A multi-source automatic switching control method and system for power distribution network

Abstract

The application discloses a kind of multi-source automatic switching control method and system for power distribution network, wherein, method includes the following steps: system starts and enters the locking state;First round of closed loop verification is executed, line state safety verification, voltage verification, first state quantity verification and first delay verification are sequentially carried out;After first round of closed loop verification passes, disconnect the working power supply switch, remove the standby power supply side bus locking operation, convert system state and enter the waiting state;Second round of closed loop verification is executed, line state safety verification, second state quantity verification and second time delay verification are sequentially carried out;After second round of closed loop verification passes, close the standby power supply switch, lock the working power supply side, convert system state and enter the confirmation state;In confirmation state, judge self-throwing hand mode.The application solves the technical problems of low reliability, insufficient safety and poor working condition adaptability caused by existing automatic switching control relying on single criterion, open-loop execution and fixed delay.

Description

Technical Field

[0001] This invention relates to the field of power Internet of Things (IoT) technology, and in particular to a method and system for automatic switching control of multiple power sources in power distribution networks. Background Technology

[0002] Automatic switching control technology is one of the core technologies in power systems, industrial power supply, and critical load protection. It is used to automatically and quickly switch loads to backup power sources when the main power source fails, maximizing power supply continuity. Existing distribution networks generally adopt a hierarchical distributed protection and control architecture: the local layer deploys intelligent terminals with data acquisition and logic processing capabilities (such as automatic transfer switches and PLCs); the network layer transmits data via fieldbus or industrial Ethernet; and the master station layer is responsible for centralized monitoring and advanced strategy formulation. In the field of industrial automation, state machines and sequential control logic have been widely used to describe the behavior of discrete event systems with multi-step, multi-condition judgments.

[0003] Currently, existing technologies commonly employ the following three types of solutions: First, a time-limited automatic transfer switch (ATS) scheme based on a single voltage / frequency criterion. This is the most widely used traditional ATS implementation method. Its control steps are: continuously monitoring the bus voltage; when the voltage drops below the preset no-voltage setting and remains below it for a fixed delay, it determines that the working power supply has lost power; then it executes a fixed process of "tripping the working power switch—confirming the tripping—closing the standby power switch," and waits for the next startup after logic reset. This scheme relies solely on a single electrical quantity criterion and lacks the ability to distinguish between instantaneous disturbances and atypical faults, easily leading to false tripping or failure to trip. Second, a voltage-type ATS scheme that introduces directional blocking or incoming current criterion. This scheme adds auxiliary verification of the direction of incoming current or power on top of the voltage criterion to distinguish whether the bus voltage loss is caused by an incoming power supply fault or a bus body fault, thereby blocking the ATS during a bus fault to prevent closing the circuit at the fault point. However, its control process is still an open-loop execution; once started, it completes the preset steps and cannot re-verify changes in system state during operation. Third, a centralized intelligent switching control system based on microprocessors and communication; this solution relies on the master station system to collect global data such as voltage, current, and switch status of the entire station, generates switching strategies through topology analysis and power flow calculation, and then sends remote control commands to the field switches; this solution has comprehensive decision-making basis, but it is highly dependent on the real-time performance and reliability of the communication network, has the risk of single-point failure of the master station, and does not have the ability to make local adaptive adjustments.

[0004] It is evident that existing technologies generally suffer from the following technical deficiencies: reliance on a single criterion leads to a high risk of maloperation / failure to operate under complex power grid disturbances; the control logic operates in an open-loop manner, lacking process verification and dynamic error correction capabilities; fixed action delays prevent the balance between selectivity and speed under different operating modes; the lack of device health and system status as decision-making prerequisites results in a lack of proactive safety interlocking mechanisms in case of anomalies; and abrupt switching between automation and manual intervention makes it impossible to smoothly introduce manual decision-making into automated processes. For example, Chinese patent document CN202110808301.7 discloses a multi-power source automatic switching control system and method, but it does not solve the above problems. Therefore, to address these technical issues, there is an urgent need to propose a multi-power source automatic switching control method and system for power distribution networks. Summary of the Invention

[0005] The main objective of this invention is to propose a multi-source automatic switching control method and system for power distribution networks, aiming to solve the technical problems of low reliability, insufficient safety, and poor adaptability to operating conditions caused by existing automatic switching control relying on a single criterion, open-loop execution, and fixed delay.

[0006] To achieve the above objectives, the present invention provides a method for automatic switching control of multiple power sources in a power distribution network, wherein the method includes the following steps:

[0007] S1. When the system starts up, it unconditionally enters the lockout state, prohibits all output control commands, and performs system status self-check and monitoring.

[0008] S2. Perform the first round of closed-loop verification, sequentially performing line status safety verification, voltage verification, first state quantity verification, and first delay verification. If any verification fails to meet the conditions, the timer is cleared, and the process returns to line status safety verification to restart the loop. After the first round of closed-loop verification passes, the working power switch is disconnected, the backup power supply side busbar interlocking operation is released, and the system status is switched to the waiting state.

[0009] S3. The second round of closed-loop verification involves sequentially performing line status safety verification, second state quantity verification, and second time delay verification. If any verification fails to meet the conditions, the process returns to line status safety verification and restarts the loop. After the second round of closed-loop verification passes, the backup power switch is closed, the working power supply side is locked, and the system status is switched to the confirmation state.

[0010] S4. In the confirmed state, determine the automatic reset mode. If it is the automatic reset mode, return to step S2 and enter the continuous monitoring loop; if it is the manual reset mode, enter the system manual operation interface and wait for intervention.

[0011] One preferred embodiment is that the line status safety verification includes checking whether the voltage and current sampling circuit is normal, whether the switch position is normal, whether the device self-test status is normal, and whether the communication status is normal. If any verification is abnormal, the automatic switching logic is immediately terminated and an alarm is reported.

[0012] One preferred embodiment is that step S2, voltage verification, specifically involves:

[0013] Determine if the bus voltage is higher than the no-voltage set value. If so, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

[0014] One preferred embodiment is that step S2, the first state variable verification, specifically involves:

[0015] Determine the running volume If the value is below the first threshold, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

[0016] One preferred option is the amount of operation. This is the working incoming current.

[0017] One preferred embodiment is that step S3, the second state quantity verification, specifically involves:

[0018] Determine whether the operating quantity related to the backup power supply is less than the second threshold. If so, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S3 to start the loop again.

[0019] In one preferred embodiment, the operational quantities related to the activation of the backup power supply include voltage difference and frequency difference.

[0020] In one preferred embodiment, in step S3, if the line status safety verification fails while in the waiting state, the automatic switching logic is immediately terminated and the system returns to the locked state, locking all switch operations and reporting an alarm.

[0021] A system including the aforementioned method for automatic switching control of multiple power sources in a power distribution network, comprising:

[0022] Main control equipment, first incoming line switch, second incoming line switch and bus tie switch;

[0023] The first incoming line switch is used to control the on / off state of the first incoming line;

[0024] The second incoming line switch is used to control the on / off state of the second incoming line;

[0025] The bus tie switch is used to control the connection and disconnection between the two bus sections;

[0026] The main control device is communicatively connected to the first incoming line switch, the second incoming line switch, and the bus tie switch. The main control device is used to collect the three-phase voltage, three-phase current, and bus tie switch current of the two incoming lines in real time, and send opening and closing control commands to each switch.

[0027] In one preferred embodiment, the main control device is also connected to a local human-machine interface, which is used to configure delay settings, switch operating modes, display alarm information, and receive manual operation instructions.

[0028] In the above technical solution of the present invention, the multi-power source automatic switching control method for power distribution networks includes the following steps: Upon system startup, the system unconditionally enters a locked state, prohibiting all output control commands and performing system status self-checks and monitoring; a first round of closed-loop verification is performed, sequentially conducting line status safety verification, voltage verification, first state quantity verification, and first delay verification. If any verification fails, the timer is reset, and the system returns to line status safety verification, restarting the cycle; after the first round of closed-loop verification passes, the working power switch is disconnected, the backup power supply side busbar lockout operation is released, and the system state is switched to a waiting state; a second round of closed-loop verification is performed, sequentially conducting line status safety verification, second state quantity verification, and second delay verification. If any verification fails, the system returns to line status safety verification, restarting the cycle; after the second round of closed-loop verification passes, the backup power switch is closed, the working power supply side is locked, and the system state is switched to a confirmation state; in the confirmation state, the automatic switching manual reset mode is determined. If it is an automatic reset mode, the system returns to the second step and enters a continuous monitoring cycle; if it is a manual reset mode, the system enters the manual operation interface and waits for intervention. This invention solves the technical problems of low reliability, insufficient safety, and poor adaptability to operating conditions caused by existing automatic switching control relying on a single criterion, open-loop execution, and fixed delay.

[0029] In this invention, a fixed-order verification loop is constructed for line status safety verification, voltage verification, status quantity verification, and delay verification. If any criterion is not met, the process does not simply terminate. Instead, after the timer is cleared, it is forcibly returned to the highest priority line status safety verification to start the loop again. This mechanism transforms a one-time judgment into a continuous, closed-loop AND judgment logic, ensuring the continuity and anti-interference of the action conditions.

[0030] In this invention, line status safety verification (including voltage and current sampling circuits, switch positions, device self-test status, and communication status) is placed at the forefront of all verification and judgment logic and given the highest interrupt priority. Once any abnormality is detected, the control flow immediately jumps out of all loops and judgments, executes the operation of reporting the abnormality and exiting the automatic switching logic. This design takes system health as a prerequisite for logic execution, realizes proactive safety defense, and avoids post-alarm processing.

[0031] In this invention, the control flow is divided into multiple discrete states such as the lockout state, the waiting state, and the confirmation state. The state transition is driven by strict verification conditions. In particular, after the confirmation state, the flow can automatically return to the initial verification loop based on the judgment result of the automatic switching mode, realizing full closed-loop monitoring, or switch to the manual operation interface. It integrates automatic loop and manual collaborative entry, realizing dynamic error correction and flexible operation of the multi-power automatic switching control method.

[0032] In this invention, a timer accumulates as the criteria are continuously met, and immediately resets to zero once the criteria are broken. At the same time, two independent and configurable delay thresholds are set for the action condition maturity judgment and the final confirmation judgment before the switch, respectively. This condition accumulation and multi-time delay mechanism realizes the dynamic correlation between delay and real-time system status, and optimizes the coordination between speed and selectivity.

[0033] In this invention, a self-starting manual mode judgment node is set to determine whether the process automatically returns to the continuous closed-loop monitoring cycle or transfers control to the manual operation interface, thus realizing a smooth and safe switch between automation and manual intervention. Attached Figure Description

[0034] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of an automatic switching control method for multiple power sources in a power distribution network according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of a multi-power automatic switching control system for a power distribution network according to an embodiment of the present invention.

[0037] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0040] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0041] See Figure 1 According to one aspect of the present invention, the present invention provides a method for automatic switching control of multiple power sources in a power distribution network, wherein the method includes the following steps:

[0042] S1. When the system starts up, it unconditionally enters the lockout state, prohibits all output control commands, and performs system status self-check and monitoring.

[0043] S2. Perform the first round of closed-loop verification, sequentially performing line status safety verification, voltage verification, first state quantity verification, and first delay verification. If any verification fails to meet the conditions, the timer is cleared, and the process returns to line status safety verification to restart the loop. After the first round of closed-loop verification passes, the working power switch is disconnected, the backup power supply side busbar interlocking operation is released, and the system status is switched to the waiting state.

[0044] S3. The second round of closed-loop verification involves sequentially performing line status safety verification, second state quantity verification, and second time delay verification. If any verification fails to meet the conditions, the process returns to line status safety verification and restarts the loop. After the second round of closed-loop verification passes, the backup power switch is closed, the working power supply side is locked, and the system status is switched to the confirmation state.

[0045] S4. In the confirmed state, determine the automatic reset mode. If it is the automatic reset mode, return to step S2 and enter the continuous monitoring loop; if it is the manual reset mode, enter the system manual operation interface and wait for intervention.

[0046] Specifically, in this embodiment, the system unconditionally enters a locked state upon startup, prohibiting all output control commands and performing system status self-checks and monitoring. This establishes an absolutely safe starting point for subsequent logic, ensuring that the system will not malfunction at the moment of power-on or startup.

[0047] Specifically, in this embodiment, the line status safety verification includes whether the voltage and current sampling circuit is normal, whether the switch position is normal, whether the device self-test status is normal, and whether the communication status is normal. If any verification is abnormal, the automatic switching logic is immediately terminated and an alarm is reported.

[0048] Specifically, in this embodiment, step S2, voltage verification, specifically includes:

[0049] Determine if the bus voltage is higher than the no-voltage set value. If so, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

[0050] Specifically, in this embodiment, step S2, the first state quantity verification, specifically involves: determining the running quantity. If the value is below the first threshold, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

[0051] Specifically, in this embodiment, the operational volume This is the working incoming current.

[0052] Specifically, in this embodiment, when the line status safety check, voltage check, and first state quantity check continuously meet the conditions, the timer is incremented, and it is determined whether the timer is greater than the first delay threshold. If it is not true, the loop continues to wait. If the condition is broken midway, the timer is cleared and the process returns to the line status safety check, ensuring that the action conditions are continuous and resistant to disturbances.

[0053] Specifically, in this embodiment, after the first round of closed-loop verification passes, the system disconnects the working power switch, releases the backup power supply bus lockout, clears the timer, and changes the system control state from the lockout state to the waiting state.

[0054] Specifically, in this embodiment, in the waiting state, the system performs a final confirmation of the conditions for closing the backup power supply, wherein the line status security check in step S3 is the same as the line status security check in step S2.

[0055] Specifically, in this embodiment, step S3, the second state quantity verification, specifically includes:

[0056] Determine whether the operating quantities related to the activation of the backup power supply are less than the second threshold. If so, proceed to the next verification. Otherwise, clear the timer and return to the line status safety verification in step S3 to start the loop again. The operating quantities related to the activation of the backup power supply include voltage difference and frequency difference.

[0057] Specifically, in this embodiment, when the line status safety check and the second state quantity check continuously meet the conditions, the timer is incremented and it is determined whether the timer is greater than the second delay threshold. If it is not true, the line status safety check in step S3 is returned to restart the loop. The second delay check is used to ensure that the switching action interval or the synchronization requirement is met.

[0058] Specifically, in this embodiment, in step S3, if the line status safety verification fails while in the waiting state, the automatic switching logic is immediately terminated and the system returns to the locked state, locking all switch operations and reporting an alarm.

[0059] Specifically, in this embodiment, after the second round of closed-loop verification is passed, the backup power switch is closed, the working power supply side is locked, the timer is cleared, and the system control state is changed from the waiting state to the confirmation state.

[0060] See Figure 2 According to another aspect of the present invention, the present invention provides a multi-source automatic switching control system for a power distribution network, wherein the multi-source automatic switching control system for a power distribution network includes: a main control device, a first incoming line switch, a second incoming line switch, and a bus tie switch;

[0061] The first incoming line switch is used to control the on / off state of the first incoming line;

[0062] The second incoming line switch is used to control the on / off state of the second incoming line;

[0063] The bus tie switch is used to control the connection and disconnection between the two bus sections;

[0064] The main control device is communicatively connected to the first incoming line switch, the second incoming line switch and the bus tie switch respectively. The main control device is used to collect the three-phase voltage, three-phase current and bus tie switch current of the two incoming lines in real time, and send opening and closing control commands to each switch.

[0065] Among them, #1 is the first incoming line switch, #2 is the second incoming line switch, and #3 is the bus tie switch.

[0066] Specifically, in this embodiment, the main control device is also connected to a local human-machine interface, which is used to configure delay settings, switch operating modes, display alarm information, and receive manual operation instructions.

[0067] Specifically, in this embodiment, the multi-power automatic switching control system for power distribution networks includes a bus tie automatic switching mode and an incoming line automatic switching mode. The application scenario of the bus tie automatic switching mode is: when the bus tie is switched on or off, the incoming line is abnormal, and it is necessary to use a single incoming line to drive two lines. The application scenario of the incoming line automatic switching mode is: when the incoming line is switched on or off, the main line is abnormal, and it is necessary to switch to the backup line.

[0068] Specifically, in this embodiment, the invention introduces the core logic of multiple closed-loop verification and state machine control, fundamentally reconstructing the decision-making and execution process of automatic switching, thereby systematically improving its overall performance. The sequential verification and loop mechanism of multiple criteria, by constructing a logical closed loop of continuous verification and automatic restart if the condition is not met, effectively filters instantaneous disturbances and abnormal operating conditions, directly solving the problem that it is difficult to simultaneously address erroneous operation and refusal to operate under traditional single criteria, significantly improving the accuracy and reliability of the action. At the same time, the architecture of the invention organically combines the highest priority safety verification, dynamically correctable closed-loop process, and adaptive delay linked with the operating state. This enables the system to not only immediately lock out when an anomaly occurs, but also to reconfirm and self-correct based on the real-time state during the action, thereby greatly enhancing the system's adaptability to complex operating conditions and overall safety. Finally, through the embedded self-switching and manual re-judgment node, the invention achieves safe and smooth collaboration between automated processes and manual decision-making, providing a flexible solution for high-reliability control scenarios that combines automation efficiency with manual assurance.

[0069] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for automatic switching control of multiple power sources in a power distribution network, characterized in that, Includes the following steps: S1. When the system starts up, it unconditionally enters the lockout state, prohibits all output control commands, and performs system status self-check and monitoring. S2. Perform the first round of closed-loop verification, sequentially performing line status safety verification, voltage verification, first state quantity verification, and first delay verification. If any verification fails to meet the conditions, the timer is cleared, and the process returns to line status safety verification to restart the loop. After the first round of closed-loop verification passes, the working power switch is disconnected, the backup power supply side busbar interlocking operation is released, and the system status is switched to the waiting state. S3. The second round of closed-loop verification involves sequentially performing line status safety verification, second state quantity verification, and second time delay verification. If any verification fails to meet the conditions, the process returns to line status safety verification and restarts the loop. After the second round of closed-loop verification passes, the backup power switch is closed, the working power supply side is locked, and the system status is switched to the confirmation state. S4. In the confirmed state, determine the automatic reset mode. If it is the automatic reset mode, return to step S2 and enter the continuous monitoring loop; if it is the manual reset mode, enter the system manual operation interface and wait for intervention.

2. The method for automatic switching control of multiple power sources in a power distribution network according to claim 1, characterized in that, The line status safety verification includes checking whether the voltage and current sampling circuit is normal, whether the switch position is normal, whether the device self-test status is normal, and whether the communication status is normal. If any verification is abnormal, the automatic switching logic will be terminated immediately and an alarm will be reported.

3. A method for automatic switching control of multiple power sources in a power distribution network according to any one of claims 1-2, characterized in that, The voltage verification step S2 is specifically as follows: Determine if the bus voltage is higher than the no-voltage set value. If so, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

4. A method for automatic switching control of multiple power sources in a power distribution network according to any one of claims 1-2, characterized in that, The first state variable verification in step S2 is specifically as follows: Determine the running volume If the value is below the first threshold, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S2 to start the loop again.

5. A method for automatic switching control of multiple power sources in a power distribution network according to claim 4, characterized in that, The amount of operation This is the working incoming current.

6. A method for automatic switching control of multiple power sources in a power distribution network according to any one of claims 1-2, characterized in that, The second state quantity verification in step S3 specifically involves: Determine whether the operating quantity related to the backup power supply is less than the second threshold. If so, proceed to the next check; otherwise, clear the timer and return to the line status safety check in step S3 to start the loop again.

7. A method for automatic switching control of multiple power sources in a power distribution network according to claim 6, characterized in that, The operational quantities related to the activation of backup power include voltage difference and frequency difference.

8. A method for automatic switching control of multiple power sources in a power distribution network according to any one of claims 1-2, characterized in that, In step S3, if the line status safety verification fails while in the waiting state, the automatic switching logic is immediately terminated and the system returns to the locked state, locking all switch operations and reporting an alarm.

9. A system comprising the multi-source automatic switching control method for a power distribution network as described in any one of claims 1-8, characterized in that, include: Main control equipment, first incoming line switch, second incoming line switch and bus tie switch; The first incoming line switch is used to control the on / off state of the first incoming line; The second incoming line switch is used to control the on / off state of the second incoming line; The bus tie switch is used to control the connection and disconnection between the two bus sections; The main control device is communicatively connected to the first incoming line switch, the second incoming line switch, and the bus tie switch. The main control device is used to collect the three-phase voltage, three-phase current, and bus tie switch current of the two incoming lines in real time, and send opening and closing control commands to each switch.

10. A multi-source automatic switching control system for power distribution networks according to claim 9, characterized in that, The main control device is also connected to a local human-machine interface, which is used to configure delay settings, switch operating modes, display alarm information, and receive manual operation instructions.

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