CN114400629A - Method for improving 5G differential protection economy based on disturbance identification - Google Patents
Method for improving 5G differential protection economy based on disturbance identification Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
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Abstract
The application discloses a method for improving 5G differential protection economy based on disturbance identification, which comprises the following steps: in the 5G differential protection of the distribution network line, normal messages are sent to other sides every T1 local side differential protection in a normal state; when disturbance occurs, the slave computer side continuously sends full data messages to the master computer side; the invention considers that the power distribution network has certain probability of disturbance and fault occurrence in normal operation, regularly sends synchronous state and state quantity related to differential motion in a normal state, and continuously sends full data messages only when disturbance, abnormality or fault occurs, thereby reducing the monthly average flow of 5G differential motion to the maximum extent, effectively reducing the monthly average flow of 5G differential motion, promoting the large popularization and application of 5G differential motion in the power distribution network, and improving the fault identification capability of the power distribution network, thereby solving the problems that the fault of a multi-terminal power line of the power distribution network cannot be accurately identified and the relay protection selectivity of the current power distribution network line is not high.
Description
Technical Field
The invention belongs to the technical field of distribution network line relay protection, and relates to a method for improving the economy of 5G differential protection based on disturbance identification.
Background
In recent years, with the improvement of the requirement on the power supply reliability of a power distribution network and the massive access of distributed power supplies, the traditional three-stage overcurrent protection cannot meet the requirement of relay protection of a power distribution network line.
The current differential protection is widely applied to the power transmission line as a main protection by virtue of a simple principle and good selectivity and quick action. The current differential protection is applied to the power distribution network line, and the problems that the relay protection selectivity of the existing power distribution network line is not high, and faults of a multi-terminal power supply line cannot be accurately identified can be well solved.
However, since the conventional line current differential protection must rely on optical fiber communication, most lines of the power distribution network are not suitable for laying a large number of optical fibers due to high investment cost, which results in that the application of the line current differential protection to the lines of the power distribution network is difficult to develop on a large scale.
At any time, the 5G communication technology is rapidly developed, a large number of base stations are built, and the current differential protection is generated on the basis of the 5G communication technology by combining the characteristics of short time delay, large capacity, high bandwidth and the like of the 5G. However, the data transmission amount of the current channel of the differential protection is large, the 5G month average data flow is high after 5G communication is used, the economy of 5G differential application is reduced, and the channel becomes one of limiting factors for limiting the application of the 5G differential protection in a power distribution network.
Disclosure of Invention
In order to overcome the defects in the prior art, the method for improving the 5G differential protection economy based on disturbance identification is provided.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a method for improving 5G differential protection economy based on disturbance identification specifically comprises the following steps:
in the 5G differential protection of the distribution network line, normal messages are sent to other sides every T1 local side differential protection in a normal state;
when disturbance occurs, the slave computer side continuously sends full data messages to the master computer side;
the T1 is the first period.
The invention further comprises the following preferred embodiments:
preferably, in the 5G differential protection of each side of the distribution network line, only one side is a master side, and the other sides are slave sides;
the host side determination mode is as follows: the side with the maximum address code setting value of the side device is the host side, and when the original host side protection exits due to abnormality, the side with the maximum address code setting value of the side device in the rest side protection automatically becomes the new host side.
Preferably, after receiving the request command from the host side, the slave side sends a full data message to the host side;
and after receiving the tripping command of the master machine side, the slave machine side executes the tripping command.
Preferably, the master side sends a request command to the slave side when a line is disturbed or a full data message of the slave side is received, and the master side summarizes the full data message of each slave side to perform trip logic judgment, where the judgment conditions are as follows:
|i1+i2+…+in|≥I0
|i1+i2+…+in|≥K·(|i1|+|i2|+…+|in|)
in the formula i1、i2、…、inIs a 1-n side current, K is a braking coefficient, I0Is the threshold of the differential current, n is the total number of each side;
if the tripping condition is met, the master side trips and simultaneously sends tripping commands and differential calculation results to all slave sides, after disturbance disappears and T2 passes, the master recovers normal operation, and normal messages are sent to all slave sides every T1;
if the tripping condition is not met, the disturbance disappears, and after the T2, the host machine recovers to normal operation, and normal messages are sent to each slave machine side every T1;
the T2 is a second period.
Preferably, when the line is disturbed or a request command of the host side is received, the slave side sends a full data message to the host side;
if the slave side receives the tripping command of the master side, the tripping command is executed, the disturbance disappears, the request command of the master cannot be received, after T2, the slave side recovers normal operation, and normal messages are sent to all the sides every T1;
if the tripping command of the host side is not received, the disturbance disappears and the request command of the host cannot be received, after T2, the local side recovers normal operation, and normal messages are sent to each side every T1;
the T2 is a second period.
Preferably, the distribution network line adopts a full data transmission mode in the maintenance or debugging stage, in the mode, each slave side is subjected to differential protection to continuously send full data messages to the master side, and the master side sends differential calculation results to each slave side, so that a user can conveniently check information such as differential current, braking current and the like in real time.
Preferably, in the distribution network line, the disturbance identification method specifically includes:
the differential protection terminal performs disturbance identification according to the collected voltage, current and frequency information of the local side in combination with disturbance identification criteria;
the disturbance identification criterion comprises a mutation criterion, a sequence component current criterion, an overcurrent criterion, a low-frequency criterion, a low-voltage criterion and a symmetry criterion.
Preferably, the disturbance identification criterion is specifically:
1) mutation criterion:
wherein, IQDFor setting the current to an abrupt change, UQDSetting a value for the voltage of the mutation quantity;
the specific calculation method of the mutation quantity comprises the following steps:
wherein the content of the first and second substances,
the three phases AB, BC and CA; k refers to the current moment of sampling; n is the number of sampling points in a power frequency period; (K-N) refers to sampling time 1 week before point K; (K-2N) refers to the sampling time 2 weeks before the K point;
when any mutation quantity continuously exceeds a fixed value for 4 times, the protection judges that the mutation quantity is disturbance;
2) judging a sequence component current;
when positive sequence current I1Greater than the secondary side rated current InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when negative sequence current I2Greater than the secondary side rated current by 0.25InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when positive sequence current 3I0Is greater than I0DZAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein: 3I03 times of zero sequence current; i is0DZSetting a zero sequence current value;
3) judging an overcurrent criterion;
the abrupt change disturbance element does not act, any phase current is more than 0.9 multiplied by min (the constant values of sections I, II and III of overcurrent), and after the current lasts for 30ms, the protection is judged as disturbance;
4) low-frequency and low-voltage criterion:
when the system frequency is detected to be lower than the low-frequency deloading frequency fixed value, the protection judges the system frequency to be disturbance;
when the voltage of any line is detected to be lower than a low voltage fixed value, the protection judges that the line is disturbance;
5) the symmetry criterion is as follows:
Imax/Imin>k, and Imin>0.05InAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein, ImaxIs the maximum value of the three-phase current, IminIs the minimum value of the three-phase current, and K is the symmetry coefficient.
Preferably, the normal state message includes a synchronous state of the terminal at the local side of the differential protection and a state quantity related to the differential protection;
the full data message comprises analog quantity data sampling points, synchronous states and state quantities.
Preferably, the method comprises in particular the steps of:
step 1: when the 5G differential protection of the distribution network line is put into operation and the channel is normal, judging whether a full data transmission mode is adopted, if so, entering a step 2, otherwise, entering a step 3;
step 2: the slave machine sends a full data message to the master machine, the master machine sends a request command and a differential calculation result to the slave machine, whether a tripping condition is met is judged, if the condition is met, a tripping logic is executed, and the step 1 is returned;
and step 3: each side of the distribution network line judges whether disturbance exists or a request order or a full data message of other sides is received, if so, the step 5 is carried out, otherwise, the step 4 is carried out;
and 4, step 4: sending normal messages every T1 and returning to the step 3;
and 5: judging whether the host is the host, if so, entering a step 6, otherwise, entering a step 8;
step 6: sending a request command to the slave machine side, summarizing the full data message of each slave machine side by the master machine side to carry out logic judgment, judging whether the trip information is met, if so, entering the local trip, sending a trip command and a differential calculation result to the slave machine side, entering the step 7, otherwise, directly entering the step 7;
and 7: judging whether the disturbance disappears and reaches T2, and when the disturbance disappears and reaches T2, the host machine recovers to normal operation and returns to 4;
and 8: sending a full data message to the host side, judging whether a tripping command is received, if so, tripping the host side to enter the step 9, otherwise, directly entering the step 9;
and step 9: judging whether the disturbance disappears, whether the request order cannot be received and reaches T2, and when the disturbance disappears and the request order of the host cannot be received, after T2, the slave machine recovers normal operation and returns to 4;
the T2 is a second period.
The beneficial effect that this application reached:
the invention considers that the power distribution network has certain probability of disturbance and fault occurrence in normal operation, regularly sends synchronous state and state quantity related to differential motion in a normal state, and continuously sends full data messages only when disturbance, abnormity or fault occurs, thereby reducing the monthly average flow of 5G differential motion to the maximum extent, effectively reducing the monthly average flow of 5G differential motion, promoting the large popularization and application of 5G differential motion in the power distribution network, and improving the fault identification capability of the power distribution network, thereby solving the problems that the multi-terminal power line fault of the power distribution network cannot be accurately identified and the relay protection selectivity of the current power distribution network line is not high, in particular, compared with the existing 5G line protection technology, the invention has the following advantages:
1. the invention identifies sending full data message when disturbance (not limited to fault), and only sends normal message when non-disturbance; the sending interval and the sent content are different, and the sending frequency of the same content is different in a conventional way;
2. the message with large flow rate is only sent from the slave to the host, and the flow rate is saved by at least one time compared with the mutual sending mode in the prior art;
3. the invention can be provided with two ends or multiple ends, especially the distribution network of a novel power system can be provided with multiple ends in the future, and the invention has wider adaptability;
4. the invention provides a symmetry criterion for the first time, and based on the more obvious asymmetry, the more recent the fault is away from a protection installation point, the possible fault is identified, and the existing line protection scheme does not use the solution;
5. in the invention, the distribution network line adopts a full data transmission mode in the maintenance or debugging stage, under the mode, each slave side is subjected to differential protection to continuously send full data messages to the master side, and the master side sends differential calculation results to each slave side, so that a user can conveniently check differential current and brake current information in real time.
Drawings
FIG. 1 illustrates an information transfer mechanism between a terminal and an associated terminal according to the present invention;
FIG. 2 is a flow chart of the method of the present invention;
FIG. 3 is a schematic diagram of a double-ended differential of the present invention;
FIG. 4 is a schematic diagram of the multi-terminal differential of the present invention.
In the drawings, M, N, K denotes the line terminals, CB: circuit Breaker denotes a Circuit Breaker, CT: current transformer denotes Current transformer, CPE: the Customer Premise Equipment represents a front-end 5G signal receiving device.
Detailed Description
The present application is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present application is not limited thereby.
The invention discloses a method for improving the economy of 5G differential protection based on disturbance identification, which specifically comprises the following steps:
in the 5G differential protection of the distribution network line, normal messages are sent to other sides every T1 local side differential protection in a normal state;
when disturbance, abnormity or fault occurs, the slave computer side continuously sends full data messages to the master computer side;
the T1 is the first period.
The information transmission mechanism of the present invention is shown in fig. 1, and the flow chart is shown in fig. 2, and channel optimization can be realized, and the differential connection mode of double-end or multi-end (taking three ends as an example) is shown in fig. 3 and fig. 4.
In specific implementation, in the 5G differential protection of each side of the distribution network line, only one side is a host side, and the other sides are slave sides;
the host side determination mode is as follows: the side with the maximum address code setting value of the side device is the host side, and when the original host side protection exits due to abnormality, the side with the maximum address code setting value of the side device in the rest side protection automatically becomes the new host side.
After receiving a request order of the host side, the slave side sends a full data message to the host side;
and after receiving the tripping command of the master machine side, the slave machine side executes the tripping command.
When the line is disturbed or the full data message of the slave side is received, the master side sends a request order to the slave side, and the master side collects the full data message of each slave side to carry out logic judgment:
when the line is disturbed or the full data message of the slave side is received, the master side sends a request order to the slave side, the master side collects the full data message of each slave side to carry out trip logic judgment, and the judgment conditions are as follows:
|i1+i2+…+in|≥I0
|i1+i2+…+in|≥K·(|i1|+|i2|+…+|in|)
in the formula i1、i2、…、inIs a 1-n side current, K is a braking coefficient, I0Is the threshold of the differential current, n is the total number of each side;
if the tripping condition is met, the host side trips and simultaneously sends tripping commands and differential calculation results to all slave sides, namely the tripping logic judgment content disappears, the host recovers normal operation after T2, and normal messages are sent to all slave sides every T1;
if the tripping condition is not met, the disturbance disappears, and after the T2, the host machine recovers to normal operation, and normal messages are sent to each slave machine side every T1;
the T2 is a second period.
When the line is disturbed or a request order of the host side is received, the slave side sends a full data message to the host side;
if the slave side receives the tripping command of the master side, the tripping command is executed, the disturbance disappears, the request command of the master cannot be received, after T2, the slave side recovers normal operation, and normal messages are sent to other sides every T1;
if the tripping command of the host side is not received, the disturbance disappears and the request command of the host cannot be received, after T2, the local side recovers normal operation, and normal messages are sent to other sides every T1;
the distribution network line adopts a full data transmission mode in the maintenance or debugging stage, under the mode, each slave side is subjected to differential protection to continuously send full data messages to the master side, and the master side sends differential calculation results to each slave side, so that a user can conveniently check information such as differential current, braking current and the like in real time.
In the distribution network line, the disturbance identification method specifically comprises the following steps:
the differential protection terminal performs disturbance identification by combining the information such as voltage, current, frequency and the like collected by the local side with disturbance identification criteria;
the disturbance identification criterion comprises a mutation criterion, a sequence component current criterion, an overcurrent criterion, a low-frequency criterion, a low-voltage criterion and a symmetry criterion.
The disturbance identification criterion is specifically as follows:
1) mutation criterion:
wherein, IQDFor setting the current to an abrupt change, UQDSetting a value for the voltage of the mutation quantity;
the specific calculation method of the mutation quantity comprises the following steps:
wherein the content of the first and second substances,
the three phases AB, BC and CA; k refers to the current moment of sampling; n is the number of sampling points in a power frequency period; (K-N) refers to sampling time 1 week before point K; (K-2N) refers to the sampling time 2 weeks before the K point;
when any mutation quantity continuously exceeds a fixed value for 4 times, the protection judges that the mutation quantity is disturbance;
2) judging a sequence component current;
when positive sequence current I1Greater than the secondary side rated current InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when negative sequence current I2Greater than the secondary side rated current by 0.25InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when positive sequence current 3I0Is greater than I0DZAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein: 3I03 times of zero sequence current; i is0DZSetting a zero sequence current value;
3) judging an overcurrent criterion;
the abrupt change disturbance element does not act, any phase current is more than 0.9 multiplied by min (the constant values of sections I, II and III of overcurrent), and after the current lasts for 30ms, the protection is judged as disturbance;
4) low-frequency and low-voltage criterion:
when the system frequency is detected to be lower than the low-frequency deloading frequency fixed value, the protection judges the system frequency to be disturbance;
when the voltage of any line is detected to be lower than a low voltage fixed value, the protection judges that the line is disturbance;
5) the symmetry criterion is as follows:
Imax/Imin>k, and Imin>0.05InAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein, ImaxIs the maximum value of the three-phase current, IminThe minimum value of the three-phase current is obtained, and K is a symmetry coefficient which can be set.
The normal state message comprises a differential protection local side terminal synchronous state and differential related state quantity;
the full data message comprises analog quantity data sampling points, synchronous states and state quantities.
As shown in fig. 2, a method for improving the economy of 5G differential protection based on disturbance identification of the present invention includes the following steps:
step 1: when the 5G differential protection of the distribution network line is put into operation and the channel is normal, judging whether a full data transmission mode is adopted, if so, entering a step 2, otherwise, entering a step 3;
step 2: the slave machine sends a full data message to the master machine, the master machine sends a request command and a differential calculation result to the slave machine, whether a tripping condition is met is judged, if the condition is met, a tripping logic is executed, and the step 1 is returned;
and step 3: each side of the distribution network line judges whether disturbance exists or a request order or a full data message of other sides is received, if so, the step 5 is carried out, otherwise, the step 4 is carried out;
and 4, step 4: sending normal messages every T1 and returning to the step 3;
and 5: judging whether the host is the host, if so, entering a step 6, otherwise, entering a step 8;
step 6: sending a request command to the slave machine side, summarizing the full data message of each slave machine side by the master machine side to carry out logic judgment, judging whether the trip information is met, if so, entering the local trip, sending a trip command and a differential calculation result to the slave machine side, entering the step 7, otherwise, directly entering the step 7;
and 7: judging whether the disturbance disappears and reaches T2, and when the disturbance disappears and reaches T2, the host machine recovers to normal operation and returns to 4;
and 8: sending a full data message to the host side, judging whether a tripping command is received, if so, tripping the host side to enter the step 9, otherwise, directly entering the step 9;
and step 9: judging whether the disturbance disappears, whether the request order cannot be received and reaches T2, and when the disturbance disappears and the request order of the host cannot be received, after T2, the slave machine recovers normal operation and returns to 4;
the T2 is a second period.
In recent years, with the improvement of the requirement on the power supply reliability of a power distribution network and the rapid development of a 5G communication technology, the differential protection pilot point based on the 5G communication is applied to a power distribution network circuit, and the problems that faults of a multi-terminal power supply circuit cannot be accurately identified and the relay protection selectivity of the current power distribution network circuit is not high can be well solved. However, at present, the data transmission amount of the 5G differential protection channel is large, so that the data flow rate in 5G month is high, the economy of 5G differential application is not competitive, and the popularization of 5G differential is hindered. The invention provides a method for improving the 5G differential protection economy based on disturbance identification, and aims to solve the economic problem that 5G differential protection can be popularized and applied in batches.
The present applicant has described and illustrated embodiments of the present invention in detail with reference to the accompanying drawings, but it should be understood by those skilled in the art that the above embodiments are merely preferred embodiments of the present invention, and the detailed description is only for the purpose of helping the reader to better understand the spirit of the present invention, and not for limiting the scope of the present invention, and on the contrary, any improvement or modification made based on the spirit of the present invention should fall within the scope of the present invention.
Claims (10)
1. A method for improving the economy of 5G differential protection based on disturbance identification is characterized in that:
the method specifically comprises the following steps:
in the 5G differential protection of the distribution network line, normal messages are sent to other sides every T1 local side differential protection in a normal state;
when disturbance occurs, the slave computer side continuously sends full data messages to the master computer side;
the T1 is a first period;
in the 5G differential protection of each side of the distribution network line, only one side is a host side, and the other sides are slave sides;
the host side determination mode is as follows: the side with the maximum address code setting value of the side device is the host side, and when the original host side protection exits due to abnormality, the side with the maximum address code setting value of the side device in the rest side protection automatically becomes the new host side.
2. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
after receiving a request order of the host side, the slave side sends a full data message to the host side;
and after receiving the tripping command of the master machine side, the slave machine side executes the tripping command.
3. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
the master side sends a request command to the slave side when a line is disturbed or a full data message of the slave side is received, and the master side collects the full data messages of the slave sides to carry out trip logic judgment;
if the tripping condition is met, the master side trips and simultaneously sends tripping commands and differential calculation results to all slave sides, after disturbance disappears and T2 passes, the master recovers normal operation, and normal messages are sent to all slave sides every T1;
if the tripping condition is not met, the disturbance disappears, and after the T2, the host machine recovers to normal operation, and normal messages are sent to each slave machine side every T1;
the T2 is a second period.
4. The method for improving the 5G differential protection economy based on disturbance identification according to claim 3, wherein the method comprises the following steps:
the master side collects the full data messages of all the slave sides to carry out trip logic judgment, and the judgment conditions are as follows:
|i1+i2+…+in|≥I0
|i1+i2+…+in|≥K·(|i1|+|i2|+…+|in|)
in the formula i1、i2、…、inIs a 1-n side current, K is a braking coefficient, I0The differential current threshold is, n is the total number of sides.
5. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
when the line is disturbed or a request order of the host side is received, the slave side sends a full data message to the host side;
if the slave side receives the tripping command of the master side, the tripping command is executed, the disturbance disappears, the request command of the master cannot be received, after T2, the slave side recovers normal operation, and normal messages are sent to other sides every T1;
if the tripping command of the host side is not received, the disturbance disappears and the request command of the host cannot be received, after T2, the local side recovers normal operation, and normal state messages are sent to other sides every T1;
the T2 is a second period.
6. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
the distribution network line adopts a full data transmission mode in the maintenance or debugging stage, under the mode, each slave side is subjected to differential protection to continuously send full data messages to the master side, and the master side sends differential calculation results to each slave side, so that a user can conveniently check differential current and braking current information in real time.
7. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
in the distribution network line, the disturbance identification method specifically comprises the following steps:
the differential protection terminal performs disturbance identification according to the collected voltage, current and frequency information of the local side in combination with disturbance identification criteria;
the disturbance identification criterion comprises a mutation criterion, a sequence component current criterion, an overcurrent criterion, a low-frequency criterion, a low-voltage criterion and a symmetry criterion.
8. The method for improving the 5G differential protection economy based on disturbance identification according to claim 7, wherein the method comprises the following steps:
the disturbance identification criterion is specifically as follows:
1) mutation criterion:
wherein, IQDFor setting the current to an abrupt change, UQDSetting a value for the voltage of the mutation quantity;
the specific calculation method of the mutation quantity comprises the following steps:
wherein the content of the first and second substances,
the three phases AB, BC and CA; k refers to the current moment of sampling; n is the number of sampling points in a power frequency period; (K-N) refers to sampling time 1 week before point K; (K-2N) refers to the sampling time 2 weeks before the K point;
when any mutation quantity continuously exceeds a fixed value for 4 times, the protection judges that the mutation quantity is disturbance;
2) judging a sequence component current;
when positive sequence current I1Greater than the secondary side rated current InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when negative sequence current I2Greater than the secondary side rated current by 0.25InAfter the time lasts for 30ms, the protection is judged to be disturbance;
when positive sequence current 3I0Is greater than I0DZAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein: 3I03 times of zero sequence current; i is0DZSetting a zero sequence current value;
3) judging an overcurrent criterion;
the abrupt change disturbance element does not act, any phase current is more than 0.9 multiplied by min (the constant values of sections I, II and III of overcurrent), and after the current lasts for 30ms, the protection is judged as disturbance;
4) low-frequency and low-voltage criterion:
when the system frequency is detected to be lower than the low-frequency deloading frequency fixed value, the protection judges the system frequency to be disturbance;
when the voltage of any line is detected to be lower than a low voltage fixed value, the protection judges that the line is disturbance;
5) the symmetry criterion is as follows:
Imax/Imin>k, and Imin>0.05InAfter the time lasts for 30ms, the protection is judged to be disturbance;
wherein, ImaxIs the maximum value of the three-phase current, IminIs the minimum value of the three-phase current, and K is the symmetry coefficient.
9. The method for improving the 5G differential protection economy based on disturbance identification according to claim 1, wherein the method comprises the following steps:
the normal state message comprises a differential protection local side terminal synchronous state and differential related state quantity;
the full data message comprises analog quantity data sampling points, synchronous states and state quantities.
10. The method for improving the 5G differential protection economy based on disturbance identification according to any one of claims 1-9, characterized by:
the method specifically comprises the following steps:
step 1: when the 5G differential protection of the distribution network line is put into operation and the channel is normal, judging whether a full data transmission mode is adopted, if so, entering a step 2, otherwise, entering a step 3;
step 2: the slave machine sends a full data message to the master machine, the master machine sends a request command and a differential calculation result to the slave machine, whether a tripping condition is met is judged, if the condition is met, a tripping logic is executed, and the step 1 is returned;
and step 3: each side of the distribution network line judges whether disturbance exists or a request order or a full data message of other sides is received, if so, the step 5 is carried out, otherwise, the step 4 is carried out;
and 4, step 4: sending normal messages every T1 and returning to the step 3;
and 5: judging whether the host is the host, if so, entering a step 6, otherwise, entering a step 8;
step 6: sending a request command to the slave machine side, summarizing the full data message of each slave machine side by the master machine side to carry out logic judgment, judging whether the trip information is met, if so, entering the local trip, sending a trip command and a differential calculation result to the slave machine side, entering the step 7, otherwise, directly entering the step 7;
and 7: judging whether the disturbance disappears and reaches T2, and when the disturbance disappears and reaches T2, the host machine recovers to normal operation and returns to 4;
and 8: sending a full data message to the host side, judging whether a tripping command is received, if so, tripping the host side to enter the step 9, otherwise, directly entering the step 9;
and step 9: judging whether the disturbance disappears, whether the request order cannot be received and reaches T2, and when the disturbance disappears and the request order of the host cannot be received, after T2, the slave machine recovers normal operation and returns to 4;
the T2 is a second period.
Priority Applications (1)
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115313328A (en) * | 2022-08-30 | 2022-11-08 | 国网安徽省电力有限公司淮北供电公司 | Power system 5G communication differential protection method and storage medium |
| CN116866157A (en) * | 2023-09-05 | 2023-10-10 | 珠海菲森电力科技有限公司 | Data transmission method based on 5G longitudinal differential protection |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115313328A (en) * | 2022-08-30 | 2022-11-08 | 国网安徽省电力有限公司淮北供电公司 | Power system 5G communication differential protection method and storage medium |
| CN116866157A (en) * | 2023-09-05 | 2023-10-10 | 珠海菲森电力科技有限公司 | Data transmission method based on 5G longitudinal differential protection |
| CN116866157B (en) * | 2023-09-05 | 2023-11-14 | 珠海菲森电力科技有限公司 | Data transmission method based on 5G longitudinal differential protection |
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