Synchronous system non-stop prevention method and device based on multiple redundancy and intelligent control

Abstract

The invention provides a synchronous system non-stop prevention method and device based on multiple redundancy and intelligent control. According to the synchronous system non-stop prevention method based on multiple redundancy and intelligent control, the failure rate of synchronous grid connection of the generator can be effectively reduced, the impact current is controlled to be 1.1 times of the rated value or below, and the device reliability and the grid connection safety are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of generator grid-connected synchronization control technology, and in particular to a method and device for preventing unplanned outages in a synchronization system based on multiple redundancy and intelligent control. Background Technology

[0002] With the continuous expansion of the power system and the increasing proportion of new energy integration, automatic generator synchronization and grid connection, as a key link in ensuring the stable operation of the power grid, faces increasingly stringent technical requirements. In thermal power, hydropower, wind power, and new energy storage systems, generator grid connection operations need to achieve dynamic synchronization of voltage, frequency, and phase angle, ensuring that the inrush current is controlled within 1.2 times the rated current. Related technologies typically employ a microprocessor-based automatic quasi-synchronization device in conjunction with a synchronization meter, using PID control algorithms to achieve frequency and voltage regulation, constructing a complete control system from signal acquisition and logic judgment to closing execution. Specifically, this system includes key components such as voltage transformer sampling, circuit breaker position signal acquisition, and closing circuit control. Among these, issues such as voltage transformer sampling error, circuit breaker closing time dispersion, and system frequency fluctuations (±0.2Hz / s) have become major bottlenecks restricting the improvement of grid connection success rates.

[0003] However, existing synchronization system configurations directly use a single synchronization device and synchronization table for parallel judgment, without achieving end-to-end redundancy in hardware and control logic. This may lead to asynchronous closing due to device failure or parameter deviation, or secondary impacts during timeout reset, thus affecting the unit's start-up success rate and equipment safety. Especially against the backdrop of increased frequency fluctuations caused by renewable energy integration, traditional control strategies are unable to meet the requirements for millisecond-level precise grid connection. Inrush currents exceeding 1.2 times the rated value will directly threaten the generator shaft life, increase the risk of unplanned shutdowns, and limit the efficient operation and safe stability of the power system. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the first objective of this invention is to propose a method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control.

[0006] The second objective of this invention is to propose a synchronization system anti-unplanned shutdown device based on multiple redundancy and intelligent control.

[0007] To achieve the above objectives, a first aspect of the present invention proposes a method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control, comprising: S1 is equipped with two completely independent and mutually redundant synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the main device fails to complete the synchronization process within the set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal. S2 connects the secondary signals from voltage transformers with different windings to each set of synchronizing devices to achieve physical isolation of the voltage sampling circuit and ensure that the synchronizing closing function can still be maintained when any voltage transformer fails. S3, set up an independent and redundant circuit breaker position signal acquisition circuit, each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable, and automatically locks the device and switches to the standby device in case of abnormality. S4 employs independent redundant closing output relays, cables, terminal blocks, and circuit breaker closing coils. When any closing circuit malfunctions, the main synchronizing device automatically switches to the standby device after a timeout and performs synchronizing operations via the standby closing circuit.

[0008] In one embodiment of the present invention, S1 includes: S11, when the main synchronizing device detects an internal fault, it analyzes the fault type in real time through the built-in diagnostic module and generates the corresponding fault code; S12, when the primary synchronizing device detects an external fault, it sends a fault signal through the communication interface with the monitoring system and maintains the continuity of the PID adjustment parameters while switching to the backup device.

[0009] In one embodiment of the present invention, S2 includes: S21, the secondary signal of the voltage transformer connected to each set of synchronizing devices comes from the independent sampling points of different windings of the generator and is transmitted in isolation through shielded cables; S22, each set of synchronization devices is equipped with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

[0010] In one embodiment of the present invention, S3 includes: S31, the auxiliary contact groups of the circuit breaker connected to each set of synchronous devices are respectively from two different normally open contacts of the circuit breaker, and are electrically isolated by independent signal isolators; S32, when a certain synchronizing device detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends an abnormal position signal alarm to the monitoring system.

[0011] In one embodiment of the present invention, S4 includes: S41, each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails. S42, the standby closing circuit remains in standby mode when not activated, and periodic self-checks ensure it can be put into operation at any time.

[0012] In one embodiment of the present invention, it further includes: S5, after the synchronizing device is switched to the standby device, the monitoring system dynamically adjusts the PID control parameters according to the preset frequency fluctuation compensation model to adapt to the ±0.2Hz / s frequency change rate caused by the access of new energy sources, and ensures that the frequency difference at the moment of closing is within ±0.1Hz.

[0013] To achieve the above objectives, a second aspect of the present invention provides a synchronization system anti-outage device based on multiple redundancy and intelligent control, comprising: The redundancy switching control module is used to configure two completely independent and mutually backup synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the primary device fails to complete the synchronization process within a set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal. The voltage signal isolation access module is used to connect the secondary signals from voltage transformers with different windings to each set of synchronizing devices, realize the physical isolation of the voltage sampling circuit, and ensure that the synchronizing closing function can still be maintained when any voltage transformer fails. The circuit breaker position redundancy acquisition module is used to set up independent redundant circuit breaker position signal acquisition circuits. Each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable. In case of abnormality, the device is automatically locked and switched to the backup device. The redundant execution module for the closing circuit is used to employ independent redundant closing output relays, cables, terminal blocks and circuit breaker closing coils. When any closing circuit is abnormal, the main synchronizing device will automatically switch to the standby device after the timeout and perform the synchronizing operation through the standby closing circuit.

[0014] In one embodiment of the present invention, the redundancy switching control module is further configured to: when the primary synchronizing device detects an internal fault, analyze the fault type in real time through a built-in diagnostic module and generate a corresponding fault code; when the primary synchronizing device detects an external fault, send a fault signal through a communication interface with the monitoring system, and maintain the continuity of the PID adjustment parameters while switching to the backup device.

[0015] In one embodiment of the present invention, the voltage signal isolation access module is further configured to: the secondary signals of the voltage transformers connected to each set of synchronizing devices come from independent sampling points of different windings of the generator, and are transmitted in isolation through shielded cables; each set of synchronizing devices is configured with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

[0016] In one embodiment of the present invention, the circuit breaker position redundancy acquisition module is further configured to: the circuit breaker auxiliary contact groups connected to each set of synchronizing devices are respectively from two different normally open contacts of the circuit breaker, and are electrically isolated by independent signal isolators; when a set of synchronizing devices detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends a position signal abnormality alarm to the monitoring system.

[0017] In one embodiment of the present invention, the redundant execution module of the closing circuit is further configured to: each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails; the backup closing circuit is continuously in standby state when it is not activated, and ensures that it can be put into operation at any time through periodic self-testing.

[0018] In one embodiment of the present invention, it further includes: a frequency fluctuation compensation module, used to dynamically adjust PID control parameters according to a preset frequency fluctuation compensation model after the synchronizing device is switched to the standby device, so as to adapt to the ±0.2Hz / s frequency change rate caused by the access of new energy sources, and ensure that the frequency difference at the moment of closing is within ±0.1Hz.

[0019] The method and apparatus of this invention effectively reduce the failure rate of generator synchronization and grid connection, control the inrush current to below 1.1 times the rated value, and significantly improve system reliability and grid connection safety.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of a method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control according to an embodiment of the present invention; Figure 2 This is a structural diagram of a synchronization system anti-sudden stop device based on multiple redundancy and intelligent control according to an embodiment of the present invention. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] The following description, with reference to the accompanying drawings, describes a method and apparatus for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control, according to an embodiment of the present invention.

[0025] Example 1 Figure 1 This is a flowchart of a synchronous system anti-outage method based on multiple redundancy and intelligent control according to an embodiment of the present invention.

[0026] like Figure 1 As shown, a method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control includes the following steps: S1 is equipped with two completely independent and mutually redundant synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the main device fails to complete the synchronization process within the set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal.

[0027] Furthermore, this step employs two completely independent microcomputer-based automatic synchronizing devices and two microcomputer-based multi-functional synchronizing meters, each configured with independent power supplies, input / output interfaces, and control logic units. The primary and backup devices synchronize their states via a redundant communication bus (such as CAN or Ethernet redundancy protocol), while an intelligent switching algorithm is embedded in the control logic. When the primary device fails to complete the synchronization process within the set synchronization time limit (typically 5-10 seconds, adjusted according to unit type and grid standards), or detects an internal fault (such as CPU malfunction, sampling distortion) or an external fault (such as voltage transformer disconnection, circuit breaker position signal abnormality), the system will automatically trigger the switching logic, seamlessly transferring control to the backup device and outputting a closing signal through an independent closing circuit.

[0028] Furthermore, the switching criteria for the primary device include, but are not limited to: frequency difference Δf ≤ 0.5Hz, voltage difference ΔU ≤ 10%UN, phase angle difference Δθ ≤ 30°, and failure to meet the closing conditions within a set time (e.g., 8 seconds). The switching process must be completed within 50ms to ensure the continuity of PID control parameters and avoid secondary impacts caused by the switching. Simultaneously, after the switching is triggered, the system should immediately send an alarm signal to the monitoring system, complying with the system reliability requirements of relay protection standards such as IEC 60255-111.

[0029] Furthermore, this technical solution is widely applicable to the grid connection operation of thermal power, hydropower, wind power, and new energy storage systems. It exhibits significant adaptability and stability advantages, particularly in complex grid environments where the integration of new energy sources leads to large frequency fluctuations (±0.2Hz / s). Through hot standby and automatic switching mechanisms, the system can maintain the continuity of grid connection control under extreme operating conditions, ensuring the safe startup of the units.

[0030] Furthermore, this step effectively improves the fault tolerance and response speed of the synchronization system, significantly reducing the synchronization failure rate to below 0.05 times / 10,000 times, while ensuring that the inrush current is controlled within 1.1 times the rated value, thereby extending the generator shaft life and improving the grid connection success rate, which has significant engineering practical value and economic benefits.

[0031] Furthermore, S1 includes: S11 When the main synchronizing device detects an internal fault, it analyzes the fault type in real time through the built-in diagnostic module and generates the corresponding fault code.

[0032] Furthermore, in some implementations, when the primary synchronizing device detects an internal fault, it analyzes the fault type in real time and generates a corresponding fault code through a built-in diagnostic module. This is a key technical step in the non-stop prevention method of this invention to achieve system self-diagnosis and rapid fault response. This step is based on an embedded real-time operating system (RTOS) platform, combining hardware status monitoring and software logic judgment to construct a multi-level fault identification mechanism. Specifically, the primary synchronizing device integrates a diagnostic module based on ARM Cortex-M series or FPGA architecture. This module periodically scans key signals such as CPU running status, memory access anomalies, communication link interruptions, and voltage sampling circuit anomalies, and performs pattern matching in conjunction with a preset fault feature library to identify typical fault types such as power module failure, sampling channel disconnection, and control logic deadlock.

[0033] Optionally, the diagnostic module employs a multi-threaded mechanism to handle hardware status acquisition, fault feature extraction, and fault code generation tasks separately, ensuring the real-time performance and accuracy of the diagnostic process. Fault code generation follows the anomaly coding specifications in IEC 60870-5-104 or DL / T 634.5104 standards. Each fault type corresponds to a unique 16-bit or 32-bit fault code, facilitating rapid identification and classification by the monitoring system. For example, a voltage transformer sampling anomaly can be coded as 0x0001, a frequency regulation timeout as 0x0003, and a circuit breaker position signal loss as 0x0005, etc.

[0034] Furthermore, this step is widely applicable in practical applications to grid-connected scenarios such as thermal power, hydropower, wind power, and energy storage systems. Especially when the integration of new energy sources causes significant system frequency fluctuations (±0.2Hz / s), it effectively prevents asynchronous closing caused by internal device anomalies. By generating fault codes in real time, the system can complete fault identification and alarm within 0.5 seconds, providing a decision-making basis for subsequent automatic switching of primary and backup devices and closing circuit interlocking. This significantly improves the reliability and grid connection success rate of the synchronous system and reduces the probability of unplanned outages.

[0035] S12, when the primary synchronizing device detects an external fault, it sends a fault signal through the communication interface with the monitoring system and maintains the continuity of the PID adjustment parameters while switching to the backup device.

[0036] Specifically, in some implementations, when the primary synchronizing device detects an external fault (such as abnormal voltage transformer sampling, loss of circuit breaker position signal, or sudden change in system frequency), it sends a fault signal in real time through its standard communication interface with the monitoring system (such as IEC 60870-5-103 or Modbus TCP / IP protocol). This signal contains key information such as fault type, occurrence time, and fault source device number, ensuring that the monitoring system can quickly identify and respond. Simultaneously, the redundancy switching logic module within the primary synchronizing device initiates an automatic switching mechanism, seamlessly transferring control to the backup synchronizing device. During the switching process, the primary device transmits the currently operating PID control parameters (including proportional coefficient Kp, integral time Ti, and derivative time Td) to the backup device in real time via an internal high-speed communication bus (such as CAN or Ethernet), ensuring that the backup device can immediately continue the original control process after taking over control, avoiding secondary shocks or control instability caused by parameter mutations.

[0037] Optionally, the switching logic module employs a time-stamped and state-synchronized non-disruptive switching algorithm to ensure the consistency of control output between the primary and backup devices at the moment of switching. Specifically, the switching response time should be controlled within 50ms, and the PID parameter propagation error should not exceed ±1%, to meet the grid-connected control continuity requirements of the IEEE 1547-2018 standard. Furthermore, this step is applicable to the grid-connected operation of various generator units, including thermal power, hydropower, wind power, and energy storage systems, especially in scenarios where the access of new energy sources leads to significant frequency fluctuations, demonstrating a significant improvement in stability and reliability.

[0038] The technical advantage of this step is that it effectively prevents unplanned downtime caused by main device failure or external interference through rapid fault detection and continuous parameter switching, while ensuring a smooth transition during grid connection, and significantly improving the safety of system operation and grid connection success rate.

[0039] S2 connects the secondary signals from voltage transformers with different windings to each set of synchronizing devices, realizing physical isolation of the voltage sampling circuit and ensuring that the synchronizing closing function can still be maintained when any voltage transformer fails.

[0040] Specifically, this step involves the redundant design of the voltage sampling circuit in the synchronization system. The core technology lies in achieving physical isolation of voltage signal acquisition by connecting each synchronization device to secondary signals from voltage transformers (PTs) of different windings, thereby improving the system's fault tolerance and operational reliability. In some implementations, each microprocessor-based automatic quasi-synchronizer and multi-functional synchronizing meter is equipped with an independent voltage sampling channel, connected to different secondary windings of the main transformer or bus PT, such as phase A, phase B, or phase C windings, ensuring that the two voltage signals are completely independent in their electrical paths and do not interfere with each other.

[0041] In terms of specific operation, voltage transformers typically have multiple independent windings on their secondary side, each used for different protection and control functions. In this scheme, two synchronization devices are connected to the secondary side of different windings, and voltage transformation is performed through independent voltage transformer ratios (e.g., 110kV / √3 : 100V / √3). A high-precision voltage sampling module (sampling accuracy ≥0.2%, sampling frequency ≥1kHz) is used to acquire and process the voltage amplitude, frequency, and phase in real time. The sampled signals are then converted from analog to digital (ADC) and input to the DSP or FPGA processing unit inside the synchronization device to calculate key synchronization parameters such as voltage difference, frequency difference, and phase angle difference.

[0042] Furthermore, the voltage sampling circuit must meet the accuracy and response time requirements for voltage transformers used for measurement as specified in IEC 60044-1 or GB / T 20840.1-2013. Simultaneously, the system sets the voltage difference threshold to ±5% of the rated voltage, the frequency difference threshold to ±0.2Hz, and the phase angle difference threshold to ±10° to ensure that the instantaneous inrush current during grid connection is controlled within 1.1 times the rated current.

[0043] This procedure is applicable to the grid connection operation of various generator sets, including thermal power, hydropower, wind power, and energy storage systems, especially in scenarios where the integration of new energy sources causes significant system frequency fluctuations, demonstrating remarkable anti-interference capabilities. When any PT fails or the sampling circuit malfunctions, the other device can still complete synchronization judgment and closing operations based on an independent voltage signal, effectively preventing equipment damage and grid disturbances caused by asynchronous closing.

[0044] Furthermore, this design establishes a redundancy mechanism for voltage signal acquisition, enhancing the fault tolerance and stability of the synchronization system. It is a key component in realizing the four-level protection system, providing a reliable data foundation for subsequent PID regulation and closing control, significantly reducing the synchronization failure rate, and improving the success rate and safety of grid connection operations.

[0045] Furthermore, S2 includes: S21, the secondary signals of the voltage transformers connected to each set of synchronizing devices come from independent sampling points of different windings of the generator and are transmitted in isolation through shielded cables.

[0046] Specifically, in the steps of this invention, the secondary signals of the voltage transformers connected to each set of synchronizing devices come from independent sampling points of different windings of the generator and are transmitted in isolation through shielded cables. The technical implementation principle is based on the redundant acquisition and physical isolation transmission mechanism of voltage signals in the power system, aiming to improve the signal reliability and anti-interference capability of the synchronizing system under complex operating conditions.

[0047] In some implementations, each microprocessor-based automatic synchronizing device is connected to the secondary side signals of voltage transformers (PTs) of different phases in the generator stator winding. For example, one device is connected to the A-phase winding PT, and another to the B-phase winding PT, ensuring that the two voltage signals are completely independent in the electrical path. The rated voltage of the secondary side of the voltage transformer is typically 100V or 110V, with a transformation ratio of (e.g.) 20000 / 100, and a sampling frequency of not less than 1kHz to meet the real-time monitoring requirements of voltage amplitude, frequency, and phase during synchronization. The sampled signal is transmitted to the synchronizing device via a shielded cable (such as a flame-retardant shielded cable with a shield grounding impedance ≤0.1Ω). The cable shield is reliably grounded at both ends to effectively suppress electromagnetic interference (EMI) and common-mode noise, ensuring the accuracy and stability of signal transmission.

[0048] Furthermore, this design complies with relevant power system relay protection and automatic device standards such as IEC 60255-11 and DL / T 755-2001, requiring the voltage sampling channel to have good linearity (error ≤0.2%), phase consistency (phase deviation ≤0.5°), and anti-interference capability. Through physically isolated voltage sampling paths, even if a PT in one winding fails or experiences sampling abnormalities, another device can still perform synchronization judgment based on an independent signal source, thereby effectively preventing asynchronous closing caused by signal abnormalities.

[0049] This step is widely applicable in practical applications to grid connection operations of thermal power, hydropower, wind power, and new energy storage systems. It is particularly valuable in scenarios where the integration of new energy sources leads to significant frequency fluctuations, demonstrating substantial anti-interference and fault tolerance capabilities. Its technical value lies in establishing redundant protection at the signal acquisition level, providing a high-precision and highly reliable data foundation for subsequent frequency, voltage, and phase difference assessments. It is a crucial link in achieving the first level of protection in the "four-level protection system."

[0050] S22, each set of synchronization devices is equipped with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

[0051] Specifically, this step involves configuring an independent sampling channel verification module for each synchronization device, and automatically switching to another sampling channel and recording the abnormal event when the sampling signal is abnormal. Its technical implementation principle is based on redundant sampling and real-time signal quality monitoring mechanisms, aiming to improve the signal reliability and system fault tolerance of the synchronization system under complex operating conditions.

[0052] In some implementations, each microprocessor-based automatic synchronizing device has an independent voltage sampling channel, connected to secondary side signals from different voltage transformer (PT) windings. The sampling channel verification module monitors the amplitude, frequency, phase, and sampling consistency of the sampled signals in real time to determine whether they meet the sampling accuracy requirements specified in the IEC 60255-111 standard (e.g., voltage sampling error should be less than ±0.5%, frequency error less than ±0.01Hz). When any sampling channel experiences signal loss, abrupt amplitude changes, frequency drift, or abnormal sampling period, the verification module triggers switching logic, automatically switching the synchronizing device's sampling source to another independent channel. The switching process must be completed within 50ms to ensure the continuity and real-time performance of the synchronization control.

[0053] Optionally, the switching logic can be based on a state machine design, combined with a hardware watchdog and software self-testing mechanism to achieve dual monitoring of the sampling channel. During the switching process, the system will retain the current PID adjustment parameters to ensure that the control process is undisturbed after the switch, complying with the requirements for grid-connected control continuity in IEEE 1547-2018. In addition, the system has a built-in event logging module that can record the switching time, sampled value, fault type, and duration of abnormal sampling channels, facilitating subsequent fault analysis and system optimization.

[0054] This step is applicable to grid-connected scenarios for thermal power, hydropower, wind power, and energy storage systems, especially in situations with high voltage transformer failure rates or complex sampling environments (such as severe electromagnetic interference). It can significantly improve the availability and safety of the synchronous system. Its technical value lies in constructing redundant protection at the signal acquisition layer, which is a key link in the four-level protection system. It effectively prevents asynchronous closing caused by sampling anomalies, thereby reducing inrush current, improving grid connection success rate, and extending equipment life.

[0055] S3, set up an independent redundant circuit breaker position signal acquisition circuit, each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable, and automatically locks the device and switches to the standby device in case of abnormality.

[0056] Specifically, this step involves the redundant configuration of the circuit breaker position signal acquisition circuit in the synchronization system. Its core lies in improving the system's fault tolerance and operational reliability under abnormal operating conditions through physical isolation and logical interlocking mechanisms. In some implementations, each synchronization device is configured with an independent circuit breaker position signal acquisition circuit, connected to different auxiliary contact groups of the circuit breaker (such as normally open contact group 1 and normally open contact group 2), and uses independent shielded cables for signal transmission to avoid signal acquisition failure due to cable sharing or contact group failure. Specifically, circuit breakers are typically configured with at least two sets of auxiliary contacts, one for the main control system and the other for the protection system. In this scheme, two of these sets of contacts are assigned to the primary and backup synchronization devices respectively, ensuring complete isolation between the two signal acquisition paths and physical structures.

[0057] Furthermore, the switching response time of the circuit breaker auxiliary contacts should be controlled within 5ms to meet the real-time requirements of the synchronization system; the anti-interference capability of the signal acquisition circuit must comply with the IEC 60255-1 standard, possessing a voltage fluctuation tolerance of ±15% and a common-mode rejection ratio ≥60dB. In terms of logic control, when the primary synchronization device detects an abnormal circuit breaker position signal (such as signal loss, jitter, or discrepancy with the actual state), the system will automatically block the closing output of that device and complete a seamless switch to the standby device within 100ms, simultaneously triggering an alarm signal in the SCADA system for timely intervention by operators.

[0058] This step is widely applicable in practical scenarios for grid connection control of thermal power, hydropower, wind power, and energy storage systems, especially in situations with frequent circuit breaker operations or strong environmental electromagnetic interference. Its redundant design effectively prevents erroneous or unresponsive closing due to signal acquisition failures. In terms of technical effectiveness, through independent redundant circuit breaker position signal acquisition, the system possesses higher fault tolerance, significantly reducing the probability of unplanned downtime caused by signal anomalies, thereby improving grid connection success rate and system stability. It is a crucial component in constructing a four-level protection system.

[0059] Furthermore, S3 includes: S31, the circuit breaker auxiliary contact groups connected to each set of synchronizing devices are respectively from two different normally open contacts of the circuit breaker, and are electrically isolated by independent signal isolators.

[0060] Specifically, the step in this invention, "the auxiliary contact groups of the circuit breaker connected to each set of synchronizing devices are respectively from two different normally open contacts of the circuit breaker, and are electrically isolated by independent signal isolators," aims to build a redundancy and isolation mechanism for circuit breaker position signal acquisition, thereby improving the reliability and safety of the synchronizing system under complex operating conditions.

[0061] Furthermore, this step involves configuring an independent circuit breaker position signal acquisition circuit for each synchronizing device, connecting it to two physically independent normally open auxiliary contacts (NO contacts) of the circuit breaker. These two sets of contacts typically originate from different mechanical contact groups within the circuit breaker body, possessing independent mechanical action paths and electrical connection paths. This ensures that even if one set of contacts becomes stuck, oxidized, or malfunctions, the other set can still provide accurate circuit breaker position feedback. The signal input is electrically isolated via an independent signal isolator (such as a DC-DC isolation module or optocoupler isolator), with an isolation voltage level typically not lower than 1500VDC, to meet the anti-interference standards for power system relay protection equipment such as IEC 60255-11 or GB / T 15145-2017. The isolator output is connected to the digital input module of the synchronizing device, enabling real-time and reliable acquisition of the circuit breaker position status.

[0062] Furthermore, the response time of the circuit breaker auxiliary contacts should be controlled within 5ms to meet the millisecond-level accuracy requirements of the synchronization system for closing timing; the input and output impedance matching of the signal isolator must meet the error range of ±5% to ensure the stability and consistency of signal transmission. In addition, the two signal acquisition circuits should use shielded cables with different paths, and the cable shielding layer should be grounded at both ends to reduce the impact of electromagnetic interference (EMI) on the signal.

[0063] Furthermore, this design is widely applicable to grid-connected control scenarios for thermal power, hydropower, wind power, and new energy storage systems. Particularly in systems where the integration of new energy sources leads to significant frequency fluctuations, accurate acquisition of circuit breaker position signals is crucial for preventing asynchronous closing. Through redundant acquisition and electrical isolation, the system can automatically lock out the current synchronizing device and switch to the standby device when the circuit breaker position signal is abnormal, thereby avoiding unplanned shutdowns caused by signal misinterpretation.

[0064] The technical effect of this step is that it establishes a redundancy and isolation mechanism for circuit breaker position signal acquisition, effectively improving the anti-interference capability and signal reliability of the synchronization system in complex electromagnetic environments. It is a key link in realizing "signal acquisition redundancy" in the four-level protection system, providing a solid data foundation for subsequent logic judgment and closing execution, significantly reducing the risk of asynchronous closing, and improving the safety and success rate of grid connection operation.

[0065] S32, when a certain synchronizing device detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends an abnormal position signal alarm to the monitoring system.

[0066] Specifically, when a synchronizing device detects a discrepancy between the circuit breaker position signal and its actual state, it immediately locks the synchronizing closing logic of that device and sends a position signal anomaly alarm to the monitoring system. This is one of the key control steps in this invention to prevent unauthorized shutdowns in the synchronizing system. This step, through real-time verification of the circuit breaker position signal, ensures that the synchronizing device has accurate circuit breaker status information before closing, thereby preventing asynchronous closing accidents caused by signal misinterpretation.

[0067] Furthermore, each synchronization device is equipped with an independent circuit breaker position signal acquisition circuit, which is connected to the normally open contacts of different auxiliary contact groups of the circuit breaker. Independent cables are used for signal transmission to achieve redundant acquisition. Internally, the device samples the circuit breaker position signal using a high-precision digital input module (DI module), with a sampling frequency typically set above 100Hz to ensure real-time response to changes in the circuit breaker's state. Before the synchronization closing logic is initiated, the device compares the acquired circuit breaker position signal with the expected circuit breaker state in the current synchronization process. If an inconsistency is found (e.g., the device determines the circuit breaker is in the open state, but it is actually closed), the closing logic is immediately blocked to prevent erroneous closing signal output.

[0068] Furthermore, the acquisition accuracy of the circuit breaker position signal should meet the requirements for auxiliary contact signal stability in the IEC 60255-1 standard, and the signal response time should be less than 50ms to meet the needs of rapid synchronization control. Simultaneously, the device should have an internal signal consistency judgment threshold; for example, if the position signal is inconsistent within three consecutive sampling cycles, a blocking mechanism should be triggered to prevent malfunctions caused by momentary interference.

[0069] Furthermore, this step is widely used in the grid connection operation of thermal power, hydropower, wind power, and new energy storage systems, especially in situations where circuit breakers are frequently operated or auxiliary contacts are severely aged, providing significant protection. Through real-time detection and interlocking mechanisms, it can effectively prevent accidental closing caused by abnormal circuit breaker position signals, thereby avoiding damage to the generator shaft system and excitation system from asynchronous inrush currents (typically up to 1.2 times the rated current).

[0070] The technical advantage of this step lies in its ability to improve the safety and reliability of the synchronous system through redundant acquisition and real-time verification of circuit breaker position signals, making it a crucial component in building a four-level protection system. Its innovation lies in the close integration of physical signal acquisition and logical judgment, achieving millisecond-level response and precise interlocking, providing critical protection against unplanned power outages for new power systems.

[0071] S4 employs independent redundant closing output relays, cables, terminal blocks, and circuit breaker closing coils. When any closing circuit malfunctions, the main synchronizing device automatically switches to the standby device after a timeout and performs synchronizing operations via the standby closing circuit.

[0072] Furthermore, the primary and backup synchronizing devices are each equipped with independent closing output relays, and their contact outputs are connected to the two independent closing coils of the circuit breaker via independent shielded cables. The terminal blocks also adopt a physical isolation design to ensure that the two signals do not interfere with each other at the wiring level. Under normal operating conditions, the primary device is responsible for outputting the closing signal, while the backup device is in hot standby mode, monitoring the operating status of the primary device and the integrity of the closing circuit in real time. When the primary closing circuit experiences a disconnection, relay failure, or failure to respond to the closing signal within a preset time, the primary synchronizing device will trigger a timeout mechanism and automatically switch to the backup device within a set switching time (e.g., within 500ms), performing synchronization operations through the backup closing circuit.

[0073] Furthermore, the switching time of the closing circuit should be controlled within 500ms to meet the requirements of IEC 60255-22-1 standard for fast response of relay protection systems. The closing signal output voltage is typically DC 220V, and the current capacity is not less than 5A to ensure reliable relay operation. The rated voltage and current of the circuit breaker closing coil must match the relay output parameters, typically DC 220V / 2A, meeting the relevant requirements of GB / T 14285 "Technical Specification for Relay Protection and Safety Automatic Devices".

[0074] Furthermore, this design is widely applicable to the automatic grid connection operation of thermal power, hydropower, wind power, and new energy storage systems. Especially in scenarios where the access of new energy sources causes significant frequency fluctuations, it can effectively prevent asynchronous closing events caused by abnormal closing circuits. In actual operation, the monitoring system issues closing commands through a PLC or DCS system. The primary device responds first; if closing is not completed within the time limit, it automatically switches to the backup device to ensure reliable output of the closing signal.

[0075] Furthermore, this step significantly improves the reliability and fault tolerance of the synchronous system through physical redundancy and intelligent switching mechanisms. In the event of a primary circuit failure, the system can complete a seamless switchover within milliseconds, avoiding unplanned unit shutdowns due to closing failures. This effectively reduces the grid inrush current to below 1.1 times the rated value, improves grid connection success rate, and extends equipment lifespan.

[0076] Furthermore, S4 includes: S41, each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails.

[0077] Specifically, the step in this invention, "each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails," is a key technical measure in the "closing execution" link of the four-level protection system, which aims to improve the reliability and fault tolerance of the synchronous system under extreme conditions.

[0078] Furthermore, each closing output relay adopts an independent power supply design. Its power supply module is typically a DC 220V or DC 110V isolated switching power supply with input overvoltage, undervoltage, and short-circuit protection functions. The output terminal provides a stable DC power supply to the relay through a DC-DC isolated converter. The drive circuit is composed of optocoupler isolation + power MOSFET or relay drive module to ensure electrical isolation between the control signal and the execution circuit, preventing interference signals from entering the control logic. The two closing output circuits are completely independent in hardware, including independent relay coils, independent closing coil power supply paths, and independent terminal blocks, avoiding simultaneous failure of both circuits due to common-mode faults.

[0079] Furthermore, the power supply module must meet the stability requirements for relay protection device power supplies in the IEC 61850-8-1 standard, with output voltage ripple less than ±1% and response time less than 10ms. The drive circuit should have sufficient drive capability to meet the starting current (generally 2-5A) and holding current (0.5-1A) requirements of the circuit breaker closing coil, while also having overcurrent protection to prevent damage to the power supply module caused by coil short circuits. The relay operating time should be controlled within 5ms to ensure timely response to the closing signal.

[0080] Furthermore, this design is widely applicable to grid-connected scenarios such as thermal power, hydropower, wind power, and energy storage systems. Especially when the frequency fluctuations (±0.2Hz / s) caused by the access of new energy sources are large, it can ensure that the backup circuit can still reliably perform the closing operation when the main circuit power supply is abnormal (such as voltage drop, power outage, etc.), thereby effectively preventing asynchronous impacts (the impact current is controlled within 1.1 times the rated current).

[0081] The technical effect of this step is to significantly improve the fault tolerance of the synchronous system under power failure conditions, ensure the continuity and reliability of the closing output signal, and provide an important guarantee for achieving millisecond-level accurate grid connection and reducing the non-stop rate (from 1.2 times / 10,000 times to 0.05 times / 10,000 times).

[0082] S42, the standby closing circuit remains in standby mode when not activated, and periodic self-checks ensure it can be put into operation at any time.

[0083] Specifically, in some implementations, the backup closing circuit remains in a standby state when not inactive, and periodic self-checks ensure its readiness for operation. This is one of the key steps in achieving high reliability of the synchronization system in this invention. This step, by constructing a physically independent and logically redundant closing circuit system, ensures that the backup circuit can seamlessly take over and complete the closing operation when the primary closing circuit malfunctions or times out, thereby effectively preventing asynchronous grid connection accidents.

[0084] Furthermore, the standby closing circuit consists of an independent closing output relay, an independent cable, an independent terminal block, and an independent circuit breaker closing coil, completely isolated from the primary closing circuit in electrical connection. The standby circuit enters standby mode immediately after system startup and does not actively participate in the synchronization process. Only when the primary circuit malfunctions or times out (such as exceeding the set synchronization closing time threshold, typically 10-15 seconds), the monitoring system or primary synchronization device triggers automatic switching logic to activate the standby circuit and perform the closing operation. To ensure the standby circuit is always available, the system is equipped with a periodic self-test mechanism, typically with a test cycle of 30 seconds to 1 minute, to perform online testing on key nodes in the standby circuit, such as relay status, cable continuity, and terminal contact resistance, ensuring that its impedance value is less than 0.5Ω and the signal response time is less than 50ms, meeting the requirements of the IEC60255-13 standard for relay protection devices.

[0085] Furthermore, the self-test frequency, anomaly detection threshold, and switching response time of the standby closing circuit are all configurable parameters. For example, the self-test cycle can be set from 30 seconds to 5 minutes, and the switching response time should be controlled within 100ms to avoid missing grid connection opportunities due to switching delays. Meanwhile, the closing pulse width of the standby circuit is typically set to 50-100ms, consistent with the primary circuit, to ensure the consistency and reliability of circuit breaker operation.

[0086] Furthermore, this procedure is widely applicable to grid connection operations of thermal power, hydropower, wind power, and new energy storage systems. Particularly in complex grid environments where new energy access leads to significant frequency fluctuations (±0.2Hz / s), the rapid response capability of the backup closing circuit can significantly improve the grid connection success rate. In actual operation, the self-checking and switching logic of the backup circuit is uniformly scheduled by the monitoring system, ensuring that in the event of a primary device failure or timeout, the backup device can immediately take over and complete the closing, thereby achieving millisecond-level grid connection response.

[0087] Furthermore, this step, through physical isolation and periodic self-inspection mechanisms, effectively improves the fault tolerance and availability of the synchronous system, ensuring the integrity of the closing function can still be maintained under extreme operating conditions. It is an important support for the "closing execution" link in the construction of a four-level protection system, and has significant technical value for reducing the number of non-stops, extending equipment life and improving grid connection success rate.

[0088] S5, after the synchronizing device is switched to the standby device, the monitoring system dynamically adjusts the PID control parameters according to the preset frequency fluctuation compensation model to adapt to the ±0.2Hz / s frequency change rate caused by the access of new energy sources, and ensures that the frequency difference at the moment of closing is within ±0.1Hz.

[0089] Specifically, after the monitoring system switches the synchronizing device to the standby device, in order to cope with the dynamic fluctuations in system frequency (the rate of change can reach ±0.2Hz / s) caused by the access of new energy sources, the system needs to dynamically adjust the PID control parameters according to the preset frequency fluctuation compensation model to ensure that the frequency difference at the moment of closing is controlled within ±0.1Hz. This step is a key link in achieving millisecond-level precise grid connection, and its technical implementation is based on the combination of real-time frequency deviation feedback and adaptive control strategies.

[0090] Furthermore, the monitoring system collects frequency signals from the grid side and the generator to be connected, and calculates the frequency difference Δf and its rate of change df / dt in real time. When the primary synchronizing unit is switched to the standby unit due to a fault or timeout, the monitoring system immediately invokes a preset frequency fluctuation compensation model. This model is established based on historical frequency response data and the system inertia constant (H value), and typically employs fuzzy PID or adaptive PID control algorithms. The PID parameters (proportional coefficient Kp, integral time Ti, derivative time Td) are adjusted online according to the current frequency difference and rate of change. For example, when df / dt > 0.15 Hz / s, the system automatically increases Kp to accelerate the frequency response speed, while appropriately decreasing Ti to suppress integral saturation, thereby improving the system's dynamic adjustment capability.

[0091] Furthermore, the compensation model must meet the control requirements for grid connection frequency deviation in the IEEE 1547-2018 standard, with a frequency difference threshold set at ±0.1Hz and a response time controlled within 100ms. In practical applications, this step is often used in scenarios involving the integration of highly volatile new energy sources such as wind power and photovoltaics, especially when the grid frequency changes rapidly or the system inertia decreases. Through dynamic optimization of PID parameters, the accumulation of frequency deviation can be effectively suppressed, improving the accuracy of the closing timing.

[0092] This technology significantly improves the robustness and adaptability of the synchronous system, ensuring safe and reliable grid connection operation even in complex power grid environments, thereby reducing unplanned outage risks and increasing the unit start-up success rate, and has significant engineering application value.

[0093] The synchronous system anti-outage method based on multiple redundancy and intelligent control in this invention effectively reduces the failure rate of synchronous grid connection, improves the reliability of closing, controls the inrush current to below 1.1 times the rated current, extends the service life of equipment, and ensures the stable operation of the power grid.

[0094] Example 2 To ensure the safe and stable operation of the power grid, improve the success rate of power plant startup, and prevent abnormal startup events of generating units, a method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control has been researched and invented.

[0095] To address the aforementioned problems, this invention proposes a method for preventing unplanned outages in synchronous systems based on multiple redundancy and intelligent control. The invention provides the following:

[0096] In one embodiment of the present invention, the synchronous system is configured as follows: To prevent the synchronizing system from being mistakenly activated, which could lead to unit asynchrony, the synchronizing system adopts a dual-series connection of a synchronizing device and a synchronizing meter for the closing output. At the hardware level, a microcomputer-based automatic quasi-synchronizing device and a microcomputer-based multi-functional synchronizing meter are connected in series for output. The normally open contacts of the two are connected in series to the closing circuit. If either condition is not met, the closing circuit is physically disconnected.

[0097] In one embodiment of the present invention, the synchronization device is configured as follows: To prevent synchronization failure due to the failure of a single synchronization device or the timeout of the synchronization process, the synchronization system adopts a redundant configuration of two completely independent and mutually backup devices. Specifically, the two microcomputer-based automatic quasi-synchronization devices and the two microcomputer-based multi-functional synchronization meters adopt a hot standby plus automatic switching working mode. When the main unit fails to complete the synchronization process within the set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal at the same time.

[0098] In one embodiment of the present invention, the synchronous voltage is designed as follows: To prevent synchronization failure due to voltage transformer malfunction or sampling deviation, the two sets of microcomputer-based automatic synchronizing devices and two microcomputer-based multi-function synchronizing meters use completely independent synchronizing voltages. Specifically, each synchronizing device is connected to the secondary signals from voltage transformers with different windings, and the two voltage sampling circuits are physically completely isolated to ensure that synchronization can still be maintained even if any voltage transformer fails.

[0099] In one embodiment of the present invention, the synchronous input quantity is designed as follows: The synchronous input design adopts a fully independent redundant architecture. Each synchronous device is equipped with an independent circuit breaker position input acquisition circuit. Specifically, the two synchronous devices are connected to normally open contacts from different auxiliary contact groups of the circuit breaker, and the two input signals use independent cables. In case of abnormality, the device is automatically locked and switched to the backup device, achieving redundant safety for circuit breaker position signal acquisition.

[0100] In one embodiment of the present invention, the synchronous closing output is designed as follows: To ensure the reliability of the synchronizing closing system, the closing outputs of the two synchronizing devices adopt a completely independent and redundant design. Specifically, each synchronizing device is equipped with an independent closing output relay, and the two closing pulse outputs are connected to the circuit breaker closing coil via independent cables. The two closing circuits are physically completely isolated, with independent closing relays, independent cables, independent terminal blocks, and independent closing coils. When either closing circuit malfunctions, after the primary synchronizing device times out, it automatically switches to the backup synchronizing device and synchronizes via the backup closing circuit output.

[0101] In one embodiment of the present invention, the monitoring system synchronous process is as follows: During the transition from no-load to generating state, the monitoring system executes a redundant control process for synchronizing the generator set with two sets of synchronizing devices according to preset logic: First, it issues a command to activate the voltage of synchronizing device 1 and start synchronizing device 1. Upon receiving the command, synchronizing device 1 immediately performs an input quantity check. After confirming the initial conditions, it automatically starts the frequency and voltage regulation program and dynamically adjusts the unit speed and excitation through a PID control algorithm. When the voltage difference, frequency difference, and phase angle difference between the side to be paralleled and the system side are detected to meet the predetermined parameters, it issues a closing signal, and the synchronization process ends. If the closing is not completed within the synchronization time limit set by the monitoring system, it automatically executes a reset to activate the voltage of synchronizing device 1 and start synchronizing device 1. Simultaneously, the voltage and start signal of synchronizing device 2 are sent. Upon receiving the command, synchronizing device 2 immediately performs input quantity checks. After confirming the initial conditions, it automatically starts the frequency and voltage regulation program. The unit speed and excitation are dynamically adjusted through the PID control algorithm. When the voltage difference, frequency difference, and phase angle difference between the side to be paralleled and the system side meet the predetermined parameters, a closing signal is sent, and the synchronization process ends. If the synchronization timeout (the synchronization process time set by the monitoring system) occurs, the synchronization process is exited, and the start-up fails.

[0102] The embodiments of the present invention also have the following technical effects: Reduce non-outage assessment losses: Avoiding a single non-outage for a 300MW unit can reduce direct economic losses by approximately 400,000 yuan (according to grid assessment standards); Extend equipment lifespan: Controlling the inrush current to below 1.1 times the rated value can extend the generator overhaul cycle by 2-3 years; Improve grid connection success rate: Actual test data shows that the failure rate can be reduced from 1.2 times / 10,000 times to 0.05 times / 10,000 times.

[0103] The full-process dual-criteria architecture achieves dual verification of closing conditions through hardware serialization of the synchronization device and the synchronization table; an intelligent switching algorithm is developed to maintain continuous PID adjustment parameters during the switching of the main and backup devices to avoid secondary impacts; and a four-level protection system is established with full-link redundancy in signal acquisition, logic judgment, closing execution, and process monitoring.

[0104] Example 3 To achieve the above embodiments, such as Figure 2 As shown, this embodiment also provides a synchronization system anti-unplanned shutdown device 10 based on multiple redundancy and intelligent control, including: The redundancy switching control module 100 is used to configure two completely independent and mutually backup synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the main device fails to complete the synchronization process within a set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal. The voltage signal isolation access module 200 is used to connect the secondary signals of voltage transformers from different windings to each set of synchronizing devices, realize the physical isolation of the voltage sampling circuit, and ensure that the synchronizing closing function can still be maintained when any voltage transformer fails. The circuit breaker position redundancy acquisition module 300 is used to set up independent redundant circuit breaker position signal acquisition circuits. Each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable. In case of abnormality, the device is automatically locked and switched to the backup device. The closing circuit redundant execution module 400 is used to employ independent redundant closing output relays, cables, terminal blocks and circuit breaker closing coils. When any closing circuit is abnormal, the main synchronizing device will automatically switch to the standby device after the timeout and perform synchronizing operation through the standby closing circuit.

[0105] Furthermore, the redundancy switching control module 100 is also used for: When the main synchronizing device detects an internal fault, it analyzes the fault type in real time through the built-in diagnostic module and generates the corresponding fault code. When the primary synchronizing device detects an external fault, it sends a fault signal through the communication interface with the monitoring system and maintains the continuity of PID adjustment parameters while switching to the backup device.

[0106] Furthermore, the voltage signal isolation access module 200 is also used for: The secondary signals of the voltage transformers connected to each set of synchronizing devices come from independent sampling points of different windings of the generator and are transmitted in isolation through shielded cables; Each synchronization device is equipped with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

[0107] Furthermore, the circuit breaker position redundancy acquisition module 300 is also used for: Each set of synchronous devices is connected to two different sets of normally open contacts of the circuit breaker, and is electrically isolated by an independent signal isolator. When a synchronizing device detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends an abnormal position signal alarm to the monitoring system.

[0108] Furthermore, the redundant execution module 400 for the closing circuit is also used for: Each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails. The standby closing circuit remains in standby mode when not activated, and periodic self-checks ensure it can be put into operation at any time.

[0109] Furthermore, it also includes: The frequency fluctuation compensation module is used to dynamically adjust the PID control parameters according to the preset frequency fluctuation compensation model after the synchronizing device is switched to the standby device, so as to adapt to the frequency change rate of ±0.2Hz / s caused by the access of new energy sources and ensure that the frequency difference at the moment of closing is within ±0.1Hz.

[0110] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A method for preventing unplanned outages in a synchronous system based on multiple redundancy and intelligent control, characterized in that, include: S1 is equipped with two completely independent and mutually redundant synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the main device fails to complete the synchronization process within the set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal. S2 connects the secondary signals from voltage transformers with different windings to each set of synchronizing devices to achieve physical isolation of the voltage sampling circuit and ensure that the synchronizing closing function can still be maintained when any voltage transformer fails. S3, set up an independent and redundant circuit breaker position signal acquisition circuit, each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable, and automatically locks the device and switches to the standby device in case of abnormality. S4 employs independent redundant closing output relays, cables, terminal blocks, and circuit breaker closing coils. When any closing circuit malfunctions, the main synchronizing device automatically switches to the standby device after a timeout and performs synchronizing operations via the standby closing circuit.

2. The method as described in claim 1, characterized in that, The S1 further includes: S11, when the main synchronizing device detects an internal fault, it analyzes the fault type in real time through the built-in diagnostic module and generates the corresponding fault code; S12, when the primary synchronizing device detects an external fault, it sends a fault signal through the communication interface with the monitoring system and maintains the continuity of the PID adjustment parameters while switching to the backup device.

3. The method as described in claim 1, characterized in that, The S2 further includes: S21, the secondary signal of the voltage transformer connected to each set of synchronizing devices comes from the independent sampling points of different windings of the generator and is transmitted in isolation through shielded cables; S22, each set of synchronization devices is equipped with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

4. The method as described in claim 1, characterized in that, The S3 further includes: S31, the auxiliary contact groups of the circuit breaker connected to each set of synchronous devices are respectively from two different normally open contacts of the circuit breaker, and are electrically isolated by independent signal isolators; S32, when a certain synchronizing device detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends an abnormal position signal alarm to the monitoring system.

5. The method as described in claim 1, characterized in that, The S4 further includes: S41, each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails. S42, the standby closing circuit remains in standby mode when not activated, and periodic self-checks ensure it can be put into operation at any time.

6. The method as described in claim 1, characterized in that, Also includes: S5, after the synchronizing device is switched to the standby device, the monitoring system dynamically adjusts the PID control parameters according to the preset frequency fluctuation compensation model to adapt to the ±0.2Hz / s frequency change rate caused by the access of new energy sources, and ensures that the frequency difference at the moment of closing is within ±0.1Hz.

7. A synchronization system anti-unplanned shutdown device based on multiple redundancy and intelligent control, characterized in that, include: The redundancy switching control module is used to configure two completely independent and mutually backup synchronization devices and synchronization meters. It adopts a hot standby plus automatic switching working mode. When the primary device fails to complete the synchronization process within a set time or detects an internal or external fault, it automatically and seamlessly switches to the backup device and triggers an alarm signal. The voltage signal isolation access module is used to connect the secondary signals from voltage transformers with different windings to each set of synchronizing devices, realize the physical isolation of the voltage sampling circuit, and ensure that the synchronizing closing function can still be maintained when any voltage transformer fails. The circuit breaker position redundancy acquisition module is used to set up independent redundant circuit breaker position signal acquisition circuits. Each synchronization device is connected to different auxiliary contact groups of the circuit breaker through an independent cable. In case of abnormality, the device is automatically locked and switched to the backup device. The redundant execution module for the closing circuit is used to employ independent redundant closing output relays, cables, terminal blocks and circuit breaker closing coils. When any closing circuit is abnormal, the main synchronizing device will automatically switch to the standby device after the timeout and perform the synchronizing operation through the standby closing circuit.

8. The apparatus as claimed in claim 7, characterized in that, The redundancy switching control module is also used for: When the main synchronizing device detects an internal fault, it analyzes the fault type in real time through the built-in diagnostic module and generates the corresponding fault code. When the primary synchronizing device detects an external fault, it sends a fault signal through the communication interface with the monitoring system and maintains the continuity of PID adjustment parameters while switching to the backup device.

9. The apparatus as claimed in claim 7, characterized in that, The voltage signal isolation access module is also used for: The secondary signals of the voltage transformers connected to each set of synchronizing devices come from independent sampling points of different windings of the generator and are transmitted in isolation through shielded cables; Each synchronization device is equipped with an independent sampling channel verification module, which automatically switches to another sampling channel and records the abnormal event when the sampling signal is abnormal.

10. The apparatus as claimed in claim 7, characterized in that, The circuit breaker position redundancy acquisition module is also used for: Each set of synchronous devices is connected to two different sets of normally open contacts of the circuit breaker, and is electrically isolated by an independent signal isolator. When a synchronizing device detects that the circuit breaker position signal is inconsistent with the actual state, it immediately blocks the synchronizing closing logic of the device and sends an abnormal position signal alarm to the monitoring system.

11. The apparatus as claimed in claim 7, characterized in that, The redundant execution module for the closing circuit is also used for: Each set of closing output relays is equipped with an independent power supply module and drive circuit to ensure that the backup circuit can still work normally when the main circuit power supply fails. The standby closing circuit remains in standby mode when not activated, and periodic self-checks ensure it can be put into operation at any time.

12. The apparatus as claimed in claim 7, characterized in that, Also includes: The frequency fluctuation compensation module is used to dynamically adjust the PID control parameters according to the preset frequency fluctuation compensation model after the synchronizing device is switched to the standby device, so as to adapt to the frequency change rate of ±0.2Hz / s caused by the access of new energy sources and ensure that the frequency difference at the moment of closing is within ±0.1Hz.

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