Sampling moment alignment method and device for multi-terminal differential protection, terminal equipment and storage medium

Abstract

The invention discloses a sampling time alignment method and device for multi-terminal differential protection, terminal equipment and a storage medium, and belongs to the technical field of differential protection, and the method comprises the steps: determining a reference equipment terminal and a plurality of equipment terminals to be calibrated according to the application identification of each equipment terminal to be synchronized; for each to-be-calibrated device end, channel delay between the current to-be-calibrated device end and the reference device end is calculated through a ping-pong principle; determining a third sampling moment of the current to-be-calibrated equipment end according to the first sampling moment, the sampling delay, the channel delay and the sampling moment interval; determining communication total delay according to the third sampling moment and the first sampling moment; and adjusting the second sampling moment according to the communication total delay, so that the adjusted second sampling moment is aligned with the first sampling moment. By implementing the method and the device, the problem that the sampling moments of the equipment ends are not aligned due to different internal synchronization mechanisms of the equipment ends participating in the multi-end differential protection during the multi-end differential protection in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the field of differential protection technology, and in particular to a sampling time alignment method, device, terminal equipment and storage medium for multi-terminal differential protection. Background Art

[0002] Traditional multi-terminal differential protection, such as traditional three-terminal differential protection, is mainly used in T-connected lines of power grids. Figure 1 In the T-connection diagram, the three ends are manufacturer A, manufacturer B, and manufacturer C. Each manufacturer has channel 1 and channel 2, each of which includes an optical transmitter and receiver. Manufacturer A's channel 1 optical transmitter is connected to manufacturer B's channel 1 optical receiver, which in turn is connected to manufacturer B's channel 1 optical transmitter; manufacturer B's channel 2 optical transmitter is connected to manufacturer C's channel 2 optical receiver, which in turn is connected to manufacturer C's channel 2 optical transmitter; manufacturer C's channel 1 optical transmitter is connected to manufacturer A's channel 2 optical receiver, which in turn is connected to manufacturer A's channel 1 optical receiver. Although manufacturers A, B, and C can communicate through the established T-connection, the communication protocols used within each manufacturer are generally proprietary, meaning that the synchronization mechanisms within each manufacturer are incompatible. This internal use of proprietary protocols can lead to misaligned sampling times between manufacturers, which in turn can cause errors in differential current calculation. These errors in differential current calculation can create the risk of false tripping, leading to misjudgment of protective devices and power outages, which is detrimental to the safe and stable operation of the power grid. Summary of the Invention

[0003] An embodiment of the present invention provides a sampling time alignment method, apparatus, terminal device and storage medium for multi-terminal differential protection, which can solve the problem in the prior art that, during multi-terminal differential protection, the sampling times of each device end are not aligned due to the different internal synchronization mechanisms of each device end participating in the multi-terminal differential protection, thereby causing differential current calculation errors and the resulting grid operation stability problems. The sampling time of each device end to be calibrated is adjusted after determination by a single reference device end, so that the sampling time of each device end after adjustment is aligned with the reference device end, thereby achieving sampling time alignment of each device end in the multi-terminal differential protection, and helping to improve the accuracy of differential current calculation and grid operation stability.

[0004] An embodiment of the present invention provides a sampling time alignment method for multi-terminal differential protection, comprising:

[0005] Obtaining the application identification of each device end to be synchronized, and determining a reference device end and a plurality of device ends to be calibrated according to the application identification of each device end to be synchronized;

[0006] Obtaining a first sampling time, a sampling delay, a sampling time interval of the reference device and a second sampling time interval of each device to be calibrated; wherein the reference device and each device to be calibrated use the same sampling time interval;

[0007] For each device to be calibrated, the channel delay between the current device to be calibrated and the reference device is calculated using the ping-pong principle.

[0008] Determine a third sampling time of the current device to be calibrated according to the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval;

[0009] Determine the total communication delay between the reference device and the device to be calibrated according to the third sampling time and the first sampling time;

[0010] The second sampling moment is adjusted according to the total communication delay so that the adjusted second sampling moment is aligned with the first sampling moment.

[0011] Furthermore, for each device to be calibrated, calculating the channel delay between the current device to be calibrated and the reference device using the ping-pong principle includes:

[0012] For each device to be calibrated, construct a first message for the current device to be calibrated;

[0013] At a first moment of the current device to be calibrated, the first message is sent to the reference device, and the moment of receiving the second message sent by the reference device is used as the second moment; wherein, after receiving the first message, the reference device uses the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device to be calibrated;

[0014] Determine the total communication duration of the device to be calibrated according to the first moment and the second moment;

[0015] Determine the dwell delay duration of the reference device end according to the third moment and the fourth moment;

[0016] The channel delay between the current device to be calibrated and the reference device is calculated based on the dwell delay time and the total communication time.

[0017] Furthermore, the obtaining of the application identifiers of the devices to be synchronized and determining a reference device and a plurality of devices to be calibrated according to the application identifiers of the devices to be synchronized include:

[0018] When the communication channels between the devices to be synchronized are normal, the device to be synchronized with the smallest application ID is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0019] When there is an abnormality in the communication channel of any device to be synchronized, the device to be synchronized with the smallest application identifier and whose communication channel is normal is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0020] Furthermore, the adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time includes:

[0021] When the total communication delay is greater than the sampling time interval, calculating the sampling time interval remainder according to the total communication delay and the sampling time interval;

[0022] If the sampling time interval remainder is greater than a preset threshold, the second sampling time is roughly adjusted by the total communication delay so that the adjusted second sampling time is aligned with the first sampling time;

[0023] If the sampling time interval remainder is not greater than a preset threshold, the second sampling time is fine-tuned according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0024] Based on the above method embodiment, the present invention provides a corresponding device embodiment;

[0025] An embodiment of the present invention provides a sampling time alignment device for multi-terminal differential protection, comprising: a reference device end determination module, a data acquisition module, a channel delay calculation module, a communication total delay calculation module, and a sampling time alignment module;

[0026] The reference device end determination module is used to obtain the application identification of each device end to be synchronized, and determine a reference device end and several device ends to be calibrated according to the application identification of each device end to be synchronized;

[0027] The data acquisition module is used to acquire the first sampling time, sampling delay, sampling time interval of the reference device end and the second sampling time of each device end to be calibrated; wherein the reference device end and each device end to be calibrated use the same sampling time interval;

[0028] The channel delay calculation module is used to calculate the channel delay between the current device to be calibrated and the reference device by using the ping-pong principle for each device to be calibrated.

[0029] The total channel delay calculation module is used to determine the third sampling time of the current device to be calibrated based on the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval; and determine the total communication delay between the reference device and the current device to be calibrated based on the third sampling time and the first sampling time;

[0030] The sampling time alignment module is used to adjust the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0031] Furthermore, for each device to be calibrated, calculating the channel delay between the current device to be calibrated and the reference device using the ping-pong principle includes:

[0032] For each device to be calibrated, construct a first message for the current device to be calibrated;

[0033] At a first moment of the current device to be calibrated, the first message is sent to the reference device, and the moment of receiving the second message sent by the reference device is used as the second moment; wherein, after receiving the first message, the reference device uses the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device to be calibrated;

[0034] Determine the total communication duration of the device to be calibrated according to the first moment and the second moment;

[0035] Determine the dwell delay duration of the reference device end according to the third moment and the fourth moment;

[0036] The channel delay between the current device to be calibrated and the reference device is calculated based on the dwell delay time and the total communication time.

[0037] Furthermore, the obtaining of the application identifiers of the devices to be synchronized and determining a reference device and a plurality of devices to be calibrated according to the application identifiers of the devices to be synchronized include:

[0038] When the communication channels between the devices to be synchronized are normal, the device to be synchronized with the smallest application ID is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0039] When there is an abnormality in the communication channel of any device to be synchronized, the device to be synchronized with the smallest application identifier and whose communication channel is normal is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0040] Furthermore, the adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time includes:

[0041] When the total communication delay is greater than the sampling time interval, calculating the sampling time interval remainder according to the total communication delay and the sampling time interval;

[0042] If the sampling time interval remainder is greater than a preset threshold, the second sampling time is roughly adjusted by the total communication delay so that the adjusted second sampling time is aligned with the first sampling time;

[0043] If the sampling time interval remainder is not greater than a preset threshold, the second sampling time is fine-tuned according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0044] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the sampling time alignment method for multi-terminal differential protection described in the above-mentioned embodiment of the invention.

[0045] Another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the sampling time alignment method for multi-terminal differential protection described in the above-mentioned embodiment of the invention.

[0046] The following beneficial effects are achieved by implementing the present invention:

[0047] The present invention provides a sampling time alignment method, apparatus, terminal device and storage medium for multi-terminal differential protection. The method obtains the application identifier of each device end to be synchronized that participates in the multi-terminal differential protection, determines a reference device end and a plurality of device ends to be calibrated, and combines the use of the ping-pong principle. After sequentially calculating the channel delay between the device end to be calibrated and the reference device end, and the third sampling time of the device end to be calibrated, calculates the total communication delay between the reference device end and the current device end to be calibrated, and then adjusts the second sampling time according to the total communication delay. That is, the difference between the first sampling time and the second sampling time is determined by calculating the total communication delay between each device end to be calibrated and the reference device end, and then adjusts the second sampling time based on the determined difference to align it with the first sampling time. The invention solves the problem in the prior art that, in multi-terminal differential protection, the sampling moments of the various equipment ends involved in the multi-terminal differential protection are not aligned due to the different internal synchronization mechanisms, which in turn leads to errors in differential current calculation and the resulting grid operation stability problems. The invention adjusts the sampling moments of the equipment ends to be calibrated after determination by a single reference equipment end, so that the sampling moments of the various equipment ends after adjustment are aligned with the reference equipment end, thereby achieving alignment of the sampling moments of the various equipment ends in the multi-terminal differential protection, and helping to improve the accuracy of differential current calculation and the stability of grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the existing three-terminal differential protection T-connected circuit.

[0049] Figure 2 The present invention is a flowchart of a sampling time alignment method for multi-terminal differential protection provided by an embodiment of the present invention.

[0050] Figure 3 The figure is a schematic diagram of communication between the equipment ends of a three-terminal differential protection T-connected line provided by one embodiment of the present invention under normal conditions.

[0051] Figure 4 The present invention provides a communication diagram of a three-terminal differential protection T-connected line device with abnormal communication channels between terminals.

[0052] Figure 5 This is a schematic diagram of a three-terminal differential protection channel delay provided by an embodiment of the present invention.

[0053] Figure 6 Schematic diagram of the sampling time of each device before the three-terminal differential protection sampling time is aligned according to an embodiment of the present invention

[0054] Figure 7 1 is a schematic diagram of the sampling time of each device end after the three-terminal differential sampling time is aligned provided by an embodiment of the present invention.

[0055] Figure 8 The present invention is a schematic structural diagram of a sampling time alignment device for multi-terminal differential protection provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] like Figure 2 As shown, in order to solve the problem in the prior art that, during multi-terminal differential protection, the sampling times of the various devices participating in the multi-terminal differential protection are not aligned due to different internal synchronization mechanisms, which in turn leads to errors in differential current calculation and the resulting grid operation stability problems, an embodiment of the present invention provides a method for aligning the sampling times of multi-terminal differential protection, including:

[0058] Step S1: obtaining the application identification of each device end to be synchronized, and determining a reference device end and a plurality of device ends to be calibrated according to the application identification of each device end to be synchronized;

[0059] Step S2: Obtain the first sampling time, sampling delay, sampling time interval of the reference device and the second sampling time of each device to be calibrated; wherein the reference device and each device to be calibrated use the same sampling time interval;

[0060] Step S3: For each device to be calibrated, the channel delay between the current device to be calibrated and the reference device is calculated using the ping-pong principle.

[0061] Step S4: determining a third sampling time of the current device to be calibrated according to the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval;

[0062] Step S5: determining the total communication delay between the reference device and the device to be calibrated according to the third sampling time and the first sampling time;

[0063] Step S6: adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0064] In step S1, the application identification of each device end to be synchronized participating in the multi-terminal differential protection is obtained, and then a device end is selected as the reference device end according to the application identification, and the remaining device ends to be synchronized that are not selected as the reference device end are the device ends to be calibrated.

[0065] In a preferred embodiment, the application identification of each device end to be synchronized is obtained, and a reference device end and several device ends to be calibrated are determined based on the application identification of each device end to be synchronized, including: when the communication channels between the device ends to be synchronized are normal, the device end to be synchronized with the smallest application identification is used as the reference device end, and the remaining device ends to be synchronized except the reference device end are used as the device ends to be calibrated; when there is an abnormality in the communication channel of any device end to be synchronized, the device end to be synchronized with the smallest application identification and whose communication channels are normal is used as the reference device end, and the remaining device ends to be synchronized except the reference device end are used as the device ends to be calibrated.

[0066] Specifically, in Figure 3 In the three-terminal differential protection shown, the equipment terminals participating in the three-terminal differential protection include Manufacturer A, Manufacturer B, and Manufacturer C. Manufacturer A's application identifier is 0x4001, Manufacturer B's application identifier is 0x4002, and Manufacturer C's application identifier is 0x4003. Furthermore, the communication channels between Manufacturer A, Manufacturer B, and Manufacturer C are all connected normally. At this point, by comparing the application identifiers of Manufacturer A, Manufacturer B, and Manufacturer C, it can be seen that Manufacturer A's application identifier is the smallest among the three terminals. In this case, Manufacturer A is selected as the reference equipment terminal, and Manufacturer B and Manufacturer C, which were not selected, are selected as the equipment terminals to be calibrated.

[0067] In such Figure 4In the three-terminal differential protection shown, the devices participating in the three-terminal differential protection are also from manufacturers A, B, and C. Manufacturer A's application identifier is 0x4001, manufacturer B's application identifier is 0x4002, and manufacturer C's application identifier is 0x4003. The communication channel between manufacturers A and C is abnormal, meaning the communication channel between manufacturers A and C is faulty. In this case, only manufacturer B's communication channel is fully operational. In this case, manufacturer B is selected as the reference device, and manufacturers A and C are selected as the devices to be calibrated.

[0068] Regarding step S2, after determining the reference device end and the device end to be calibrated, the first sampling time, sampling delay, sampling time interval of the reference device end and the second sampling time of each device end to be calibrated are obtained.

[0069] In step S3, for each device to be calibrated, the channel delay of the communication channel between the current device to be calibrated and the reference device needs to be calculated using the ping-pong principle.

[0070] In a preferred embodiment, for each device end to be calibrated, the channel delay between the current device end to be calibrated and the reference device end is calculated by the ping-pong principle, including: for each device end to be calibrated, constructing a first message for the current device end to be calibrated; sending the first message to the reference device end at a first moment of the current device end to be calibrated, and taking the moment of receiving the second message sent by the reference device end as the second moment; wherein, after receiving the first message, the reference device end takes the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device end to be calibrated; determining the total communication time of the current device end to be calibrated based on the first moment and the second moment; determining the residence delay time of the reference device end based on the third moment and the fourth moment; and calculating the channel delay between the current device end to be calibrated and the reference device end based on the residence delay time and the total communication time.

[0071] Specifically, such as Figure 5 As shown in the figure, the equipment terminals involved in the three-terminal differential protection include manufacturers A, B, and C. Manufacturer A is used as the reference equipment terminal, manufacturer B as the equipment terminal to be calibrated 1, and manufacturer C as the equipment terminal to be calibrated 2. The channel delay between manufacturers A and B and the channel delay between manufacturers A and C need to be calculated separately.

[0072] Taking the calculation of the channel delay between manufacturers A and B as an example, manufacturer B needs to construct a message (the first message mentioned above) and transmit this constructed first message to manufacturer A through the communication channel between manufacturers A and B at time tss1 (the first time mentioned above). After manufacturer A receives the first message sent by manufacturer B at time tmr1 (the third time mentioned above), it will experience a dwell delay of length Trest1. Then, at time tms1 (the fourth time mentioned above), it will generate a response message (the second message mentioned above) to the first message and transmit it back to manufacturer B through the communication channel between manufacturers A and B. Manufacturer B receives the message from manufacturer A at time tsr1 (the second time mentioned above).

[0073] According to the above description, the total communication time from when manufacturer B sends the first message to manufacturer A to when it receives the second message is total 1 = tsr1 - tss1. After the first message is transmitted to manufacturer A, the residence delay time Trest1 = tms1 - tmr1 in manufacturer A. The total communication path length from when manufacturer B sends the first message to manufacturer A to when it receives the second message is the distance of the two communication channels between manufacturer A and manufacturer B (the messages go back and forth through the same channel, so the transmission delay can be considered the same). Therefore, the channel delay T between manufacturer B and manufacturer A can be calculated. d1 for:

[0074]

[0075] Similarly, the channel delay T between manufacturer C and manufacturer A can be calculated d2 for:

[0076]

[0077] For step S4 and step S5, illustratively, Figure 6 Figure 2 shows the sampling times of each device before three-terminal differential protection sampling time alignment. Before alignment, manufacturer A's sampling time tm(i) (the first sampling time) is misaligned with manufacturer B's sampling time ts1(j) (the second sampling time of manufacturer B). Manufacturer A's sampling time tm(i) (the first sampling time) is misaligned with manufacturer C's sampling time ts2(j) (the second sampling time of manufacturer C). The purpose of sampling time alignment is to align manufacturer B's sampling time ts1(j) with manufacturer A's sampling time tm(i), and manufacturer C's sampling time ts2(j) with manufacturer A's sampling time tm(i).

[0078] Taking the example of aligning the sampling time ts1(j) of manufacturer B with the sampling time tm(i) of manufacturer A, the difference between the sampling time tm(i) and the sampling time tm(i+1) of manufacturer A corresponds to the sampling time interval. First, after manufacturer A determines to send a message to manufacturer B at sampling time tm(i), manufacturer A needs to experience a sampling delay △Tm1 starting from tm(i). The time corresponding to the time after adding the sampling delay △Tm1 to tm(i) is the sending time of manufacturer A to manufacturer B. The channel delay T between manufacturer B and manufacturer A is the time from the sending time of manufacturer A to the time when manufacturer B receives the message. d1 Then the time it takes for manufacturer A to send a message to manufacturer B and receive the message can be expressed as △Tm1+T d1 .from Figure 6 As can be seen from the figure, when manufacturer B receives the message, it is within the sampling time interval, that is, within the interval ts1(j+3) to ts1(j+4). Therefore, after manufacturer B receives the message, the delay from the next sampling time interval to the sampling time ts1(j+4) (that is, the third sampling time) is △Ts1. The total communication delay between manufacturer A and manufacturer B is:

[0079] whole_dt1=ΔTm1+Td1+ΔTs1.

[0080] It can be further rewritten as:

[0081] whole_dt1=ΔTm1+Td1+[ts1(j+4)-tsr1].

[0082] The total communication delay whole_dt1 between manufacturer A and manufacturer B reflects the total deviation in sampling time between manufacturer B and manufacturer A.

[0083] Similarly, the total communication delay between manufacturer A and manufacturer C can be obtained:

[0084] whole_dt2=ΔTm1+Td2+[ts2(j+4)-tsr2].

[0085] For step S6, after determining the total communication delay between manufacturer A and manufacturer B, and the total communication delay between manufacturer A and manufacturer C, the sampling time of manufacturer B is aligned with that of manufacturer A, and the sampling time of manufacturer C is aligned with that of manufacturer A through coarse adjustment and fine adjustment.

[0086] In a preferred embodiment, the adjusting of the second sampling moment according to the total communication delay so that the adjusted second sampling moment is aligned with the first sampling moment includes: when the total communication delay is greater than the sampling moment interval, calculating the sampling moment interval remainder according to the total communication delay and the sampling moment interval; if the sampling moment interval remainder is greater than a preset threshold, coarsely adjusting the second sampling moment through the total communication delay so that the adjusted second sampling moment is aligned with the first sampling moment; if the sampling moment interval remainder is not greater than the preset threshold, fine-adjusting the second sampling moment through the total communication delay so that the adjusted second sampling moment is aligned with the first sampling moment.

[0087] Specifically, such as Figure 7 Figure 2 shows the sampling times of each device after three-terminal differential sampling time alignment. Taking the example of aligning the sampling time of manufacturer B with that of manufacturer A through coarse and fine tuning, the relationship between the total communication delay (whole_dt1) and the sampling interval between manufacturers A and B is first calculated. This means determining the number of sampling intervals spanned and the corresponding sampling interval remainder. Assuming a sampling interval of 833µs, the number of sampling intervals (bay) is equal to the integer portion of whole_dt / 833, and the sampling interval remainder is the remainder portion of dt_fract = whole_dt / 833. The preset threshold is set to 4µs.

[0088] If the remainder of the sampling interval is dt_fract>4us, a coarse adjustment method can be used to quickly align the sampling times. In the coarse adjustment, the adjustment time difference dt1 = 1us is set. At this time, the sampling period of manufacturer B is adjusted to Tsmpl = Tsmpl-dt1.

[0089] If the remainder of the sampling interval is dt_fract≤4us, fine adjustment is used to align to prevent excessive adjustment from affecting the adjustment accuracy. At this time, the adjustment time difference dt2 is set to dt_fract / 8. At this time, the sampling period of manufacturer B is adjusted to Tsmpl=Tsmpl-dt2.

[0090] The sampling time interval remainder dt_fract obtained by manufacturer B after the above adjustment approaches 0, so that the next sampling time after the adjusted second sampling time is aligned with the first sampling time, or the adjusted second sampling time is aligned with the first sampling time.

[0091] Similarly, the second sampling time of manufacturer B can be aligned with the first sampling time of manufacturer A.

[0092] Preferably, after aligning the sampling times between the various device terminals in multi-terminal differential protection, differential current calculation can also be performed. By obtaining the instantaneous current values ​​at corresponding sampling times at adjacent sampling times, the difference in the instantaneous current values ​​between adjacent sampling times can be calculated, i.e., the difference in the instantaneous current values ​​at the corresponding sampling time interval. This instantaneous current difference can be used as a basis for differential protection judgment.

[0093] Based on the above method embodiments, the present invention provides corresponding device embodiments.

[0094] like Figure 8 As shown, an embodiment of the present invention provides a sampling time alignment device for multi-terminal differential protection, comprising: a reference device end determination module, a data acquisition module, a channel delay calculation module, a communication total delay calculation module, and a sampling time alignment module;

[0095] The reference device end determination module is used to obtain the application identification of each device end to be synchronized, and determine a reference device end and several device ends to be calibrated according to the application identification of each device end to be synchronized;

[0096] The data acquisition module is used to acquire the first sampling time, sampling delay, sampling time interval of the reference device end and the second sampling time of each device end to be calibrated; wherein the reference device end and each device end to be calibrated use the same sampling time interval;

[0097] The channel delay calculation module is used to calculate the channel delay between the current device to be calibrated and the reference device by using the ping-pong principle for each device to be calibrated.

[0098] The total channel delay calculation module is used to determine the third sampling time of the current device to be calibrated based on the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval; and determine the total communication delay between the reference device and the current device to be calibrated based on the third sampling time and the first sampling time;

[0099] The sampling time alignment module is used to adjust the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0100] In a preferred embodiment, for each device to be calibrated, calculating the channel delay between the current device to be calibrated and the reference device using the ping-pong principle includes:

[0101] For each device to be calibrated, construct a first message for the current device to be calibrated;

[0102] At a first moment of the current device to be calibrated, the first message is sent to the reference device, and the moment of receiving the second message sent by the reference device is used as the second moment; wherein, after receiving the first message, the reference device uses the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device to be calibrated;

[0103] Determine the total communication duration of the device to be calibrated according to the first moment and the second moment;

[0104] Determine the dwell delay duration of the reference device end according to the third moment and the fourth moment;

[0105] The channel delay between the current device to be calibrated and the reference device is calculated based on the dwell delay time and the total communication time.

[0106] In a preferred embodiment, the step of obtaining the application identifier of each device to be synchronized and determining a reference device and a plurality of devices to be calibrated according to the application identifier of each device to be synchronized includes:

[0107] When the communication channels between the devices to be synchronized are normal, the device to be synchronized with the smallest application ID is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0108] When there is an abnormality in the communication channel of any device to be synchronized, the device to be synchronized with the smallest application identifier and whose communication channel is normal is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

[0109] In a preferred embodiment, adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time includes:

[0110] When the total communication delay is greater than the sampling time interval, calculating the sampling time interval remainder according to the total communication delay and the sampling time interval;

[0111] If the sampling time interval remainder is greater than a preset threshold, the second sampling time is roughly adjusted by the total communication delay so that the adjusted second sampling time is aligned with the first sampling time;

[0112] If the sampling time interval remainder is not greater than a preset threshold, the second sampling time is fine-tuned according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

[0113] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement the present invention without inventive effort.

[0114] Those skilled in the art will clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0115] Based on the above method embodiment, the present invention provides a corresponding terminal device embodiment.

[0116] An embodiment of the present invention provides a terminal device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a sampling time alignment method for multi-terminal differential protection as described in any one of the present inventions is implemented.

[0117] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0118] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device using various interfaces and lines.

[0119] The memory can be used to store the computer program, and the processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created based on the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0120] Based on the above method embodiment, the present invention provides a corresponding storage medium embodiment.

[0121] An embodiment of the present invention provides a storage medium, which includes a stored computer program. When the computer program is running, the device where the storage medium is located is controlled to execute a sampling time alignment method for multi-terminal differential protection as described in any one of the present inventions.

[0122] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. The computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium.

[0123] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A sampling time alignment method for multi-terminal differential protection, characterized in that: include: Obtaining the application identification of each device end to be synchronized, and determining a reference device end and a plurality of device ends to be calibrated according to the application identification of each device end to be synchronized; Obtaining a first sampling time, a sampling delay, a sampling time interval of the reference device and a second sampling time interval of each device to be calibrated; wherein the reference device and each device to be calibrated use the same sampling time interval; For each device to be calibrated, the channel delay between the current device to be calibrated and the reference device is calculated using the ping-pong principle. Determine a third sampling time of the current device to be calibrated according to the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval; Determine the total communication delay between the reference device and the device to be calibrated according to the third sampling time and the first sampling time; The second sampling moment is adjusted according to the total communication delay so that the adjusted second sampling moment is aligned with the first sampling moment.

2. The sampling time alignment method for multi-terminal differential protection according to claim 1, characterized in that: For each device to be calibrated, calculating the channel delay between the current device to be calibrated and the reference device using the ping-pong principle includes: For each device to be calibrated, construct a first message for the current device to be calibrated; At a first moment of the current device to be calibrated, the first message is sent to the reference device, and the moment of receiving the second message sent by the reference device is used as the second moment; wherein, after receiving the first message, the reference device uses the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device to be calibrated; Determine the total communication duration of the device to be calibrated according to the first moment and the second moment; Determine the dwell delay duration of the reference device end according to the third moment and the fourth moment; The channel delay between the current device to be calibrated and the reference device is calculated based on the dwell delay time and the total communication time.

3. The sampling time alignment method for multi-terminal differential protection according to claim 2, characterized in that: The step of obtaining the application identifiers of the devices to be synchronized and determining a reference device and a plurality of devices to be calibrated according to the application identifiers of the devices to be synchronized includes: When the communication channels between the devices to be synchronized are normal, the device to be synchronized with the smallest application ID is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated. When there is an abnormality in the communication channel of any device to be synchronized, the device to be synchronized with the smallest application identifier and whose communication channel is normal is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

4. The sampling time alignment method for multi-terminal differential protection according to claim 3, characterized in that: The adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time includes: When the total communication delay is greater than the sampling time interval, calculating the sampling time interval remainder according to the total communication delay and the sampling time interval; If the sampling time interval remainder is greater than a preset threshold, the second sampling time is roughly adjusted by the total communication delay so that the adjusted second sampling time is aligned with the first sampling time; If the sampling time interval remainder is not greater than a preset threshold, the second sampling time is fine-tuned according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

5. A sampling time alignment device for multi-terminal differential protection, characterized in that: include: Reference device end determination module, data acquisition module, channel delay calculation module, communication total delay calculation module and sampling time alignment module; The reference device end determination module is used to obtain the application identification of each device end to be synchronized, and determine a reference device end and several device ends to be calibrated according to the application identification of each device end to be synchronized; The data acquisition module is used to acquire the first sampling time, sampling delay, sampling time interval of the reference device end and the second sampling time of each device end to be calibrated; wherein the reference device end and each device end to be calibrated use the same sampling time interval; The channel delay calculation module is used to calculate the channel delay between the current device to be calibrated and the reference device by using the ping-pong principle for each device to be calibrated. The total channel delay calculation module is used to determine the third sampling time of the current device to be calibrated based on the first sampling time, the sampling delay, the channel delay between the current device to be calibrated and the reference device, and the sampling time interval; and determine the total communication delay between the reference device and the current device to be calibrated based on the third sampling time and the first sampling time; The sampling time alignment module is used to adjust the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

6. The sampling time alignment device for multi-terminal differential protection according to claim 5, characterized in that: For each device to be calibrated, calculating the channel delay between the current device to be calibrated and the reference device using the ping-pong principle includes: For each device to be calibrated, construct a first message for the current device to be calibrated; At a first moment of the current device to be calibrated, the first message is sent to the reference device, and the moment of receiving the second message sent by the reference device is used as the second moment; wherein, after receiving the first message, the reference device uses the moment of receiving the first message as the third moment, and generates a second message at a fourth moment and sends it to the current device to be calibrated; Determine the total communication duration of the device to be calibrated according to the first moment and the second moment; Determine the dwell delay duration of the reference device end according to the third moment and the fourth moment; The channel delay between the current device to be calibrated and the reference device is calculated based on the dwell delay time and the total communication time.

7. The sampling time alignment device for multi-terminal differential protection according to claim 6, characterized in that: The step of obtaining the application identifiers of the devices to be synchronized and determining a reference device and a plurality of devices to be calibrated according to the application identifiers of the devices to be synchronized includes: When the communication channels between the devices to be synchronized are normal, the device to be synchronized with the smallest application ID is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated. When there is an abnormality in the communication channel of any device to be synchronized, the device to be synchronized with the smallest application identifier and whose communication channel is normal is used as the reference device, and the remaining devices to be synchronized except the reference device are used as the devices to be calibrated.

8. The sampling time alignment device for multi-terminal differential protection according to claim 7, characterized in that: The adjusting the second sampling time according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time includes: When the total communication delay is greater than the sampling time interval, calculating the sampling time interval remainder according to the total communication delay and the sampling time interval; If the sampling time interval remainder is greater than a preset threshold, the second sampling time is roughly adjusted by the total communication delay so that the adjusted second sampling time is aligned with the first sampling time; If the sampling time interval remainder is not greater than a preset threshold, the second sampling time is fine-tuned according to the total communication delay so that the adjusted second sampling time is aligned with the first sampling time.

9. A terminal device, characterized in that: The invention comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a sampling time alignment method for multi-terminal differential protection according to any one of claims 1 to 4 is implemented.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the sampling time alignment method for multi-terminal differential protection according to any one of claims 1 to 4.

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