Spare power automatic switching device verification platform and method based on self-holding double-coil relay

Abstract

The invention relates to the technical field of power system relay protection, and relates to a backup power automatic switching device verification platform and method based on a self-hold double-coil relay, and the platform comprises a circuit breaker simulation unit which comprises a closing coil and an opening coil; the control signal input interface is electrically connected with the closing coil and the opening coil and is used for receiving closing and opening control pulses output by the spare power automatic switching device to be verified; the state feedback output interface is electrically connected with a first state contact of the self-holding double-coil relay and is used for feeding back the opening and closing state of the simulated circuit breaker to the spare power automatic switching device to be verified; and the manual control loop is connected in parallel to a circuit of the closing coil and the opening coil, and is used for manually setting or resetting the circuit breaker simulation unit under the condition of being separated from the spare power automatic switching device. Through high-fidelity closed-loop simulation, linkage logic under various working conditions is completely reproduced, and the accuracy, depth and convenience of verification work are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of power system relay protection technology, and more specifically, to a verification platform and method for automatic transfer switch based on a self-holding dual-coil relay. Background Technology

[0002] Automatic transfer switching (ATS) devices are critical secondary protection and control equipment in power systems, ensuring continuous power supply. They are widely used in various substations, distribution rooms, and industrial, commercial, and civil facilities with extremely high power supply reliability requirements. Their core function is to monitor the real-time operating status of multiple power sources. When the primary power source experiences a power outage due to a fault or maintenance shutdown, the ATS can quickly and accurately disconnect the faulty line and activate the backup power source or connect the tie switch based on preset logic and safety interlocking conditions, thereby restoring power supply to critical loads in the shortest possible time. To ensure 100% reliable operation of ATS devices in critical moments and prevent serious power grid accidents such as cascading trips or accidental closing caused by logic errors or component failures, regular, comprehensive, and accurate functional verification and logic validation are crucial and indispensable parts of power grid safety operation procedures. Currently, the verification methods for ATS devices have inherent limitations and safety hazards. On the one hand, traditional on-site verification methods require testing in actual electrical bays, directly linking the testing process to primary high-voltage equipment. This involves cumbersome power outage applications and safety measure arrangements, consuming significant manpower and time. Furthermore, during testing, any unknown defects in the automatic transfer switch or wiring could lead to erroneous switching actions, causing unplanned power outages or even damaging expensive primary equipment, posing a very high safety risk. On the other hand, purely theoretical drawing verification or simple benchtop testing, detached from the field, cannot realistically simulate the closed-loop feedback relationship between circuit breaker position signals and device commands. Simplified testing not only fails to fully verify complete logic chains with strict timing and interlocking conditions, such as "opening first, then closing," but also cannot effectively test the device's anti-misoperation interlocking capability when receiving abnormal feedback signals, resulting in incomplete testing and the potential for overlooking safety hazards. Summary of the Invention

[0003] The purpose of this invention is to provide a verification platform and method for a standby automatic transfer device based on a self-holding dual-coil relay. Through high-fidelity closed-loop simulation, it fully reproduces the interlocking logic under various operating conditions, effectively avoids the risk of power outages and safety hazards in field testing, and significantly improves the accuracy, depth and convenience of the verification work.

[0004] This invention is achieved through the following technical solution:

[0005] A verification platform for automatic transfer switch devices based on self-holding dual-coil relays includes: The circuit breaker simulation unit has a self-holding dual-coil relay as its core, which includes a closing coil and a opening coil. The control signal input interface is electrically connected to the closing coil and the opening coil respectively, and is used to receive the closing and opening control pulses output by the standby automatic transfer device to be verified; The status feedback output interface is electrically connected to the first status contact of the self-holding dual coil relay and is used to provide feedback on the real-time open / closed status of the simulated circuit breaker to the standby automatic transfer device to be verified. A manual control circuit, connected in parallel to the circuits of the closing coil and the opening coil, is used to manually set or reset the circuit breaker simulation unit when the automatic transfer switch is disconnected.

[0006] Optionally, the manual control circuit includes a manual closing controller connected in parallel with the closing coil and a manual opening controller connected in parallel with the opening coil.

[0007] Optionally, it also includes an AC voltage simulation circuit, which is equipped with a power control switch to control the supply or disconnection of simulated working power supply voltage to the standby automatic transfer device to be calibrated, so as to simulate the line power failure or power-on conditions.

[0008] Optionally, it also integrates three independent circuit breaker simulation units, which are used to simulate the first incoming circuit breaker, the second incoming circuit breaker, and the tie circuit breaker, respectively.

[0009] Optionally, the circuit breaker simulation unit may further include a status indicator light driven by the second status contact of the self-holding dual-coil relay, for displaying the open and closed status of the simulated circuit breaker.

[0010] A verification method for automatic transfer switch (ATS) devices based on self-holding dual-coil relays is applied to a verification platform for ATS devices based on self-holding dual-coil relays. The method includes the following steps: Connect the trip and close command output terminals of the standby automatic transfer device to be tested to the control signal input interface of the corresponding circuit breaker simulation unit on the test platform, respectively. At the same time, connect the status feedback output interface of the corresponding circuit breaker simulation unit on the test platform to the circuit breaker position signal input terminal of the standby automatic transfer device to be tested. Verify whether the standby automatic transfer device to be verified can issue the first control pulse in its preset logic according to the set initial verification conditions and drive the circuit breaker simulation unit to operate. After the circuit breaker simulation unit operates, its status is fed back to the automatic transfer switch in real time through the status feedback output interface. Based on this, it is further verified whether the automatic transfer switch can execute the next action in its logic chain according to the new status received.

[0011] Optionally, the initial verification condition specifically includes: By controlling the switch of the AC voltage simulation circuit, the supply of one simulated AC voltage is cut off to simulate the scenario of power loss in this incoming line.

[0012] Optionally, the verification specifically involves verifying whether the automatic transfer switch can send control pulses to the verification platform in sequence according to a preset safety sequence after detecting a power outage. The preset safety sequence is set as follows: the incoming line circuit breaker opens first, and the connecting circuit breaker closes second.

[0013] Optionally, it also includes self-recovery logic: after the backup automatic transfer device completes the power failure switching, the power supply of this circuit is restored by operating the control switch of the AC voltage simulation circuit, and the control logic of whether the backup automatic transfer device automatically executes the priority contact circuit breaker opening and the secondary incoming line circuit breaker closing is verified.

[0014] Optionally, when the automatic transfer switch has issued a tripping command for the tie circuit breaker and the verification platform has simulated this action, at the instant it is about to issue a closing command for the incoming line circuit breaker: By using the manual control loop on the operating platform, the circuit breaker simulation unit that was opened is forced to be put back into the closed state to simulate a single manual misoperation that conflicts with the self-recovery logic. Based on this, it is verified whether the automatic transfer switch can detect this conflict state and block its subsequent incoming circuit breaker closing commands.

[0015] The technical solution of the present invention has at least the following advantages and beneficial effects: This invention, on the one hand, employs a low-voltage self-holding dual-coil relay to accurately simulate the opening and closing states and mechanical holding characteristics of a high-voltage circuit breaker. This achieves complete physical isolation between the testing process and the primary high-voltage system, eliminating the need for power outages on the primary equipment during verification. This significantly simplifies the testing process, shortens the work cycle, and fundamentally eliminates the risk of power outages or equipment damage caused by testing, ensuring the safety of personnel and equipment. On the other hand, this invention constructs a complete "command-action-feedback" closed-loop simulation system. This system not only allows the automatic transfer switch to issue commands and drive the simulated circuit breaker to operate, but also provides real-time feedback of the new state after the operation back to the device. This enables comprehensive and in-depth verification of the entire complex logic chain, including automatic transfer after power failure, automatic power restoration, manual / automatic interlocking, and anti-misoperation interlocking. The simulation fidelity is high, and the test conclusions are reliable, greatly enhancing the depth and breadth of the verification work. Attached Figure Description

[0016] Figure 1 The control principle diagram of the interconnection circuit breaker simulation unit provided by the present invention; Figure 2The control principle diagram of the II-stage incoming line circuit breaker simulation unit provided by the present invention; Figure 3 The control principle diagram of the I-section incoming line circuit breaker simulation unit provided by the present invention; Figure 4 This is a schematic diagram of the power supply and status feedback loop connection of the automatic transfer switch provided by the present invention. Figure 5 The schematic diagram of the AC voltage simulation circuit provided by the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] This invention provides a portable, highly secure functional verification platform for automatic transfer switch (BZT) devices. The core idea of ​​this platform is to construct a "circuit breaker simulation unit" using low-voltage electrical components, capable of completely simulating all electrical characteristics of a field high-voltage circuit breaker (switch). It also integrates auxiliary circuits such as AC voltage simulation and manual control, thereby enabling closed-loop, high-fidelity verification of all control logic, interlocking logic, and timing logic of the BZT device in an environment completely physically isolated from the primary high-voltage system.

[0019] Reference Figures 1 to 5 As shown, the verification platform of this invention is mainly integrated into a portable housing. Its panel is equipped with various interfaces, switches, buttons, and indicator lights, while the core analog circuitry is integrated internally. It mainly includes the following parts: Circuit Breaker Simulation Units: In this embodiment, three identical circuit breaker simulation units are set up to simulate the "Section I Busbar Incoming Circuit Breaker," "Section II Busbar Incoming Circuit Breaker," and "Tie Circuit Breaker" in the field, respectively. Each unit is an independent and fully functional simulation system. Taking the circuit breaker simulation unit one simulating the "Section I Busbar Incoming Circuit Breaker" as an example, its structure is as follows: The core simulation component is the self-holding double-coil relay (KA1), which is the core of the simulation of circuit breaker behavior. It has a "tripping coil" and a "closing coil." When either coil receives a DC pulse voltage (DC220V in this embodiment), the internal mechanical structure of the relay flips and latches, changing the state of its main contacts (from open to closed, or from closed to open). Even after the control pulse disappears, its state remains unchanged. This characteristic perfectly replicates the physical characteristics of a real circuit breaker: "receiving a pulse to operate and maintaining the mechanical position."

[0020] Control signal input interface: The control signal input interface is used to receive trip and close commands from the automatic transfer switch (ATS) to be verified. Specifically, it is connected to terminals XT1:5 and XT1:6 on the platform panel. Internally, terminal XT1:5 is connected in series to one end of the closing coil of relay KA1, and the other end of this coil is connected to the negative terminal of the DC220V power supply. Terminal XT1:6 is connected in series to one end of the opening coil of relay KA1, and the other end of this coil is also connected to the negative terminal of the DC220V power supply. When the "I-stage incoming line closing" output relay of the ATS operates, outputting positive DC220V to XT1:5, the closing coil of KA1 is energized; when the "I-stage incoming line tripping" output relay of the ATS operates, outputting positive DC220V to XT1:6, the opening coil of KA1 is energized.

[0021] Status Feedback Output Interface: The status feedback output interface is used to provide real-time feedback of the current "open" or "closed" status of the analog circuit breaker to the automatic transfer switch (ATS). It utilizes the auxiliary contacts of relay KA1, specifically terminals XT1:3 and XT1:4 on the platform panel. Internally, a common DC 220V positive signal is introduced and then output through a pair of normally open (NO) contacts and a pair of normally closed (NC) contacts of KA1. The output of the normally open contact is connected to terminal XT1:3 to provide a "closed" signal (when KA1 is closed, this contact closes, and XT1:3 outputs a high level). The output of the normally closed contact is connected to terminal XT1:4 to provide a "open" signal (when KA1 is open, this contact closes, and XT1:4 outputs a high level). These two terminals are directly connected to the "I-stage incoming circuit breaker position signal" input of the ATS.

[0022] Manual Control Circuit: The manual control circuit is used by test personnel to manually intervene or set the initial state on the platform. It includes a "local manual closing" button (instantaneous button, SB1-Close) and a "local manual opening" button (instantaneous button, SB1-Open). One end of button SB1-Close is connected to DC 220V positive power, and the other end is connected in parallel to the closing coil input of KA1. One end of button SB1-Open is connected to DC 220V positive power, and the other end is connected in parallel to the opening coil input of KA1. Pressing SB1-Close will manually close KA1; pressing SB1-Open will manually open KA1.

[0023] Status Indicator Lights: To visually display the status of the simulated circuit breaker, a red indicator light and a green indicator light are provided. The red indicator light is connected in series in the normally open contact circuit of KA1; when KA1 is closed, the red light illuminates. The green indicator light is connected in series in the normally closed contact circuit of KA1; when KA1 is open, the green light illuminates.

[0024] Similarly, circuit breaker simulation unit two (with relay KA2 as its core, simulating the II section incoming line) and circuit breaker simulation unit three (with relay KA3 as its core, simulating the tie switch) have the same internal circuit structure and external interface, only their interface terminal numbers are different (for example, the control input of KA2 is XT1:7 / XT1:8, and the control input of KA3 is XT1:14 / XT1:15, etc., and the specific terminal numbers can be arranged in sequence), respectively used to connect to the control / signal terminals of the II section incoming line of the automatic transfer switch and the tie switch.

[0025] AC Voltage Simulation Circuit: The AC voltage simulation circuit provides simulated AC operating voltage to the sampling terminal of the PT (voltage transformer) of the automatic transfer switch (ATS) to simulate the "energized" or "de-energized" state of the line. It mainly consists of two independent AC voltage sources (which can be provided by a 220V / 100V control transformer) and two control switches, SA1 and SA2. Switch SA1 controls the on / off state of the first simulated AC voltage, and its output is connected to terminals XT1:9 and XT1:10 on the platform panel. These two terminals are used to connect to the PT input of the I-section busbar of the ATS. Switch SA2 controls the on / off state of the second simulated AC voltage, and its output is connected to terminals XT1:11 and XT1:12 on the platform panel. These two terminals are used to connect to the PT input of the II-section busbar of the ATS. By operating switches SA1 and SA2, the energization and de-energization conditions of either the I-section or II-section busbar can be easily simulated.

[0026] Below, this embodiment takes a typical standby automatic transfer device in a dual-input, single-connection wiring mode as an example to explain in detail how to use this platform to complete a comprehensive verification from basic functions to complex interlocking logic.

[0027] Step 1: Before starting the verification, first perform the electrical connections, including: Control circuit connection: Using wires, connect the "I-stage incoming line trip / close" command output terminal of the automatic transfer switch to be verified to the control signal input interfaces XT1:6 and XT1:5 of the circuit breaker simulation unit 1 of this platform, respectively. Similarly, connect the "II-stage incoming line trip / close" command output terminal of the automatic transfer switch to the corresponding interface of unit 2, and connect the "tethering switch trip / close" command output terminal to the corresponding interface of unit 3. Status feedback circuit connection: Connect the status feedback output interfaces XT1:3 (closed) and XT1:4 (open) of the circuit breaker simulation unit 1 of this platform to the "I-stage incoming line circuit breaker position signal" input terminal of the automatic transfer switch. Similarly, connect the status feedback signals of unit 2 and unit 3. Analog Voltage Connection: Connect the output terminals XT1:9 / XT1:10 of the AC voltage analog circuit of this platform to the input terminal of the PT on the I-section busbar of the automatic transfer switch; connect XT1:11 / XT1:12 to the input terminal of the PT on the II-section busbar of the automatic transfer switch. Power Supply for the Platform: Connect the platform to a DC220V control power supply.

[0028] Step 2: Verification of the automatic transfer function of the incoming line in section I. Step 2 aims to verify the core function of the automatic transfer device: whether it can correctly and safely switch to another power source automatically after one power source loses power.

[0029] Setting the initial verification conditions: First, using the manual control buttons on the platform, place circuit breaker simulation units 1 (KA1) and 2 (KA2) in the "closed" state (red light on), and unit 3 (KA3, tie) in the "open" state (green light on). This simulates the normal operating state of the system: both incoming lines are running, and the tie switch is in the standby open state. Close the AC voltage simulation circuit switches SA1 and SA2 on the platform, so that the automatic transfer switch detects that the voltage of both busbars is normal.

[0030] On the platform, manually disconnect the control switch SA1 of the AC voltage simulation circuit. This operation instantly cuts off the simulated voltage of section I supplied to the automatic transfer switch, thus accurately simulating the scenario of power loss in section I.

[0031] After disconnecting SA1, closely observe the operation of the automatic transfer switch. According to its internal logic, after detecting a voltage loss in section I and after a preset delay (e.g., 2 seconds), it must issue the first control pulse in its logic chain—the "section I incoming line trip" command. At this time, you should be able to observe this command being sent to terminal XT1:6 of the platform via wiring, driving the core relay KA1 of circuit breaker simulation unit one to flip its state from the closed position to the open position. Simultaneously, the indicator light for KA1 on the platform panel changes from red to green.

[0032] After KA1 activates, its normally closed contact closes, sending a clear "Incoming line in section I has been successfully tripped" status feedback signal to the automatic transfer switch (ATS) via terminal XT1:4. Upon receiving this new status, the ATS's internal safety interlocking logic is satisfied, and it continues to execute subsequent actions in its logic chain. At this point, the ATS should be able to observe the issuance of a second control pulse—a "Tethering switch closed" command. This command is sent to the closing control terminal of platform unit three, driving relay KA3 to flip to the closed position, and its indicator light changes from green to red.

[0033] Throughout the process, the automatic transfer switch strictly followed the preset safety sequence of "first the line circuit breaker (KA1) opens, then the tie circuit breaker (KA3) closes," proving that its automatic transfer function in the event of power failure and the related timing interlocking logic were correct.

[0034] Step 3: Power restoration self-recovery function verification. Step 3 aims to verify whether the automatic transfer switch can automatically return to normal operation after the faulty power supply is restored.

[0035] Based on the completion of step two (at this point, KA1 is open and KA3 is closed), the previously disconnected AC voltage simulation circuit switch SA1 is re-closed on the platform. This simulates the scenario of power restoration for the incoming power supply of section I. After detecting the restoration of the section I voltage, the automatic transfer switch should initiate its self-recovery logic. After a set delay, the following sequence of actions should be observed on the platform: First, the automatic transfer switch issues a "tethering switch open" command, driving KA3 to flip from the closed position to the open position (red light off, green light on). Then, after receiving the status feedback signal that KA3 has been opened, the automatic transfer switch issues a "section I incoming line closed" command, driving KA1 to flip from the open position to the closed position (green light off, red light on). Conclusion: The automatic transfer switch strictly follows the recovery logic of "tethering circuit breaker open first, then incoming line circuit breaker closed," proving that its self-recovery function is normal.

[0036] Step Four: Anti-misoperation interlocking verification during self-recovery: Repeat the "simulated power restoration" operation in Step Three. When it is observed that the automatic transfer switch has issued the "tie circuit breaker trip" command, and KA3 on the platform has correctly responded and flipped to the trip position, at the critical moment when it is about to issue the next "I-section incoming line circuit breaker close" command (usually with a delay of a few seconds), the tester immediately performs a manual intervention on the platform that conflicts with the logic. The tester quickly presses the "local manual closing" button of circuit breaker simulation unit three (tie) on the platform. This operation, through the manual control circuit, forces the relay KA3, which was just automatically tripped by the logic, back to the "closed" state. The manual forced closing action causes the "closed" status signal of KA3 to be immediately transmitted back to the automatic transfer switch through the feedback interface. At this time, the internal logic of the automatic transfer switch is preparing to issue the "close KA1" command, but it simultaneously receives a signal that contradicts the precondition (the tie switch must be in the trip position) - "KA3 is in the closed position".

[0037] At this moment, the automatic transfer switch reliably blocked the subsequent "I-section incoming circuit breaker closing" command. The indicator light of circuit breaker simulation unit 1 (KA1) on the platform remained green, with no change in status. This test proves that the anti-misoperation interlocking function of the automatic transfer switch is extremely reliable, effectively preventing serious electrical accidents caused by on-site personnel misoperation during dynamic recovery, which could result in parallel connection of two power supplies (asynchronous closing). Its safety has been verified to the highest level.

[0038] In summary, the verification platform and method provided by the embodiments of the present invention, by constructing a safe, controllable, and high-fidelity closed-loop simulation environment, can perform comprehensive, in-depth, and risk-free verification of automatic transfer switches from basic functions to extreme safety logic. The depth and breadth of its testing far exceed those of existing technologies, providing strong technical support for ensuring the safe and stable operation of the power grid.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A verification platform for a standby automatic transfer device based on a self-holding dual-coil relay, characterized in that, include: The circuit breaker simulation unit has a self-holding dual-coil relay as its internal core, which includes a closing coil and a opening coil. The control signal input interface is electrically connected to the closing coil and the opening coil respectively, and is used to receive the closing and opening control pulses output by the standby automatic transfer device to be verified; The status feedback output interface is electrically connected to the first status contact of the self-holding dual coil relay and is used to provide feedback on the real-time open / closed status of the simulated circuit breaker to the standby automatic transfer device to be verified. A manual control circuit, connected in parallel to the circuits of the closing coil and the opening coil, is used to manually set or reset the circuit breaker simulation unit when the automatic transfer switch is disconnected.

2. The verification platform for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 1, characterized in that, The manual control circuit includes a manual closing controller connected in parallel with the closing coil and a manual opening controller connected in parallel with the opening coil.

3. The verification platform for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 1, characterized in that, It also includes an AC voltage simulation circuit, which is equipped with a power control switch to control the supply or disconnection of the simulated working power supply voltage to the standby automatic transfer device to be calibrated, so as to simulate the line power failure or power-on conditions.

4. The verification platform for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 1, characterized in that, It also integrates three independent circuit breaker simulation units, which are used to simulate the first incoming circuit breaker, the second incoming circuit breaker, and the tie circuit breaker, respectively.

5. The verification platform for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 4, characterized in that, The circuit breaker simulation unit also includes a status indicator light driven by the second status contact of the self-holding double coil relay, used to display the open and closed status of the simulated circuit breaker.

6. A method for verifying a standby automatic transfer switch based on a self-holding dual-coil relay, applied to the standby automatic transfer switch verification platform based on a self-holding dual-coil relay as described in any one of claims 1-5, characterized in that, The steps of this method include: Connect the trip and close command output terminals of the standby automatic transfer device to be tested to the control signal input interface of the corresponding circuit breaker simulation unit on the test platform, respectively. At the same time, connect the status feedback output interface of the corresponding circuit breaker simulation unit on the test platform to the circuit breaker position signal input terminal of the standby automatic transfer device to be tested. Verify whether the standby automatic transfer device to be verified can issue the first control pulse in its preset logic according to the set initial verification conditions and drive the circuit breaker simulation unit to operate. After the circuit breaker simulation unit operates, its status is fed back to the automatic transfer switch in real time through the status feedback output interface. Based on this, it is further verified whether the automatic transfer switch can execute the next action in its logic chain according to the new status received.

7. The verification method for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 6, characterized in that, The initial verification condition is as follows: By controlling the switch of the AC voltage simulation circuit, the supply of one simulated AC voltage is cut off to simulate the scenario of power loss in this incoming line.

8. The verification method for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 7, characterized in that, The verification specifically involves verifying whether the automatic transfer switch can send control pulses to the verification platform in sequence according to a preset safety sequence after detecting a power outage. The preset safety sequence is set as follows: the incoming line circuit breaker opens first, and the connecting circuit breaker closes second.

9. The verification method for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 8, characterized in that, It also includes self-recovery logic: after the backup automatic transfer device completes the power failure switching, the power supply of this circuit is restored by operating the control switch of the AC voltage simulation circuit, and the control logic of whether the backup automatic transfer device automatically executes the priority contact circuit breaker opening and the secondary incoming line circuit breaker closing is verified.

10. The verification method for the standby automatic transfer device based on a self-holding dual-coil relay according to claim 9, characterized in that, When the automatic transfer switch has issued a tripping command for the tie circuit breaker, and the verification platform has simulated this action, at the instant it is about to issue a closing command for the incoming line circuit breaker: By using the manual control loop on the operating platform, the circuit breaker simulation unit that was opened is forced to be put back into the closed state to simulate a single manual misoperation that conflicts with the self-recovery logic. Based on this, it is verified whether the automatic transfer switch can detect this conflict state and block its subsequent incoming circuit breaker closing commands.

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