WO2023087943A1

WO2023087943A1 - Method and apparatus for discriminating consistency of receiving and sending delays of differential channel, and electronic device and differential protection communication system

Info

Publication number: WO2023087943A1
Application number: PCT/CN2022/122507
Authority: WO
Inventors: 张洪喜; 赵青春; 徐晓春; 徐海洋; 谢华; 戴光武; 陆金凤; 卜立之; 李奔
Original assignee: 南京南瑞继保电气有限公司; 南京南瑞继保工程技术有限公司
Priority date: 2021-11-18
Filing date: 2022-09-29
Publication date: 2023-05-25
Also published as: CN114050559A

Abstract

Disclosed in the present application are a method and apparatus for discriminating the consistency of receiving and sending delays of a differential channel, and an electronic device and a differential protection communication system, which are used for a host side or a slave side of a differential channel. The method comprises: calculating a channel delay of a differential channel; adjusting sampling data on two sides of the differential channel to a synchronous state; calculating, in real time, a variation amount of the channel delay, and when the variation amount of the channel delay is greater than a first threshold value, starting to discriminate the consistency of receiving and sending delays of the differential channel, so as to obtain a discrimination result of the consistency of the receiving and sending delays of the channel; and according to the discrimination result of the consistency of the receiving and sending delays of the channel, determining whether to lock differential protection.

Description

Distinguishing method and device, electronic equipment, differential protection communication system for differential channel transmission and reception delay consistency

related application

This application claims the priority of the Chinese patent application submitted to the China Patent Office on November 18, 2021 with the application number 2021113736564 and the application name "Method, device and differential protection communication system for judging the inconsistency of transmission and reception delays of differential channels" , the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the field of electrotechnical technology, and in particular to a method for judging the consistency of sending and receiving delays of differential channels, its device, electronic equipment, and a differential protection communication system.

Background technique

With the development of communication technology, differential protection has been widely used. In the field of differential protection technology, longitudinal differential protection has the advantages of clear protection range, simple principle, stability and reliability. Differential protection uses the communication network to exchange information, transmits information such as the current on the opposite side to the local side, calculates the differential current and braking current based on the current on the local side and the opposite side, and judges whether it is an internal fault based on the differential action characteristics .

The prerequisite for differential protection to work normally is that the data on the local side and the opposite side are synchronized. Therefore, data synchronization technology on both sides is the key to realize differential protection. At present, the commonly used synchronization methods for line differential protection include synchronous clock source method, Ping-Pong method, reference phasor method, etc. The Ping-Pong method is stable and reliable because it does not rely on external time synchronization sources, so it can be used in differential protection been widely used in.

Contents of the invention

The exemplary embodiments of the present application aim to provide a method, device and differential protection communication system for judging the inconsistency of transmission and reception delays of differential channels, and overcome the consistency of differential channels by judging the consistency of transmission and reception delays of channels in real time Insufficiency that cannot be monitored, and timely detection of inconsistencies in channel sending and receiving delays. The method can discriminate the single-channel mode and the dual-channel mode, and block the differential protection in time when the channel delays are inconsistent, so as to improve the reliability and stability of the differential protection function. At the same time, this method does not rely on external time synchronization sources, does not increase additional costs, and does not consume additional resources.

According to an embodiment of the present application, a method for discriminating the consistency of the transmission and reception delay of a differential channel is proposed, which is used on the master side or the slave side of the differential channel, including:

calculating the channel delay of the differential channel;

adjusting the sampling data on both sides of the differential channel to a synchronous state;

Calculate the variation of the channel delay in real time, and when the variation of the channel delay is greater than the first threshold, start the judgment of the consistency of the transmission and reception delay of the channel, so as to obtain the transmission and reception delay of the channel The discriminant result of the consistency at the time; and

According to the judgment result of the consistency of the sending and receiving delay of the channel, it is determined whether to block the differential protection.

In an optional embodiment, when the variation of the channel delay is greater than the first threshold, the first differential protection activation threshold is changed to a second differential protection activation threshold, wherein the first differential protection activation threshold is The second differential protection activation threshold is greater than the first differential protection activation threshold.

In an optional embodiment, when the judgment result of the consistency of the sending and receiving delays of the channels is that the sending and receiving delays of the channels are consistent, after delay confirmation, the second differential changing the protection activation threshold to said first differential protection activation threshold; and

When the determination result of the consistency of the transmission and reception delays of the channels is that the transmission and reception delays of the channels are inconsistent, the differential protection is blocked.

In an optional embodiment, the step of adjusting the sampled data on the two sides of the differential channel to a synchronous state includes:

After calculating the channel delay, calculate the error Δt between the sampling time of the master side and the sampling time of the slave side according to the channel delay; and

Keep the sampling time on the master side unchanged, and gradually adjust the sampling time on the slave side until Δt tends to 0.

In an optional embodiment, the real-time calculation of the change amount of the channel delay, when the change amount of the channel delay is greater than the first threshold, start the transmission and reception delay of the channel The steps of identifying the consistency include:

Calculate the channel delay value T _d (K) of the current sampling point K in real time, and compare it with the channel delay value T d (K-1) of the previous sampling point K-1 to obtain the channel delay value T _d (K-1) The amount of change ΔT _d , the calculation formula of the amount of change ΔT _d is as follows:

ΔT _d =abs(T _d (K)-T _d (K-1)),

Wherein, abs represents an absolute value, and when the change amount ΔT _d of the channel delay is greater than the first threshold, the determination of the consistency of the sending and receiving delay of the channel is started.

In an optional embodiment, the step of starting the determination of the consistency of the transmission and reception delay of the channel includes:

In the case of using a single channel, start a method for judging the consistency of the sending and receiving delay of the channel in the single channel mode; or

In the case of dual-channel input, start the method of judging the consistency of channel sending and receiving delay in dual-channel mode.

In an optional embodiment, the method for judging the consistency of the transmission and reception delay of the channel in the single channel mode includes:

The protection devices on both sides of the differential channel are not activated, and the three-phase differential current I _DiffΦ is greater than the first threshold value I _Diffset , and the three-phase differential current variation ΔI _DiffΦ is greater than the first threshold value I Diffset . When the second threshold setting value ΔI _Diffset and the three-phase braking current variation ΔI _BiasΦ are all smaller than the third threshold setting value ΔI _Biasset , it is determined that the sending and receiving delays of the channels are inconsistent, and the three-phase differential current changes The calculation formula of the amount and the braking current variation of the three phases is as follows:

Among them, I _DiffΦ (k), I _BiasΦ (k) are respectively the three-phase differential current and the three-phase brake current at the current sampling time point; and I _DiffΦ (kn), I _BiasΦ (kn) are respectively a cycle The differential current of the previous three phases and the braking current of the three phases, where n is the number of sampling points of one cycle.

In an optional embodiment, the method for judging the consistency of sending and receiving delays of the channels in the dual-channel mode includes:

When the channel delay variation ΔT _d of only one of the two channels is greater than the first threshold, select the channel whose channel delay variation ΔT _d is less than or equal to the first threshold as the first channel, The other channel is the second channel, and the sampling data on both sides of the two channels are adjusted to a synchronous state based on the channel delay of the first channel; and

calculating the channel delay of the second channel, and the slave side calculates an error Δt between the sampling time of the slave side and the sampling time of the master side according to the channel delay of the second channel;

Wherein, when the error Δt is smaller than the second threshold, it is judged that the sending and receiving delays of the second channel are consistent; and

When the error Δt is greater than or equal to the second threshold, it is determined that the sending and receiving delays of the second channel are inconsistent.

In an optional embodiment, the method for determining the consistency of the sending and receiving delays of the channels in the dual-channel mode further includes:

When the variation ΔT _d of the channel delay of the two channels in the dual channels is greater than the first threshold, the channel with a smaller variation of the channel delay is selected as the first channel, and the variation of the channel delay is The larger channel is the second channel; and

Adjust the sampling data on both sides of the first channel to a synchronous state, and then perform the channel detection on the first channel according to the method for determining the consistency of the sending and receiving delay of the channel in the single channel mode Discrimination of the consistency of sending and receiving delays.

In an optional embodiment, when the judgment result of the first channel is that the channel delays of the first channel are consistent, the channel delay of the second channel is calculated, and the slave side calculating an error Δt between the sampling moment of the slave side and the sampling moment of the master side according to the channel delay of the second channel;

In an optional embodiment, after it is judged that the channel delays of the first channel are inconsistent, the channel delay of the second channel is used as a reference to adjust the sampling data on both sides of the dual channels to a synchronous state, The second channel is then judged according to the method for judging the consistency of the sending and receiving delays of the channels in the single-channel mode.

In an optional embodiment, the step of calculating the channel delay of the differential channel includes:

The slave side sends the first frame message to the master side, and records the sending time t _ss , when the master side receives the first frame message, records the receiving time t _mr , and The second frame message is returned to the slave side at t _ms time, and the time difference (t _ms -t _mr ) is sent to the slave side as the message content of the second frame message at the same time, and the slave The side receives the returned second frame message at time t _sr , and extracts the time difference (t _ms -t _mr ) from the second frame message, wherein the channel is calculated by the following formula Delay T _d :

In an optional embodiment, after the step of adjusting the sampled data on the two sides of the differential channel to a synchronous state, the method further includes:

According to the synchronized current data on both sides, the differential current and braking current are calculated by the following formula:

in,

are the Φ-phase currents of the master side and the slave side, respectively, and I _DiffΦ , I _BiasΦ are the differential current and the braking current of the Φ-phase, respectively.

According to another embodiment of the present application, a device for discriminating the consistency of transmission and reception delays of differential channels is proposed, including:

A delay calculation module configured to calculate the channel delay of the differential channel;

a synchronization module, configured to adjust the sampling data on both sides of the differential channel to a synchronous state;

The delay change monitoring module is configured to calculate the change amount of the channel delay in real time, wherein, when the change amount of the channel delay is greater than a first threshold, the consistency of the transmit and receive delay of the channel is started discriminate; and

The judging module is configured to judge the consistency of channel sending and receiving delays.

According to one aspect of the present application, an electronic device is proposed, comprising:

A memory, a processor, and a computer program stored in the memory and operable on the processor, wherein the processor implements the method described in any one of the foregoing when executing the computer program.

According to another aspect of the present application, a differential protection communication system is provided, including the aforementioned device and/or the aforementioned electronic device.

In the related art, the premise of the ping-pong principle method is that the sending and receiving delays of the channels are required to be consistent. In order to improve the reliability of differential protection data transmission, the communication network generally has a self-healing function. In other words, when a communication device fails, it can automatically switch the channel route within a short period of time, and at this time, the delay of sending and receiving routes may be inconsistent. If the transmission and reception delays of the channels are inconsistent, the precondition of the ping-pong principle method will be destroyed, resulting in false synchronization, affecting the reliability of differential protection, and in extreme cases, it will cause differential misoperation.

When the transmission and reception delays of the channel are inconsistent, theoretically, external time synchronization can be used to achieve data synchronization on both sides. However, due to restrictions, some countries and regions do not have external time synchronization conditions. In addition, the external timing is greatly affected by the environment, and the stability cannot be guaranteed.

According to an exemplary embodiment of the present application, the differential channel delay inconsistency discrimination method provided in the present application solves the problem that the consistency of the differential channel delay cannot be monitored without external time synchronization. It is possible to judge the consistency of the transmission and reception delay of the channel, and choose whether to block the differential protection according to the judgment result, which improves the reliability and stability of the differential protection.

It is to be understood that both the foregoing general description and the following detailed description are exemplary only and are not restrictive of the application.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings that need to be used in the description of the embodiments.

Fig. 1 shows a schematic diagram of a differential protection communication system according to an exemplary embodiment of the present application.

2A and 2B show schematic diagrams of channel delay calculation and sampling time adjustment based on the ping-pong principle method according to an example embodiment of the present application.

Fig. 3 shows a flow chart of a method for judging consistency of sending and receiving delays of differential channels according to an example embodiment of the present application.

Fig. 4 shows a logic diagram for judging consistency of sending and receiving delays in a single channel mode according to an example embodiment of the present application.

5A and 5B are schematic diagrams illustrating synchronous sampling of channels A and B in a dual-channel mode according to an exemplary embodiment of the present application.

Fig. 6 shows a block diagram of an apparatus for judging inconsistent transmission and reception delays of differential channels according to an exemplary embodiment of the present application.

Fig. 7 shows a block diagram of an electronic device according to an exemplary embodiment.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The same reference numerals denote the same or similar parts in the drawings, and thus their repeated descriptions will be omitted.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided in order to give a thorough understanding of the embodiments of the application. However, those skilled in the art will appreciate that the technical solutions of the present application may be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be employed. In other instances, well-known methods, apparatus, implementations, or operations have not been shown or described in detail to avoid obscuring aspects of the application.

Unless the context indicates otherwise, the block diagrams shown in the figures are merely functional entities and do not necessarily correspond to physically separate entities. In other words, these functional entities may be implemented in software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices entity.

The flow charts shown in the drawings are only exemplary illustrations, and do not necessarily include all contents and operations/steps, nor must they be performed in the order described. For example, some operations/steps can also be decomposed, while some operations/steps can be combined or partially combined. Therefore, the actual execution order may be changed according to the actual situation.

It will be understood that although the terms first, second, third etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Thus, a first component discussed below could be termed a second component without departing from the teachings of the concepts of the present application. As used herein, the term "and/or" includes any one and all combinations of one or more of the associated listed items.

Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of exemplary embodiments, and the modules or processes in the accompanying drawings are not necessarily necessary for implementing the present application, and thus cannot be used to limit the protection scope of the present application.

In the prior art, the data exchange between devices on both sides of the differential protection channel usually adopts a multiplexing method, that is, it is realized through an external communication network, and these networks generally use a self-healing ring network. When the original transmission channel fails, the data exchange will automatically switch to the backup channel in a short time. The channel after switching may have inconsistent delays of the sending and receiving routes, which destroys the precondition of differential synchronization (the delays of the sending and receiving routes are required to be consistent). Once the delay of sending and receiving routes is inconsistent, and the device does not judge it, there is a risk of misoperation of the device.

In order to solve the above problems and improve the stability of differential protection, each exemplary embodiment of the present application proposes a method for judging the consistency of sending and receiving delays of differential channels, which can also be understood as inconsistent sending and receiving delays of differential channels Discrimination method. This method is based on the premise that the transmission and reception delays of the channel are consistent, calculates the channel delay based on the ping-pong principle, adjusts the differential data on both sides to a synchronous state, and calculates the variation of the channel delay in real time. When the variation of the channel delay is greater than the set value, the differential start threshold is immediately raised, and at the same time, the judgment of the consistency of the sending and receiving delays of the differential channel is started. The determination of the consistency of the sending and receiving delays may include two types: the determination of the consistency of the sending and receiving delays in the single-channel mode and the determination of the consistency of the sending and receiving delays in the dual-channel mode. When it is judged that the sending and receiving delays of the channels are consistent, the original differential protection function will be restored after the delay is confirmed. When it is judged that the sending and receiving delays are inconsistent, an alarm signal is output and the differential protection function is blocked immediately, and the differential protection function is put into operation after the channel is repaired.

The method for judging the delay consistency of the differential channel provided by the exemplary embodiments of the present application solves the problem that the delay consistency of the differential channel cannot be monitored in the absence of external time synchronization. The method can judge the consistency of the transmission and reception delay of the channel, and select whether to block the differential protection according to the judgment result, thereby improving the reliability and stability of the differential protection.

The technical solutions of the present application will be described in detail below in conjunction with the accompanying drawings.

In the differential protection system shown in Figure 1, the communication channel (for example, a communication network) connected to the differential protection device at both ends is a differential protection channel, that is, a differential channel, which is used for differential protection on both sides of the differential channel. Data exchange between protective devices. One end of the differential channel is connected to the master, and the other end is connected to the slave, so as to perform channel delay calculation and synchronization adjustment.

Fig. 3 shows a flowchart of a method for judging consistency of sending and receiving delays of a differential channel according to an exemplary embodiment of the present application.

According to an exemplary embodiment, the channel delay is calculated based on the ping-pong principle, and the sampling data on both sides are adjusted to a synchronous state.

Referring to Fig. 3, in step S301, the channel delay of the differential channel is calculated.

With reference to the exemplary embodiment shown in FIG. 2A , the M side is selected as the master side, and the N side is selected as the slave side. The slave side sends a frame message to the master side, and records the sending time t _ss . When the master side receives the frame message, record the receiving time t _mr , and return a frame message to the slave side at t _ms time, and send the time difference (t _ms -t _mr ) as the message content to the slave side aircraft side. The slave side receives the returned message at time t _sr , and extracts (t _ms -t _mr ) information from it to calculate the channel delay T _d , as shown in formula (1):

In step S303, adjust the sampling data on both sides of the differential channel to a synchronous state.

With reference to the exemplary embodiment shown in FIG. 2B , after the channel delay T _d is calculated, the slave side calculates the error Δt between the sampling time of the slave side and the sampling time of the master side according to the channel delay. Then the sampling time on the master side remains unchanged, and the slave side gradually adjusts its own sampling time until Δt tends to 0, so that the sampling data on both sides are synchronized.

Calculate the differential current and braking current according to the synchronized current data on both sides, as shown in formula (2):

in,

are the M-side and N-side Φ-phase currents, and I _DiffΦ and I _BiasΦ are the Φ-phase differential current and braking current, respectively.

In step S305, the change amount of channel delay is calculated in real time, and when the change amount of channel delay is greater than the first threshold, the determination of the consistency of sending and receiving delays of the channel is started.

When the delay variation of the channel is greater than the first threshold, increase the differential start threshold, and at the same time start the judgment of the consistency of the send and receive delay of the channel, that is, change the first differential protection start threshold to the second differential protection start threshold , wherein the second differential protection activation threshold is greater than the first differential protection activation threshold.

Real-time calculation of the channel delay, when the channel delay changes, the method of determining the consistency of the channel sending and receiving delay may include: calculating the channel delay value T _d (K) of the current sampling time point in real time, and comparing it with the previous sampling time Compared with the channel delay value T _d (K-1) of the point, the delay variation ΔT _d is obtained, as shown in the formula (3):

ΔT _d =abs(T _d (K)-T _d (K-1)) (3)

When the delay variation ΔT _d is greater than the threshold T _set , the judgment of the consistency of the sending and receiving delays of the channel is started.

The differential protection device provides two sets of independent differential protection functions, each of which can be switched on or off independently. When a certain set of protection functions is turned on, there will be a corresponding turn-on sign. The input status of the channel can be judged by the input signs of the two sets of protection devices. One device provides two sets of independent differential protection functions, and the user determines whether to use a single channel or a dual channel according to the external channel conditions, which requires that each set of differential protection functions can be turned on or off independently. If it is used in a single-channel scenario, only one set of differential protection functions can be used to cooperate with it, and the other set should be withdrawn; if it is used in a dual-channel scenario, both sets of differential protection functions need to be enabled.

Automatically identify the inconsistency of the sending and receiving delays of the channel according to the input status of the channel. Channel inputs include single-channel inputs and dual-channel inputs. When a single channel is enabled, the judgment of the consistency of the sending and receiving delays of the channel in the single channel mode is adopted. When dual channels are enabled, the judgment of the consistency of the sending and receiving delays of the channels in the dual channel mode is adopted.

The following first takes the single-channel mode as an example to describe the method for judging the consistency of the sending and receiving delays of the channels in the single-channel mode.

The method for judging the consistency of the sending and receiving delays of the channel in the single-channel mode may include the following steps: During the starting period of the judging and starting of the sending and receiving delay consistency of the single-channel, the devices on both sides are not activated. The protection device will diagnose whether the system fails in real time. When a fault is detected in the system, the protection device will start and send a start signal.

Fig. 4 shows a logic diagram for judging inconsistent sending and receiving delays in a single channel mode according to an exemplary embodiment of the present application.

Referring to Figure 4, when the calculated channel delay variation ΔT _d is greater than the set threshold T _set , and the devices on both sides are not activated, and the differential currents I _DiffΦ of the three phases are all greater than the first threshold value I _Diffset , and If the three-phase differential current variation ΔI _DiffΦ is greater than the second threshold value ΔI _Diffset , and the three-phase brake current variation ΔI _BiasΦ is smaller than the third threshold value ΔI _Biasset , then the judgment result is the transmission and reception of the channel. Latency is inconsistent.

The calculation formulas of three-phase differential current variation and three-phase braking current variation are as follows:

Among them, I _DiffΦ (k), I _BiasΦ (k) are the three-phase differential current and the three-phase brake current at the current sampling time point respectively; and I _DiffΦ (kn), I _BiasΦ (kn) are respectively a cycle The differential current of the previous three phases and the braking current of the three phases.

In single-channel mode, when the channel delay change ΔT _d calculated in real time is greater than the threshold T _set , the judgment of the consistency of the sending and receiving delays of the channel is started. According to the differential current of the three phases, the variation of the differential current of the three phases and the variation of the braking current of the three phases, the consistency of the sending and receiving delay of the channel is judged, and the conditions for judging are:

Three-phase differential current I _DiffΦ >I _Diffset =,

The variation of the three-phase differential current ΔI _DiffΦ >ΔI _Diffset , and

The variation of the three-phase braking current ΔI _BiasΦ <ΔI _Biasset ,

Among them, Φ represents any one of the three phases, and the three phases must meet the above conditions at the same time when judging.

Next, taking the dual-channel mode as an example, the method for judging the consistency of the sending and receiving delays of the channels in the dual-channel mode will be described.

The methods for judging the consistency of channel sending and receiving delays in dual-channel mode include: in dual-channel mode, judging the consistency when one of the channel delays changes and the consistency when the delays of two channels change at the same time judge.

1) The first case

In the dual-channel mode, the method for judging the consistency of the delay change of one of the channels can be: when the delay of channel A does not change, but the delay of channel B changes, select channel A as the reference for sampling synchronization adjustment .

In the dual-channel mode, the channel delay T _d A is calculated according to formula (1) based on channel A. Then, calculate the sampling time on both sides according to T _d A, and adjust the sampling time on the slave side (N side) until the sampling time on both sides is completely synchronized. The sampling time of channel A after synchronization is shown in Fig. 5A.

Next, the channel delay T _d B of channel B is also calculated according to formula (1). Then, the theoretical sampling time of the slave side (N side) is calculated according to the channel _TdB . Compare this theoretical sampling time with the actual sampling time (the actual sampling time has been adjusted and synchronized by channel A), and calculate the sampling time difference ΔtB. Then, according to the size of ΔtB, it is judged whether the sending and receiving delays of channel B are consistent. When the sending and receiving delays of channel B are inconsistent, the sampling time error is shown in FIG. 5B .

In an optional embodiment, the above-mentioned judging method may include the following steps. First calculate the delay T _d A of channel A, and adjust the sampling synchronization based on T _d A. The sampling moments on both sides after adjustment are consistent. T _s A is a certain sampling moment after channel A sampling synchronization adjustment. Then calculate the delay time T _d B of channel B, and push back the delay time T d B of channel B according to the data receiving time T _r B of channel B, so as to obtain the theoretical sampling time T _s _B of channel B on this side, and then obtain The sampling time difference between the two channels is ΔtB=abs(T _s AT _s B).

When the sending and receiving delays of channel B are consistent, ΔtB is a value equal to 0 (considering the error, it should be a value close to 0). When the sending and receiving delays of channel B are inconsistent, ΔtB is a value greater than 0. Therefore, judge whether the channel B delay is consistent according to the size of ΔtB. In an embodiment, when ΔtB is greater than or equal to the set threshold δ _set , it may be determined that the sending and receiving delays are inconsistent.

2) The second case

In the dual-channel mode, the method for judging the consistency when the delays of two channels change at the same time can be: when the delays of both channels change, the one with the smaller delay change (set as channel A) is used as the The reference is adjusted synchronously, and at the same time, the delay consistency of the channel is judged for the channel A according to the above-mentioned method of judging the consistency of the sending and receiving delay of the channel in the single-channel mode.

If channel A has the same delay, another channel (set as channel B) is used to judge the delay consistency of the channel. The discrimination method is the same as the method in the first case of 1) above.

If it is judged that the sending and receiving delays of channel A are inconsistent, then the synchronization adjustment is performed based on channel B. Then, the above-mentioned method for judging the consistency of the sending and receiving delay of the channel in the single-channel mode is used to judge the consistency of the channel delay for the channel B.

Specifically, the delay T _d of channel B is calculated. The slave side calculates the error Δt between the sampling time of the slave side and the sampling time of the master side according to the delay T _d of channel B. Subsequently, the sampling time on the master side remains unchanged, and the slave side gradually adjusts its own sampling time until Δt tends to 0, so that the sampling data on both sides are synchronized.

Calculate the differential current and braking current according to the formula (2) according to the synchronized current data on both sides.

Then calculate the three-phase differential current, the variation of the three-phase differential current and the variation of the three-phase braking current according to the formula (4), to judge whether the three-phase differential current I _DiffΦ >I _Diffset and the variation of the three-phase differential current ΔI _DiffΦ are satisfied at the same time >ΔI _Diffset , three-phase braking current variation ΔI _BiasΦ <ΔI _Biasset .

In step S307, it is determined whether to block the differential protection according to the judgment result of the consistency of the sending and receiving delays of the channels.

When it is judged that the channel delays are inconsistent, an alarm signal is output and the differential protection is blocked. After the consistency of the channel delay is judged, if the judgment result is that the channel delay is inconsistent, the alarm signal of the inconsistent sending and receiving delay of the corresponding channel will be output, and at the same time, the differential protection function of the corresponding channel will be automatically blocked, and it will be put into operation after the channel is repaired. Differential Protection.

It should be clearly understood that the application describes how to make and use specific examples, but the application is not limited to any details of these examples. Rather, these principles can be applied to many other embodiments based on the teachings of the present disclosure.

Those skilled in the art can understand that all or part of the steps for implementing the above embodiments are implemented as computer programs executed by a CPU. When the computer program is executed by the CPU, the program for executing the above-mentioned functions defined by the above-mentioned methods provided in the present application can be stored in a computer-readable storage medium, which can be a read-only memory, a magnetic disk or an optical disk, and the like.

In addition, it should be noted that the above figures are only schematic illustrations of the processing included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is easy to understand that the processes shown in the above figures do not imply or limit the chronological order of these processes. In addition, it is also easy to understand that these processes may be executed synchronously or asynchronously in multiple modules, for example.

Through the description of the example embodiments, those skilled in the art can easily understand that the method for judging inconsistent transmission and reception delays of differential channels according to the embodiments of the present application has at least one or more of the following advantages.

According to the exemplary embodiment, through the real-time judgment of the consistency of channel transmission and reception delays, the deficiency that the differential channel consistency cannot be monitored can be overcome, and the inconsistency of channel transmission and reception delays can be found in time.

According to an example embodiment, the method can discriminate between a single-channel mode and a dual-channel mode. When the delay of the channel is inconsistent, the differential protection is blocked in time.

According to an example embodiment, the method improves the reliability and stability of the differential protection function. At the same time, this method does not rely on external time synchronization sources, does not increase additional costs, and does not consume additional resources.

The following describes the embodiment of the device of the present application, which can be used to execute the method embodiment of the present application. For details not disclosed in the device embodiments of the present application, reference may be made to the method embodiments of the present application.

Fig. 6 shows a block diagram of an apparatus for judging consistency of sending and receiving delays of a differential channel according to an exemplary embodiment of the present application.

The device shown in FIG. 6 can execute each step of the method for judging consistency of transmission and reception delays of differential channels according to various embodiments of the present application.

As shown in FIG. 6 , the apparatus for judging consistency of sending and receiving delays of differential channels may include: a delay calculation module 610 , a synchronization module 620 , a delay change monitoring module 630 , and a judging module 640 .

Referring to FIG. 6 and referring to the foregoing description, the delay calculation module 610 is configured to calculate channel delay.

The synchronization module 620 is configured to adjust the sampling data on both sides of the differential channel to a synchronous state.

The delay change monitoring module 630 is configured to calculate the delay change of the channel in real time, and when the delay change of the channel is greater than the first threshold, start the judgment of the consistency of the channel sending and receiving delay.

The judging module 640 is configured to judge consistency of sending and receiving delays of channels.

The device implements a function similar to the method provided above, and other functions may refer to the previous description, and will not be repeated here.

An electronic device 200 according to this embodiment of the present application is described below with reference to FIG. 7 . The electronic device 200 shown in FIG. 7 is only an example, and should not limit the functions and scope of use of this embodiment of the present application.

As shown in FIG. 7, electronic device 200 takes the form of a general-purpose computing device. Components of the electronic device 200 may include, but are not limited to: at least one processing unit 210, at least one storage unit 220, a bus 230 connecting different system components (including the storage unit 220 and the processing unit 210), a display unit 240, and the like.

Wherein, the storage unit 220 stores program codes, and the program codes can be executed by the processing unit 210, so that the processing unit 210 executes the methods according to various exemplary implementations of the present application.

The storage unit 220 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 2201 and/or a cache storage unit 2202 , and may further include a read-only storage unit (ROM) 2203 .

The storage unit 220 may also include a program/utility 2204 having a set (at least one) of program modules 2205 . Such program modules 2205 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Implementations of networked environments may be included in each or some combination of these examples.

Bus 230 may represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local area using any of a variety of bus structures. bus.

The electronic device 200 can also communicate with one or more external devices 300 (such as keyboards, pointing devices, Bluetooth devices, etc.), and can also communicate with one or more devices that enable the user to interact with the electronic device 200, and/or communicate with Any device (eg, router, modem, etc.) that enables the electronic device 200 to communicate with one or more other computing devices. Such communication may occur through input/output (I/O) interface 250 . In addition, the electronic device 200 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN) and/or a public network such as the Internet) through the network adapter 260. The network adapter 260 can communicate with other modules of the electronic device 200 through the bus 230 . It should be appreciated that although not shown, other hardware and/or software modules may be used in conjunction with electronic device 200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives And data backup storage system, etc.

Through the description of the above implementations, those skilled in the art can easily understand that the example implementations described here can be implemented by software, or by combining software with necessary hardware. The technical solution according to the embodiment of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, U disk, mobile hard disk, etc.) or on a network, including Several instructions enable a computing device (which may be a personal computer, a server, or a network device, etc.) to execute the above-mentioned method according to the embodiments of the present application.

A software product may utilize any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: electrical connection with one or more conductors, portable disk, hard disk, random access memory (RAM), read only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

A computer readable storage medium may include a data signal carrying readable program code in baseband or as part of a carrier wave traveling as part of a data signal. Such propagated data signals may take many forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. A readable storage medium may also be any readable medium other than a readable storage medium that can send, propagate or transport a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the readable storage medium may be transmitted by any suitable medium, including but not limited to wireless, cable, optical cable, RF, etc., or any suitable combination of the above.

The program codes for performing the operations of the exemplary embodiments of the present application can be written in any combination of one or more programming languages, and the programming languages include object-oriented programming languages—such as Java, C++, etc., and also include A conventional procedural programming language - such as the "C" language or a similar programming language. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server to execute. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (for example, using an Internet service provider). business to connect via the Internet).

Those skilled in the art can understand that the above modules can be distributed in the device according to the description of the embodiment, or can be changed correspondingly in one or more devices that are uniquely different from the exemplary embodiments of the present application. The modules in the above embodiments can be combined into one module, and can also be further split into multiple sub-modules.

Exemplary embodiments of the present application have been specifically shown and described above. It should be understood that the application is not limited to the detailed structures, arrangements or methods of implementation described herein; on the contrary, this application is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

A method for discriminating the consistency of sending and receiving delays of a differential channel, used on the master side or the slave side of the differential channel, comprising:

calculating the channel delay of the differential channel;

adjusting the sampling data on both sides of the differential channel to a synchronous state;

Calculate the variation of the channel delay in real time, and when the variation of the channel delay is greater than the first threshold, start the judgment of the consistency of the transmission and reception delay of the channel, so as to obtain the transmission and reception delay of the channel The discriminant result of the consistency at the time; and

According to the judgment result of the consistency of the sending and receiving delay of the channel, it is determined whether to block the differential protection.
The method according to claim 1, wherein when the variation of the channel delay is greater than the first threshold, changing the first differential protection start threshold to a second differential protection start threshold, wherein, The second differential protection activation threshold is greater than the first differential protection activation threshold.
The method of claim 2, wherein,

When the judgment result of the consistency of the transmission and reception delays of the channels is that the transmission and reception delays of the channels are consistent, after the delay is confirmed, the second differential protection activation threshold is changed to the first a differential protection activation threshold; and

When the determination result of the consistency of the transmission and reception delays of the channels is that the transmission and reception delays of the channels are inconsistent, the differential protection is blocked.
The method according to claim 1, wherein the step of adjusting the sampled data on the two sides of the differential channel to a synchronous state comprises:

After calculating the channel delay, calculate the error Δt between the sampling time of the master side and the sampling time of the slave side according to the channel delay; and

Keep the sampling time on the master side unchanged, and gradually adjust the sampling time on the slave side until Δt tends to 0.
The method according to claim 1, wherein the real-time calculation of the change amount of the channel delay, when the change amount of the channel delay is greater than the first threshold value, start the channel delay The step of judging the consistency of sending and receiving delay includes:

Calculate the channel delay value T d (K) of the current sampling point K in real time, and compare it with the channel delay value T d (K-1) of the previous sampling point K-1 to obtain the channel delay value T d (K-1) The amount of change ΔT d , the calculation formula of the amount of change ΔT d is as follows:

ΔT d =abs(T d (K)-T d (K-1)),

Wherein, abs represents an absolute value, and when the change amount ΔT d of the channel delay is greater than the first threshold, the determination of the consistency of the sending and receiving delay of the channel is started.
The method according to claim 1, wherein the step of starting the determination of the consistency of the transmission and reception delay of the channel comprises:

In the case of using a single channel, start a method for judging the consistency of the sending and receiving delay of the channel in the single channel mode; or

In the case of dual-channel input, start the method of judging the consistency of channel sending and receiving delay in dual-channel mode.
The method according to claim 6, wherein the method for judging the consistency of the transmission and reception delay of the channel in the single channel mode comprises:

The protection devices on both sides of the differential channel are not activated, and the three-phase differential current I DiffΦ is greater than the first threshold value I Diffset , and the three-phase differential current variation ΔI DiffΦ is greater than the first threshold value I Diffset . When the second threshold setting value ΔI Diffset and the three-phase braking current variation ΔI BiasΦ are all smaller than the third threshold setting value ΔI Biasset , it is determined that the sending and receiving delays of the channels are inconsistent, and the three-phase differential current changes The calculation formula of the amount and the braking current variation of the three phases is as follows:

Among them, I DiffΦ (k), I BiasΦ (k) are the three-phase differential current and the three-phase brake current at the current sampling time point respectively; and I DiffΦ (kn), I BiasΦ (kn) are respectively a cycle The differential current of the previous three phases and the braking current of the three phases, where n is the number of sampling points of one cycle.
The method according to claim 6, wherein the method for judging the consistency of the sending and receiving delays of the channels in the dual-channel mode comprises:

When the channel delay variation ΔT d of only one of the two channels is greater than the first threshold, select the channel whose channel delay variation ΔT d is less than or equal to the first threshold as the first channel, The other channel is the second channel, and the sampling data on both sides of the two channels are adjusted to a synchronous state based on the channel delay of the first channel; and

calculating the channel delay of the second channel, and the slave side calculates an error Δt between the sampling time of the slave side and the sampling time of the master side according to the channel delay of the second channel;

Wherein, when the error Δt is smaller than the second threshold, it is judged that the sending and receiving delays of the second channel are consistent; and

When the error Δt is greater than or equal to the second threshold, it is determined that the sending and receiving delays of the second channel are inconsistent.
The method according to claim 6, wherein the method for determining the consistency of the sending and receiving delays of the channels in the dual-channel mode further comprises:

When the variation ΔT d of the channel delay of the two channels in the dual channels is greater than the first threshold, the channel with a smaller variation of the channel delay is selected as the first channel, and the variation of the channel delay is The larger channel is the second channel; and

Adjust the sampling data on both sides of the first channel to a synchronous state, and then perform the channel detection on the first channel according to the method for determining the consistency of the sending and receiving delay of the channel in the single channel mode Discrimination of the consistency of sending and receiving delays.
The method of claim 9, wherein,

When the judgment result of the first channel is that the channel delays of the first channel are consistent, the channel delay of the second channel is calculated, and the slave side calculates the channel delay of the second channel according to the channel delay of the second channel. The channel delay calculates the error Δt between the sampling moment of the slave side and the sampling moment of the master side;

Wherein, when the error Δt is smaller than the second threshold, it is judged that the sending and receiving delays of the second channel are consistent; and

When the error Δt is greater than or equal to the second threshold, it is determined that the sending and receiving delays of the second channel are inconsistent.
The method of claim 9, wherein,

When it is determined that the channel delays of the first channel are inconsistent, then the channel delay of the second channel is used as a benchmark to adjust the sampling data on both sides of the dual channels to a synchronous state, and then follow the single channel mode The method for judging the consistency of the sending and receiving delays of the channels judges the second channel.
The method according to claim 1, wherein the step of calculating the channel delay of the differential channel comprises:

The slave side sends the first frame message to the master side, and records the sending time t ss , when the master side receives the first frame message, records the receiving time t mr , and The second frame message is returned to the slave side at t ms time, and the time difference (t ms -t mr ) is sent to the slave side as the message content of the second frame message at the same time, and the slave The side receives the returned second frame message at time t sr , and extracts the time difference (t ms -t mr ) from the second frame message, wherein, the channel is calculated by the following formula Delay T d :
The method according to claim 12, wherein, after the step of adjusting the sampled data on the two sides of the differential channel to a synchronous state, the method further comprises:

According to the synchronized current data on both sides, the differential current and braking current are calculated by the following formula:

in,
are the Φ-phase currents of the master side and the slave side, respectively, and I DiffΦ , I BiasΦ are the differential current and the braking current of the Φ-phase, respectively.
A device for discriminating the consistency of sending and receiving delays of a differential channel, comprising:

A delay calculation module configured to calculate the channel delay of the differential channel;

a synchronization module, configured to adjust the sampling data on both sides of the differential channel to a synchronous state;

The delay change monitoring module is configured to calculate the change amount of the channel delay in real time, wherein, when the change amount of the channel delay is greater than a first threshold, the consistency of the transmit and receive delay of the channel is started discriminate; and

The judging module is configured to judge the consistency of channel sending and receiving delays.
An electronic device comprising:

A memory, a processor, and a computer program stored in the memory and operable on the processor, wherein, when the processor executes the computer program, the method described in any one of claims 1 to 13 is realized method steps.
A differential protection communication system, comprising the device according to claim 14 and/or the electronic device according to claim 15.