A delay compensation-based all-condition uninterrupted power transfer control method and device

Abstract

The application discloses a kind of full-condition uninterrupted power supply control method and device based on delay compensation, and it relates to power distribution network automation field.The method comprises: when meeting the safe ring access condition, issue instruction to start contactor of tie-in switch;After starting, according to the time sequence of the action of tie-in switch contactor and sectionalizing switch disconnector, the physical ring coexistence time is controlled in target overlap time;The delay compensation parameter is calculated based on the action time delay of tie-in switch, the arc extinguishing time delay of sectionalizing switch disconnector and the one-way real-time communication delay determined according to the time slot phase of wireless channel time division duplex (TDD), and the time slot phase is obtained by sending non-equidistant probe sequence and phase locking to round-trip delay envelope.The application is used to solve the problem of impact current caused by lack of check in power supply, and the problem of difficult control of ring overlap time and easy protection misoperation caused by the asymmetry of wireless channel TDD uplink and downlink time slot queuing.

Description

Technical Field

[0001] This invention relates to the field of power grid automation technology, and more specifically, to a method and apparatus for uninterrupted power supply control under all operating conditions based on delay compensation. Background Technology

[0002] Loop-connected power transfer in distribution networks is a key technology for improving power supply continuity and ensuring uninterrupted power supply to users during load switching. In power transfer control, to guarantee uninterrupted power supply to the load during switching, the timing of the tie switches and sectionalizing switches must be coordinated to allow the power supplies at both ends to operate in parallel for a short period before quickly disconnecting the original circuit. This control process places stringent safety boundary requirements on the prediction of the loop-connected transient inrush current and the millisecond-level coordination of the switch timing.

[0003] Regarding the safety of closed-loop circuits, existing technologies, such as the one disclosed in CN112350303B, provide a fast power transfer method. This method obtains parameters such as impedance, voltage, and current of the fitted loop line, establishes an electromagnetic transient model to calculate the closed-loop current obtained by adding the circulating power current and the supply current, and subtracts it from the set current to obtain the inrush current. It then determines whether the inrush current exceeds a threshold for safety verification. If it does not exceed the threshold, it directly controls the tie switch to close for power transfer. If it exceeds the threshold, it controls multiple pole-mounted switches to perform sequential opening and closing operations and controls the tie switch to close through the distribution automation terminal.

[0004] However, the aforementioned existing technologies have the following limitations in full-condition applications: First, their control strategies focus on the sequential control of switches, neglecting time delays such as relay action, inherent mechanical action of switches, and arc extinguishing time, making it difficult to accurately adjust the physical loop overlap time. Second, the scheme lacks horizontal collaborative control and fault recovery logic between terminals; once a switch fails to operate, it can easily lead to long-term parallel operation of dual power supplies or power outages for users. Furthermore, its inrush current calculation model does not take into account the equivalent impedance of the circuit and the load current, making it impossible to accurately avoid the instantaneous overcurrent setting value of the microprocessor-based protection. Finally, in wireless communication environments, existing solutions fail to effectively address the asymmetrical uplink and downlink queuing delays of time-division duplex (TDD) channels. Simply using a method of halving the round-trip delay makes it difficult to obtain accurate one-way transmission delays, affecting the control accuracy of the action timing and posing a risk of protection maloperation due to large circulating currents caused by excessively long physical loop coexistence times. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a full-condition uninterrupted power transfer control method based on delay compensation. This method uses loop-closed safety verification and adjusts the opening and closing sequence based on the one-way communication delay determined by the TDD time slot phase locked using a detection sequence and a phase-locked loop algorithm. This solves the problems of large inrush current during power transfer and protection maloperation caused by excessively long loop-closed time due to wireless TDD time slot waiting.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for uninterrupted power transfer control under all operating conditions based on delay compensation includes the following steps: acquiring the operating parameters of the tie switch and the sectionalizing switch and performing a loop-closing safety verification; when the safe loop-closing access conditions are met, issuing a power transfer command to the distribution terminal corresponding to the tie switch and the sectionalizing switch, and initiating the closing of the tie switch; after initiating the closing of the tie switch, controlling the sectionalizing switch to delay its opening according to the delay compensation parameters, so as to control the physical loop coexistence time within the target overlap time; wherein, the delay compensation parameters are calculated based on the action delay of the tie switch, the opening and arc-extinguishing delay of the sectionalizing switch, and the real-time communication delay; the real-time communication delay is a unidirectional delay determined according to the time-division duplex (TDD) time slot phase of the wireless channel, and the time slot phase is obtained by sending a non-equal interval detection sequence to the distribution terminal at the other end and performing phase locking on the round-trip delay envelope.

[0007] In a preferred embodiment, the delay compensation parameter is calculated using the following formula:

[0008] In a preferred embodiment, when the time slot phase cannot be locked, causing the real-time communication delay to be unavailable, the real-time communication delay is obtained in the following manner: the power distribution terminals exchange heartbeat detection packets at fixed intervals and record the round-trip time, and half of the average value of the round-trip time is taken as the real-time communication delay.

[0009] In a preferred embodiment, obtaining the real-time communication delay includes: during the power transfer preset stage, the power distribution terminal at the tie switch continuously sends non-equal interval detection sequences to the power distribution terminal at the sectionalizing switch and records the corresponding round-trip delay sequences; using a phase-locked loop algorithm to perform phase locking on the periodic fluctuation envelope generated by time slot waiting in the round-trip delay sequences to identify the relative projection phase of the uplink / downlink time slot switching point of the underlying wireless channel on the local clock axis, which is used as the time slot phase; and calculating the one-way time slot alignment delay of the power transfer command based on the local timestamp when the power transfer command is issued and the relative projection phase to obtain the corresponding real-time communication delay.

[0010] In a preferred embodiment, the loop closure safety verification based on the operating parameters includes: real-time acquisition of voltage amplitude, phase angle, and current line current on both sides of the tie switch; determining the voltage vector difference on both sides based on the voltage amplitude difference and voltage phase angle difference, and calculating the expected maximum loop closure inrush current and the loop closure steady-state current by combining the equivalent impedance of the loop closure circuit and the load current on the feeder side before loop closure; determining whether the expected maximum loop closure inrush current is less than the maximum allowable inrush current limit of the line, and whether the loop closure steady-state current is less than the maximum allowable current carrying capacity of the feeder; if both are satisfied, the safe loop closure access conditions are met; otherwise, the power supply transfer function is blocked.

[0011] In a preferred embodiment, the formula for calculating the maximum expected closing-loop impact current is as follows:

[0012] In a preferred embodiment, the method further includes a remedial step for the failure to close the tie switch: after issuing the power transfer command, if the tie switch is not successfully closed within a preset time limit, it is determined that the tie switch has failed to close; the power distribution terminal at the tie switch sends a closing failure signal to the power distribution terminal at the sectionalizing switch to block the local unblocking and tripping operation of the sectionalizing switch.

[0013] In a preferred embodiment, the method further includes a remedial step for the sectionalizing switch to resolve loop failure: after the sectionalizing switch is driven to open, if it is determined that the sectionalizing switch has failed to open successfully, the loop failure is determined; the distribution terminal at the sectionalizing switch sends a loop failure signal to the distribution terminal at the tie switch, triggering the tie switch to perform the opening action and lock the closing, so as to disconnect the dual-source parallel loop.

[0014] In a preferred embodiment, the method further includes a backup protection step under communication anomaly: when communication between the two distribution terminals is abnormal and the system is in a dual-source closed loop state, if the duration of the circulating current generated by the closed loop reaches the set closed loop high current action time limit, the backup current protection set at the tie switch and / or the sectionalizing switch trips and blocks the closed loop to cut off the closed loop; wherein, the closed loop high current action time limit of the backup current protection precedes the protection action time limit of the outgoing circuit breaker in the substation.

[0015] In addition, the present invention provides a full-condition uninterrupted power transfer control device based on delay compensation, comprising: a verification module, used to acquire the operating parameters of the tie switch and the sectionalizing switch and perform a loop-closing safety verification to determine whether the safe loop-closing access conditions are met; an execution module, used to issue a power transfer command and start the closing of the tie switch when the safe loop-closing access conditions are met; and a timing control module, used to control the opening action sequence of the sectionalizing switch according to the delay compensation parameters after the tie switch is started, so as to control the physical loop coexistence time within the target overlap time; wherein, the delay compensation parameters are calculated based on the action delay of the tie switch, the opening and arc extinguishing delay of the sectionalizing switch, and the real-time communication delay; the real-time communication delay is a unidirectional delay determined according to the time-division duplex (TDD) time slot phase of the wireless channel, and the time slot phase is obtained by sending a non-equal interval detection sequence to the peer power distribution terminal and performing phase locking on the round-trip delay envelope.

[0016] The present invention also provides an electronic device, the device including a processor and a memory: the memory is used to store a computer program and send the instructions of the computer program to the processor; the processor executes the method for uninterrupted power supply control under all operating conditions based on delay compensation according to the instructions of the computer program.

[0017] In summary, the present invention provides a full-condition uninterrupted power supply control method based on delay compensation, which has the following technical effects and advantages: This invention performs loop-closed safety verification by acquiring the operating parameters of tie switches and sectional switches, and initiates the closing of tie switches when the access conditions are met. Simultaneously, it calculates delay compensation parameters based on the action delay of the corresponding tie switch, the opening and arc-extinguishing delay of the corresponding sectional switch, and the one-way real-time communication delay determined by the time-division duplex (TDD) time slot phase of the wireless channel. The sectional switch is then controlled to delay the opening of the switch after receiving the power transfer command triggered by the tie switch closing, based on the delay compensation parameters. This solves the technical problems of large current surges caused by lack of verification during power transfer in distribution networks, and excessively long physical loop-closed coexistence times due to the asymmetry of TDD time slot queuing and the superposition of switching equipment delays. It achieves control of the physical loop-closed coexistence time of tie switches and sectional switches within the target overlap time. By sending non-equal interval detection sequences and performing phase locking on the round-trip delay envelope to obtain accurate one-way delays, it eliminates timing alignment deviations caused by communication asymmetry, ensuring continuous power supply during power transfer while avoiding protection maloperation due to large currents. Attached Figure Description

[0018] Figure 1 A schematic diagram of the uninterrupted power supply control method based on delay compensation for all operating conditions provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the telemetry function of the storage device provided in an embodiment of the present invention; Figure 3 This is a diagram of the "hand-in-hand" circuit topology provided in an embodiment of the present invention; Figure 4 A schematic diagram of a full-condition uninterrupted power supply control device based on delay compensation provided in an embodiment of the present invention; Figure 5 A schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1, Figure 1 This invention presents a full-condition uninterrupted power supply control method based on delay compensation, comprising the following steps: Step 1: Obtain the operating parameters of the tie switch and the sectionalizing switch, and perform a closed-loop safety verification based on the operating parameters.

[0021] In this embodiment, the loop-closing safety verification is performed in the preset stage before the power transfer operation. In step 1, the voltage amplitude, phase angle, and current line current on both sides of the tie switch are first collected in real time. Figure 2 In the schematic diagram of the telemetry function of the device shown, automatic data acquisition is achieved by means of dual-sided voltage sampling function; specifically, through bidirectional synchronous measurement, the load current, loop current, line voltage, voltage angle difference and voltage difference of the local installation point and the tie switch installation point are monitored in real time, and the switch action characteristics are statistically analyzed. The above telemetry parameters are transmitted to the background for real-time monitoring, thereby obtaining the operating parameters.

[0022] Furthermore, after obtaining the operating parameters, the voltage vector difference between the two sides is determined based on the voltage amplitude difference and voltage phase angle difference. Combined with the equivalent impedance of the closed-loop circuit and the load current on the feeder side before the closed loop, the expected maximum closed-loop inrush current and the closed-loop steady-state current are calculated. The expected maximum closed-loop inrush current... The calculation model is shown in formula (1): (1) In the formula: This is the maximum value of the expected closed-loop impact current; The voltage vector difference across the two sides of the interconnecting switch; The equivalent impedance of the closed loop includes the sum of the equivalent internal impedance of the upstream substation, the feeder impedance, and the transformer impedance. This is the load current on this side of the feeder before the loop is closed.

[0023] Wherein, the voltage vector difference Determined by the voltage amplitude difference and voltage phase angle difference on both sides, its mathematical complex vector expansion is shown in formula (2): (2) In the formula: This refers to the voltage amplitude on the first side of the interconnecting switch; The voltage phase angle on the first side of the interconnecting switch; This refers to the voltage amplitude on the second side of the interconnecting switch; This refers to the voltage phase angle on the second side of the interconnecting switch.

[0024] Furthermore, after completing the calculation of the current trend, an admission logic judgment is performed, that is, to determine whether the maximum value of the expected closed-loop impact current is less than the upper limit of the maximum allowable impact current of the line, and whether the closed-loop steady-state current is less than the maximum allowable current carrying capacity of the feeder; if both are satisfied, it is determined that the safe closed-loop admission condition is met, otherwise the power supply transfer function is blocked. The mathematical constraint boundary of the logic judgment is shown in formula (3): (3) In the formula: The maximum allowable inrush current limit for the line is set to avoid the instantaneous overcurrent setting value of the microprocessor protection of the distribution network. This refers to the closed-loop steady-state current; This is the maximum allowable current carrying capacity of a 10kV feeder.

[0025] If both inequality constraints in formula (3) are met simultaneously, the system is confirmed to have the conditions for safe loop closure and the power transfer process is activated; if either inequality constraint is not met, the system locks out the power transfer function.

[0026] Step 1 of this paper solves the technical problem of inrush current generated during the loop closing operation of the distribution network due to unknown topological impedance and excessive voltage and angle differences. The technical effect is to predict the inrush current by simultaneously measuring the multi-dimensional telemetry parameters of the installation point on this side and the installation point of the tie switch, and incorporating the mathematical model of the equivalent impedance of the loop and the load current. Based on the logical judgment result, the power transfer function is conditionally blocked, thus avoiding the microprocessor protection from tripping due to inrush current.

[0027] Step 2: When the safety loop access conditions are met, issue a power supply transfer command and start the closing of the interconnection switch.

[0028] In this embodiment, as Figure 1 The flowchart shown and as Figure 3 As shown in the "hand-in-hand" line topology diagram, D is the tie switch, A, B, C, E, and F are sectionalizing switches, S1 is the outgoing circuit breaker of the first substation, and S2 is the outgoing circuit breaker of the second substation. The outgoing circuit breakers S1 and S2 are located on the power supply side of the substations at both ends of the "hand-in-hand" line. The distribution terminals corresponding to sectionalizing switch A and tie switch D have distributed peer-to-peer direct communication functionality. After determining that the safety loop-closing access conditions are met in step S1, the power transfer execution phase begins. First, a power transfer preset operation is performed, sending a power transfer preset command to tie switch D and sectionalizing switch A, which is the target for loop unclosing. After both sides complete the local protection logic and telemetry parameter verification without error and return a preset success signal, the power transfer execution function is activated, and a power transfer execution command is sent to start the closing of tie switch D.

[0029] Furthermore, during the process of initiating the closing of the tie switch D, the tie switch D side calculates the delay compensation parameter for adjusting the timing of the tripping action based on the acquired operating parameters, and simultaneously sends a power transfer command with a timestamp and delay compensation factor to the sectionalizing switch A side. The tie switch D responds to the power transfer command by performing a physical closing action, connecting the power supply circuits on both sides and entering a dual-source parallel closed-loop state. This provides a triggering basis for the subsequent tripping action of the sectionalizing switch A after responding to the power transfer command and delaying the delay compensation parameter.

[0030] Step 2 of this paper solves the technical problems of issuing closing commands and synchronously transmitting timing control parameters in the power supply control process. The technical effect is to control the access of the operation through preset and executed progressive logic, and simultaneously send the notification carrying the delay compensation parameters to the sectionalizing switch side when the tie switch is started to close, thereby realizing the timing binding of closing action triggering and delay compensation parameters.

[0031] Step 3: Use delay compensation to control the timing of closing the tie switch and opening the sectionalizing switch to complete the uninterrupted power supply transfer.

[0032] In this embodiment, to ensure that the load does not experience instantaneous power outages during power supply circuit switching, it is essential to maintain a physical overlap time between the closing of the tie switch and the opening of the sectionalizing switch, allowing the system to briefly operate in a closed-loop state. In step 3, based on the acquired action delay of the corresponding tie switch, the opening and arc-extinguishing delay of the corresponding sectionalizing switch, and the real-time communication delay between the two distribution terminals, a delay compensation parameter for adjusting the opening action sequence is calculated. The sectionalizing switch is then controlled to delay the opening operation by the delay compensation parameter after receiving the power transfer command triggered by the closing of the tie switch, thereby controlling the physical closed-loop coexistence time of the tie switch and the sectionalizing switch within the target overlap time.

[0033] Furthermore, in wireless communication environments, because the uplink and downlink channels of time-division duplex (TDD) systems alternate on the time axis, the round-trip delay halving method cannot eliminate the asymmetric queuing delay caused by waiting for time slot alignment. Therefore, in this embodiment, the real-time communication delay is a unidirectional delay determined based on the TDD time slot phase of the wireless channel. The time slot phase is obtained by sending unequal-interval probe sequences to the peer and performing phase locking on the round-trip delay envelope. By incorporating the time slot alternation pattern of the wireless channel into the delay calculation, the unidirectional transmission delay can be obtained, avoiding the timing alignment deviation caused by fixed halving.

[0034] Furthermore, the delay compensation parameter is calculated using the following formula, as shown in formula (4): (4) In the formula: The delay compensation parameter is... Corresponding to the operation delay of the aforementioned contact switch, wherein The relay output operating time of the interconnecting switch. The inherent mechanical closing time of the interconnecting switch; The target overlap time is set; This refers to the real-time communication delay between the two power distribution terminals. Corresponding to the opening and arc extinguishing delays of the sectionalizing switch, wherein This refers to the relay output operating time of the sectionalizing switch. The inherent mechanical opening time of the sectionalizing switch. This refers to the arc extinguishing time of the sectionalizing switch.

[0035] Further, obtaining the real-time communication delay includes: during the power transfer preset stage, the power distribution terminal at the contact switch continuously sends a non-uniformly spaced detection sequence with gradually changing time intervals to the power distribution terminal at the sectionalizing switch, and records the corresponding round-trip delay sequence; using a phase-locked loop algorithm to perform phase locking on the periodic fluctuation envelope generated by time slot waiting in the round-trip delay sequence, so as to identify the relative projection phase of the uplink and downlink time slot switching point of the underlying wireless channel on the local clock axis, which is used as the time slot phase; and calculating the one-way time slot alignment delay of the power transfer command based on the local timestamp when the power transfer command is issued and the relative projection phase, to obtain the corresponding real-time communication delay.

[0036] Specifically, due to the time-division multiplexing (TDD) transmission characteristics, when the probe packet arrives at the network card queue at different times, its waiting time for transmission slots exhibits a fluctuating envelope with the same frequency as the TDD frame structure period. By actively sending non-equal interval probe packets with gradually changing time intervals during the preset phase, frequency sweep sampling of the TDD subframe boundary phase can be achieved in the time domain, thereby recording the round-trip delay sequence containing the slot waiting characteristics. Subsequently, the fluctuating envelope of the sequence is phase-locked using a digital phase-locked loop (PLL) algorithm to identify the relative projection phase of the time-division multiplexing (TDD) uplink / downlink slot switching point of the underlying wireless channel mapped onto the local clock axis. When a power transfer command needs to be issued during the power transfer execution phase, the difference between the local timestamp of the current transmission time and the locked relative projection phase can be compared to calculate the one-way slot alignment delay experienced by the frame notification in the network card queue before the next uplink slot opens. This one-way slot alignment delay is added to the inherent physical transmission delay of the wireless channel to obtain the corresponding real-time communication delay, which is then used as the input parameter in formula (4). .

[0037] The phase-locked loop algorithm is used to phase-lock the fluctuation envelope of the sequence, as follows: The input data of the digital phase-locked loop algorithm is a discrete sequence of sampling points containing the local timestamp of transmission and the corresponding round-trip delay value. Since the frame structure of the underlying time-division duplex (TDD) has a preset fixed physical period, the algorithm performs a modulo operation on the local timestamp of each sampling point with the physical period to extract the relative time domain position of each sampling point within a single frame period, thereby constructing a transient delay envelope feature for loop identification; The digital phase-locked loop (PLL) algorithm internally employs a phase detector, a digital loop filter, and a digitally controlled oscillator for closed-loop iteration. Specifically, the phase detector compares the peak phase of the transient delay envelope feature with the locally estimated time slot phase currently output by the digitally controlled oscillator, outputting a phase error. The digital loop filter performs low-pass smoothing filtering on the phase error to remove random non-periodic jitter noise from the network and generates a frequency control word. The digitally controlled oscillator dynamically adjusts its oscillation frequency and phase according to the frequency control word until the phase error converges to a set small threshold range. At this point, the PLL enters a locked state, enabling the tracking of the periodic fluctuation envelope in the round-trip delay sequence. The output data of the digital phase-locked loop algorithm is the relative projected phase output by the digitally controlled oscillator in the locked state, mapped onto the local clock axis. This relative projected phase, in the form of a timestamp or phase angle, quantifies the recurrence position on the local time axis of each uplink / downlink time slot switching point of the underlying wireless channel.

[0038] This step solves the technical problem that the one-way communication delay cannot be accurately measured due to the asymmetric queuing of uplink and downlink when using the TDD standard in wireless communication. The technical effect is that by using non-equal interval frequency sweep detection and phase-locked loop regression, a dynamic phase mapping of the TDD time slot switching point is established and locked on the local clock axis, eliminating the delay calculation error caused by queuing time slot alignment.

[0039] Furthermore, in order to ensure system availability when the wireless channel is subject to sudden interference, obstruction, or multipath fading that causes phase-locked loop failure, the control method also includes a communication degradation processing step: when the time slot phase cannot be locked, causing the real-time communication delay to be unavailable, the real-time communication delay is switched to be obtained in the following way: the two power distribution terminals at both ends exchange heartbeat detection packets at a fixed period, record the round-trip time, and take half of the average round-trip time as the communication delay.

[0040] Specifically, if the wireless network channel quality deteriorates or the delay jitter causes the phase-locked loop algorithm to fail to converge and regress the envelope of the round-trip delay sequence, i.e., it fails to identify the stable relative projection phase, the system determines that the one-way real-time communication delay is currently unavailable. At this time, the control flow initiates self-healing complementary logic and automatically degrades to backup statistical mode: the control switches the two-end power distribution terminals to exchanging heartbeat probe packets at a fixed period of 500ms, continuously recording multiple round-trip times on-site, calculating the average round-trip time using a smoothing filter, and using half of this average value as the converted communication delay input into formula (4) to maintain the delay compensation parameter. Backup calculations ensure that the power supply control process is not interrupted or blocked.

[0041] This step solves the technical problem of the control system falling into blind control or direct blocking when one-way delay phase-locking fails due to the deterioration of the wireless channel. The technical effect is that by introducing a backup degradation processing mechanism based on heartbeat detection, the system still has basic delay compensation calculation and transfer capabilities under harsh communication conditions, thereby improving the fault tolerance and availability of the control method under all operating conditions.

[0042] Furthermore, when executing the control logic, if the delay compensation parameter calculated by formula (4) is... Then, after receiving the power transfer command, the sectionalizing switch will delay the delay compensation parameter. The trip relay is then activated; if the calculated delay compensation parameters are... This indicates that the current real-time communication latency has exceeded the allowable timing alignment boundary. In this case, the latency compensation parameter should be adjusted. Set it to 0, and adjust the closing trigger sequence of the interconnection switch accordingly, or directly block the current power transfer operation when the communication delay jitter exceeds the set envelope. For example... Figure 3 In the topology shown, under successful power transfer conditions, after the sectionalizing switch A successfully performs the loop-breaking and tripping action, it sends a successful loop-breaking action signal back to the tie switch D, and the power transfer is successfully completed.

[0043] Step 3 addresses the technical problem of uncontrollable physical loop coexistence time caused by wireless communication delay jitter and inherent physical action delay of switching equipment during power transfer control. The technical effect is to dynamically compensate for delays by comprehensively balancing network communication delay, relay output action delay, switch mechanical action delay, and arc extinguishing time, thereby limiting the physical loop coexistence time to the target overlap time, controlling the circulating current level in the loop operation state, and avoiding protection actions.

[0044] To address abnormal operating conditions that may arise during power transfer due to equipment mechanical failures, electrical faults, or sudden interference in the power supply channel, this embodiment provides multi-level distributed self-healing and local backup protection logic in addition to the control process described above.

[0045] Furthermore, the control method also includes a remedial step for the failure to close the tie switch: after issuing the power transfer command, if the tie switch is not successfully closed within a preset time limit, it is determined that the tie switch has failed to close; the power distribution terminal at the tie switch sends a closing failure signal to the power distribution terminal at the sectionalizing switch to block the local unblocking and tripping operation of the sectionalizing switch.

[0046] In this embodiment, combined with, as Figure 1 The flowchart shown illustrates the branching process where the loop closure operation failed to complete, and as... Figure 3The evolution of the "hand-in-hand" circuit topology shown is illustrated in the scenario of the tie switch failing to close: After issuing a power transfer command, if the tie switch D fails to physically close due to mechanical or electrical abnormalities, the following cannot be achieved: Figure 1 The judgment condition for successful completion of the loop closing operation leads the control flow to the branch indicating loop closing failure. Specifically, if the closing of the tie switch D is not detected within a preset time limit, it is determined that the tie switch loop closing operation has failed. At this time, the distribution terminal at tie switch D sends a "ticket closing operation failed" signal to the distribution terminal at sectionalizing switch A. After receiving this signal, sectionalizing switch A blocks the local loop opening and tripping operation, keeping sectionalizing switch A in the closed state. This operating condition corresponds to... Figure 1 The logic flow shown is as follows: the power grid operation mode remains unchanged, the intelligent unlinking operation device returns, the system safely exits the power transfer operation and restores to the initial operating topology.

[0047] This step solves the technical problem that the sectionalizing switch may be erroneously tripped due to the failure of the tie switch to operate. The technical effect is that by distributing the locally detected loop failure state, reverse blocking of the loop opening action is achieved, avoiding power outages caused by tripping when the tie fails.

[0048] Furthermore, the control method also includes a remedial step for the sectionalizing switch to disengage and fail to operate: after the sectionalizing switch is driven to open, if it is determined that the sectionalizing switch has failed to open successfully, then the disengagement is determined to have failed; the distribution terminal at the sectionalizing switch sends a disengagement and failure signal to the distribution terminal at the tie switch, triggering the tie switch to perform the opening action and lock the closing, so as to disconnect the dual-source closed-loop parallel circuit.

[0049] In this embodiment, combined with, as Figure 3 The evolution of the "hand-in-hand" line topology shown is illustrated in the scenario of sectionalizing switch loop-breaking failure: After the master station issues the power transfer execution command, the tie switch D closes normally and sends a "tied switch loop-breaking action" notification to the sectionalizing switch A. Upon receiving the notification and after a delay compensation, the distribution terminal at sectionalizing switch A drives the local tripping relay. If sectionalizing switch A fails to operate due to its own fault and cannot successfully disconnect the circuit, its auxiliary contact remains unchanged and the line current still exists, the system determines that the loop-breaking has failed. The distribution terminal at sectionalizing switch A immediately sends a "distribution switch loop-breaking failure" signal back to the distribution terminal at tie switch D; upon receiving this failure signal, tie switch D triggers the tripping action and locks the closing, disconnecting the established dual-source parallel circuit and reverting the network security to the initial operating topology.

[0050] This step solves the technical problem of the distribution network being in a dual-source closed-loop parallel operation state for a long time due to the failure of the sectionalizing switch to operate; the technical effect is to quickly disconnect the closed-loop circuit when the loop fails to be de-looped through distributed reverse tripping closed-loop control, thereby eliminating the equipment overload risk caused by the long-term parallel operation of the two power sources.

[0051] Furthermore, the control method also includes a backup protection step under communication anomaly: when the communication between the two distribution terminals is abnormal and the system is in a dual-source closed loop state, if the duration of the circulating current generated by the closed loop reaches the set closed loop high current action time limit, the backup current protection set at the tie switch and / or the sectionalizing switch will trip and block the closed loop to cut off the closed loop; wherein, the closed loop high current action time limit of the backup current protection precedes the protection action time limit of the outgoing circuit breaker in the substation.

[0052] In this embodiment, combined with, as Figure 3 The illustrated "hand-in-hand" line topology is used to explain the application scenario where the distribution terminal does not receive a power transfer instruction: After the main station issues a power transfer execution instruction, the tie switch D successfully closes and sends a "tied switch loop closing action" notification to the sectionalizing switch A. If the wireless communication link between the two distribution terminals suddenly malfunctions at this time, and the sectionalizing switch A fails to receive the notification, then the sectionalizing switch A will not perform a loop opening action, and the power grid is forced into a dual-source loop closing operation state. Due to the potential difference between the two power grids, a transient large current is generated in the loop closing circuit. When the duration of this current reaches the set loop closing large current action time limit, the local backup current protection set at the tie switch D and / or sectionalizing switch A trips and blocks the closing, disconnecting the loop closing circuit. The loop closing large current action time limit strictly precedes the protection action time limit of the outgoing circuit breaker within the substation, thereby preventing cascading tripping.

[0053] Furthermore, also based on such Figure 3 The "hand-in-hand" line topology diagram shown illustrates an application scenario where the tie switch does not receive a notification of the loop-breaking action: If the tie switch D closes and sends a notification to the section switch A, and section switch A successfully executes the loop-breaking action, but due to communication abnormalities, the tie switch D does not receive the "distribution switch loop-breaking action" signal returned by section switch A, then if telemetry detection reveals that no large current is generated on the line or the current has not reached the set protection time limit, the tie switch D remains closed to maintain power supply to the load on the opposite side and avoid expanding the power outage area.

[0054] This step solves the technical problem that the closed loop cannot be cut off by normal control logic under extreme conditions of abnormal failure of distributed communication links; the technical effect is that by using the differential coordination of local protection, an electrical safety defense line is built when the control layer fails, realizing the rapid local cut-off of large current in the closed loop and preventing the over-tripping of switches in the substation.

[0055] In this embodiment, based on the above-described control method, the present invention also provides an apparatus and device entity for executing the control method. Specifically, as shown... Figure 4 As shown, this embodiment provides a full-condition uninterrupted power supply control device based on delay compensation, which includes: The verification module is used to obtain the operating parameters of the tie switch and the sectionalizing switch and perform a closed-loop safety verification to determine whether the safe closed-loop access conditions are met. The execution module is used to issue a power transfer command and start the closing of the interconnection switch when the safety loop access conditions are met; The timing control module is used to control the opening action timing of the sectionalizing switch according to the delay compensation parameter after the closing of the tie switch is started, so as to control the physical loop coexistence time within the target overlap time. The delay compensation parameter is calculated based on the action delay of the tie switch, the opening and arc extinguishing delay of the sectionalizing switch, and the real-time communication delay. The real-time communication delay is a one-way delay determined according to the time-division duplex (TDD) time slot phase of the wireless channel. The time slot phase is obtained by sending a non-equal interval detection sequence to the distribution terminal at the other end and performing phase locking on the round-trip delay envelope.

[0056] In addition, this embodiment also provides an electronic device, such as... Figure 5 As shown, the device includes a processor and a memory: the memory is used to store computer programs and send the instructions of the computer programs to the processor; the processor executes a power supply control method based on delay compensation for all operating conditions without power interruption according to the instructions of the computer programs.

[0057] The logical interactions, mathematical formula evolution, and signal transmission processes between the modules or hardware units in the device and equipment completely correspond to the aforementioned method steps and the scenarios in the circuit topology diagram, and will not be repeated here.

[0058] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0059] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0060] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0061] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0062] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0063] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for uninterrupted power supply control under all operating conditions based on delay compensation, characterized in that, The method includes: The system acquires the operating parameters of the tie switch and the sectionalizing switch and performs a loop closure safety verification. When the safety loop closure access conditions are met, it issues a power transfer command to the power distribution terminal corresponding to the tie switch and the sectionalizing switch and starts the tie switch to close. After the tie switch is closed, the sectionalizing switch is delayed in opening according to the delay compensation parameter, so as to control the physical loop coexistence time within the target overlap time. The delay compensation parameter is calculated based on the action delay of the tie switch, the opening and arc extinguishing delay of the sectionalizing switch, and the real-time communication delay. The real-time communication delay is a one-way delay determined according to the time-division duplex (TDD) time slot phase of the wireless channel. The time slot phase is obtained by sending a non-equal interval detection sequence to the distribution terminal at the other end and performing phase locking on the round-trip delay envelope.

2. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, The delay compensation parameter is calculated using the following formula: In the formula: These are delay compensation parameters; The corresponding operating delay of the contact switch, where The relay output operating time of the interconnecting switch. The inherent mechanical closing time of the interconnecting switch; The target overlap time is set; For real-time communication latency; The corresponding opening and arc extinguishing delays of the sectionalizing switch, among which This refers to the relay output operating time of the sectionalizing switch. The inherent mechanical opening time of the sectionalizing switch. This refers to the arc extinguishing time of the sectionalizing switch.

3. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, When the time slot phase cannot be locked, causing the real-time communication delay to be unavailable, the real-time communication delay is obtained in the following way: The power distribution terminals exchange heartbeat detection packets at fixed intervals and record the round-trip time, and use half of the average round-trip time as the real-time communication delay.

4. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, Obtaining the real-time communication latency includes: During the power transfer pre-setting stage, the power distribution terminal at the tie switch continuously sends non-equal interval detection sequences to the power distribution terminal at the sectional switch and records the corresponding round-trip delay sequence. A phase-locked loop algorithm is used to phase-lock the periodic fluctuation envelope generated by time slot waiting in the round-trip delay sequence, so as to identify the relative projection phase of the uplink and downlink time slot switching point of the underlying wireless channel on the local clock axis, which is used as the time slot phase; Based on the local timestamp when the power transfer command is issued and the relative projection phase, the one-way timeslot alignment delay of the power transfer command is calculated to obtain the corresponding real-time communication delay.

5. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, The loop closure security verification includes: Collect the voltage amplitude, phase angle, and current line current on both sides of the interconnection switch; The voltage vector difference between the two sides is determined based on the voltage amplitude difference and voltage phase angle difference. Combined with the equivalent impedance of the closed loop and the load current on the feeder side before the closed loop, the maximum expected closed loop impact current and the closed loop steady-state current are calculated. Determine whether the maximum expected closing-loop impact current is less than the maximum allowable impact current limit of the line, and whether the closing-loop steady-state current is less than the maximum allowable current carrying capacity of the feeder. If all conditions are met, the safety loop access conditions are deemed met; otherwise, the power supply transfer function is blocked.

6. The all-condition uninterrupted power supply control method based on delay compensation according to claim 5, characterized in that, The formula for calculating the maximum expected closing-loop impact current is as follows: In the formula, This represents the expected maximum closing-loop impact current. The voltage vector difference across the two sides of the interconnecting switch; This is the equivalent impedance of the closed loop; This is the load current on this side of the feeder before the loop is closed.

7. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, Also includes: If the closing of the interconnecting switch is not detected within a preset time limit after the power supply transfer command is issued, the interconnecting switch is determined to be closed and the operation is deemed to be unsuccessful. The power distribution terminal at the interconnecting switch sends a loop-closing failure signal to the power distribution terminal at the sectionalizing switch to block the loop-opening and tripping operation of the sectionalizing switch.

8. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, Also includes: If, after controlling the sectionalizing switch to open, it is determined that the sectionalizing switch has failed to open successfully, then the loop breaking has failed. The distribution terminal at the sectionalizing switch sends a loop-breaking and refusal-to-operate signal to the distribution terminal at the tie switch, triggering the tie switch to perform a tripping action and lock the closing action, thereby disconnecting the dual-source parallel loop.

9. The all-condition uninterrupted power supply control method based on delay compensation according to claim 1, characterized in that, Also includes: When the communication between the two power distribution terminals is abnormal and the system is in a dual-source closed loop state, if the duration of the circulating current generated by the closed loop reaches the set closed loop large current action time limit, the backup current protection set at the tie switch and / or the sectionalizing switch will trip and block the closed loop to cut off the closed loop. The closing-loop high-current operation time limit of the backup current protection is earlier than the protection operation time limit of the outgoing circuit breaker in the substation.

10. A full-condition uninterrupted power supply control device based on delay compensation, characterized in that, include: The verification module is used to obtain the operating parameters of the tie switch and the sectionalizing switch and perform a closed-loop safety verification to determine whether the safe closed-loop access conditions are met. The execution module is used to issue a power transfer command and start the closing of the interconnection switch when the safety loop access conditions are met; The timing control module is used to control the opening action timing of the sectionalizing switch according to the delay compensation parameter after the closing of the tie switch is started, so as to control the physical loop coexistence time within the target overlap time. The delay compensation parameter is calculated based on the action delay of the tie switch, the opening and arc extinguishing delay of the sectionalizing switch, and the real-time communication delay. The real-time communication delay is a one-way delay determined according to the time-division duplex (TDD) time slot phase of the wireless channel. The time slot phase is obtained by sending a non-equal interval detection sequence to the distribution terminal at the other end and performing phase locking on the round-trip delay envelope.

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