0119] in, is the amplitude of the reference square wave signal, and They are the theoretical rise time and the theoretical fall time, is the time constant, is the base of the exponential function.

[0120] The theoretical rising slope of the theoretical signal slope is The theoretical slope of decline is .

[0121] The parameter similarity between the output signal parameters and the preset theoretical signal parameters is calculated using a pre-set program in the microcontroller and a similarity calculation formula. Commonly used similarity calculation formulas include the weighted Euclidean distance formula and the cosine similarity formula. Taking the cosine similarity formula as an example, the vectors of the output signal parameters and the theoretical signal parameters are first constructed respectively to obtain the output signal vector and the theoretical signal vector. The output signal vector and the theoretical signal vector are input into the cosine similarity formula to obtain the parameter similarity between the output signal parameters and the preset theoretical signal parameters. If the parameter similarity is greater than the preset similarity threshold, it means that the pressure plate state standard signal has charge and discharge characteristics. If the parameter similarity is less than or equal to the preset similarity threshold, it means that the pressure plate state standard signal does not have charge and discharge characteristics. When the potential state of the outlet hard pressure plate is in a non-floating state, the inductive capacitor component and the lower terminal of the outlet hard pressure plate form an equivalent capacitor. Since there is a built-in resistor in the inductive capacitor component, an RC circuit can be formed between the built-in resistor and the equivalent capacitor. When a reference square wave signal is input into the RC circuit, due to the presence of an equivalent capacitor and a built-in resistor in the RC circuit, the reference square wave signal will undergo a charge and discharge process, and ultimately obtain a pressure plate state signal with charge and discharge characteristics. Conversely, if the potential state of the outlet hard pressure plate is in a floating state, the inductive capacitor component and the lower terminal of the outlet hard pressure plate do not form an equivalent capacitor, and therefore there is no RC circuit. When the same reference square wave signal is input into the non-RC circuit, the final pressure plate state signal is still a square wave, without charge and discharge characteristics. According to the above principle, whether the potential state of the outlet hard pressure plate is in a floating state can be judged based on whether the pressure plate state standard signal has charge and discharge characteristics. That is, if the pressure plate state standard signal does not have charge and discharge characteristics, the potential state is determined to be a floating state. If the pressure plate state standard signal has charge and discharge characteristics, the pressure plate state is determined to be a non-floating state.

[0122] In one embodiment, the method further comprises the steps of:

[0123] Calculate the actual capacitance between the inductive capacitor assembly and the outlet hard pressure plate according to the output signal parameters, and calculate the capacitance difference between the actual capacitance and the pre-calculated theoretical capacitance;

[0124] If the capacitance difference is greater than a preset difference threshold, it is determined that there is a capacitance component abnormality in the sensing capacitance component;

[0125] If the capacitance difference is less than or equal to the preset difference threshold, it is determined that there is no capacitance component abnormality in the sensing capacitance component.

[0126] In this embodiment, when it is determined that the pressure plate state standard signal has charge and discharge characteristics, the actual capacitance can be calculated based on the rise time or fall time and using the calculation program preset in the microcontroller. The actual capacitance calculation formula is: , is the rise time, is the resistance value of the built-in resistor. The theoretical capacitance is calculated based on the capacitor type selection formula formed by the sensing plate and the metal adapter. When the capacitor type is a planar capacitor, the theoretical equivalent capacitance is calculated as C=εA / d, where C represents capacitance, ε represents the dielectric constant, A represents the overlapping area of the circular sensing plate cross section and the metal adapter nut cross section perpendicularly mapped to the same plane, and d represents the distance between the circular sensing plate and the metal adapter nut. If the capacitance difference is greater than the preset difference threshold, it is judged that there is a capacitance component abnormality in the inductive capacitor assembly. This is because when the high-voltage insulating material in the inductive capacitor assembly is damaged or the high-voltage insulating material is aged, the capacitance value of the equivalent capacitance formed between the inductive capacitor assembly and the lower terminal of the outlet hard pressure plate will increase or decrease significantly. This is because when the high-voltage insulating material is damaged, the metal plate and the inductive plate may be in direct contact, forming a short circuit. In addition, due to the damage of the high-voltage insulating material, the distance between the inductive plate and the metal adapter is reduced, resulting in a significant increase in the actual capacitance. If the high-voltage insulating material is aged, the dielectric constant of the high-voltage insulating material may be reduced, resulting in a significant decrease in the actual capacitance. Therefore, when the capacitance difference is greater than the preset difference threshold, it can be determined that there is a capacitance component abnormality in the inductive capacitor assembly. When the capacitance difference is less than or equal to the preset difference threshold, it can be determined that there is no capacitance component abnormality in the inductive capacitor assembly. An LED or buzzer can be connected to the microcontroller. When the capacitance difference exceeds a preset threshold, indicating a capacitor component is present, the LED starts flashing or the buzzer sounds, alerting personnel that the inductive capacitor component in the exit platen status monitoring device needs to be repaired or replaced. Long-term use of an inductive capacitor component with an abnormal capacitor component for exit platen status monitoring may result in abnormal monitoring results, affecting the normal operation of the relay protection circuit.

[0127] Among them, the processor can adopt a central processing unit (CPU). Of course, according to actual usage, other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), off-the-shelf field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor Q1 logic devices, discrete hardware components, etc. can also be adopted. The general-purpose processor can adopt a microprocessor or any conventional processor, etc., and this application does not impose any restrictions on this.

[0128] Among them, the memory can be an internal storage unit of a computer device, such as a hard disk or memory of a computer device, or an external storage device of a computer device, such as a plug-in hard disk, smart memory card (SMC), secure digital card (SD) or flash memory card (FC) equipped on the computer device. In addition, the memory can also be a combination of an internal storage unit and an external storage device of a computer device. The memory is used to store computer programs and other programs and data required by the computer device. The memory can also be used to temporarily store data that has been output or is to be output. This application does not impose any restrictions on this.

[0129] An embodiment of the present application also provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute the above-mentioned method for monitoring the status of the outlet hard pressure plate of the non-invasive relay protection device.

[0130] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0131] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0134] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0135] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0136] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can be implemented using any method or technology for information storage. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change RAM (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0137] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0138] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A non-intrusive relay protection device outlet hard plate state monitoring device, applied to the outlet hard plate in the relay protection circuit, characterized in that: The device includes a signal generating module and a pressure plate monitoring module. The signal generating module includes an inductive capacitor component and a square wave generating source. The inductive capacitor component is fixedly connected to the lower terminal of the outlet hard pressure plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the inductive plate in the inductive capacitor component and the lower terminal form an equivalent capacitor, and the built-in resistor in the inductive capacitor component and the equivalent capacitor form an RC circuit. The square wave generating source is connected to the inductive capacitor component and is used to generate a reference square wave signal. The reference square wave signal is converted into a pressure plate state signal after passing through the RC circuit. The pressure plate monitoring module is connected to the inductive capacitor component and receives the pressure plate state signal. The pressure plate monitoring module is connected to the signal generating module. The pressure plate monitoring module is used to receive and analyze the pressure plate state signal to obtain output signal parameters. The pressure plate monitoring module is also used to analyze the output signal parameters to obtain the potential state of the outlet hard pressure plate and feedback the switching state of the outlet hard pressure plate in the relay protection circuit based on the potential state.

2. The device according to claim 1, characterized in that The pressure plate monitoring module includes an element protection unit, an analog-to-digital converter, a microcontroller and a first relay connected in series in sequence. The element protection unit is connected to the signal generating module. The element protection unit protects the pressure plate monitoring module. The analog-to-digital converter is used to receive the pressure plate status signal and transmit the pressure plate status signal to the microcontroller after analog-to-digital conversion. The microcontroller is used to analyze the pressure plate status signal after analog-to-digital conversion to obtain output signal parameters, and obtain the potential state of the outlet hard pressure plate based on the output signal parameters. The first relay feeds back the potential state output by the microcontroller through the on-off state of the built-in passive switch contact.

3. The device according to claim 2, characterized in that The component protection unit includes a second resistor, a third resistor, a fourth resistor, a voltage regulator diode, a voltage comparator, an optocoupler, a transistor and a second relay. One end of the second resistor and the third resistor are both connected to the non-inverting end of the voltage comparator, the other end of the second resistor is connected to the signal generating module, the other end of the third resistor is grounded, the anode of the voltage regulator diode is connected to the inverting end of the voltage comparator, the cathode of the voltage regulator diode is grounded, the output end of the voltage comparator is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the anode of the optocoupler, the cathode of the optocoupler is grounded, the emitter of the optocoupler is connected to the base of the transistor, the collector of the transistor is connected to one end of the second relay, the emitter of the transistor is grounded, the other end of the second relay is connected to the analog-to-digital converter, and the collector of the optocoupler, the voltage comparator and the second relay are all connected to the power supply.

4. The device according to claim 1, characterized in that The inductive capacitor assembly includes a metal adapter and a capacitive sensor, wherein the inductive plate is embedded in one end of the capacitive sensor, and one side of the inductive plate that is in contact with the interior of the capacitive sensor is connected to the built-in resistor inside the capacitive sensor. The other side of the inductive plate is completely covered with a high-voltage resistant insulating material. One end of the metal adapter is threadedly connected to the lower terminal of the outlet hard pressure plate, and the other end of the metal adapter is fixedly attached to the side of the high-voltage resistant insulating material away from the inductive plate. When the lower terminal of the outlet hard pressure plate is in a non-floating state, the lower terminal of the outlet hard pressure plate forms an equivalent capacitor with the inductive plate via the metal adapter, and the equivalent capacitor forms an RC circuit with the built-in resistor.

5. A non-invasive method for monitoring the status of an outlet hard plate, applied to the device according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: The signal generating module continuously outputs a reference square wave signal, and based on the state change of the outlet hard pressure plate, the signal generating module is used to convert the reference square wave signal to obtain a pressure plate state signal; Performing analog-to-digital conversion on the pressure plate state signal through an analog-to-digital converter to obtain a pressure plate state conversion signal; The pressure plate state conversion signal is de-noised by using a microcontroller and a filtering algorithm to obtain a pressure plate state low-noise signal; The low-noise signal of the platen state is corrected using a baseline correction algorithm, and the corrected low-noise signal of the platen state is de-jittered to obtain a standard signal of the platen state; The voltage change rate of the pressure plate state standard signal is calculated by the microcontroller, and the charge and discharge interval and the high and low level interval of the pressure plate state standard signal are extracted according to the voltage change rate; Extract the edge time of the pressure plate state standard signal according to the charge and discharge interval, and calculate the rise time and fall time of the pressure plate state standard signal according to the edge time; Calculate the average voltage of the pressure plate state standard signal within the high and low level intervals, and calculate the signal amplitude of the pressure plate state standard signal based on the average voltage; The signal slope of the platen state standard signal is calculated by combining the rise time, fall time and state signal amplitude; Integrate the rise time, fall time, signal amplitude and signal slope to obtain output signal parameters; The output signal parameters are analyzed by the pressure plate monitoring module to obtain the potential state of the outlet hard pressure plate; If the potential state is floating, the feedback outlet hard pressure plate is in the exit state in the relay protection device circuit; If the potential state is non-floating state, the feedback outlet hard pressure plate is in the engaged state in the relay protection device circuit.

6. The method according to claim 5, characterized in that The step of converting the pressure plate state signal into a digital signal by using an analog-to-digital converter to obtain a pressure plate state conversion signal comprises the following steps: The pressure plate state signal is sampled by an analog-to-digital converter using preset sampling parameters to obtain a signal sampling value; The sample-and-hold circuit in the analog-to-digital converter is used to lock the signal sampling value, and the locked signal sampling value is mapped into a discrete signal value; The discrete signal value is encoded, and the pressure plate state conversion signal is obtained according to the information encoding result.

7. The method according to claim 5, characterized in that The step of analyzing the output signal parameters by the pressure plate monitoring module to obtain the potential state of the outlet hard pressure plate includes the following steps: Calculate the parameter similarity between the output signal parameters and the preset theoretical signal parameters using the similarity calculation formula; Judging whether the standard signal of the platen state has charge and discharge characteristics based on parameter similarity; If the standard signal of the pressure plate state does not have the charge and discharge characteristics, the potential state is determined to be a floating state; If the pressure plate state standard signal has charge and discharge characteristics, it is determined that the pressure plate state is a non-floating state.

8. The method according to claim 7, characterized in that The method further comprises the steps of: Calculate the actual capacitance between the inductive capacitor assembly and the outlet hard pressure plate according to the output signal parameters, and calculate the capacitance difference between the actual capacitance and the pre-calculated theoretical capacitance; If the capacitance difference is greater than a preset difference threshold, it is determined that there is a capacitance component abnormality in the sensing capacitance component; If the capacitance difference is less than or equal to the preset difference threshold, it is determined that there is no capacitance component abnormality in the sensing capacitance component.

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