A substation anti-bypass tripping system and method based on a dedicated port

Abstract

The application discloses a substation anti-leapfrog tripping system and method based on a special port and belongs to the technical field of relay protection. The application is used for realizing current amplitude real-time mutation quantity monitoring and starting of a feeder protection device, rapidly judging a sudden large current and reliably sending a blocking information, and ensuring that the blocking signal is sent to the special port within a short time limit after the sudden large current, and when a line-in protection device detects self-speed breaking protection action, a short time delay is added to broadcast and call an overcurrent state of a relevant feeder and the next level protection device. When the feeder and the next level protection device start the speed breaking protection during the period, the self-speed breaking protection is blocked within a predetermined time limit. Within the blocking time limit, if the feeder switch fails to successfully remove the fault, it is judged that the feeder circuit breaker fails, and the line-in protection device must immediately release the phase blocking and send a tripping command to avoid expansion of a fault interval.

Description

Technical Field

[0001] This invention belongs to the technical field of relay protection, and in particular relates to a substation anti-over-level tripping system and method based on a dedicated port. Background Technology

[0002] In railway substations, overcurrent protection is typically categorized into three types based on time: instantaneous overcurrent, overcurrent protection, and overload protection. All of these are achieved by assessing the magnitude and duration of the current. For short-circuit faults near the substation, the fault current is large, and the current detected by each level of protection device is similar. This fault current can simultaneously meet the protection settings of multiple circuit breakers, causing them to trip simultaneously, posing a risk of cascading tripping.

[0003] The incoming and feeder circuit breakers in railway substations primarily rely on instantaneous overcurrent and definite-time overcurrent protection. Both levels of instantaneous overcurrent protection are set to a 0-second delay. Although the capacity of the incoming circuit breaker is larger than that of the feeder, the large current caused by a fault near the feeder also exceeds the instantaneous overcurrent of the incoming circuit breaker. Considering the need for matching with the protection of the upstream substation, the instantaneous overcurrent time limit is difficult and unsuitable to adjust. Therefore, the existing conventional instantaneous overcurrent protection in substations cannot effectively prevent cascading tripping. If bus differential protection is used as the main protection for the incoming circuit breaker, and instantaneous overcurrent protection is disabled while only overcurrent protection (with a delay of over 300 milliseconds) is enabled, there are disadvantages such as complex wiring, high overall cost, and increased maintenance. Currently, there is no mature protection device for preventing cascading tripping in railway substations. Summary of the Invention

[0004] To address the technical problems existing in the background art described above, this invention provides a substation anti-over-level tripping system and method based on a dedicated port.

[0005] The present invention adopts the following technical solution: a substation anti-over-level tripping system based on a dedicated port, comprising: a feeder protection device and a feeder protection switch installed on the feeder, a bus tie protection device and a tie protection switch installed on the bus tie, and an incoming line protection device and an incoming line protection switch installed on the incoming line.

[0006] Among them, the feeder protection device, bus tie protection device and incoming line protection device share information with each other using a star-shaped GOOSE network structure. Each protection device's GOOSE port uses an independent chip and a switch with traffic suppression function is selected.

[0007] In a further embodiment, each protection device receives a GOOSE message from a subscription device; wherein the subscription device includes: other protection devices in this substation and other protection devices outside this substation that are directly connected to it.

[0008] The substation anti-cascading tripping method based on dedicated ports, using the substation anti-cascading tripping system described above, includes the following steps:

[0009] The protection device monitors whether a current surge occurs by monitoring the real-time surge in current amplitude. If a surge occurs, the corresponding protection switch type is obtained based on the monitored protection device. The corresponding data adjustment mode is selected based on the protection switch type, and the time point of the next data conversion is updated using the data adjustment mode to obtain the effective value of the fundamental current. The corresponding overcurrent judgment logic is pre-configured according to the protection switch type.

[0010] Based on the fundamental effective value of the current, the corresponding overcurrent judgment logic is selected to obtain the logic judgment result, and the corresponding protection scheme is generated according to the logic judgment result; the protection device includes at least one of the following: feeder protection device, bus tie protection device and incoming line protection device; the type of protection switch corresponds to the protection device.

[0011] In a further embodiment, the protection switch type includes: incoming line protection switch, tie protection switch, and feeder protection switch;

[0012] The protection switch type is an incoming line protection switch. The data adjustment mode is to adjust one cycle of data starting from the abrupt change point. After adjustment, the data is converted using the full-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0013] The protection switch type is a tie protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0014] The protection switch type is a feeder protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0015] In a further embodiment, the overcurrent judgment logic includes: overcurrent judgment logic for incoming line protection switches, overcurrent judgment logic for tie protection switches, and overcurrent judgment logic for feeder protection switches.

[0016] In a further embodiment, the flow of the overcurrent judgment logic regarding the incoming line protection switch is as follows:

[0017] The obtained fundamental current RMS value is compared and analyzed with the preset overcurrent setting. When the fundamental current RMS value is greater than the preset overcurrent setting: any subscribed device is overcurrent, that is, a blocking GOOSE message is received from any subscribed device, and a blocking overcurrent protection action is generated according to the blocking GOOSE message; when the duration of the blocking overcurrent protection action exceeds the blocking time limit, the incoming line protection device trips due to overcurrent.

[0018] If any subscription device experiences an overcurrent, the incoming line protection device will immediately lock out the overcurrent trip.

[0019] In a further embodiment, the overcurrent judgment logic for the interconnection protection switch is as follows:

[0020] The obtained fundamental RMS value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental RMS value of the current is greater than the preset overcurrent setting, an overcurrent action GOOSE message is sent immediately. The bus tie protection device adjusts the time point for the next full-cycle Fourier calculation based on the time of the current change. After the full-cycle Fourier calculation is performed, the overcurrent protection judgment is performed again.

[0021] If the bus tie protection device experiences an overcurrent, and any subscribed device experiences an overcurrent, i.e., a blocking GOOSE message is received from any subscribed device, then a blocking overcurrent protection action is generated based on the blocking GOOSE message; if the duration of the blocking overcurrent protection action exceeds the blocking time limit, the bus tie protection device will trip due to overcurrent.

[0022] In a further embodiment, the overcurrent judgment logic for the feeder protection switch is as follows:

[0023] The obtained fundamental effective value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental effective value of the current is greater than the preset overcurrent setting, an overcurrent action GOOSE message is sent immediately, and the feeder protection switch trips due to overcurrent.

[0024] In a further embodiment, the blocking GOOSE message includes: the name of the substation, the name of the protection device and the GoID identifier, as well as the blocking action command and the blocking time limit.

[0025] In a further embodiment, the overcurrent action GOOSE message includes: the name of the substation, the name of the protection device and the GoID identifier, and the overcurrent action command.

[0026] The beneficial effects of this invention are as follows: This invention achieves system-wide linkage of protection devices within railway substations, effectively reducing the incidence of cascading trips. The digital current protection scheme utilizes a GOOSE network to share information between protection devices within and between stations, thereby quickly locating fault sections, ensuring consistent action times across different fault points, and effectively reducing the amount of hardwiring between devices. By setting VLANs on the GOOSE switches, it is ensured that each device only receives GOOSE messages from subscribed devices, and each device must be designed with operating parameters according to the main power supply wiring. A network storm suppression mechanism ensures the reliability of data communication between protection devices. This includes adopting a star topology network, using independent chips for the GOOSE ports of each device, and selecting switches with traffic suppression capabilities.

[0027] For feeder protection devices, real-time monitoring of sudden current amplitude changes is implemented to quickly identify sudden large current changes and reliably send blocking information. This ensures that the blocking signal can be sent to a dedicated port within a short time limit (e.g., 10 milliseconds) after a sudden large current change. For upstream protection devices such as incoming lines, when they detect their own instantaneous overcurrent protection action, a short delay (e.g., 20 milliseconds) is added to broadcast the overcurrent status of related downstream protection devices such as feeders. When the downstream protection device receives a signal to activate its instantaneous overcurrent protection during this period, it blocks its own instantaneous overcurrent protection within a certain time limit. Due to the sum of the feeder protection device's own instantaneous overcurrent action time and the inherent action time of a typical circuit breaker, the fault area can generally be isolated within 80 milliseconds. When the incoming line protection device detects an instantaneous overcurrent exceeding 100 milliseconds and the feeder switch issues an instantaneous overcurrent blocking GOOSE message, it is determined that the feeder circuit breaker has failed. The incoming line protection device must immediately release the phase blocking and issue a trip command to prevent the fault area from expanding. Attached Figure Description

[0028] Figure 1 This is a flowchart of a substation anti-over-level tripping method based on a dedicated port.

[0029] Figure 2 This is the operation logic diagram for the incoming line protection switch.

[0030] Figure 3 This is the operation logic diagram for the bus tie switch.

[0031] Figure 4 This is the operation logic diagram of the voltage regulator switch.

[0032] Figure 5 A schematic diagram of the power distribution lines that supply power to the system.

[0033] Figure 6 This is a schematic diagram showing that the power supply fault point on this side occurs in the feeder.

[0034] Figure 7 This is the timing diagram for the normal fault clearing of feeder 2 in condition one.

[0035] Figure 8 The timing diagram is for the failure of the feeder 2 circuit breaker in condition one.

[0036] Figure 9 A schematic diagram showing a fault point in a feeder line supplying power to the bus coupler.

[0037] Figure 10 This is the timing diagram for the normal clearing of the fault in feeder 2 under condition 2.

[0038] Figure 11 This is the timing diagram for the failure of the feeder 2 circuit breaker in scenario two.

[0039] Figure 12This diagram shows a power supply to the incoming line on this side, with the fault occurring in a through or automatically closed line.

[0040] Figure 13 A schematic diagram showing a fault point in a through-line or self-closing line supplying power to the bus tie.

[0041] Figure 14 This is the timing diagram for the normal disconnection of the fault in feeder 2 under condition 4.

[0042] Figure 15 The timing diagram for the failure of the feeder 2 circuit breaker in situation four is shown. Detailed Implementation

[0043] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0044] Example 1

[0045] This embodiment discloses a substation anti-overlapping tripping system based on dedicated ports, including: feeder protection devices and feeder protection switches installed on feeders, bus tie protection devices and tie protection switches installed on bus tie, and incoming line protection devices and incoming line protection switches installed on incoming lines; wherein, the feeder protection devices, bus tie protection devices and incoming line protection devices share information with each other using a star-shaped GOOSE network structure, and each protection device's GOOSE port uses an independent chip and selects a switch with flow suppression function.

[0046] In this embodiment, the GOOSE port is 100Mbps. A GOOSE switch is used to network the relevant digital overcurrent devices, enabling information sharing between protection devices within and between stations. The GOOSE switch's VLAN needs to be configured to ensure that each protection device only receives GOOSE messages from the relevant line protection device. Each protection device must operate according to the substation's main power supply wiring design parameters to achieve integrated protection across the entire substation, rapid fault location, consistent action time across different fault points, and effectively reduce the number of hardwired connections between devices.

[0047] In other words, each protection device receives GOOSE messages from the subscribing devices; wherein, the subscribing devices include: other protection devices in this substation and other protection devices outside this substation that are directly connected to it.

[0048] Example 2

[0049] This embodiment discloses a substation anti-cascading tripping method based on a dedicated port, such as... Figure 1As shown, the process includes the following steps: The protection device monitors whether a current surge occurs by using real-time current amplitude surge monitoring; if a surge occurs, the corresponding protection switch type is obtained based on the monitored protection device; the corresponding data adjustment mode is selected based on the protection switch type, and the time point of the next data conversion is updated using the data adjustment mode to obtain the effective value of the current fundamental wave; the corresponding overcurrent judgment logic is pre-configured according to the protection switch type.

[0050] Based on the fundamental effective value of the current, the corresponding overcurrent judgment logic is selected to obtain the logic judgment result, and the corresponding protection scheme is generated according to the logic judgment result; the protection device includes at least one of the following: feeder protection device, bus tie protection device and incoming line protection device; the type of protection switch corresponds to the protection device.

[0051] Specifically, the types of protection switches include: incoming line protection switches, tie protection switches (such as bus tie, voltage regulator, etc.) and feeder protection switches; the corresponding interlocking relationships are as follows: when the feeder overcurrent protection operates, the incoming line or bus tie overcurrent protection is interlocked; when the bus tie overcurrent protection operates, the incoming line overcurrent protection is interlocked.

[0052] In this embodiment, the protection switch type is an incoming line protection switch, and the data adjustment mode is to adjust one cycle of data starting from the abrupt change point. After adjustment, the data is converted using the full-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0053] The protection switch type is a tie protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0054] The protection switch type is a feeder protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave.

[0055] The overcurrent judgment logic in this embodiment includes: overcurrent judgment logic for incoming line protection switches, overcurrent judgment logic for tie protection switches, and overcurrent judgment logic for feeder protection switches.

[0056] Combination Figure 2 The flow of the overcurrent judgment logic for the incoming line protection switch is as follows:

[0057] The obtained fundamental RMS value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental RMS value of the current is greater than the preset overcurrent setting: if any subscribed device is overcurrent, i.e., a blocking GOOSE message is received from any subscribed device, then a blocking overcurrent protection action is generated according to the blocking GOOSE message; if the duration of the blocking overcurrent protection action exceeds the blocking time limit, the incoming line protection device will trip due to overcurrent; if any subscribed device is overcurrent, the incoming line protection device will immediately block the overcurrent trip.

[0058] Combination Figure 3 and Figure 4 Taking the bus tie switch and voltage regulator switch as examples respectively, the overcurrent judgment logic of the tie protection switch is as follows:

[0059] The obtained fundamental RMS value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental RMS value of the current is greater than the preset overcurrent setting, an overcurrent action GOOSE message is sent immediately. The bus tie protection device adjusts the time point for the next full-cycle Fourier calculation based on the time of the current change. After the full-cycle Fourier calculation is performed, the overcurrent protection judgment is performed again.

[0060] If the bus tie protection device experiences an overcurrent, and any subscribed device experiences an overcurrent, i.e., a blocking GOOSE message is received from any subscribed device, then a blocking overcurrent protection action is generated based on the blocking GOOSE message; if the duration of the blocking overcurrent protection action exceeds the blocking time limit, the bus tie protection device will trip due to overcurrent.

[0061] The flow of the overcurrent judgment logic for the feeder protection switch is as follows:

[0062] The obtained fundamental effective value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental effective value of the current is greater than the preset overcurrent setting, an overcurrent action GOOSE message is sent immediately, and the feeder protection switch trips due to overcurrent.

[0063] Based on the above description, the blocking GOOSE message includes: the substation name, the name of the protection device, the GoID identifier, the blocking action command, and the blocking time limit. The overcurrent action GOOSE message includes: the substation name, the name of the protection device, the GoID identifier, and the overcurrent action command. In other words, the substation name and the switch name constitute the GoID identifier of the GOOSE message. A table is created where each GoID corresponds to a unique APPID. Both the GoID and APPID are unique across the entire substation. The device receiving this message determines whether it is a message it has subscribed to based on the destination MAC address (this step is not required for simplicity), the GoID, and the APPID. The station_name + IED_name and the APPID (0x0000~0x3FFF, where the high byte is the station identifier and the low byte is the device identifier) ​​are both unique across the entire network.

[0064] This method places significant demands on and reliance on the internal network channel. To prevent protection failures due to network channel issues, digital protection devices need to monitor the network channel in real time. Upon receiving network interruption blocking information, the instantaneous overcurrent protection judgment logic and blocking should be immediately released within 30 milliseconds, and all levels of instantaneous overcurrent protection should resume normal function. Once the network interruption blocking information is released, the instantaneous overcurrent protection judgment logic and blocking conditions should be restored immediately. Because the blocking information directly affects the protection action output delay, the timeliness and accuracy of the protection device's scanning are extremely important, requiring verification through completeness and speed.

[0065] The following will illustrate this with specific examples. Figure 5 In the middle section, the incoming line, feeder, voltage regulator, through-connector, and automatic shut-off are all in the closed position; the bus tie is in the open position.

[0066] The subscription relationships between protection devices and protection switches via the GOOSE port are shown in the table below:

[0067] Switch number Subscription switch number Incoming Line 1 Feeder 1, Feeder 2, Feeder 3, Voltage Regulator 1, Bus Tie Line 2 Feeder 4, Feeder 5, Feeder 6, Voltage Regulator 2, Bus Tie Mother joint Feeder 1, Feeder 2, Feeder 3, Voltage Regulator 1, Feeder 4, Feeder 5, Feeder 6, Voltage Regulator 2 Feeder 1 --- Feeder 2 --- Feeder 3 --- Voltage Regulator 1 West through, East through West through --- East through --- Feeder 4 --- Feeder 5 --- Feeder 6 --- Voltage regulator 2 Western autism, Eastern autism West Autism --- East Autism ---

[0068] The overcurrent setting is explained as follows:

[0069] The incoming line overcurrent starting value shall not be less than the feeder overcurrent starting value (primary value);

[0070] The overcurrent delay of the incoming line shall not be less than the overcurrent delay of the feeder line (0.00 seconds to 10.00 seconds);

[0071] The incoming line overcurrent starting value shall not be less than the bus tie overcurrent starting value (primary value);

[0072] The overcurrent delay of the incoming line shall not be less than the overcurrent delay of the connection (0.00 seconds to 10.00 seconds);

[0073] The overcurrent starting value of the connection shall not be less than the overcurrent starting value of the feeder (primary value);

[0074] The overcurrent delay of the connection shall not be less than the overcurrent delay of the feeder (0.00 seconds to 10.00 seconds);

[0075] The maximum time limit for overcurrent blocking, i.e. the circuit breaker failure delay, shall not be less than the circuit breaker tripping time, with a default value of 100 milliseconds.

[0076] Situation 1: The incoming power supply is on this side, and the fault point is in the feeder.

[0077] Combination Figure 6 and Figure 8 ,contrast Figure 7 and Figure 8 The following methods for preventing cascading tripping are implemented using this approach:

[0078] (1) Both the feeder 2 protection device and the incoming line 1 protection device simultaneously sensed a sudden change in current;

[0079] (2) The feeder 2 protection device adjusts the timing of the next half-cycle Fourier calculation based on the timing of the current sudden change.

[0080] (3) The incoming line 1 protection device adjusts the timing of the next full-cycle Fourier calculation based on the timing of the current sudden change.

[0081] (4) After the feeder 2 protection device performs half-cycle calculation (approximately 10ms after the sudden change), it performs the blocking logic judgment.

[0082] (5) After the feeder 2 protection device finishes its judgment, it immediately issues a GOOSE message (overcurrent start);

[0083] (6) If the feeder 2 protection device operates in an overcurrent condition, it will trip immediately;

[0084] (7) After the full cycle calculation of the incoming line 1 protection device (approximately 20ms after the sudden change), the overcurrent protection judgment is performed;

[0085] (8) If the incoming line 1 protection device is overcurrent and any subscribed device is overcurrent, the incoming line overcurrent protection is blocked. If no subscribed device is overcurrent, the incoming line 1 protection device will trip immediately.

[0086] (9) The overcurrent protection device of incoming line 1 is blocked for more than the maximum blocking time limit, that is, the circuit breaker of feeder 2 fails and the overcurrent trip of incoming line 1.

[0087] Scenario 2: Bus tie power supply, the fault point is in the feeder.

[0088] Combination Figure 9 and Figure 11 ,contrast Figure 10 and Figure 11 The following methods for preventing cascading tripping are implemented using this approach:

[0089] (1) Feeder 2 protection device, bus tie protection device and incoming line 2 protection device simultaneously sense a sudden current change;

[0090] (2) The feeder 2 protection device and the bus tie protection device adjust the timing of the next half-cycle Fourier calculation according to the timing of the current sudden change.

[0091] (3) The protection device for incoming line 2 adjusts the timing of the next full-cycle Fourier calculation based on the timing of the current sudden change.

[0092] (4) After the feeder 2 protection device performs half-cycle calculation (approximately 10ms after the sudden change), it performs the blocking logic judgment.

[0093] (5) After the feeder 2 protection device finishes its judgment, it immediately sends a GOOSE message;

[0094] (6) If the feeder 2 protection device operates in an overcurrent condition, it will trip immediately;

[0095] (7) After the bus tie protection device performs half-cycle calculation (approximately 10ms after the sudden change), the blocking logic judgment is performed.

[0096] (8) The bus tie protection device shall immediately issue a GOOSE message (overcurrent start) after the judgment is completed;

[0097] (9) The bus tie protection device adjusts the timing of the next full-cycle Fourier calculation based on the timing of the current surge.

[0098] (10) After the bus tie protection device performs full-cycle calculation (approximately 20ms after a sudden change), it performs overcurrent protection judgment;

[0099] (11) The bus tie protection device is overcurrent, and the subscribed feeder 2 protection device is overcurrent. It blocks its own overcurrent protection, and the blocking delay is the set time. At the same time, it publishes a GOOSE message (overcurrent action is blocked and blocking delay).

[0100] (12) After the full cycle calculation of the protection device of incoming line 2 (approximately 20ms after the sudden change), the overcurrent protection judgment is performed;

[0101] (13) When the incoming line 2 protection device is overcurrent, and the subscribed bus tie protection device is in overcurrent lockout state, the incoming line overcurrent protection is locked out. The time limit for the overcurrent lockout of the incoming line 2 protection device is the set time plus the time limit for the bus tie to be locked out.

[0102] (14) The overcurrent protection device of the bus tie is blocked for more than the maximum blocking time limit, that is, the circuit breaker of feeder 2 fails and the bus tie is activated.

[0103] (15) The overcurrent protection device of incoming line 2 is blocked for more than twice the maximum blocking time limit, that is, the overcurrent action of incoming line 2 is caused by the failure of the feeder 2 circuit breaker plus the failure of the bus tie circuit breaker.

[0104] Scenario 3: The incoming line supplies power to this side, and the fault occurs in a through-line or automatically closed line. The following anti-over-level tripping method is implemented using this approach:

[0105] (1) The West Through Protection Device, Voltage Regulator 1 Protection Device and Incoming Line 1 Protection Device simultaneously sensed a sudden change in current.

[0106] (2) The West-through protection device and the voltage regulator 1 protection device adjust the time of the next half-cycle Fourier calculation according to the time when the current sudden change occurs.

[0107] (3) The incoming line 1 protection device adjusts the timing of the next full-cycle Fourier calculation based on the timing of the current sudden change.

[0108] (4) After the west-through protection device performs half-cycle calculation (approximately 10ms after the sudden change), the blocking logic judgment is performed.

[0109] (5) The West Through Protection Device shall immediately issue a GOOSE message after the judgment is completed;

[0110] (6) The through-current protection device will trip immediately if it operates under overcurrent conditions;

[0111] (7) After the voltage regulator 1 protection device performs half-cycle calculation (approximately 10ms after the sudden change), the interlocking logic judgment is performed;

[0112] (8) After the voltage regulator 1 protection device finishes its judgment, it immediately issues a GOOSE message (overcurrent start);

[0113] (9) The voltage regulator 1 protection device adjusts the time of the next full-cycle Fourier calculation according to the time when the current sudden change occurs.

[0114] (10) After the voltage regulator 1 protection device performs full-cycle calculation (approximately 20ms after a sudden change), it performs overcurrent protection judgment;

[0115] (11) When the voltage regulator 1 protection device is overcurrent and the subscribed through device is overcurrent, it locks its own overcurrent protection. The lockout time limit is the set time, and at the same time, it publishes a GOOSE message (overcurrent action is locked and the lockout time limit).

[0116] (12) After the full cycle calculation of the incoming line 1 protection device (approximately 20ms after the sudden change), the overcurrent protection judgment is performed;

[0117] (13) If the incoming line 1 protection device is overcurrent and the subscribed voltage regulator 1 protection device is overcurrent, the incoming line overcurrent protection is locked. The time limit for the overcurrent protection device of the incoming line 1 to be locked is the set time plus the time limit for the voltage regulator 1 to be locked.

[0118] (14) The overcurrent protection device of voltage regulator 1 is locked for more than the maximum locking time limit, that is, the circuit breaker of the west-through circuit breaker fails and the circuit breaker of voltage regulator 1 operates.

[0119] (15) The overcurrent protection device of incoming line 1 is locked for more than twice the maximum locking time limit, that is, the failure of the west-through circuit breaker plus the failure of the voltage regulator 1 circuit breaker causes the overcurrent action of incoming line 1.

[0120] Status 4: Bus tie power supply, the fault point is located on the through-line or automatic shut-off line. The following anti-over-tripping method is adopted using this approach:

[0121] (1) The West Through Protection Device, Voltage Regulator 1 Protection Device, Bus Tie Protection Device, and Incoming Line 2 Protection Device simultaneously sensed a sudden change in current.

[0122] (2) The West Through Protection Device, Voltage Regulator 1 Protection Device, and Bus Tie Protection Device shall adjust the timing of the next half-cycle Fourier calculation according to the timing of the current sudden change.

[0123] (3) The protection device for incoming line 2 adjusts the timing of the next full-cycle Fourier calculation based on the timing of the current sudden change.

[0124] (4) After the west-through protection device performs half-cycle calculation (approximately 10ms after the sudden change), the blocking logic judgment is performed.

[0125] (5) The West Through Protection Device shall immediately issue a GOOSE message after the judgment is completed;

[0126] (6) The through-current protection device will trip immediately if it operates under overcurrent conditions;

[0127] (7) After the voltage regulator 1 protection device performs half-cycle calculation (approximately 10ms after the sudden change), the interlocking logic judgment is performed;

[0128] (8) After the voltage regulator 1 protection device finishes its judgment, it immediately issues a GOOSE message (overcurrent start);

[0129] (9) The voltage regulator 1 protection device adjusts the time of the next full-cycle Fourier calculation according to the time when the current sudden change occurs.

[0130] (10) After the voltage regulator 1 protection device performs full-cycle calculation (approximately 20ms after a sudden change), it performs overcurrent protection judgment;

[0131] (11) When the voltage regulator 1 protection device is overcurrent and the subscribed through device is overcurrent, it locks its own overcurrent protection. The lockout time limit is the set time, and at the same time, it publishes a GOOSE message (overcurrent action is locked and the lockout time limit).

[0132] (12) After the bus tie protection device performs full-cycle calculation (approximately 20ms after a sudden change), it performs overcurrent protection judgment;

[0133] (13) If the bus tie protection device is overcurrent and the subscribed voltage regulator 1 protection device is overcurrent, the bus tie overcurrent protection is locked. The time limit for the bus tie protection device to be locked is the set time plus the time limit for the voltage regulator 1 to be locked.

[0134] (14) After the full cycle calculation of the protection device of incoming line 2 (approximately 20ms after the sudden change), the overcurrent protection judgment is performed;

[0135] (15) If the incoming line 2 protection device is overcurrent and the subscribed bus tie protection device is overcurrent, the incoming line overcurrent protection is blocked. The time limit for the incoming line 2 protection device to be blocked due to overcurrent is the set time plus the time limit for the bus tie to be blocked.

[0136] (16) The overcurrent protection device of voltage regulator 1 is locked for more than the maximum locking time limit, that is, the circuit breaker of the west-through circuit breaker fails and the circuit breaker of voltage regulator 1 operates.

[0137] (15) The overcurrent protection device of the bus tie is blocked for more than twice the maximum blocking time limit, that is, the failure of the west-through circuit breaker plus the failure of the voltage regulator 1 circuit breaker and the overcurrent action of the incoming line 1.

[0138] (16) The overcurrent protection device of incoming line 2 is blocked for more than three times the maximum blocking time limit, that is, the west through circuit breaker fails, the voltage regulator 1 circuit breaker fails, and the bus tie circuit breaker fails, and the overcurrent action of incoming line 2 is activated.

[0139] Based on the above description, the present invention is used for feeder protection in railway substations to prevent cascading trips in railway power distribution, achieve rapid fault location, automatically activate the protection tripping of the corresponding area to clear the fault, and simultaneously block the tripping of the upstream circuit breaker within a certain time limit, thereby achieving the ability of multi-level linkage protection for the entire substation.

Claims

1. A substation anti-cascading tripping method based on a dedicated port, characterized in that, This method uses the following substation anti-overlapping tripping system, including: feeder protection devices and feeder protection switches installed on feeders, bus tie protection devices and tie protection switches installed on bus tie, and incoming line protection devices and incoming line protection switches installed on incoming lines. Among them, the feeder protection device, bus tie protection device and incoming line protection device share information with each other using a star-shaped GOOSE network structure. Each protection device's GOOSE port uses an independent chip and a switch with traffic suppression function is selected. The method includes the following steps: The protection device monitors whether a current surge occurs by monitoring the real-time surge in current amplitude. If a surge occurs, the corresponding protection switch type is obtained based on the monitored protection device. The corresponding data adjustment mode is selected based on the protection switch type, and the time point of the next data conversion is updated using the data adjustment mode to obtain the effective value of the fundamental current. The corresponding overcurrent judgment logic is pre-configured according to the protection switch type. The protection switch type is an incoming line protection switch. The data adjustment mode is to adjust one cycle of data starting from the abrupt change point. After adjustment, the data is converted using the full-wave Fourier algorithm to obtain the effective value of the current fundamental wave. The protection switch type is a tie protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave. The protection switch type is a feeder protection switch. The data adjustment mode is to adjust half a cycle of data starting from the abrupt change point. After adjustment, the data is converted using the half-wave Fourier algorithm to obtain the effective value of the current fundamental wave. Based on the fundamental effective value of the current, the corresponding overcurrent judgment logic is selected to obtain the logic judgment result, and the corresponding protection scheme is generated according to the logic judgment result; the protection switch type corresponds to the protection device.

2. The substation anti-cascading tripping method based on a dedicated port according to claim 1, characterized in that, Each protection device receives GOOSE messages from subscribing devices; wherein, subscribing devices include: other protection devices in this substation and other protection devices outside this substation that are directly connected to them.

3. The substation anti-cascading tripping method based on a dedicated port according to claim 1, characterized in that, The overcurrent judgment logic includes: overcurrent judgment logic for incoming line protection switches, overcurrent judgment logic for tie protection switches, and overcurrent judgment logic for feeder protection switches.

4. The substation anti-cascading tripping method based on a dedicated port according to claim 3, characterized in that, The flow of the overcurrent judgment logic for the incoming line protection switch is as follows: The obtained fundamental RMS value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental RMS value of the current is greater than the preset overcurrent setting: if any subscribed device is overcurrent, that is, if a blocking GOOSE message is received from any subscribed device, then a blocking overcurrent protection action is generated according to the blocking GOOSE message; if the duration of the blocking overcurrent protection action exceeds the blocking time limit, the incoming line protection device will trip due to overcurrent.

5. The substation anti-cascading tripping method based on a dedicated port according to claim 3, characterized in that, The overcurrent judgment logic of the interconnection protection switch is as follows: The obtained fundamental current RMS value is compared and analyzed with the preset overcurrent setting value. When the fundamental current RMS value is greater than the preset overcurrent setting value, an overcurrent action GOOSE message is sent immediately. The bus tie protection device adjusts the timing of the next full-cycle Fourier calculation based on the moment of the current surge. After the full-cycle Fourier calculation is performed, the overcurrent protection judgment is checked again. If the bus tie protection device experiences an overcurrent, and any subscribed device experiences an overcurrent, i.e., a blocking GOOSE message is received from any subscribed device, then a blocking overcurrent protection action is generated based on the blocking GOOSE message; if the duration of the blocking overcurrent protection action exceeds the blocking time limit, the bus tie protection device will trip due to overcurrent.

6. The substation anti-cascading tripping method based on a dedicated port according to claim 3, characterized in that, The flow of the overcurrent judgment logic for the feeder protection switch is as follows: The obtained fundamental effective value of the current is compared and analyzed with the preset overcurrent setting. When the fundamental effective value of the current is greater than the preset overcurrent setting, an overcurrent action GOOSE message is sent immediately, and the feeder protection switch trips due to overcurrent.

7. The substation anti-cascading tripping method based on a dedicated port according to any one of claims 4 or 5, characterized in that, The blocking GOOSE message includes: the name of the substation, the name of the protection device and the GoID identifier, as well as the blocking action command and blocking time limit.

8. The substation anti-cascading tripping method based on a dedicated port according to any one of claims 5 or 6, characterized in that, The overcurrent action GOOSE message includes: the name of the substation, the name of the protection device and the GoID identifier, and the overcurrent action command.

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