Remote control system and method for low-voltage circuit breaker of box-type substation

Abstract

The invention belongs to the technical field of power distribution control, and relates to a box-type substation low-voltage circuit breaker remote control system and method, and the system comprises a control power input terminal, a local and remote mode switching unit, an electric operation mechanism, a low-voltage circuit breaker, a state indication unit, and an alarm indication unit. The source state switching module is used for judging the states of the equipment side power supply and the standby power supply and supplying power to the control loop according to a priority rule; the mode interlocking module is used for selecting an instruction source according to a mode state and shielding a non-corresponding signal; and the state freezing module is used for outputting an abnormal signal and freezing the control loop when the auxiliary contact state is inconsistent with the mechanism position signal. According to the technical scheme, through multi-layer logic of power supply judgment, mode interlocking and state freezing, continuous power supply control, safe mode switching and reliable state monitoring are achieved, and the operation requirements of continuous controllability, safe action and accurate state display are met.

Description

Technical Field

[0001] This invention belongs to the field of power distribution control technology, and specifically relates to a remote control system and method for low-voltage circuit breakers in prefabricated substations. Background Technology

[0002] In existing technologies, remote control of low-voltage side circuit breakers in prefabricated substations typically relies on electric operating mechanisms in conjunction with switches and signal circuits within the control cabinet. Opening and closing commands are issued via a remote communication interface to meet the automation requirements of unattended operation and remote maintenance. However, existing remote control systems often employ fixed power supply paths and single-channel control logic. During operation, their response to the determination and switching of control power supply status is slow, and untimely power switching can easily lead to short-term malfunctions in the control circuit, affecting the continuity of circuit breaker operation and system stability.

[0003] In operation and management, existing control systems generally switch between local and remote modes through mechanical transfer switches. This method is greatly affected by the timing of operation and the stability of the switch contacts. When remote and local control signals are in a state of competition or signal superposition at the switching edge, it may cause the circuit breaker to malfunction or fail to operate. Especially in the case of concurrent on-site maintenance or remote dispatch commands, the safety risks are significant.

[0004] Furthermore, traditional circuit breaker status indications are based solely on auxiliary contact signals and cannot verify the actual mechanical position of the operating mechanism. When the mechanism lags behind, contacts stick together, or position signals drift, the status indications may not match the actual circuit breaker position, potentially causing misjudgments by the monitoring system. If the instructions continue to be executed, it can easily lead to abnormal operations such as accidental opening or closing, affecting the reliability of power supply.

[0005] It is evident that existing technologies often suffer from problems such as insufficient continuity of control power supply, low security during mode switching, and unstable consistency of status indication. These are the shortcomings of existing technologies.

[0006] In view of this, it is very necessary to provide a remote control system and method for low-voltage circuit breakers in prefabricated substations to solve the above-mentioned defects in the prior art. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of the existing technology, such as insufficient continuity of control power supply, low safety during mode switching, and unstable consistency of status indication, by providing a remote control system and method for low-voltage circuit breakers in prefabricated substations to solve the aforementioned technical problems.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A remote control system for a low-voltage circuit breaker in a prefabricated substation includes a low-voltage circuit breaker, an electric operating mechanism connected to the low-voltage circuit breaker, a local / remote mode switching unit installed in a control cabinet, a control power input terminal, a status indication unit, and an alarm indication unit, and further includes: The source-state switching module is used to distinguish the power supply status from the equipment-side power supply and the backup power supply, and to provide control power to the control circuit of the electric operating mechanism according to the preset power supply priority rules. The mode interlock module has its input end connected to the local and remote mode switching unit. The mode interlock module is used to select the source of the command that is allowed to enter the control circuit of the electric operating mechanism according to the mode status, and to shield non-corresponding commands. The status freeze module has its input terminals connected to the auxiliary contacts of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism, respectively, and its output terminal connected to the alarm indicator unit and the control circuit of the electric operating mechanism. The status freeze module is used to output an abnormal status signal when the status of the auxiliary contacts is inconsistent with the mechanism position signal, and to freeze the control circuit of the electric operating mechanism.

[0009] By adopting the above technical solution, and introducing multi-layer logic of power supply discrimination and priority control, mode interlock control and state consistency freeze control into the system, the system achieves continuous power supply, safe mode switching and reliable circuit breaker status monitoring, which can meet the operational requirements of low-voltage circuit breakers in unattended environments for continuous controllability, safe operation and accurate status display.

[0010] The source-state switching module automatically selects and prioritizes power supply paths by real-time determination of the status of the equipment-side power supply and backup power supply. This ensures that the control power supply remains stable even when the main power supply is interrupted, guaranteeing that the electric operating mechanism remains responsive and maintaining system control continuity. The mode interlocking module determines the local and remote mode status and limits the command channel in the control logic, allowing only commands in the corresponding mode to enter the control loop and shielding non-corresponding signals. This ensures that the signal flow during mode switching is clear and does not interfere with each other, guaranteeing the safety and consistency of command execution. The state freeze module collects auxiliary contact signals and mechanism position signals to establish a correspondence between action state and mechanical position. When an inconsistency is detected, an abnormal signal is output and the control loop is temporarily frozen, achieving linkage protection between state detection and action control, preventing the circuit breaker from performing the next operation under uncertain state conditions. Overall, the system forms a collaborative control structure with power management, mode control and status monitoring as its core, enabling low-voltage circuit breakers to maintain reliable operation, accurate signals and safe operation in both remote and local modes, thereby meeting the comprehensive control requirements of prefabricated substations for power supply continuity, operational safety and status consistency in complex operating environments.

[0011] Preferably, the source state switching module includes a source state detection submodule and a priority determination submodule. The source state detection submodule is used to sample the voltage signals of the equipment-side power supply and the backup power supply in real time. The priority determination submodule is used to generate a power supply discrimination signal based on the sampling results. When it is detected that the status of both the equipment-side power supply and the backup power supply is available, the power supply discrimination signal of one of the power supplies is selected according to the preset power supply priority rules and output to the control loop as the control power input.

[0012] By linking power status acquisition with priority output through a linkage logic, the following technical effects can be achieved in this source-state switching module: First, the source state detection submodule continuously collects the operating status of the two power sources, enabling the control system to maintain real-time awareness of the current power source when the power state changes. This ensures the clarity and availability of the control link even when power conditions fluctuate, preventing uncertain operations from occurring on the control side due to information lag. Second, the priority determination submodule outputs a single path of control power when both power sources have the ability to supply power, avoiding problems such as voltage superposition, mutual influence or circulating current caused by the simultaneous supply of power to the control loop by both sources, thereby maintaining the electrical stability of the control loop and ensuring that the electric operating mechanism has continuous and consistent driving conditions when performing opening and closing operations. Third, the priority selection result is directly used as the control power input, enabling the control loop to smoothly switch to the backup power supply path in the event of a main power supply interruption or performance degradation, reducing the risk of control link interruption, supporting the system to remain in an executable command working state in unattended scenarios, and meeting the operational requirements of prefabricated substations for continuous circuit breaker operation.

[0013] Preferably, the source-state switching module also includes an anomaly detection submodule. The anomaly detection submodule is used to output a power-off holding signal when both the equipment-side power supply and the backup power supply are in an abnormal state. The power-off holding signal is used to maintain the current opening and closing position of the electric operating mechanism before the control power supply is interrupted, and to block the input of new opening and closing command signals to the control circuit.

[0014] By adding triggering logic for a power-off retention signal to the power supply status detection, this anomaly detection submodule achieves the following technical effects: First, when both the equipment-side power supply and the backup power supply are in an abnormal state, a power outage holding signal is output in a timely manner so that the control circuit can keep the current opening and closing position of the electric operating mechanism stable before the power supply is about to be interrupted, so as to avoid the circuit breaker from being interrupted or having an uncertain position due to the loss of control energy, and maintain the continuity and consistency of power distribution operation. Second, the power failure holding signal blocks the input of new opening and closing commands, so that the control circuit will no longer accept state change commands when the power supply is unreliable, preventing incomplete action, partial action or command execution deviation under insufficient power conditions, and maintaining the clarity and controllability of control behavior. Third, this logic links the power supply status judgment with the stability of the control logic, enabling the control system to have automatic shutdown protection capability in abnormal power supply scenarios. This not only maintains the position of the circuit breaker but also avoids additional operational risks caused by erroneous command triggering, thus meeting the operational requirements of the prefabricated substation to maintain the stable operation status of the circuit breaker under unattended conditions.

[0015] Preferably, the mode interlock module also includes a switching delay submodule, which generates a shielding delay signal when a mode state change is detected. During a preset delay time after the mode switch, any control command is prohibited from entering the control loop. The duration of the shielding delay signal covers the response period required for the mode signal to stabilize.

[0016] By setting a delay masking control for mode state changes in this switching delay submodule, the following technical effects can be achieved: First, a shielding delay signal is generated at the moment of mode switching, so that the control loop does not immediately execute external commands at the edge stage of switching between local and remote modes, thereby avoiding command channel jitter caused by the unstable mode signal, and keeping the control loop in a static state before the signal state is fully determined, thus maintaining the determinism and consistency of circuit breaker operation. Second, the shielding delay signal blocks any control command within a preset delay time, so that local and remote commands cannot directly enter the control circuit of the electric operating mechanism during mode switching, thereby preventing situations such as local and remote commands overlapping, competing or overriding each other during the switching transition, and eliminating the risk of false separation, false engagement or failure to operate that may be caused at the moment of mode switching. Third, the duration of the shielding delay signal covers the response period required for the mode state signal to stabilize, enabling the control system to have a smooth buffering capability during the transition from an unstable to a stable mode state. This avoids abnormal state transmission caused by signal jumps, and makes the mode switching process form a continuous action chain of "detection-delay-unlocking". This improves the controllability and stability of mode selection behavior and meets the operational requirements for the safety of command channel switching in the unattended environment of the prefabricated substation.

[0017] Preferably, the state freeze module includes a consistency judgment submodule and a freeze execution submodule. The consistency judgment submodule is used to generate a consistency judgment result based on the combination result of the status signal of the auxiliary contact and the position signal of the mechanism. The freeze execution submodule is used to cut off the drive path of the control loop when the consistency judgment result is inconsistent, and to issue an abnormal status signal through the alarm indication unit. When the consistency is restored, the freeze execution submodule recloses the drive path of the control loop.

[0018] By linking state consistency judgment with the on / off state of the control loop in this state freeze module, the following technical effects can be achieved: First, the consistency judgment submodule generates a consistency judgment result based on the combination of the auxiliary contact status signal and the mechanism position signal, so that the electrical state and mechanical execution state of the circuit breaker can be synchronously verified, thereby making the state judgment no longer dependent on the feedback of a single electrical contact, ensuring that the state recognition has higher authenticity and verifiability. Second, the freeze execution submodule cuts off the drive path of the control loop when the consistency judgment result is inconsistent, so that the control loop automatically enters the static state under the condition of uncertainty, avoiding the circuit breaker from continuing to perform opening and closing operations when the feedback is not clear, reducing the probability of malfunction, continuous operation or interruption caused by state information deviation, and enhancing the robustness of the control logic. Third, when consistency is restored, the frozen execution submodule recloses the drive path, enabling the control loop to return to the executable state after the state returns to normal. This ensures that the recovery behavior of the control system after an anomaly has clear triggering conditions and paths, giving the system the operability and controllability to return from the abnormal state to the normal state. This meets the comprehensive requirements of the prefabricated substation for the accuracy of circuit breaker status determination, the continuity of action execution, and the safety of operation behavior in a long-term unattended environment.

[0019] Preferably, the state freeze module also includes a position storage submodule, which records the combined result when a state inconsistency event is detected and transmits it to the state indication unit for echoing.

[0020] This positional storage submodule achieves the following technical effects by recording and echoing inconsistent state events: First, when an inconsistent state event is detected, the combined result is recorded, so that the system retains the correspondence between the auxiliary contact state and the mechanism position signal when the circuit breaker operates abnormally. This provides a clear source of information for subsequent operation and maintenance review, avoids the loss of operation records due to instantaneous recovery of the state after the anomaly occurs, and makes the abnormal state traceable and verifiable. Second, the recorded results are transmitted to the status indication unit for display, so that abnormal information can be presented intuitively on the control cabinet side, making it easy for operators to quickly identify the status when the abnormality occurs on-site or at the remote monitoring end. This allows the source of the abnormality to be determined without additional disassembly or in-depth investigation, shortening the diagnostic path and improving maintenance efficiency. Third, by recording and displaying inconsistent state events, the action of the state freeze module is no longer simply to freeze the control loop. It can also provide transparent information on the cause of the abnormality while triggering the freeze, so that the control behavior, state feedback and operation and maintenance diagnosis form a continuous chain of correlation, which meets the operation requirements of the prefabricated substation in the unattended management mode for the visibility of abnormal records, the traceability of state changes and the basis for maintenance processing.

[0021] Preferably, the alarm indication unit includes a multi-level alarm display structure, which is used to display the abnormal status signal output by the status freeze module in a hierarchical manner, and automatically restore the initial display state when the consistency is restored. Different abnormal types correspond to different display features, including color, flashing frequency or on / off mode.

[0022] By displaying abnormal states in a tiered manner, this alarm indication unit achieves the following technical effects: First, the abnormal status signals are displayed in a hierarchical manner according to their abnormality type, so that the control system can generate clearly distinguishable warning information when there is inconsistency in status, control loop freezing or other abnormal situations. This allows operators to intuitively identify the type and scope of the abnormality when viewing the status indicators, reducing judgment errors caused by unclear warning information and making the status feedback clear in terms of hierarchy and judgment. Secondly, different types of anomalies correspond to different display features, which makes the alarm presentation mode differentiated in terms of information expression. Without additional explanations or text labels, the severity, location, or scope of impact of the anomaly can be directly expressed through display features. This changes the information transmission path from data interpretation to status recognition, reduces the cognitive burden on on-site maintenance personnel, and improves the speed of anomaly location and execution response efficiency. Third, when consistency is restored, the alarm indicator unit automatically restores the initial display state, giving the alarm state a self-regressive capability. After the anomaly is eliminated, the normal state indication of the system can be restored without additional reset operation. This enables the control system to independently complete the complete closed loop from anomaly prompt to state restoration under unattended conditions, making the presentation of the system's operating status more continuous and reliable, and meeting the display and operation management requirements of prefabricated substations for alarm identification, readable status, and self-resettable process.

[0023] Preferably, the system also includes a fault self-test module, which performs functional tests on the source-state switching module, mode interlock module and state freeze module respectively when the system is powered on. The test content includes at least one of the control signal continuity, module response delay and alarm output validity, and feeds back the test results to the status indication unit for display.

[0024] This fault self-test module achieves the following technical effects by executing a module-level self-test process during the system power-on phase: First, when the system is powered on, the source state switching module, mode interlock module and state freeze module are respectively tested for functionality. This allows the control system to confirm whether the key control logic is in an executable state before entering normal operation, thereby avoiding the risk of exposing module malfunctions only after the system officially receives control commands. This enables the control system to have the ability to self-confirm its state before operation, and ensures that subsequent opening and closing operations are based on a verifiable foundation. Second, the testing content includes at least one of the following: control signal connectivity, module response delay, and alarm output validity. This ensures that the self-test process not only confirms the existence of communication or logic status but also tests the response process of the module's execution behavior. This allows the self-test results to reflect the module's real-time execution capability and availability, ensuring that the self-test behavior has practical diagnostic significance rather than being a formal test, thereby enhancing the reliability of the control system. Third, the test results are fed back to the status indicator unit for display, making the self-test results readable and presentable. This allows operators to directly know the initial state of the control system during the system startup phase, facilitating timely maintenance or re-initialization when self-test anomalies are detected. This prevents the system from entering the power supply operation process under abnormal conditions, enabling the control system to complete availability verification before entering unattended operation, thus meeting the management requirements of prefabricated substations for startup self-confirmation, verifiable operation, and presentable status.

[0025] Preferably, the control circuit uses shielded signal lines for electrical connection between modules, and the common grounding terminal of each module is connected to an independent grounding busbar in the control cabinet.

[0026] In this technical solution, the control loop uses shielded signal lines and connects the common ground terminal to an independent grounding bus, achieving the following technical effects: First, shielded signal lines are used for electrical connections between modules, which enables the control circuit to have signal anti-interference capability in the high electromagnetic interference environment of the box-type substation, keeps the signal transmission path of the source-state switching module, mode interlocking module and state freezing module stable, reduces the offset, jitter or uncertainty of the control signal caused by external electromagnetic coupling, and makes the control logic judgment process more stable and reliable. Second, the common grounding terminal of each module is connected to an independent grounding busbar to keep the reference points of each branch signal in the control loop consistent, avoid signal reference drift caused by grounding point differences, and ensure that the drive command, power switching discrimination signal and status feedback signal when the electric operating mechanism performs the action have a unified potential reference, thereby maintaining the cooperative relationship between each module and making the overall functional structure of the control system consistent and coordinated. Third, the independent grounding bus serves as the single grounding node of the control circuit, creating a clear hierarchical isolation between the control logic system and the main grounding system of the enclosure. This ensures that the control circuit is unaffected by the large current surge waveform of the main circuit during opening and closing, status detection, or mode switching, reducing misjudgments, malfunctions, or status flicker caused by ground potential fluctuations. As a result, the prefabricated substation can maintain stable control and monitoring behavior even in unattended environments, thus meeting the system's comprehensive requirements for signal integrity, electrical stability, and operational continuity.

[0027] Furthermore, the present invention also provides a remote control method for low-voltage circuit breakers in prefabricated substations, comprising the following steps: The power supply status from the equipment side power supply and the backup power supply is determined, and control power is provided to the control circuit of the electric operating mechanism according to the preset power supply priority rules; Based on the mode status of the local and remote mode switching unit, determine the source of the command that is allowed to enter the control loop, and shield command signals that do not correspond to the mode status. Based on the instruction signal from the instruction source, the low-voltage circuit breaker is opened or closed via an electric operating mechanism. The auxiliary contact status signal of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism are collected and their consistency is checked. If they are inconsistent, an abnormal status signal is output and the control circuit is frozen.

[0028] By adopting the above technical solution, and introducing a sequential execution structure of power supply discrimination and priority control, mode command selection and shielding control, and status consistency verification and freeze control into the remote control process, the system can achieve continuous power supply, clear command execution path, and reliable circuit breaker operation status presentation. This can meet the operational requirements of prefabricated substations for continuous controllability, safe operation, and accurate status display under unattended operation conditions.

[0029] Specifically, the system distinguishes between the power supply status from the equipment side and the backup power supply, enabling the control loop to actively select its mode when the power supply environment changes. This ensures the operability of the electric operating mechanism is maintained even when the main power supply is insufficient, ensuring the control process is always based on a stable power supply. Based on the mode status processing command source of the local and remote mode switching unit, the control loop maintains a single command path when the operating mode changes, avoiding signal overlap or trigger contention between local and remote control under mode boundary conditions, ensuring the circuit breaker's action remains logically clear and consistent in execution. Finally, the system executes opening or closing operations based on the command source, ensuring the electrical... The execution behavior of the operating mechanism is consistent with the control source, without generating control ambiguity or action conflict; the auxiliary contact status signal and the mechanism position signal are collected and their consistency is checked, so that the circuit breaker's operating status has dual confirmation from both the electrical and mechanical sides. When the two are inconsistent, an abnormal status output and control loop freeze are performed, so that the system can maintain the current state without further change when the operating status is uncertain. This gives the circuit breaker's operating process a clear and controllable boundary, and forms a continuous closed-loop link between control behavior, status determination and abnormal handling, meeting the comprehensive requirements of remote control scenarios for action safety, status confirmability and operational predictability.

[0030] The beneficial effects of this invention are that by introducing multi-layer logic of power supply discrimination and priority control, mode interlock control and state consistency freeze control into the system, it realizes continuous control of power supply, safe mode switching and reliable circuit breaker status monitoring, and can meet the operational requirements of low-voltage circuit breakers in unattended environments of prefabricated substations for continuous controllability, safe operation and accurate status display.

[0031] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.

[0032] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a remote control system for a low-voltage circuit breaker in a prefabricated substation provided by the present invention. Figure 2This is a flowchart of a remote control method for a low-voltage circuit breaker in a prefabricated substation provided by the present invention.

[0035] Among them, 1. Control power input terminal, 2. Source-state switching module, 3. Local and remote mode switching unit, 4. Mode interlock module, 5. Electric operating mechanism, 6. Low-voltage circuit breaker, 7. Status freeze module, 8. Status indication unit, and 9. Alarm indication unit. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following implementation methods.

[0037] Example 1: like Figure 1 As shown, this embodiment provides a remote control system for a low-voltage circuit breaker 6 in a prefabricated substation, including a low-voltage circuit breaker 6, an electric operating mechanism 5 connected to the low-voltage circuit breaker 6, a local / remote mode switching unit 3 installed in the control cabinet, a control power input terminal 1, a status indication unit 8, and an alarm indication unit 9, and further including: The source-state switching module 2 is used to determine the power supply status of the power supply from the equipment side and the backup power supply, and to provide control power to the control circuit of the electric operating mechanism 5 according to the preset power supply priority rules. The mode interlock module 4 has its input end connected to the local and remote mode switching unit 3. The mode interlock module 4 is used to select the source of the command that is allowed to enter the control circuit of the electric operating mechanism 5 according to the mode status, and to shield non-corresponding commands. The state freeze module 7 has its input terminals connected to the auxiliary contacts of the low-voltage circuit breaker 6 and the mechanism position signal of the electric operating mechanism 5, respectively, and its output terminal connected to the alarm indication unit 9 and the control circuit of the electric operating mechanism 5. The state freeze module 7 is used to output an abnormal state signal when the state of the auxiliary contacts is inconsistent with the mechanism position signal, and to freeze the control circuit of the electric operating mechanism 5.

[0038] By adopting the above technical solution, and by introducing multi-layer logic of power supply discrimination and priority control, mode interlock control and state consistency freeze control into the system, the continuous control of power supply, safe mode switching and reliable circuit breaker status monitoring are achieved. This can meet the operational requirements of the low-voltage circuit breaker 6 in the box-type substation for continuous controllability, safe operation and accurate status display in an unattended environment.

[0039] Specifically, the source-state switching module 2 automatically selects and prioritizes the power supply path by real-time judgment of the status of the equipment-side power supply and the backup power supply, so that the control power supply can still be stably maintained when the main power supply is interrupted, ensuring that the electric operating mechanism 5 is always in a responsive state, thereby maintaining the continuity of system control; the mode interlocking module 4 determines the local and remote mode status, limits the command channel in the control logic, only allows the command in the corresponding mode to enter the control loop, and shields non-corresponding signals, so that the signal flow in the mode switching process is clear and does not interfere with each other, ensuring the safety and consistency of the command execution process; the state freeze module 7 establishes the correspondence between the action state and the mechanical position state by collecting auxiliary contact signals and mechanism position signals, and outputs an abnormal signal and temporarily freezes the control loop when an inconsistency is detected, realizing the linkage protection of state detection and action control, and preventing the circuit breaker from performing the next operation under uncertain state conditions.

[0040] Overall, the system forms a collaborative control structure with power management, mode control and status monitoring as its core, enabling the low-voltage circuit breaker 6 to maintain reliable operation, accurate signals and safe operation in both remote and local modes, thereby meeting the comprehensive control requirements of the prefabricated substation for power supply continuity, operational safety and status consistency in complex operating environments.

[0041] Hereinafter, based on embodiments of this application, reference is made to... Figure 1 The schematic diagram shown provides a detailed explanation of each unit and module in the above system.

[0042] It should be noted in advance that the system in this application embodiment is equipped with a local and remote mode switching unit 3, a control power input terminal 1, a status indicator unit 8 and an alarm indicator unit 9 installed in the control cabinet, and is electrically connected to the low-voltage circuit breaker 6 and its connected electric operating mechanism 5.

[0043] The control cabinet is a metal-enclosed structure. The cabinet door panel is equipped with a local / remote mode switching element, a circuit breaker opening / closing operation element, and indicators for displaying the circuit breaker's operating status and abnormal information. Inside the cabinet, from top to bottom, there are terminal blocks, functional module mounting rails, and a grounding busbar. Control power input terminal 1 is located in the terminal block area and serves as the unified access node for the control circuit power supply.

[0044] The low-voltage circuit breaker 6 is fixedly installed in the low-voltage side circuit of the prefabricated substation. The electric operating mechanism 5 is directly mechanically connected to the circuit breaker body, and completes the opening and closing actions of the circuit breaker through an internal micro-motor drive mechanism. The control cabinet and the electric operating mechanism 5 are connected by a bundled shielded control cable. The cable contains power supply cores, control execution cores, and auxiliary status signal cores, thereby realizing the grouped transmission of control commands, execution actions, and status acquisition feedback. After entering the control cabinet, the shielded control cable is led core by core to the terminal block, and then distributed from the terminal block to the panel layer operating components, status indication unit 8, and alarm indication unit 9, realizing the logical connection between the functional modules within the cabinet.

[0045] The status indicator unit 8 indicates the current open / closed position of the circuit breaker, whether the closing was successful, and other operating statuses. It displays the status by receiving on / off status signals from the circuit breaker's auxiliary contact circuit. The alarm indicator unit 9 indicates abnormal operating conditions such as overload and short circuit. Its signal comes from the circuit breaker's alarm contact circuit and is visualized and audibly output through the audio-visual components inside the control cabinet. Both units are installed in a visible position on the outside of the control cabinet, while maintaining electrical isolation from the control circuit internally. They are all connected to a unified grounding system to enhance anti-interference capabilities and adaptability to outdoor environments.

[0046] To facilitate installation and subsequent maintenance, the control cabinet is equipped with maintenance openings for wiring and a detachable terminal area. The low-voltage circuit breaker 6 side features standardized auxiliary contact terminals and a mechanism control interface. The control cabinet side uses corresponding numbered terminals for connection, achieving a clear and traceable wiring structure of "control cabinet - electric operating mechanism 5 - low-voltage circuit breaker 6". For example, the panel layer includes a closing button 1SB1 and a opening button 1SB2 for manual operation. The electric operating mechanism 5 side provides P1 / P2 as control power terminals and S1-S4 as execution signal terminals. The signal lines of auxiliary contacts F11, F12, F14 and alarm contacts B11, B14 are led to the status indication and alarm indication circuits through terminal blocks, thus forming a unified, standardized, and easily maintained connection system.

[0047] In this embodiment of the application, the source-state switching module 2 is set between the control power input terminal 1 and the control circuit. It is used to determine the power supply availability of the equipment-side power supply and the backup power supply in real time, and to provide control power to the control circuit of the electric operating mechanism 5 continuously and stably according to the preset power supply priority rules.

[0048] Specifically, the source-state switching module 2 is designed for outdoor applications on the low-voltage side of prefabricated substations. It can adopt electrical isolation sampling and anti-interference design. The input terminal and control circuit are connected through terminal blocks in a standardized manner. Both input and output are connected to the control cabinet terminals using shielded wire harnesses and then distributed to each functional branch.

[0049] Structurally, the source state switching module 2 may include a source state detection submodule, a priority determination submodule, and an anomaly detection submodule.

[0050] The source state detection submodule samples the voltage signals of the equipment-side power supply and backup power supply in real time. The sampling link is electrically isolated from the control loop, and undervoltage, overvoltage, and power failure criteria are set. The criterion thresholds and holding times can be parameterized within the cabinet to adapt to different power grid fluctuation characteristics. The measured signal is converted into a standard state quantity after isolation and filtering, providing the priority determination submodule with "available / unavailable" discrimination input and voltage health reference. Meanwhile, to reduce the influence of external electromagnetic interference, the input of the source state detection submodule and the terminal block can be connected by a bundle of shielded control cables, and single-end grounding is implemented between the shielding layer and the control cabinet grounding system.

[0051] The priority determination submodule performs a comprehensive judgment on the two detection inputs: when only one power supply is available, that supply is directly selected; when both are available, a control power supply is output to the control loop according to the preset power supply priority rules; when both are detected to be unavailable or there is an abnormal transient that does not meet the safety criteria, the abnormal judgment link is triggered. The priority setting supports coordinated control of static configuration and panel layer mode selection. The panel layer selection is used to manually specify the working scenario, and the priority logic is used to ensure the continuity of power supply in fault scenarios. The two work together to avoid false tripping or failure to operate when the power supply is switched abnormally on site.

[0052] By linking power status acquisition with priority output through a linkage logic in this source-state switching module 2, the following technical effects can be achieved: First, the source state detection submodule continuously collects the operating status of the two power sources, enabling the control system to maintain real-time awareness of the current power source when the power state changes. This ensures the clarity and availability of the control link even when power conditions fluctuate, preventing uncertain operations from occurring on the control side due to information lag. Second, the priority determination submodule outputs a single path of control power when both power sources have the ability to supply power, avoiding problems such as voltage superposition, mutual influence or circulating current caused by the simultaneous supply of power to the control loop by both sources, thereby maintaining the electrical stability of the control loop and ensuring that the electric operating mechanism 5 has continuous and consistent driving conditions when performing opening and closing operations. Third, the priority selection result is directly used as the control power input, enabling the control loop to smoothly switch to the backup power supply path in the event of a main power supply interruption or performance degradation, reducing the risk of control link interruption, supporting the system to remain in an executable command working state in unattended scenarios, and meeting the operational requirements of prefabricated substations for continuous circuit breaker operation.

[0053] The anomaly detection submodule immediately outputs a power-off holding signal when both the equipment-side power supply and the backup power supply are simultaneously unavailable or unstable. This signal is then connected to the permissive link of the control circuit. On one hand, it maintains the current open / close position of the electric operating mechanism 5 before the control power is interrupted; on the other hand, it blocks new open / close commands from entering the execution link, thus keeping the circuit breaker in its steady-state position after the last effective operation and preventing unintended actions. This holding and blocking is a safety clamping strategy on the power supply side, independent of the interlocking strategy on the execution side. This ensures that the control circuit maintains deterministic performance under extreme power supply conditions and reduces the risk of malfunction.

[0054] By adding triggering logic for a power-off retention signal to the power supply status detection, this anomaly detection submodule achieves the following technical effects: First, when both the equipment-side power supply and the backup power supply are in an abnormal state, a power outage holding signal is output in a timely manner so that the control circuit can keep the current opening and closing position of the electric operating mechanism 5 stable before the power supply is about to be interrupted, so as to avoid the circuit breaker from being interrupted or having an uncertain position due to the loss of control energy, and maintain the continuity and consistency of power distribution operation. Second, the power failure holding signal blocks the input of new opening and closing commands, so that the control circuit will no longer accept state change commands when the power supply is unreliable, preventing incomplete action, partial action or command execution deviation under insufficient power conditions, and maintaining the clarity and controllability of control behavior. Third, this logic links the power supply status judgment with the stability of the control logic, enabling the control system to have automatic shutdown protection capability in abnormal power supply scenarios. This not only maintains the position of the circuit breaker but also avoids additional operational risks caused by erroneous command triggering, thus meeting the operational requirements of the prefabricated substation to maintain the stable operation status of the circuit breaker under unattended conditions.

[0055] In some embodiments of this application, a clear wiring and logical relationship is established between the source-state switching module 2 and the mode selection mechanism on the control cabinet panel: the two inputs come from the equipment-side power supply and the backup power supply, respectively, and are sent to the source-state detection submodule after being introduced through terminals; the priority-determined gating output forms a unified power bus for the control loop through the terminal block, and is then distributed to the power supply terminal, status indication branch, and alarm indication branch of the electric operating mechanism 5. At the same time, in order to take into account on-site operation and maintenance, the mode selection of the panel layer can directly supply the backup power supply to the control loop when necessary, so as to realize the power supply guarantee in the remote control scenario; in this case, the source-state switching module 2 still continuously monitors the input side and triggers a power failure holding signal when an abnormality is detected, so as to eliminate the risk of power supply jitter caused by single panel operation.

[0056] For example, in one arrangement, the backup power supply uses an uninterruptible power supply (UPS) as the control-side backup power supply, while the equipment-side power supply comes from the local control power supply of the controlled equipment. Both power supplies are connected to a four-terminal selection mechanism on the panel layer, with two ends connected to the backup and equipment-side power supplies respectively, and the other two ends short-circuited to lead out the control circuit power bus. When the selection mechanism rotates to the left, the equipment-side power supply is selected to provide control power for local operation; when rotated to the right, the backup power supply is selected to provide power for remote operation and power backup in fault conditions. This arrangement allows the control circuit to continue operating through the other power supply even if one power supply fails, preventing the circuit breaker from failing to trip in an emergency. The above wiring relationship is led to the terminal block via shielded control cables and then distributed to each branch. Component identification and terminal number are kept in a one-to-one correspondence within the cabinet for easy maintenance location and operation records.

[0057] From a system performance perspective, the source-state switching module 2 introduces a three-layer "detection-judgment-holding" link on the power supply side: firstly, it independently samples and decouples the health status of the two power supplies; secondly, it performs orderly selection based on priority; and finally, in extreme scenarios, it outputs a power-off holding signal to freeze the execution side state and block new commands. This structure can maintain stable control power supply even in environments with power fluctuations, power outages, and concurrent faults, and suppresses the propagation of malfunctions through the holding strategy, significantly improving the safety and controllability of the low-voltage circuit breaker 6 under complex operating conditions.

[0058] For example, the incoming power line of the equipment side can be connected to one end of the selection mechanism via a fuse unit and power point numbered 201, and the backup power supply can be connected to the other end of the selection mechanism via a fuse unit and power point numbered 101. The two output terminals of the selection mechanism are short-circuited and used as the power lead-out point of the control circuit, denoted as the control power bus. To improve environmental adaptability, the sampling line of the source state detection submodule and the control power bus adopt a unified grounding strategy. The shielding layer is grounded at one end inside the control cabinet, and the external grounding is connected to the enclosure grounding through a busbar. The neutral lines of the indicator and alarm branches are connected at the terminal block.

[0059] It should be noted that the description of the connection relationship between the source-state switching module 2 and the control loop in this embodiment is a structural illustration for the purpose of explaining the functional logic of the system and should not be construed as a limitation on the specific structural layout. Those skilled in the art will understand that the relative installation positions of panel components, terminal areas, and functional modules within the control cabinet can be adjusted according to the external dimensions of the control cabinet, the installation method, and the on-site wiring routing. The connection method between the source-state switching module 2 and the control loop can also be adapted to different wiring specifications, terminal block arrangements, or equipment types. When making the above adjustments, as long as the signal transmission relationship between source-state detection, priority determination, and abnormal maintenance is not changed, and the logical link requiring the control power supply to be selected and judged by the source-state switching module 2 before entering the control loop is not changed, all such adjustments should be considered to fall within the protection scope defined by this application.

[0060] The mode interlock module 4 is located between the local and remote mode switching unit 3 and the electric operating mechanism 5. It is used to identify the source of the opening / closing command entering the control circuit and select the command path allowed to enter the control circuit according to the current mode status. This realizes mutual exclusion control between the local operation mode and the remote operation mode, so that the system has clear command execution boundaries in different operation modes and avoids unsafe actions such as erroneous opening or closing of the circuit breaker due to the parallel existence of multiple source commands.

[0061] Specifically, structurally, the input of the mode interlock module 4 receives a mode status signal from the local and remote mode switching unit 3. This mode status signal serves as an access condition for determining whether the operation path is open. The mode interlock module 4 selects the corresponding command source based on this mode status signal: when the system is in local operation mode, the closing and opening buttons on the panel form a valid command path, while control commands from the remote end are blocked; when the system is in remote operation mode, opening / closing commands from the remote end can enter the execution link, while the button circuit on the panel is blocked. Through this interlock logic, the control circuit always allows only one command source to control the electric operating mechanism 5 at any given time, ensuring the clarity and safety of the circuit breaker's operation.

[0062] In some embodiments of this application, to prevent the control command from being falsely triggered due to signal jitter or instability during mode switching, a switching delay submodule is provided in the mode interlock module 4. When the switching delay submodule detects a change in mode state, it immediately outputs a shielding delay signal to the control loop, ensuring that the opening / closing command cannot enter the execution link of the electric operating mechanism 5 within a preset delay time. This delay time covers the response cycle required for the mode switching signal to stabilize, thus ensuring that the mode signal has reached a stable state before entering the interlock logic. This eliminates command cross-competition caused by jitter at the source and prevents the circuit breaker from performing undesirable actions under mode boundary conditions.

[0063] By setting a delay masking control for mode state changes in this switching delay submodule, the following technical effects can be achieved: First, a shielding delay signal is generated at the moment of mode switching, so that the control loop does not immediately execute external commands at the edge stage of switching between local and remote modes, thereby avoiding command channel jitter caused by the unstable mode signal, and keeping the control loop in a static state before the signal state is fully determined, thus maintaining the determinism and consistency of circuit breaker operation. Second, the shielding delay signal blocks any control command within a preset delay time, so that local and remote commands cannot directly enter the control circuit of the electric operating mechanism 5 during mode switching, thereby preventing the superposition, competition or mutual coverage of local and remote commands during the switching transition, and eliminating the risk of false separation, false engagement or failure to operate that may be caused at the moment of mode switching. Third, the duration of the shielding delay signal covers the response period required for the mode state signal to stabilize, enabling the control system to have a smooth buffering capability during the transition from an unstable to a stable mode state. This avoids abnormal state transmission caused by signal jumps, and makes the mode switching process form a continuous action chain of "detection-delay-unlocking". This improves the controllability and stability of mode selection behavior and meets the operational requirements for the safety of command channel switching in the unattended environment of the prefabricated substation.

[0064] In this embodiment, in the signal and wiring of the control cabinet, the mode interlock module 4 and the local and remote mode switching unit 3 are logically connected via a control cable, and the output of the mode interlock module 4 and the actuator of the electric operating mechanism 5 are wired through a terminal block. Local control commands and remote control commands are respectively introduced into different input channels of the mode interlock module 4. When the mode discrimination condition is met, the corresponding channel is open; when it is not met, the corresponding channel remains open. This ensures that the mode status signal undergoes signal shaping processing before entering the interlock logic, thereby enhancing the recognition stability in electromagnetic noise environments.

[0065] For example, in one structural arrangement, when the selection mechanism is in the local mode position, the contact circuits of the closing and opening buttons on the panel layer are introduced into the mode interlock module 4 via the terminal block and transferred to the control terminal of the electric operating mechanism 5; while similar control commands from the remote system are kept disconnected by the interlock link at this time. When the selection mechanism rotates to the remote mode position, the remote command link is activated, and the panel layer button circuit is automatically shielded. The switching delay submodule maintains a short-term command shielding state at the moment of switching between the two modes, thereby eliminating the influence of signal discontinuities and mechanical jitter during the contact switching process of the selection mechanism on the execution link.

[0066] The introduction of the aforementioned mode interlock module 4, through a three-layer control mechanism of "mode selection - source path selection - switching delay shielding", ensures that the electric operating mechanism 5 is always controlled by only a single command source in any mode, and maintains the determinism of the action state during the mode alternation switching phase, thereby significantly improving the safety and controllability of the circuit breaker's operating behavior.

[0067] Those skilled in the art will understand that, without changing the mode discrimination logic and the single-source selection principle of control commands, the mode interlock module 4 can be adjusted in structure and wiring form according to the internal space of the control cabinet, the terminal block wiring method and the installation position of the functional modules, and its functional effect remains consistent.

[0068] In this embodiment, the state freeze module 7 is installed between the state detection link of the low-voltage circuit breaker 6 and the execution control link of the electric operating mechanism 5. It is used to freeze the control circuit of the electric operating mechanism 5 when there is an inconsistency between the opening and closing status reflected by the auxiliary contacts of the circuit breaker and the mechanism position signal of the electric operating mechanism 5. The alarm indication unit 9 provides an abnormal prompt, which enables the state feedback after the circuit breaker performs the action to be verified in real time. This avoids misjudgment of the state due to reasons such as the actuator not being in position, contact response delay, loose mechanical linkage, or signal interference. This prevents the circuit breaker from receiving new opening and closing commands again when it is in an unclear position, which could lead to erroneous closing, failure to operate, or mechanical damage.

[0069] Structurally, the input terminals of the state freeze module 7 are connected to the auxiliary contacts of the low-voltage circuit breaker 6 and the mechanism position signal of the electric operating mechanism 5, respectively. The auxiliary contacts are used to reflect the actual opening or closing state of the circuit breaker body, and the mechanism position signal is used to reflect the execution position of the electric operating mechanism 5. The output terminals of the state freeze module 7 are connected to the alarm indication unit 9 and the control circuit of the electric operating mechanism 5, respectively. The drive path of the electric operating mechanism 5 is cut off or restored by outputting a freeze control signal.

[0070] In some embodiments of this application, the state freeze module 7 includes a consistency judgment submodule and a freeze execution submodule. The consistency judgment submodule collects and combines the status signals of the auxiliary contacts and the position signals of the actuator in real time. When the combined result shows that the circuit breaker body state and the actuator position correspond, a consistency judgment result is generated. When there is a mismatch, delayed switching, state reversal, or inability to identify the two, an inconsistency judgment result is generated and transmitted to the freeze execution submodule.

[0071] The freeze execution submodule is used to cut off the drive signal entering the electric operating mechanism 5 when the consistency judgment result is inconsistent, keeping the electric operating mechanism 5 in its current position and blocking new opening and closing control commands from entering the execution circuit, thereby keeping the circuit breaker in the mechanical position state after its last effective operation. Simultaneously, the freeze execution submodule outputs an abnormal status signal to the alarm indication unit 9, causing the alarm indication unit 9 to enter an abnormal display state, prompting on-site maintenance personnel or the remote monitoring system to check the circuit breaker status. When the two status signals return to consistency, the freeze execution submodule automatically unfreezes the execution circuit, allowing the electric operating mechanism 5 to resume normal control.

[0072] The state freeze module 7 achieves the following technical effects by linking state consistency judgment with the on / off state of the control loop: First, the consistency judgment submodule generates a consistency judgment result based on the combination of the auxiliary contact status signal and the mechanism position signal, so that the electrical state and mechanical execution state of the circuit breaker can be synchronously verified, thereby making the state judgment no longer dependent on the feedback of a single electrical contact, ensuring that the state recognition has higher authenticity and verifiability. Second, the freeze execution submodule cuts off the drive path of the control loop when the consistency judgment result is inconsistent, so that the control loop automatically enters the static state under the condition of uncertainty, avoiding the circuit breaker from continuing to perform opening and closing operations when the feedback is not clear, reducing the probability of malfunction, continuous operation or interruption caused by state information deviation, and enhancing the robustness of the control logic. Third, when consistency is restored, the frozen execution submodule recloses the drive path, enabling the control loop to return to the executable state after the state returns to normal. This ensures that the recovery behavior of the control system after an anomaly has clear triggering conditions and paths, giving the system the operability and controllability to return from the abnormal state to the normal state. This meets the comprehensive requirements of the prefabricated substation for the accuracy of circuit breaker status determination, the continuity of action execution, and the safety of operation behavior in a long-term unattended environment.

[0073] Furthermore, the state freeze module 7 also includes a positional storage submodule, which records the current combined state and judgment result when a state inconsistency event is detected, and transmits the recorded state to the state indication unit 8 for display. The positional storage submodule can leave traces of key inconsistencies during the circuit breaker state change process, enabling field maintenance personnel to analyze the causes of circuit breaker state anomalies afterward, avoiding the impact on fault diagnosis efficiency due to the lack of traces after state recovery.

[0074] This positional storage submodule achieves the following technical effects by recording and echoing inconsistent state events: First, when an inconsistent state event is detected, the combined result is recorded, so that the system retains the correspondence between the auxiliary contact state and the mechanism position signal when the circuit breaker operates abnormally. This provides a clear source of information for subsequent operation and maintenance review, avoids the loss of operation records due to instantaneous recovery of the state after the anomaly occurs, and makes the abnormal state traceable and verifiable. Second, the recorded results are transmitted to the status indication unit 8 for echo, so that the abnormal information can be presented intuitively on the control cabinet side, which makes it easy for operators to quickly identify the status when the abnormality occurs on site or at the remote monitoring end. Thus, the source of the abnormality can be determined without additional disassembly or in-depth investigation, shortening the diagnostic path and improving maintenance efficiency. Third, by recording and displaying inconsistent state events, the action of the state freeze module 7 is no longer simply to freeze the control loop. It can also provide transparent information on the cause of the abnormality while triggering the freeze, so that the control behavior, state feedback and operation and maintenance diagnosis form a continuous chain of correlation, which meets the operation requirements of the prefabricated substation in the unattended management mode to make the abnormal records visible, the state changes traceable and the maintenance handling reliable.

[0075] Furthermore, the alarm indication unit 9 may also include a multi-level alarm display structure for hierarchical display of abnormal states output by the state freeze module 7. The multi-level alarm display structure can display different indication features based on the type of inconsistent state, including color, flashing frequency, or on / off rhythm patterns. For example, when the circuit breaker mechanism position lags behind the auxiliary contact state switching, a low-level alarm state can be displayed; when the circuit breaker is detected to be possibly in the intermediate open / close position, a higher-level flashing display can be triggered. After state consistency is restored, the alarm indication unit 9 automatically exits the abnormal display state and returns to the initial state, thereby ensuring that the displayed content remains consistent with the real-time state of the circuit breaker and avoiding the long-term retention of erroneous prompts.

[0076] By displaying abnormal states in a tiered manner, the alarm indication unit 9 achieves the following technical effects: First, the abnormal status signals are displayed in a hierarchical manner according to their abnormality type, so that the control system can generate clearly distinguishable warning information when there is inconsistency in status, control loop freezing or other abnormal situations. This allows operators to intuitively identify the type and scope of the abnormality when viewing the status indicators, reducing judgment errors caused by unclear warning information and making the status feedback clear in terms of hierarchy and judgment. Secondly, different types of anomalies correspond to different display features, which makes the alarm presentation mode differentiated in terms of information expression. Without additional explanations or text labels, the severity, location, or scope of impact of the anomaly can be directly expressed through display features. This changes the information transmission path from data interpretation to status recognition, reduces the cognitive burden on on-site maintenance personnel, and improves the speed of anomaly location and execution response efficiency. Third, when consistency is restored, the alarm indicator unit 9 automatically restores the initial display state, giving the alarm state a self-regressive capability. After the anomaly is eliminated, the normal state indication of the system can be restored without additional reset operation. This enables the control system to independently complete the complete closed loop from anomaly prompt to state restoration under unattended conditions, making the presentation of the system's operating status more continuous and reliable, and meeting the display and operation management requirements of the prefabricated substation for alarm identification, readable status, and self-reset process.

[0077] By introducing the state freeze module 7 into the control loop, the circuit breaker state forms a clear action closed loop of "execution-in place-confirmation-allow next instruction", which can significantly improve the authenticity and reliability of the circuit breaker action state feedback, making the state control of the circuit breaker under complex operating conditions more controllable and verifiable, thereby improving the operational safety and maintenance reliability of the entire prefabricated substation low-voltage operating system.

[0078] In this embodiment of the application, the system also includes a fault self-test module, which is used to perform functional tests on the source state switching module 2, the mode interlock module 4 and the state freeze module 7 respectively when the system is powered on, so as to confirm that the above modules are in a usable, effective and responsive working state before entering the running state.

[0079] The fault self-test module performs at least one of the following checks on each module: control signal continuity, module response delay, and alarm output validity. This verifies the integrity of the control loop signal link, whether the action response time meets control requirements, and whether the alarm display can be triggered promptly when an anomaly occurs. This module enables the system to complete the self-calibration of critical modules before the electric operating mechanism 5 receives the first control command, effectively reducing the risk of malfunctions caused by module misconnections, signal jitter, or internal wiring abnormalities during the initial startup phase of the circuit breaker.

[0080] In terms of functionality, after the system is powered on, the fault self-test module sends detection signals sequentially to the source-state switching module 2, the mode interlock module 4, and the state freeze module 7 to detect the conduction status of their signal paths and the response behavior of the control logic to the input signals. When the power supply selection logic of the source-state switching module 2 is normal, the mode interlock module 4 can correctly shield or select the instruction path, and the state freeze module 7 can correctly judge the consistency status, the fault self-test module generates normal status feedback and displays the normal start-up operation indication status through the status indication unit 8. When any module is detected to have signal blocking, logic response timeout, or alarm output link failure, the fault self-test module generates an abnormal feedback signal, causing the status indication unit 8 to display an abnormal status indication and triggering an alarm prompt to remind on-site personnel or the upper monitoring system to perform maintenance and inspection.

[0081] This fault self-test module achieves the following technical effects by executing a module-level self-test process during the system power-on phase: First, when the system is powered on, the source state switching module 2, mode interlock module 4 and state freeze module 7 are respectively tested for function, so that the control system can confirm whether the key control logic is in an executable state before entering normal operation, thereby avoiding the risk of exposing the module function abnormality only after the system officially accepts the control command, so that the control system has the ability to self-confirm the state before operation, and the subsequent opening and closing execution is based on a verifiable basis. Second, the testing content includes at least one of the following: control signal connectivity, module response delay, and alarm output validity. This ensures that the self-test process not only confirms the existence of communication or logic status but also tests the response process of the module's execution behavior. This allows the self-test results to reflect the module's real-time execution capability and availability, ensuring that the self-test behavior has practical diagnostic significance rather than being a formal test, thereby enhancing the reliability of the control system. Third, the test results are fed back to the status indication unit 8 for display, making the self-test results readable and presentable. This allows operators to directly know the initial state of the control system during the system startup phase, facilitating timely maintenance or re-initialization when self-test anomalies are detected. This prevents the system from entering the power supply operation process under abnormal conditions, enabling the control system to complete availability verification before entering unattended operation, thus meeting the management requirements of prefabricated substations for startup self-confirmation, operational verifiability, and status presentation.

[0082] In this embodiment, shielded signal lines are used for electrical connections between modules in the control loop to reduce interference from the external electromagnetic environment and improve the anti-interference and stability of the system control signals. Simultaneously, to further reduce ground potential difference interference caused by multiple grounding points in the signal loop, the common grounding terminal of each module is connected to an independent grounding busbar in the control cabinet. This single-point grounding method achieves unified management of the grounding system, thereby forming a clear and defined grounding path for the control loop and avoiding signal drift, false triggering, and display anomalies caused by inconsistent grounding or chaotic grounding return paths. This grounding design is particularly suitable for operating environments in prefabricated substations where the low-voltage side has interference sources such as arc breaking, motor starting, and short-circuit impacts, contributing to improved long-term operational reliability of the control system.

[0083] In this technical solution, the control loop uses shielded signal lines and connects the common ground terminal to an independent grounding bus, achieving the following technical effects: First, shielded signal lines are used for electrical connections between modules, which enables the control circuit to have signal anti-interference capability in the high electromagnetic interference environment of the box-type substation, keeps the signal transmission path of source state switching module 2, mode interlock module 4 and state freeze module 7 stable, reduces the offset, jitter or uncertainty of control signals caused by external electromagnetic coupling, and makes the control logic judgment process more stable and reliable. Second, the common grounding terminal of each module is connected to an independent grounding busbar to keep the reference points of each branch signal in the control loop consistent, avoid signal reference drift caused by grounding point differences, and ensure that the drive command, power switching discrimination signal and status feedback signal of the electric operating mechanism 5 have a unified potential reference when performing actions, thereby maintaining the cooperative relationship between each module and making the overall functional structure of the control system consistent and coordinated. Third, the independent grounding bus serves as the single grounding node of the control circuit, creating a clear hierarchical isolation between the control logic system and the main grounding system of the enclosure. This ensures that the control circuit is unaffected by the large current surge waveform of the main circuit during opening and closing, status detection, or mode switching, reducing misjudgments, malfunctions, or status flicker caused by ground potential fluctuations. As a result, the prefabricated substation can maintain stable control and monitoring behavior even in unattended environments, thus meeting the system's comprehensive requirements for signal integrity, electrical stability, and operational continuity.

[0084] By introducing a fault self-checking module into the overall control architecture, the control system can complete the self-verification of key components before entering normal operation, forming an operation link of "power-on startup - module self-check - status confirmation - control execution". This enables potential faults to be detected before the system operates and prevents them from propagating to the execution layer, significantly improving the system's operational reliability and maintenance diagnostics. This gives the remote control system for the low-voltage circuit breaker 6 in the prefabricated substation higher safety and maintainability under long-term operation and complex working conditions.

[0085] For example, in this embodiment of the application, the auxiliary contacts F11, F12, and F14 provided on the low-voltage circuit breaker 6 side correspond to the closed position signal and the open position signal of the circuit breaker, respectively, and the alarm contacts B11 and B14 are used for abnormal status indication. The above contact signals are led to the terminal block of the control cabinet through bundled shielded cables, and are respectively connected to the consistency judgment submodule of the status indication unit 8 and the status freeze module 7, so as to realize the correspondence verification between the electrical status of the circuit breaker and the mechanical position signal.

[0086] For example, when the circuit breaker is in the closed position, contacts F11 and F12 form a circuit, and the closed display branch of the status indicator unit 8 is connected; when the circuit breaker is in the open position, contacts F11 and F14 form a circuit, and the open display branch of the status indicator unit 8 is connected; when alarm contacts B11 and B14 are detected to be closed, the alarm indicator unit 9 enters the audible and visual prompt mode to remind operators or remote monitoring systems to confirm and handle the fault.

[0087] Regarding mode selection, the mode switching unit on the control cabinet panel is used to select the source of control commands between local and remote modes. The equipment-side power supply and backup power supply are connected to the power bus of the control circuit through switch contacts. When the mode switching unit is in the local position, the open / close button circuit on the panel is activated, and remote control commands are blocked; when the mode switching unit is in the remote position, the remote command link is activated, and the panel buttons are blocked. The aforementioned mode signals serve as input variables for the mode interlock module 4 and work in conjunction with the switching delay submodule to ensure the stability of the command path during mode switching.

[0088] In summary, through the coordinated operation of the source-state switching module 2, mode interlocking module 4, state freeze module 7, and fault self-testing module, this system achieves automatic identification and stable supply of control power source, single-source selection of local and remote operation commands, consistency verification of the actual state and execution position of the circuit breaker, and safety self-testing during system power-on. The source-state switching module 2 ensures the continuity of power supply to the control loop under multi-power conditions; the mode interlocking module 4 ensures that only valid commands enter the execution link at any given time; the state freeze module 7 interrupts the drive path and issues an alarm when the state is inconsistent; and the fault self-testing module completes the operational validity verification before system startup. Through this structure, the remote control process of the low-voltage circuit breaker 6 possesses higher action determinism, state verifiability, and operational safety, enabling long-term reliable operation under complex conditions on the low-voltage side of the prefabricated substation.

[0089] Example 2: like Figure 2 As shown in the figure, this embodiment provides a remote control method for a low-voltage circuit breaker in a prefabricated substation, which includes the following steps: Step S1: Determine the power supply status from the equipment side power supply and the backup power supply, and provide control power to the control circuit of the electric operating mechanism according to the preset power supply priority rules; Step S2: Based on the mode state of the local and remote mode switching unit, determine the source of the command that is allowed to enter the control loop, and shield the command signals that do not correspond to the mode state; Step S3: Based on the instruction signal from the instruction source, perform the opening or closing operation of the low-voltage circuit breaker through the electric operating mechanism; Step S4: Collect the auxiliary contact status signal of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism, and perform consistency verification. If they are inconsistent, output an abnormal status signal and implement freeze control on the control circuit.

[0090] By adopting the above technical solution, and introducing a sequential execution structure of power supply discrimination and priority control, mode command selection and shielding control, and status consistency verification and freeze control into the remote control process, the system can achieve continuous power supply, clear command execution path, and reliable circuit breaker operation status presentation. This can meet the operational requirements of prefabricated substations for continuous controllability, safe operation, and accurate status display under unattended operation conditions.

[0091] Specifically, the system distinguishes between the power supply status from the equipment side and the backup power supply, enabling the control loop to actively select its mode when the power supply environment changes. This ensures the operability of the electric operating mechanism is maintained even when the main power supply is insufficient, ensuring the control process is always based on a stable power supply. Based on the mode status processing command source of the local and remote mode switching unit, the control loop maintains a single command path when the operating mode changes, avoiding signal overlap or trigger contention between local and remote control under mode boundary conditions. This ensures the circuit breaker's action remains logically clear and consistent in execution. Finally, the system executes opening or closing operations based on the command source, ensuring... The execution behavior of the electric operating mechanism is consistent with the control source, without generating control ambiguity or action conflict; the auxiliary contact status signal and the mechanism position signal are collected and their consistency is checked, so that the circuit breaker's operating status has dual confirmation from both the electrical and mechanical sides. When the two are inconsistent, an abnormal status output and control loop freeze are performed, so that the system can maintain the current state without further change when the operating status is uncertain. This gives the circuit breaker's operating process a clear and controllable boundary, and forms a continuous closed-loop link between control behavior, status determination and abnormal handling, meeting the comprehensive requirements of remote control scenarios for action safety, status confirmability and operational predictability.

[0092] Hereinafter, based on embodiments of this application, reference is made to... Figure 2 The flowchart shown above provides a detailed explanation of steps S1 to S4.

[0093] In step S1, the power supply status from the equipment-side power supply and the backup power supply needs to be collected in real time. The collected data may include the voltage status characteristics of the power supply output. Then, the availability of the two power supplies is determined according to the preset power supply priority rules, and one of them is selected as the power supply source for the control loop, so that the electric operating mechanism has a continuous power supply capability while the control loop remains closed. When the power supply status of the equipment-side power supply changes, the control power supply source is switched according to the real-time sampling results, so that the control loop remains operable when the power supply conditions fluctuate or the main power supply is interrupted, and the continuity of circuit breaker control is maintained.

[0094] In step S2, the input source of the control signal needs to be determined based on the mode status signal output by the local and remote mode switching unit. When the local mode status is detected, the panel operation signal is received and the remote control signal is masked; when the remote mode status is detected, the command from the remote control terminal is received and the panel command is masked; at the same time, the command channel can be locked during the edge process of mode status change, so that the control loop does not execute any command input before the mode switching state is stable, ensuring that the command behavior during the mode switching process is deterministic.

[0095] In step S3, the electric operating mechanism executes the opening or closing operation of the low-voltage circuit breaker according to the valid command selected in step S2. Under the condition of a stable power supply, the electric operating mechanism operates according to the input command, switching the circuit breaker from the closed state to the open state, or from the open state to the closed state. During the operation, the mechanism position signal changes with the mechanism's movement and is output synchronously for subsequent status detection.

[0096] In step S4, the auxiliary contact status signal of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism need to be acquired and their consistency checked. If there is an inconsistency between the auxiliary contact status and the mechanism position signal, an abnormal status signal is output and a freeze control is executed on the control loop, causing the electric operating mechanism to remain in its current position and not respond to new control commands. Simultaneously, the abnormal status signal is transmitted to the status indication unit and alarm indication unit for status presentation, providing an identifiable and traceable external display result for the abnormal status. When consistency is restored, the freeze control is lifted, allowing the control loop to return to an executable state.

[0097] In summary, this method distinguishes the power supply status of the equipment-side power supply and backup power supply and selects the control circuit power supply according to priority rules. Combined with mode interlock control that selects the command source according to the mode status and masks non-corresponding commands, the electric operating mechanism executes the opening and closing actions and outputs the mechanism position signal. Finally, by verifying the consistency between the auxiliary contact status signal and the mechanism position signal and implementing freeze control when they are inconsistent, the method achieves the continuity of control power input, the singleness of command channel, and the verifiability of action status feedback. This method can meet the controllable, reliable, and interpretable operation requirements of the circuit breaker remote control process in unattended conditions of the prefabricated substation.

[0098] It should be noted that, although the embodiments in this application are based on... Figure 2 Steps S1 to S4 are described sequentially, but this does not mean that steps S1 to S4 must be performed in a strict order. The reason this embodiment follows this order is... Figure 2 The order in which steps S1 to S4 are described is provided to facilitate understanding of the technical solutions of the embodiments of this application by those skilled in the art. In other words, in the embodiments of this application, the order of steps S1 to S4 can be appropriately adjusted according to actual needs.

[0099] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any non-creative variations that can be conceived by those skilled in the art, as well as any improvements and modifications made without departing from the principles of the present invention, should fall within the protection scope of the present invention.

Claims

1. A remote control system for a low-voltage circuit breaker in a prefabricated substation, comprising a low-voltage circuit breaker, an electric operating mechanism connected to the low-voltage circuit breaker, a local / remote mode switching unit disposed in a control cabinet, a control power input terminal, a status indication unit, and an alarm indication unit, characterized in that, The system includes: The source-state switching module is used to distinguish the power supply status from the equipment-side power supply and the backup power supply, and to provide control power to the control circuit of the electric operating mechanism according to the preset power supply priority rules. The mode interlock module has its input end connected to the local and remote mode switching unit. The mode interlock module is used to select the source of the instruction that is allowed to enter the control circuit of the electric operating mechanism according to the mode state, and to shield non-corresponding instructions. The status freeze module has its input terminals connected to the auxiliary contacts of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism, respectively, and its output terminal connected to the alarm indication unit and the control circuit of the electric operating mechanism. The status freeze module is used to output an abnormal status signal when the status of the auxiliary contacts is inconsistent with the mechanism position signal, and to freeze the control circuit of the electric operating mechanism.

2. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 1, characterized in that, The source state switching module includes a source state detection submodule and a priority determination submodule. The source state detection submodule is used to sample the voltage signals of the device-side power supply and the backup power supply in real time. The priority determination submodule is used to generate a power supply discrimination signal based on the sampling results. When it is detected that the status of both the device-side power supply and the backup power supply is available, the power supply discrimination signal of one of the power supplies is selected according to the preset power supply priority rule and output to the control loop as the control power input.

3. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 2, characterized in that, The source-state switching module also includes an anomaly detection submodule. The anomaly detection submodule is used to output a power-off holding signal when both the equipment-side power supply and the backup power supply are in an abnormal state. The power-off holding signal is used to maintain the current opening and closing position of the electric operating mechanism before the control power supply is interrupted, and to block new opening and closing command signals from being input to the control circuit.

4. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 1, characterized in that, The mode interlock module also includes a switching delay submodule, which generates a shielding delay signal when a change in the mode state is detected. During a preset delay period after the mode switch, any control command is prohibited from entering the control loop. The duration of the shielding delay signal covers the response period required for the mode signal to stabilize.

5. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 1, characterized in that, The state freeze module includes a consistency judgment submodule and a freeze execution submodule. The consistency judgment submodule is used to generate a consistency judgment result based on the combination result of the status signal of the auxiliary contact and the position signal of the mechanism. The freeze execution submodule is used to cut off the drive path of the control loop when the consistency judgment result is inconsistent and to issue the abnormal state signal through the alarm indication unit. When the consistency is restored, the freeze execution submodule recloses the drive path of the control loop.

6. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 5, characterized in that, The state freeze module further includes a positional storage submodule, which records the combined result when a state inconsistency event is detected and transmits it to the state indication unit for echoing.

7. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 6, characterized in that, The alarm indication unit includes a multi-level alarm display structure, which is used to display the abnormal status signal output by the status freeze module in a hierarchical manner, and automatically restore the initial display state when the consistency is restored. Different abnormal types correspond to different display features, including color, flashing frequency, or on / off mode.

8. The remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 1, characterized in that, The system also includes a fault self-test module, which performs functional tests on the source state switching module, the mode interlock module and the state freeze module respectively when the system is powered on. The test content includes at least one of the control signal on / off status, module response delay and alarm output validity, and feeds back the test results to the status indication unit for display.

9. A remote control system for a low-voltage circuit breaker in a prefabricated substation as described in claim 1, characterized in that, The control circuit uses shielded signal lines for electrical connection between modules, and the common grounding terminal of each module is connected to an independent grounding busbar in the control cabinet.

10. A remote control method for low-voltage circuit breakers in a prefabricated substation, characterized in that, Includes the following steps: The power supply status from the equipment side power supply and the backup power supply is determined, and control power is provided to the control circuit of the electric operating mechanism according to the preset power supply priority rules; Based on the mode state of the local and remote mode switching unit, determine the source of the command that is allowed to enter the control loop, and shield command signals that do not correspond to the mode state. According to the instruction signal from the instruction source, the electric operating mechanism performs the opening or closing operation of the low-voltage circuit breaker; The auxiliary contact status signal of the low-voltage circuit breaker and the mechanism position signal of the electric operating mechanism are collected and their consistency is checked. If they are inconsistent, an abnormal status signal is output and the control circuit is frozen.

Images