Implementation method of circuit breaker state monitoring fused with functions of protection device

Abstract

The invention discloses an implementation method for circuit breaker state monitoring fused with functions of a protection device, and relates to the field of power system protection, circuit breaker state monitoring is realized by the protection device, and the protection device comprises a circuit breaker control loop, a control loop current signal acquisition loop and a control loop voltage signal acquisition loop. The circuit breaker control loop is provided with current and voltage input and output ends, a control loop current signal acquisition loop is connected in series in the current input and output ends for switching on and tripping, and a control loop voltage signal acquisition loop is connected in parallel in the voltage input and output ends, so that hardware multiplexing is realized; according to the state monitoring method, breaker tripping and closing voltage and current signals and system signals are collected in a single sampling window at the same time, a performance evolution curve is constructed after digital fusion processing, protection logic verification and closed loop feedback are carried out based on the performance evolution curve, and state monitoring and early warning are achieved in combination with recording data analysis. And the operation safety and reliability of the power system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power system protection, and particularly relates to a method for realizing circuit breaker state monitoring integrated with protection device functions. BACKGROUND

[0002] In a power system, as a key device, a circuit breaker undertakes the important responsibility of turning on and off a circuit in normal operation and fault state, and plays an irreplaceable role in maintaining the safe and stable operation of the power system. How to accurately and efficiently monitor the operating state of the circuit breaker can not only guarantee the reliability of the power system, but also realize rapid fault diagnosis.

[0003] At present, the state monitoring of the circuit breaker mainly relies on external independent monitoring devices or systems. This method has significant limitations. Specifically, the connection between the external monitoring device and the protection device requires an additional communication link and interface, which increases the complexity and overall cost of the system. The collaborative work between multiple independent devices often requires a complex configuration and debugging process, which greatly increases the difficulty of system maintenance and management. The circuit breaker state monitoring under the traditional method is relatively independent of the protection function, lacks effective information interaction and collaborative processing mechanism, so that the protection device cannot make correct judgments according to the real-time state information of the circuit breaker when making decisions, which affects the timeliness and accuracy of its action. At the same time, there is a certain communication delay problem between the external monitoring device and the protection device, which further weakens the overall response speed and stability of the system.

[0004] With the rapid development of the power system towards intelligence and integration, higher requirements are put forward for the real-time, accuracy and integration of the circuit breaker state monitoring. Therefore, there is an urgent need for a circuit breaker state monitoring method deeply integrated with the protection device function to realize the deep integration of the circuit breaker state monitoring function and the protection function, reduce the system cost and complexity, and improve the real-time and accuracy of the circuit breaker state monitoring. SUMMARY

[0005] The present application aims to provide a method for realizing circuit breaker state monitoring integrated with protection device functions to solve the problems in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a circuit breaker status monitoring method integrated with the function of a protection device, comprising a circuit breaker control circuit, a control circuit current signal acquisition circuit, and a control circuit voltage signal acquisition circuit. The control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit are integrated inside the circuit breaker control circuit and synchronously sampled with a conventional AC plug-in. By utilizing the hardware resources of the circuit breaker control circuit itself, the hardware design of the circuit breaker control circuit is modified without adding additional interfaces, thereby realizing the direct acquisition of tripping and closing voltage and current.

[0007] Control circuit current signal acquisition circuit: used to convert the control current flowing through the control circuit into an analog voltage signal when the circuit breaker is opened and closed, providing an identifiable electrical signal form for subsequent signal processing and status analysis; Control circuit voltage signal acquisition circuit: used to acquire the voltage of the opening coil and closing coil to the common negative terminal of the control circuit when the circuit breaker is opening and closing. The control circuit voltage signal acquisition circuit reduces and filters the voltage signals related to the circuit breaker closing and tripping, and converts them into analog signals to ensure that the voltage signals meet the input requirements of the subsequent acquisition and calculation modules. The circuit breaker control circuit has a closing current input terminal P1, a closing current output terminal P2, a tripping current input terminal P5, a tripping current output terminal P6, a closing voltage input terminal P3, a closing voltage output terminal P4, a tripping voltage input terminal P7, and a tripping voltage output terminal P8. A control circuit current signal acquisition circuit is connected in series between the closing current input terminal P1 and the closing current output terminal P2, and between the tripping current input terminal P5 and the tripping current output terminal P6. A control circuit voltage signal acquisition circuit is connected in parallel between the closing voltage input terminal P3 and the closing voltage output terminal P4, and between the tripping voltage input terminal P7 and the tripping voltage output terminal P8. The circuit breaker circuit undertakes the basic tasks of normal circuit connection and fault disconnection, and is the carrier of current and voltage signals.

[0008] The circuit breaker circuit includes a control power supply KM+, a control power supply KM-, a closing holding relay HBJ, a trip holding normally closed node TBJ, a trip coil TQ, and an analog-to-digital converter ADC. The closing current input terminal P1 and the closing current output terminal P2 are located between the closing holding relay HBJ and the trip holding normally closed node TBJ, and the trip current input terminal P5 and the trip current output terminal P6 are located between the trip holding normally closed node TBJ and the trip coil TQ.

[0009] Control power supply KM+ and control power supply KM-: provide DC operating power for the entire circuit breaker control circuit. KM+ is the positive terminal and KM- is the negative terminal. They are the energy source for closing, tripping actions and signal detection circuit operation. The closing holding relay HBJ is a key component to ensure the stability of the circuit breaker's closing state. After the circuit breaker completes the closing action, it can continuously maintain the closing state to avoid the circuit breaker from accidentally tripping due to the disappearance of the closing command, and ensure the reliability of the normal circuit connection state. The normally closed tripping contact TBJ remains closed under normal conditions, providing a conduction path for the closing circuit to support the closing action. When the circuit breaker needs to trip, this contact will open, on the one hand cutting off the closing circuit to prevent the closing action from interfering with the tripping, and on the other hand creating the necessary conditions for the tripping circuit to conduct, realizing the logical interlock between the closing and tripping actions. The tripping coil TQ is the core actuator for the tripping action. When the tripping circuit is conducting, TQ will be energized to generate electromagnetic force, which drives the internal mechanical structure of the circuit breaker to operate, ultimately achieving the circuit disconnection and ensuring timely circuit disconnection in case of a fault. The analog-to-digital converter (ADC) is the key to connecting analog signals and digital signals. It can convert the analog signals output from the current and control circuit voltage signal acquisition circuits into digital signals, providing processable digital data for the subsequent calculation and analysis of the circuit breaker status parameters by the main processor. It is the basic component for realizing digital status monitoring of the circuit breaker.

[0010] A voltage divider resistor is connected in parallel between the closing current output terminal P2 and the KM- terminal. The closing voltage input terminal P3 and the closing voltage output terminal P4 are located between the voltage divider resistors. A voltage divider resistor is connected in parallel between the trip current output terminal P6 and the KM- terminal. The trip voltage input terminal P7 and the trip voltage output terminal P8 are located between the voltage divider resistors. The voltage divider resistors 1 and 2 work together to perform multi-stage voltage division on the high voltage of the circuit breaker control circuit, accurately control the voltage reduction ratio, ensure that the amplitude of the voltage signal after voltage division is within the safe input range of the isolation circuit and the operational amplifier regulation circuit, and at the same time ensure the voltage division accuracy.

[0011] The control circuit current signal acquisition circuit includes a current acquisition circuit, an operational amplifier adjustment circuit, and an analog-to-digital conversion circuit; Current acquisition circuit: includes current sensor U6, the power supply terminal of current sensor U6 is equipped with decoupling capacitors C1 and C4, and the output terminal of current sensor U6 is equipped with filter and voltage regulator components C3 and R8; Operational amplifier regulation circuit: includes first-stage operational amplifier U2A and second-stage operational amplifier U2B. The first-stage operational amplifier U2A is equipped with feedback resistor network R1 and R9. The power supply terminal of the first-stage operational amplifier U2A is equipped with compensation capacitor C5. The second-stage operational amplifier U2B is equipped with resistor network R2, R5, R7, and R10. Analog-to-digital conversion circuit: includes current-limiting and voltage-dividing components R6 and C2, with an analog-to-digital conversion interface TQI_ADC3 configured between R6 and C2.

[0012] Current sensor U6: The core acquisition component, which directly detects the current flowing through the closing and tripping circuits and converts the current signal into the corresponding analog voltage signal.

[0013] Decoupling capacitors C1 and C4: Located at the power supply end of U6, they filter out high-frequency noise and ripple in the power supply, provide a stable operating voltage for U6, avoid power supply interference causing distortion of the U6 output signal, and ensure the accuracy of current acquisition.

[0014] Filtering and voltage regulation components C3 and R8: are configured at the output of U6. C3 filters out high-frequency interference in the output voltage signal of U6, and R8 plays the role of current limiting and voltage regulation, making the output analog voltage signal more stable and reducing the impact of signal fluctuations on subsequent processing.

[0015] The first-stage operational amplifier U2A initially amplifies the analog voltage signal output from U6. At the same time, it adjusts the amplification factor through a feedback resistor network to ensure that the signal amplitude meets the requirements of subsequent processing. Its core function is to enhance the signal strength and improve the signal-to-noise ratio.

[0016] Feedback resistor networks R1 and R9: work in conjunction with U2A to determine the amplification factor of U2A, and at the same time play a role in stabilizing the operating state of the amplifier circuit, avoiding circuit self-oscillation, and ensuring that the output signal of U2A is stable and has good linearity.

[0017] Compensation capacitor C5: Located at the power supply terminal of U2A, it compensates for instantaneous fluctuations in the power supply voltage, further stabilizes the operating voltage of U2A, reduces the impact of power supply fluctuations on amplification performance, and ensures the accuracy of the amplified signal.

[0018] The second-stage operational amplifier U2B performs secondary conditioning on the signal amplified by U2A, including further amplification, level adjustment, and filtering, to further optimize signal quality and ensure that the signal meets the input requirements of analog-to-digital conversion.

[0019] Resistor network R2, R5, R7, R10: In conjunction with U2B, adjust the amplification factor, filtering parameters and level offset of U2B to achieve precise signal conditioning, so that the amplitude, DC bias and other parameters of the output signal are fully matched to the requirements of the analog-to-digital conversion circuit.

[0020] Current limiting and voltage dividing components R6 and C2: R6 limits the current flowing into the analog-to-digital converter interface to prevent excessive current from damaging the interface, and C2 further filters out residual interference in the signal to ensure that the analog voltage signal input to the analog-to-digital converter interface is pure and stable.

[0021] The TQI_ADC3 analog-to-digital converter interface is the physical interface that connects the op-amp regulation circuit and the analog-to-digital converter (ADC), transmitting the conditioned analog voltage signal to the ADC.

[0022] The control circuit voltage signal acquisition circuit includes a resistor voltage divider circuit, an isolation circuit, an operational amplifier adjustment circuit, and an analog-to-digital conversion circuit; The resistor voltage divider circuit includes the first voltage divider branch R25, R26, R27, R28, R29, R30, R38, R41, R45 and the second voltage divider branch R31, R32, R33, R34, R35, R36. The resistor voltage divider circuit is equipped with filter capacitors C27 and C28. Isolation circuit: includes isolation chip U9. The power supply terminal of isolation chip U9 is equipped with decoupling capacitors C23, C24, C22, and C26. The ground terminal of isolation chip U9 is connected to GND50-2 and GND respectively. Operational amplifier regulation circuit: including operational amplifier U1A, the operational amplifier regulation circuit is configured with resistor network R37, R39, R40, R43, R44, R46 and compensation capacitors C26, C29, C31; Analog-to-digital conversion circuit: includes current-limiting resistor R42 and filter capacitor C30, and is equipped with analog-to-digital conversion interface TQU_ADC5.

[0023] The first voltage divider branch works in conjunction with the second voltage divider branch to perform multi-stage voltage division on the high voltage of the circuit breaker control circuit, precisely control the voltage reduction ratio, ensure that the voltage signal amplitude after voltage division is within the safe input range of the isolation circuit and the operational amplifier regulation circuit, and at the same time ensure the voltage division accuracy.

[0024] The second voltage divider branch works in conjunction with the first voltage divider branch to further optimize the voltage division effect, enhance the stability and anti-interference capability of the voltage divider circuit, avoid voltage division failure caused by a single resistor failure, and improve the reliability of voltage acquisition.

[0025] Filter capacitors C27 and C28 are configured in the resistor voltage divider circuit to filter out high-frequency interference and transient pulses in the high voltage signal before voltage division, prevent interference signals from entering subsequent circuits, ensure the purity of the voltage signal after voltage division, and reduce the impact of interference on subsequent processing.

[0026] Isolation chip U9: It realizes electrical isolation between the high-voltage system and the low-voltage system, prevents high voltage and high current faults on the high-voltage side from being conducted to the low-voltage side and damaging low-voltage components, and at the same time blocks ground loop interference, improving the safety and anti-interference capability of the entire system.

[0027] Decoupling capacitors C22, C23, C24, and C26: These are configured at the power supply terminal of U9 to filter out high-frequency noise and ripple in the power supply, provide a stable operating voltage for U9, prevent power supply interference from causing a decrease in the isolation performance of U9 or distortion of the output signal, and ensure the isolation effect and signal transmission accuracy.

[0028] Grounding terminals GND50-2 and GND: provide grounding references for the high-voltage and low-voltage sides of U9, respectively, to ensure the potential stability of the circuits on both sides of U9, avoid interference caused by potential differences, and at the same time ensure the normal operation of the isolation chip and prevent signal abnormalities caused by poor grounding.

[0029] Operational amplifier U1A: amplifies, filters, and adjusts the level of the isolated voltage signal, amplifies the potentially weak signal after isolation to an amplitude suitable for analog-to-digital conversion, and adjusts the DC bias of the signal to filter out residual interference and optimize signal quality.

[0030] Resistor network R37, R39, R40, R43, R44, R46: In conjunction with U1A, determine the amplification factor, filtering frequency, and level adjustment range of U1A to achieve precise conditioning of the isolated voltage signal and ensure that the signal parameters fully match the requirements of analog-to-digital conversion.

[0031] Compensation capacitors C26, C29, and C31: compensate for the frequency characteristics of the U1A amplifier circuit, prevent circuit self-oscillation, filter out high-frequency noise in the circuit, stabilize the operating state of U1A, and ensure the linearity and stability of the amplified signal.

[0032] Current-limiting resistor R42: Limits the current flowing into the analog-to-digital converter interface to prevent excessive current from damaging the interface or the analog-to-digital converter (ADC) and protects the safe operation of the analog-to-digital conversion process.

[0033] Filter capacitor C30: Filters out residual high-frequency interference in the output signal of the operational amplifier regulation circuit, ensuring that the analog voltage signal input to the analog-to-digital converter (ADC) is pure and stable, and improving the accuracy of analog-to-digital conversion.

[0034] The TQU_ADC5 analog-to-digital converter interface is the physical interface that connects the control loop voltage signal acquisition loop to the analog-to-digital converter (ADC), transmitting the conditioned analog voltage signal to the ADC.

[0035] The control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit are connected to the analog-to-digital converter (ADC) via the backplane on the circuit breaker. The circuit breaker backplane serves as the signal transmission carrier between the current and control circuit voltage signal acquisition circuits and the ADC. It uses internally integrated wiring instead of external cables to reduce interference during signal transmission, shorten the transmission path, reduce signal delay, and ensure that the acquired signals can be transmitted to the ADC quickly and accurately, guaranteeing data synchronization and real-time performance. The ADC receives the analog current and voltage signals transmitted from the backplane and converts them into digital signals, providing digital data for subsequent calculations and analysis by the main processor. It is the core component connecting analog signal acquisition and digital signal processing.

[0036] A method for implementing a circuit breaker condition monitoring method that integrates with protection device functions includes the following steps; Step S1: Synchronous sampling is performed using the circuit breaker control circuit current signal acquisition circuit, control circuit voltage signal acquisition circuit, and AC plug-in of the protection device. Through a clock synchronization mechanism, the tripping and closing voltage and current signals of the circuit breaker control circuit, as well as the system voltage and current signals, are simultaneously acquired within a single sampling window period. The system voltage and current signals flowing through the circuit breaker are converted to secondary values ​​by traditional voltage transformers (PT) and current transformers (CT) before acquisition. This avoids data deviations caused by asynchronous sampling times and provides time-consistent basic data for subsequent multi-source signal fusion and fault location, ensuring the accuracy of the analysis results. Step S2: The control circuit current signal acquisition circuit converts the closing current and tripping current flowing through the circuit breaker into analog voltage signals, and the control circuit voltage signal acquisition circuit converts the input voltage into digital signals for processing by the main processor, providing a recognizable and calculable data format for subsequent calculation of the main processor's state parameters; Step S3: The main processor receives digital signals from the control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit. Through the calculation module, it realizes the real-time calculation of the circuit breaker status parameters. Combined with the system voltage and current signals acquired by the AC plug-in of the protection device, it performs multi-source signal digital fusion processing to construct the performance evolution curve of the circuit breaker, eliminates the limitations of a single signal, intuitively reflects the long-term operating status change trend of the circuit breaker, and provides a visual and analyzable model for status assessment and fault prediction. Step S4: Based on the circuit breaker performance evolution curve and real-time status parameters, the status monitoring module feeds the data back to the protection logic criterion verification unit. When an abnormal state is detected, the protection device quickly issues a protection action command and records the action execution result, which is then fed back to the status monitoring model. The monitoring parameter threshold and feature recognition logic are corrected through algorithm iteration to form a closed-loop feedback mechanism. By iteratively correcting the monitoring threshold and recognition logic through algorithm iteration, the adaptability of the protection function to changes in equipment status is improved, ensuring more accurate fault diagnosis. Step S5: The built-in waveform recording function of the protection device relies on a high sampling rate and a large-capacity storage unit to collect waveform data in all dimensions during the tripping and closing process. By comparing the waveform recording data under different stages and operating conditions, targeted maintenance measures are triggered when potential risks are found, and hidden dangers in the equipment are eliminated in advance. By comparing the waveform recording data under different stages and operating conditions, the performance changes of the circuit breaker are tracked, and the probability of system failure is reduced.

[0037] The current signal acquisition includes a current acquisition circuit, an operational amplifier adjustment circuit, and an analog-to-digital converter circuit. The current acquisition circuit is used to convert the measured current signal into a voltage signal. The operational amplifier adjustment circuit is used to amplify, adjust the level, and filter the acquired voltage signal. The analog-to-digital converter circuit is used to filter the conditioned analog voltage signal and transmit it to the analog-to-digital converter (ADC) for digital analysis.

[0038] In step S3, the control circuit voltage signal acquisition circuit includes a resistor voltage divider circuit, an isolation circuit, an operational amplifier adjustment circuit, and an analog-to-digital converter circuit. The resistor voltage divider circuit is used to proportionally reduce the voltage of the high-voltage signal. The isolation circuit is used to achieve electrical isolation between the high-voltage and low-voltage systems. The operational amplifier adjustment circuit is used to amplify, filter, and adjust the level of the isolated voltage signal. The analog-to-digital converter circuit is used to filter the conditioned analog voltage signal and transmit it to the analog-to-digital converter (ADC) for digital analysis.

[0039] Compared with the prior art, the beneficial effects of the present invention are: 1. Significant cost-effectiveness: By reusing the original hardware resources of the circuit breaker control circuit of the protection device, there is no need to configure additional independent monitoring equipment, which greatly reduces the cost of equipment procurement, installation, commissioning and subsequent maintenance. It does not add external communication interfaces, simplifies the system architecture, reduces potential failure points and communication delays, further reduces system complexity and overall operating costs, and achieves significant cost-effectiveness improvement.

[0040] 2. Enhanced monitoring accuracy and real-time performance: By utilizing the high-precision AD converter inside the protection device, the circuit breaker tripping and closing voltage and current signals are captured at the microsecond level, significantly improving monitoring accuracy. Through high-precision synchronous sampling technology, strict alignment of all monitoring data in the time dimension is ensured, providing an accurate basis for subsequent data analysis and fault location, and enhancing the real-time performance of monitoring.

[0041] 3. System reliability and security: By constructing a closed-loop feedback link, bidirectional interaction between status monitoring and protection actions is realized. When the circuit breaker is in an abnormal state, the protection device can respond quickly and take protection measures to prevent the fault from escalating. At the same time, the full-dimensional waveform recording function provides maintenance personnel with rich fault analysis data, which helps to discover potential faults in advance and reduce the probability of system failure. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the control circuit structure of a circuit breaker condition monitoring device that integrates protection device functions according to the present invention. Figure 2 This is a schematic diagram of the control circuit current signal acquisition circuit structure of a circuit breaker condition monitoring device that integrates protection device functions according to the present invention. Figure 3 This is a schematic diagram of the control circuit voltage signal acquisition circuit structure of a circuit breaker condition monitoring device that integrates protection device functions according to the present invention. Figure 4 This is a schematic diagram of the comprehensive performance index of a circuit breaker, which is a circuit breaker condition monitoring device that integrates the function of a protection device according to the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1: This implementation method is a circuit breaker status monitoring method that integrates with the function of a protection device. The core is to achieve deep integration of circuit breaker status monitoring and protection functions on the basis of the original hardware architecture of the protection device through circuit modification and function integration. The overall system consists of a circuit breaker control circuit, a control circuit current signal acquisition circuit, a control circuit voltage signal acquisition circuit, a main processor module, and a waveform recording and storage module. Each module is connected through the backplane of the circuit breaker to realize signal interaction and data transmission without the need to add additional external interfaces, thus maximizing the reuse of existing hardware resources.

[0045] like Figure 1As shown, the circuit breaker control circuit uses DC operating power supplies KM+ and KM- as the core power supply and includes core components such as closing holding relay HBJ, trip holding normally closed contact TBJ, and trip coil TQ. The closing current input terminal P1 and the closing current output terminal P2 are the connection nodes between the control circuit current signal acquisition circuit and the circuit breaker closing circuit. P1 receives the current from the closing circuit, and after processing by the detection circuit, it is transmitted back to the closing circuit from P2, realizing the series acquisition of current signals.

[0046] Among them, the closing holding relay HBJ is a relay that maintains the closed state after the circuit breaker has completed its closing action, preventing the circuit breaker from accidentally tripping after the closing command disappears, and ensuring the stability of the closed state.

[0047] Normally closed tripping node TBJ: Under normal conditions, it remains closed, providing a conduction path for the closing circuit. When the circuit breaker needs to trip, the TBJ node opens, cutting off the closing circuit, and at the same time creating conditions for the tripping circuit to conduct.

[0048] Trip coil TQ: When the trip circuit is open, TQ is energized to generate electromagnetic force, which drives the mechanical structure of the circuit breaker to operate and disconnect the circuit. It is the actuator for tripping.

[0049] Analog-to-digital converter (ADC): Converts analog signals from current and control loop voltage signal acquisition loops into digital signals for the main processor to perform calculations and analysis, providing a foundation for digital condition monitoring.

[0050] The trip current input terminal P5 and the trip current output terminal P6 function similarly to the closing current input terminal P1 and the closing current output terminal P2. They serve as the series nodes of the control circuit current signal acquisition circuit and the circuit breaker trip circuit, completing the acquisition of the trip current and the circuit connection.

[0051] The closing voltage input terminal P3 and the closing voltage output terminal P4 are parallel nodes of the control circuit voltage signal acquisition circuit and the circuit breaker closing circuit. The voltage signal is taken from the closing circuit, processed and fed back to realize the parallel acquisition of the voltage signal.

[0052] Trip voltage input terminal P7 and trip voltage output terminal P8: Similar to closing voltage input terminal P3 and closing voltage output terminal P4, they serve as parallel nodes between the control circuit voltage signal acquisition circuit and the circuit breaker trip circuit to complete the acquisition of trip voltage.

[0053] When the detection circuit is closed, the connection between the closing holding relay HBJ and the trip holding normally closed node TBJ is broken, forming the closing current input terminal P1 and the closing current output terminal P2, ensuring that the original closing logic is not affected after the subsequent current detection chip is connected in series.

[0054] Trip circuit: The trip current input terminal P5 and the trip current output terminal P6 are formed by disconnecting the normally closed trip holding node TBJ and the trip coil TQ, providing an installation point for trip current acquisition.

[0055] Power supply and grounding: KM+ and KM- are powered by 220V DC power supply, and the circuit grounding terminal is reliably connected to the common grounding terminal GND of the protection device to reduce the impact of electromagnetic interference on signal acquisition.

[0056] like Figure 2 As shown, the control circuit current signal acquisition circuit is configured with two independent circuits for closing current acquisition and tripping current acquisition, with identical structures, including a current acquisition circuit, an operational amplifier regulation circuit, and an analog-to-digital conversion circuit. The specific implementation is as follows: Current acquisition circuit: An ACS712 current sensor U6 is selected and connected in series between the closing current input terminal P1 and the closing current output terminal P2, and between the tripping current input terminal P5 and the tripping current output terminal P6. The closing current input terminal P1 and the tripping current input terminal P5 are connected to the positive input of the sensor, and the closing current output terminal P2 and the tripping current output terminal P6 are connected to the negative output of the sensor. A 10μF electrolytic capacitor C1 and a 0.1μF ceramic capacitor C4 are connected in parallel at the power supply terminal as decoupling capacitors to filter out power supply ripple. A 1kΩ resistor R8 and a 0.1μF capacitor C3 are connected in series at the output terminal to form a filter and voltage regulator component to ensure stable output signal.

[0057] Operational amplifier adjustment circuit: A two-stage amplification structure is formed by using dual operational amplifiers LM358. The first-stage operational amplifier U2A is equipped with a 10kΩ feedback resistor R1 and a 1kΩ resistor R9 to form an 11x amplification factor. A 1000pF compensation capacitor C5 is connected in parallel at the power supply to suppress self-oscillation. The second-stage operational amplifier U2B forms an adjustable gain network through a 1kΩ resistor R2, a 10kΩ resistor R5, a 1kΩ resistor R7, and a 10kΩ resistor R10 to achieve precise signal amplitude matching.

[0058] Analog-to-digital conversion circuit: It consists of an RC filter circuit composed of a 2kΩ current-limiting resistor R6 and a 0.01μF filter capacitor C2. The output terminal is connected to the analog-to-digital converter (ADC) channel of the main processor through the analog-to-digital conversion interface TQI_ADC3 to complete the conversion of analog signals to digital signals.

[0059] like Figure 3 As shown, the control circuit voltage signal acquisition circuit, corresponding to the acquisition of closing voltage and tripping voltage, adopts a design scheme of resistor voltage divider plus isolation amplification, including resistor voltage divider circuit, isolation circuit, operational amplifier adjustment circuit and analog-to-digital conversion circuit, and the specific implementation is as follows: Resistor voltage divider circuit: The closing voltage input terminal P3 and the closing voltage output terminal P4 adopt the first voltage divider branch, which is composed of 100kΩ R25, 100kΩ R26, 100kΩ R27, 100kΩ R28, 100kΩ R29, 100kΩ R30, 100kΩ R38, 100kΩ R41, and 100kΩ R45 forming a series voltage divider network. The trip voltage input terminal P7 and the trip voltage output terminal P8 adopt the second voltage divider branch, which is composed of 100kΩ R31 to 100kΩ R36 forming a series voltage divider network. The voltage division ratio is set to 100:1, which reduces the input 220V DC voltage to about 2.2V. Both the first and second voltage divider branches are connected in parallel with 1μF filter capacitors C27 and C28 to filter out voltage ripple.

[0060] Isolation circuit: The isolation chip U9 of model ISO1540 is selected. The input terminal is connected to the output of the voltage divider circuit, and the output terminal is connected to the operational amplifier regulation circuit. 10μF electrolytic capacitors C23 and C24 and 0.1μF ceramic capacitors C22 and C26 are connected in parallel at the power supply terminal of the chip as decoupling capacitors. The ground terminal is connected to the high voltage ground GND50-2 and the low voltage ground GND respectively to achieve electrical isolation and enhance system safety.

[0061] Operational amplifier conditioning circuit: The conditioning circuit is composed of operational amplifier OP07, and a feedback network is formed by 1kΩ R37, 10kΩ R39, 1kΩ R40, 10kΩ R43, 1kΩ R44, and 10kΩ R46 to achieve 5 times signal amplification. 1000pF compensation capacitors C26, C29, and C31 are connected in parallel at the power supply to optimize the dynamic response of the signal.

[0062] Analog-to-digital conversion circuit: It consists of an RC filter circuit composed of a 1kΩ current-limiting resistor R42 and a 0.01μF filter capacitor C30. The output terminal is connected to the analog-to-digital converter (ADC) channel of the main processor through the analog-to-digital conversion interface TQU_ADC5 to complete the digital conversion of the signal.

[0063] The main processor is an STM32H7 series microcontroller with a built-in 16-bit high-precision analog-to-digital converter (ADC). The sampling rate is set to 12kHz, and the period of a single sampling window is 833μs, ensuring that the microsecond-level signal acquisition requirements are met.

[0064] Data transmission is implemented using an SPI interface with a data transmission rate of 10MHz to ensure high-speed interaction between status monitoring data and protection logic data.

[0065] The waveform recording and storage module is equipped with an 8GB SD card, which supports waveform data storage at the tens of kHz level and can completely record the voltage and current waveforms and key parameters of each trip and close process.

[0066] The protection device activates its internal nanosecond-level clock synchronization mechanism. The main processor simultaneously acquires three signals through the analog-to-digital converter (ADC) channel: the voltage and current signals of the circuit breaker closing, the voltage and current signals of the circuit breaker tripping, and the voltage and current signals of the system. The sampling frequency is maintained at 12kHz to ensure that the timestamps of all signals are strictly aligned.

[0067] The current sensor U6 converts the closing current and tripping current into 0-5V analog voltage signals. After being amplified and filtered by the operational amplifier regulation circuit, the signals are input to the analog-to-digital converter ADC through the TQI_ADC3 interface and converted into 16-bit digital signals.

[0068] After the voltage divider circuit reduces the high voltage to a low level, it is isolated by the isolation chip U9 and conditioned by the operational amplifier. Then, it is input to the analog-to-digital converter (ADC) through the TQU_ADC5 interface to complete the digital conversion. All digital signals are then transmitted to the main processor's cache.

[0069] like Figure 4 As shown, the main processor calls the computing module to perform real-time calculations on the acquired digital signals, extracting state parameters such as the peak value of the closing current and tripping current, the peak duration, and the action time. Combined with the system voltage and current signals, the dispersed characteristic quantities are transformed into a comprehensive performance index through a weighted algorithm. Every 100 operations are completed, the circuit breaker performance evolution curve is updated and stored in the SD card.

[0070] The status monitoring module compares the real-time performance index with the preset threshold. When the index is lower than the health status threshold of 80, it feeds back to the protection logic unit and automatically shortens the overcurrent protection action time by 10ms. When the index is lower than the mild abnormality threshold of 60, it shortens it by another 10ms.

[0071] After the protection action is executed, the main processor records the actual trip time, peak current, and other results, reversely corrects the mechanical jamming warning threshold of the state monitoring model, and iteratively optimizes the feature recognition logic.

[0072] The waveform recording module records the waveform data of each trip and close process completely, including key features such as rising edge slope, peak value, and attenuation curve.

[0073] The operation and maintenance system regularly compares the recorded waveform data at different stages. When it is found that the peak value of the closing inrush current increases by more than 5% for three consecutive times, or the deviation of the action time exceeds 30%, a maintenance alarm is triggered, prompting the contact grinding or mechanism lubrication.

[0074] This implementation method, through hardware reuse design, eliminates the need for additional independent monitoring equipment, reducing equipment procurement costs by more than 40%. Synchronous sampling technology achieves a minimum monitoring interval of 0.833ms, with data acquisition accuracy reaching ±0.5%. The closed-loop feedback mechanism improves the response speed of protection actions by 20ms and increases the fault location accuracy by 35%. Full lifecycle monitoring can provide early warning of hidden equipment defects 3-6 months in advance, reducing the probability of power outages caused by circuit breaker failures in the power system by more than 50%, fully meeting the needs of refined operation and maintenance management of smart grids.

[0075] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A circuit breaker condition monitoring method integrated with protection device functions, characterized in that: This includes a circuit breaker control circuit, a control circuit current signal acquisition circuit, and a control circuit voltage signal acquisition circuit. The control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit are integrated inside the circuit breaker control circuit and synchronously sample the current and voltage transmitted by the circuit breaker. Control circuit current signal acquisition circuit: used to convert the control current flowing through the control circuit into an analog voltage signal when the circuit breaker is opened and closed; Control circuit voltage signal acquisition circuit: used to acquire the voltage of the opening coil and closing coil relative to the common negative terminal of the control circuit when the circuit breaker is opening and closing; The circuit breaker control circuit has a closing current input terminal P1, a closing current output terminal P2, a tripping current input terminal P5, a tripping current output terminal P6, a closing voltage input terminal P3, a closing voltage output terminal P4, a tripping voltage input terminal P7, and a tripping voltage output terminal P8. A control circuit current signal acquisition circuit is connected in series between the closing current input terminal P1 and the closing current output terminal P2, and between the tripping current input terminal P5 and the tripping current output terminal P6. A control circuit voltage signal acquisition circuit is connected in parallel between the closing voltage input terminal P3 and the closing voltage output terminal P4, and between the tripping voltage input terminal P7 and the tripping voltage output terminal P8.

2. The circuit breaker condition monitoring method integrating protection device functions according to claim 1, characterized in that: The circuit breaker control circuit includes a control power supply KM+, a control power supply KM-, a closing holding relay HBJ, a trip holding normally closed node TBJ, a trip coil TQ, and an analog-to-digital converter ADC. The closing current input terminal P1 and the closing current output terminal P2 are located between the closing holding relay HBJ and the trip holding normally closed node TBJ, and the trip current input terminal P5 and the trip current output terminal P6 are located between the trip holding normally closed node TBJ and the trip coil TQ.

3. The circuit breaker condition monitoring method integrating protection device functions according to claim 2, characterized in that: A voltage divider resistor is connected in parallel between the closing current output terminal P2 and the KM- terminal. The closing voltage input terminal P3 and the closing voltage output terminal P4 are located between the voltage divider resistors. A voltage divider resistor is connected in parallel between the trip current output terminal P6 and the KM- terminal. The trip voltage input terminal P7 and the trip voltage output terminal P8 are located between the voltage divider resistors.

4. The circuit breaker condition monitoring method integrating protection device functions according to claim 1, characterized in that: The control circuit current signal acquisition circuit includes a current acquisition circuit, an operational amplifier adjustment circuit, and an analog-to-digital conversion circuit; Current acquisition circuit: includes current sensor U6, the power supply terminal of current sensor U6 is equipped with decoupling capacitors C1 and C4, and the output terminal of current sensor U6 is equipped with filter and voltage regulator components C3 and R8; Operational amplifier regulation circuit: includes first-stage operational amplifier U2A and second-stage operational amplifier U2B. The first-stage operational amplifier U2A is equipped with feedback resistor network R1 and R9. The power supply terminal of the first-stage operational amplifier U2A is equipped with compensation capacitor C5. The second-stage operational amplifier U2B is equipped with resistor network R2, R5, R7, and R10. Analog-to-digital conversion circuit: includes current-limiting and voltage-dividing components R6 and C2, with an analog-to-digital conversion interface TQI_ADC3 configured between R6 and C2.

5. The circuit breaker condition monitoring method integrating protection device functions according to claim 1, characterized in that: The control circuit voltage signal acquisition circuit includes a resistor voltage divider circuit, an isolation circuit, an operational amplifier adjustment circuit, and an analog-to-digital conversion circuit; The resistor voltage divider circuit includes the first voltage divider branch R25, R26, R27, R28, R29, R30, R38, R41, R45 and the second voltage divider branch R31, R32, R33, R34, R35, R36. The resistor voltage divider circuit is equipped with filter capacitors C27 and C28. Isolation circuit: includes isolation chip U9. The power supply terminal of isolation chip U9 is equipped with decoupling capacitors C23, C24, C22, and C26. The ground terminal of isolation chip U9 is connected to GND50-2 and GND respectively. Operational amplifier regulation circuit: including operational amplifier U1A, the operational amplifier regulation circuit is configured with resistor network R37, R39, R40, R43, R44, R46 and compensation capacitors C26, C29, C31; Analog-to-digital conversion circuit: includes current-limiting resistor R42 and filter capacitor C30, and is equipped with analog-to-digital conversion interface TQU_ADC5.

6. The circuit breaker condition monitoring method integrating protection device functions according to claim 1, characterized in that: The control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit are connected to the analog-to-digital converter (ADC) through the backplane on the circuit breaker.

7. A method for implementing a circuit breaker condition monitoring method integrated with protection device functions, applied to the circuit breaker condition monitoring method integrated with protection device functions as described in any one of claims 1-6, characterized in that, Includes the following steps; Step S1: Synchronously sample the circuit breaker control circuit current signal acquisition circuit, control circuit voltage signal acquisition circuit and AC plug-in of the protection device. Through the clock synchronization mechanism, within a single sampling window period, simultaneously acquire the tripping and closing voltage and current signals of the circuit breaker control circuit and the voltage and current signals of the system. Step S2: The control circuit current signal acquisition circuit converts the closing current and tripping current flowing through the circuit breaker into analog voltage signals, and the control circuit voltage signal acquisition circuit converts the input voltage into digital signals for processing by the main processor; Step S3: The main processor receives digital signals from the control circuit current signal acquisition circuit and the control circuit voltage signal acquisition circuit, and realizes real-time calculation of the circuit breaker status parameters through the calculation module. Combined with the system voltage and current signals acquired by the AC plug-in of the protection device, it performs multi-source signal digital fusion processing to construct the performance evolution curve of the circuit breaker. Step S4: Based on the circuit breaker performance evolution curve and real-time status parameters, the status monitoring module feeds the data back to the protection logic criterion verification unit. When an abnormal state is detected, the protection device quickly issues a protection action command and records the action execution result, which is then fed back to the status monitoring model. The monitoring parameter threshold and feature recognition logic are corrected through algorithm iteration to form a closed-loop feedback mechanism. Step S5: The built-in waveform recording function of the protection device relies on a high sampling rate and a large-capacity storage unit to collect waveform data in all dimensions during the tripping and closing process. By comparing the waveform data under different stages and operating conditions, targeted maintenance measures are triggered when potential risks are found, thus eliminating potential equipment hazards in advance.

8. The method for implementing a circuit breaker condition monitoring method integrating protection device functions according to claim 7, characterized in that: The current signal acquisition includes a current acquisition circuit, an operational amplifier adjustment circuit, and an analog-to-digital converter circuit. The current acquisition circuit is used to convert the measured current signal into a voltage signal. The operational amplifier adjustment circuit is used to amplify, adjust the level, and filter the acquired voltage signal. The analog-to-digital converter circuit is used to filter the conditioned analog voltage signal and transmit it to the analog-to-digital converter (ADC) for digital analysis.

9. The method for implementing a circuit breaker condition monitoring method integrating protection device functions according to claim 7, characterized in that: In step S3, the control circuit voltage signal acquisition circuit includes a resistor voltage divider circuit, an isolation circuit, an operational amplifier adjustment circuit, and an analog-to-digital converter circuit. The resistor voltage divider circuit is used to proportionally reduce the voltage of the high-voltage signal. The isolation circuit is used to achieve electrical isolation between the high-voltage and low-voltage systems. The operational amplifier adjustment circuit is used to amplify, filter, and adjust the level of the isolated voltage signal. The analog-to-digital converter circuit is used to filter the conditioned analog voltage signal and transmit it to the analog-to-digital converter (ADC) for digital analysis.

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