A goose-based anti-override trip line protection device and protection system

Abstract

The application discloses a GOOSE-based anti-leapfrog tripping line protection device and a protection system, wherein the line protection device comprises a voltage transformer, a current transformer, an Ethernet communication interface, an anti-leapfrog module and a protection module; the device is distributed and connected with switches of each level of a multi-level power supply system; a lower-level anti-leapfrog tripping line protection device transmits a GOOSE signal to an upper-level anti-leapfrog tripping line protection device in the form of a GOOSE message; the GOOSE message is transmitted through the Ethernet communication interface; the anti-leapfrog module receives the GOOSE signal uploaded by the lower-level anti-leapfrog tripping line protection device, processes the GOOSE signal and drives the connected switch to execute protection; and the protection module outputs fault information according to voltage sampling values and current sampling values collected by the voltage transformer and the current transformer. The application can realize over-current protection and leakage current protection anti-leapfrog tripping and realize the reliability of the multi-level power supply system.

Description

Technical Field

[0001] This invention relates to a line protection device and system based on GOOSE to prevent over-tripping, belonging to the field of relay protection technology for multi-level power supply systems. Background Technology

[0002] Compared to high-voltage transmission networks, power distribution systems in factories and mines are characterized by multi-level radial vertical networks, short connecting lines between levels, and harsh operating environments. This results in small differences in protection setting values ​​between power supply system levels and low selectivity of leakage current protection. Consequently, when a downstream switch senses a fault and trips, upstream switches may also trip indiscriminately, causing cascading tripping accidents, expanding the scope of power outages, and seriously endangering the personal safety of enterprise personnel and the safety of power supply equipment.

[0003] To address the issue of cascading tripping accidents in multi-level power supply systems, current research focuses on several key areas: mature fiber optic current differential protection against cascading tripping, centralized control based on CAN bus fault information transmission, and solutions based on GOOSE transmission of cascading tripping blocking signals. The first two solutions suffer from drawbacks such as high cost, complex circuit design, and incompatibility with smart grid development. Existing literature only describes the effectiveness of GOOSE applications, lacking solutions for GOOSE-based cascading tripping blocking signal transmission and corresponding signal processing measures. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a GOOSE-based anti-cascading tripping line protection device and system, capable of achieving overcurrent protection and leakage current protection against cascading tripping, thus ensuring the reliability of multi-level power supply systems. To achieve the above objective, this invention employs the following technical solution:

[0005] In a first aspect, the present invention provides a GOOSE-based anti-overpass tripping line protection device, comprising a voltage transformer, a current transformer, an Ethernet communication interface, an anti-overpass module, and a protection module.

[0006] The anti-over-level tripping line protection device is multiple and distributed. Each anti-over-level tripping line protection device is connected to the switches at each level of the multi-level power supply system. The lower-level anti-over-level tripping line protection device transmits the GOOSE signal to the upper-level anti-over-level tripping line protection device in the form of a GOOSE message. The GOOSE message is transmitted through an Ethernet communication interface.

[0007] The anti-overstepping module receives the GOOSE signal uploaded by the lower-level anti-overstepping tripping line protection device, processes the GOOSE signal, and drives the connected switch to perform protection.

[0008] The protection module outputs fault information based on the voltage and current sample values ​​collected by the voltage transformer and current transformer.

[0009] In conjunction with the first aspect, further, the GOOSE signal includes an overcurrent protection blocking signal and a leakage current protection blocking signal, and the Ethernet communication interface includes an overcurrent protection GOOSE input and a leakage current protection GOOSE input.

[0010] The overcurrent protection blocking signal is transmitted to the upper-level protection circuit breaker through the overcurrent protection blocking GOOSE input, and the leakage current protection blocking signal is transmitted to the upper-level protection circuit breaker through the leakage current protection blocking GOOSE input.

[0011] In conjunction with the first aspect, the aforementioned anti-overcurrent tripping line protection device is further equipped with overcurrent anti-overcurrent control words and leakage current anti-overcurrent control words.

[0012] When the overcurrent protection level control word or the leakage current protection level control word is activated, the minimum action delay of the protection line protection device against overcurrent tripping is automatically set to 20ms.

[0013] In conjunction with the first aspect, the GOOSE signal processing further includes:

[0014] Based on the structure of the multi-level power supply system, determine the hierarchical relationship of the anti-over-level tripping line protection device;

[0015] When a small current ground fault occurs in the power supply system, all anti-overcurrent tripping line protection devices that sense the small current ground fault information activate leakage protection and send a GOOSE signal to the corresponding upstream anti-overcurrent tripping line protection device. The GOOSE signal transmission delay is less than 10ms. If the anti-overcurrent tripping line protection device closest to the fault point does not receive the GOOSE signal, after the leakage protection delay, the anti-overcurrent tripping line protection device closest to the fault point will activate and drive the switch to disconnect the fault.

[0016] After the anti-overlapping trip line protection device operates for 200ms, it continues to detect leakage fault information. If the fault information still exists, it is considered that the switch has failed to operate, and the GOOSE signal is stopped. The upstream anti-overlapping trip line protection device then operates to clear the fault. If the anti-overlapping trip line protection device receives the GOOSE signal for more than 400ms and detects that the fault still exists, it determines that the secondary switch has failed to operate. The anti-overlapping trip line protection device's blocking signal is enabled, and the anti-overlapping trip line protection device immediately operates to clear the fault.

[0017] The anti-overpass tripping line protection device receives the GOOSE signal from the lower-level anti-overpass tripping line protection device and transmits the status, quality, and maintenance information carried by the GOOSE signal to the corresponding GOOSE input of the current-level anti-overpass tripping line protection device.

[0018] The anti-over-level tripping line protection device handles each GOOSE input individually. When the GOOSE input quality is valid and the maintenance is consistent, the GOOSE input status is 1. After an interruption Δt delay, the GOOSE input is judged to be valid and the blocking logic judgment is performed.

[0019] If the time for setting the GOOSE input to 1 in the anti-over-trip line protection device is greater than 15 seconds, the protection device will determine whether any of the GOOSE inputs are set to 1, have valid quality and consistent maintenance, and have no blocked GOOSE signal. In this case, the anti-over-trip line protection device will block the leakage protection function.

[0020] In conjunction with the first aspect, further, determining the hierarchical relationship of the anti-over-tripping line protection device includes:

[0021] On a busbar, the anti-overpass tripping line protection device connected to the busbar outgoing line is the lower level, and the anti-overpass tripping line protection device connected to the busbar incoming line is the upper level.

[0022] The anti-overpass line protection device for the two separately operating busbars is a lower-level protection device of the anti-overpass line protection device connected to the busbar inlet and an upper-level protection device of the anti-overpass line protection device connected to the busbar outlet.

[0023] On the two busbar connection lines, the anti-overpass tripping line protection device connected to the busbar outgoing line is the superior protection device connected to the busbar incoming line.

[0024] In conjunction with the first aspect, the output fault information further adopts a combination of starting relay and transient first half-wave energy selection principle.

[0025] In conjunction with the first aspect, the mathematical expression for the starting relay is as follows:

[0026] Δu0(t)>u 0set +k1Δu0T (1)

[0027] Δ i0 (t)>I 0set +k1Δi0T (2)

[0028] Where: u 0set i 0set These are the zero-sequence voltage change setpoint and the zero-sequence current change setpoint, respectively.

[0029] Δi0(t) is the sudden change in current, expressed by the following formula:

[0030] Δi0(t)=||i0(t)-i0(tT)|-|i0(tT)-i0(t-2T)|| (3)

[0031] Δu0(t) is the voltage surge, expressed by the following formula:

[0032] Δu0(t)=||u(t)-u0(tT)|-|u0(tT)-u(t-2T)|| (4)

[0033] In equation (3), Δi0T is the zero-sequence current mutation threshold, which is taken as the zero-sequence current mutation of the previous cycle; in equation (4), Δu0T is the zero-sequence voltage mutation threshold, which is taken as the zero-sequence voltage mutation of the previous cycle.

[0034] In equations (1) and (2), k1 is the reliability coefficient of the floating threshold, which is taken as 1.25; T is the sampling period of the protection device.

[0035] If N out of M consecutive sampling points of the zero-sequence current mutation Δi0(t) satisfy equation (2), the zero-sequence current mutation triggers the element to operate. If N out of M consecutive sampling points of the zero-sequence voltage mutation Δu0(t)) satisfy equation (1), the zero-sequence voltage mutation triggers the element to operate. If the element is triggered when any mutation occurs, it is considered that a fault has been detected.

[0036] In conjunction with the first aspect, the transient first half-wave energy line selection principle further includes:

[0037] Define parameter variable q k (t) is

[0038] q k (t)=i0(t)*du0(t) / dt (5)

[0039] For non-faulty line q k (t) is greater than 0, the faulty line has q k (t) is less than 0;

[0040] For parameter variable q k (t) Integrating from the moment of fault initiation, we obtain the parameter variable E. q for

[0041]

[0042] Where: T1 is the time when the integration ends, which can be set to T / 2;

[0043] Non-faulty line E q Greater than 0, faulty line Eq If the value is less than 0, to prevent misjudgments caused by errors in the protection device program calculation process, the protection judgment can be defined as follows:

[0044] E q <E z (7)

[0045] Among them: E z A fixed threshold value is set for the protection device.

[0046] Secondly, the present invention provides a line protection system for preventing over-level tripping, comprising:

[0047] The first aspect describes the anti-over-tripping line protection device and SCD visualization configuration tool based on GOOSE.

[0048] The SCD visualization configuration tool is used to visualize the power supply system structure.

[0049] In conjunction with the second aspect, the SCD visualization configuration tool further includes a GOOSE signal virtual terminal and a visualization configuration display. The input terminal of the GOOSE signal virtual terminal is connected to the anti-overpass tripping line protection device, and the output terminal is connected to the visualization configuration display. The visualization configuration display provides a global visualization of the names of the lower and upper levels of each anti-overpass tripping line protection device, as well as the names of the GOOSE signals sent and received between the devices.

[0050] Compared with the prior art, the beneficial effects achieved by the GOOSE-based anti-over-trip line protection device and system provided in this embodiment of the invention include:

[0051] This invention provides a line protection device for preventing over-level tripping, including a voltage transformer, a current transformer, an Ethernet communication interface, an anti-over-level module, and a protection module. Multiple anti-over-level tripping line protection devices are distributed and connected to switches at various levels in a multi-level power supply system. Lower-level anti-over-level tripping line protection devices transmit GOOSE signals to higher-level anti-over-level tripping line protection devices via GOOSE messages, transmitted through the Ethernet communication interface. The anti-over-level module receives the GOOSE signals from lower-level anti-over-level tripping line protection devices, processes the GOOSE signals, and drives the connected switches to perform protection. Priority transmission of GOOSE signals is provided, and the device possesses comprehensive anti-over-level functions such as anti-over-level blocking and switch failure detection, including overcurrent and low-current grounding protection, without additional setting configurations. The anti-over-level module reliably returns timed-out GOOSE signals to prevent long-term blocking from causing upper-level failure to operate. Confirmation processing is performed on GOOSE inputs to improve signal reliability.

[0052] The protection module of this invention outputs fault information based on the voltage and current sampling values ​​collected by the voltage transformer and the current transformer, which can realize the grounding line selection function of the distribution network bay. It has the advantages of being unaffected by unstable electric arcs and arc suppression coils, high sensitivity, good reliability, no increase in hardware cost, and low maintenance cost in the later stage.

[0053] This invention provides a GOOSE-based anti-overpass tripping protection system, including an anti-overpass tripping line protection device and an SCD visualization configuration tool. The SCD visualization configuration tool is used to visualize the power supply system structure. For the interlocking relationship between the upper and lower levels of the multi-level power supply system protection device, it can realize the visualization operation of the entire substation anti-overpass system, which is convenient for subsequent analysis. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a multi-level power supply system in an embodiment of the present invention;

[0055] Figure 2 This is a topology diagram of the anti-level-crossing function of the multi-level power supply system in an embodiment of the present invention;

[0056] Figure 3 This is a structural block diagram of the protection system in an embodiment of the present invention.

[0057] Figure 4 This is the anti-over-level blocking signal transmission processing logic of an embodiment of the present invention;

[0058] Figure 5 This is a logic diagram for preventing cross-level GOOSE access in an embodiment of the present invention.

[0059] Figure 6 This is a logic diagram of the anti-over-level tripping protection action in an embodiment of the present invention; Detailed Implementation

[0060] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0061] A GOOSE-based anti-overpass tripping line protection device includes a voltage transformer, a current transformer, an Ethernet communication interface, an anti-overpass module, and a protection module. Multiple anti-overpass tripping line protection devices are distributed in a single configuration. Each anti-overpass tripping line protection device is connected to switches at various levels in a multi-level power supply system. Lower-level anti-overpass tripping line protection devices transmit GOOSE signals to higher-level anti-overpass tripping line protection devices via GOOSE messages, which are transmitted through the Ethernet communication interface. The anti-overpass module receives the GOOSE signals uploaded by the lower-level anti-overpass tripping line protection devices, processes the GOOSE signals, and drives the connected switches to perform protection actions. The protection module outputs fault information based on voltage and current sampling values ​​collected by the voltage and current transformers.

[0062] An anti-over-trip protection system includes: an anti-over-trip line protection device and an SCD visualization configuration tool; the SCD visualization configuration tool is used to visualize the power supply system structure.

[0063] The GOOSE signal includes an overcurrent protection blocking signal and a leakage current protection blocking signal. The Ethernet communication interface includes an overcurrent protection GOOSE input and a leakage current protection GOOSE input. The overcurrent protection blocking signal is transmitted to the upstream protection line protection device through the overcurrent protection GOOSE input, and the leakage current protection blocking signal is transmitted to the upstream protection line protection device through the leakage current protection GOOSE input.

[0064] Specifically, the protection device is equipped with 20 overcurrent protection GOOSE inputs and 20 leakage current protection GOOSE inputs.

[0065] The overcurrent protection circuit breaker is equipped with overcurrent protection and leakage protection. When the overcurrent protection or leakage protection is activated, the minimum action delay of the overcurrent protection circuit breaker is automatically set to 20ms.

[0066] like Figure 1 The diagram shows a multi-level power supply system, defining the hierarchical relationship of the anti-over-trip line protection device, including:

[0067] On a busbar, the anti-overpass tripping line protection device connected to the busbar outgoing line is the lower level, and the anti-overpass tripping line protection device connected to the busbar incoming line is the upper level.

[0068] The anti-overpass line protection device for the two separately operating busbars is a lower-level protection device of the anti-overpass line protection device connected to the busbar inlet and an upper-level protection device of the anti-overpass line protection device connected to the busbar outlet.

[0069] On the two busbar connection lines, the anti-overpass tripping line protection device connected to the busbar outgoing line is the superior protection device connected to the busbar incoming line.

[0070] Specifically, when a grounding leakage fault occurs at point K in the power supply system, the leakage protection device is activated, and the overcurrent protection function is activated. Figure 1 When the intermediate protection devices for over-level tripping are G-05, G-06, G-01, G-11, 638, and 648 detect a leakage fault, they send a leakage current over-level tripping GOOSE interlock signal to the upper-level switch.

[0071] Specifically: G-05 blocks G-06 and G-01; G-06 blocks G-11; G-01 blocks 638; G-11 blocks 648; G-05 is closest to the fault point and did not receive a GOOSE blocking signal from the lower-level switch. After a protection action delay, the G-05 leakage protection trips and clears the fault.

[0072] The SCD visual configuration tool can be used to make... Figure 2 The topology diagram of the anti-overpass function of the multi-level power supply system is shown. The SCD visualization configuration tool includes a GOOSE signal virtual terminal and a visualization configuration display. The input terminal of the GOOSE signal virtual terminal is connected to the anti-overpass tripping line protection device, and the output terminal is connected to the visualization configuration display. The visualization configuration display provides a global visualization of the lower and upper levels of each anti-overpass tripping line protection device, as well as the names of the GOOSE signals sent and received between the devices.

[0073] Specifically, import the ICD model files of the corresponding devices for line protection switches such as G-01, G-02…648 into the SCD visual configuration tool, and configure the device's MAC address, APPID, IP address, and other common communication settings. Based on the multi-level power supply system, determine the upper and lower levels of the protection devices, and establish virtual terminal connections between the internal and external signals of the anti-overpass tripping line protection devices. In the SCD configuration tool, pull the anti-overpass blocking signal from the next-level protection device into the external signal of this level of protection device, and pull the anti-overpass GOOSE input of this level of protection device into the internal signal. This completes the GOOSE signal virtual terminal configuration. Only when the GOOSE signal virtual terminal configuration is completed is the anti-overpass GOOSE input quality effective.

[0074] Taking the low-current grounding protection function of the G-01 anti-overpass tripping line protection device as an example, the leakage current protection overpass blocking signals issued by the G-02, G-03, G-04, G-05, and G-06 anti-overpass tripping line protection devices are pulled into the external signal of the G-01 anti-overpass tripping line protection device. The leakage current protection GOOSE switches 1, 2, 3, 4, and 5 of G-01 are correspondingly pulled into the internal signal of the anti-overpass tripping line protection device. This completes the leakage current protection GOOSE blocking configuration for G-01.

[0075] After configuring the GOOSE signal virtual terminal of the anti-over-trip line protection device in the power supply system, open the SCD tool's visual interface to obtain the following: Figure 2 The diagram shows the anti-level escalation topology of a multi-level power supply system. This system-level visualization of anti-level escalation facilitates on-site personnel's understanding of the anti-level escalation interlocking relationships between systems, preventing omissions or misconfigurations of anti-level escalation functions. The CCD file exported from the SCD configuration tool is downloaded to the device, completing the connection of the virtual terminals for the GOOSE signals between devices.

[0076] by Figure 1 Taking a small current ground fault at point K in the power supply system as an example, this paper details the handling measures for the anti-over-level tripping line protection device to send / receive the anti-over-level GOOSE signal, including the activation of leakage protection and leakage over-level protection functions.

[0077] like Figure 3 The diagram shown illustrates a GOOSE-based anti-overpass tripping protection system. The anti-overpass tripping line protection device receives GOOSE signals from multiple lower-level anti-overpass tripping line protection devices. After preliminary processing of the signals, the device's anti-overpass module judges the setting, quality, and maintenance status of each GOOSE signal. Then, based on the judgment results of each GOOSE signal, a GOOSE signal is synthesized and incorporated into the traditional low-current grounding protection module to achieve the anti-overpass tripping function.

[0078] GOOSE signal processing includes:

[0079] Based on the structure of the multi-level power supply system, determine the hierarchical relationship of the anti-over-level tripping line protection device;

[0080] When a small current ground fault occurs in the power supply system, all anti-overcurrent tripping line protection devices that sense the small current ground fault information activate leakage protection and send a GOOSE signal to the corresponding upstream anti-overcurrent tripping line protection device. The GOOSE signal transmission delay is less than 10ms. If the anti-overcurrent tripping line protection device closest to the fault point does not receive the GOOSE signal, after the leakage protection delay, the anti-overcurrent tripping line protection device closest to the fault point will activate and drive the switch to disconnect the fault.

[0081] After the anti-overlapping trip line protection device operates for 200ms, it continues to detect leakage fault information. If the fault information still exists, it is considered that the switch has failed to operate, and the GOOSE signal is stopped. The upstream anti-overlapping trip line protection device then operates to clear the fault. If the anti-overlapping trip line protection device receives the GOOSE signal for more than 400ms and detects that the fault still exists, it determines that the secondary switch has failed to operate. The anti-overlapping trip line protection device's blocking signal is enabled, and the anti-overlapping trip line protection device immediately operates to clear the fault.

[0082] The anti-overpass tripping line protection device receives the GOOSE signal from the lower-level anti-overpass tripping line protection device and transmits the status, quality, and maintenance information carried by the GOOSE signal to the corresponding GOOSE input of the current-level anti-overpass tripping line protection device.

[0083] The anti-over-level tripping line protection device handles each GOOSE input individually. When the GOOSE input quality is valid and the maintenance is consistent, the GOOSE input status is 1. After an interruption Δt delay, the GOOSE input is judged to be valid and the blocking logic judgment is performed.

[0084] If the time for setting the GOOSE input to 1 in the anti-over-trip line protection device is greater than 15 seconds, the protection device will determine whether any of the GOOSE inputs are set to 1, have valid quality and consistent maintenance, and have no blocked GOOSE signal. In this case, the anti-over-trip line protection device will block the leakage protection function.

[0085] Specifically, such as Figure 4 The diagram shown illustrates the logic for sending and processing the anti-overcurrent blocking signal. When G-05 detects a small current ground fault at point K, the arbitrary segment leakage current protection starting element of the G-05 anti-overcurrent trip line protection device activates, the protection delay begins timing, and an anti-overcurrent blocking signal is sent to the upstream G-06 and G-01 protection devices. If the G-05 protection device does not receive the blocking signal, it immediately trips and clears the fault after the protection delay reaches the set value.

[0086] The anti-over-trip line protection device can detect fault information within 20ms and drive the switch to clear the fault within 80ms. Considering the harsh operating environment of industrial and mining enterprises, a reliability coefficient of 2 times is determined, and a time of 200ms is ensured that the anti-over-trip line protection device can clear the fault.

[0087] After the G-05 anti-overpass tripping line protection device operates, it continues to monitor fault information. If the fault disappears, the G-05 anti-overpass tripping line protection device stops sending leakage current anti-overpass blocking information. If the fault still exists 200ms after the leakage current protection operates, it is considered that the switch has failed to operate, and the G-05 anti-overpass tripping line protection device returns the blocking signal, and the upper-level anti-overpass tripping line protection devices G-06 and G-01 operate to clear the fault.

[0088] Specifically, such as Figure 6 The illustrated anti-overcurrent tripping protection logic diagram does not consider the case where the protection setting time of the upper-level anti-overcurrent tripping line protection device is less than that of the lower-level device. When the upper-level anti-overcurrent tripping line protection devices G-06 and G-01 are in operation and blocked by the leakage current protection function, the protection delay timer of G-06 and G-01 begins at the moment the fault begins. If the delay reaches the protection setting time and then continues for another 400ms, the lower-level switch has already cleared the fault, or the lower-level protection device determines that the switch has failed to operate and returns a GOOSE signal after a 200ms delay. If G-06 and G-01 protection devices still receive the leakage current protection GOOSE signal, the fault has not been cleared, and it is determined that there is a communication failure between the protection devices or that the secondary switch has failed to operate. In this case, the protection devices are allowed to immediately and non-selectively clear the fault.

[0089] With a GOOSE signal transmission delay of less than 10ms, a reliability coefficient of 2 is determined. After the "leakage current protection over-trip function" control word of G-05 and G-06 is put into operation, the minimum action delay of leakage current protection is automatically set to 20ms to ensure that the GOOSE signal can be effectively received.

[0090] Specifically, such as Figure 5 The diagram shown illustrates the GOOSE overcurrent protection input processing logic. The protection device is configured with 20 GOOSE overcurrent protection inputs, each independently determining its status. When G-06 and G-01 protection devices receive GOOSE blocking information, the GOOSE overcurrent protection input 1 is set to 1. If the GOOSE overcurrent protection input 1 is valid and maintenance is consistent, a 2.5ms delay (one protection interrupt) confirms receipt of the GOOSE overcurrent protection blocking signal from the lower level, preventing malfunctions caused by communication channel jitter. If any GOOSE overcurrent protection input of the overcurrent protection device is set to 1, valid, and maintenance is consistent, and there are no abnormal GOOSE overcurrent protection inputs, the overcurrent protection blocking signal reception flag of the protection device is set to 1, blocking the leakage protection function of G-06 and G-01 protection devices.

[0091] When the fault disappears, the GOOSE signal of the anti-overpass tripping line protection device is reliably returned. If the anti-overpass tripping line protection device receives any lower-level GOOSE signal for more than 15 seconds, it is determined that there is a communication error between the anti-overpass tripping line protection devices, and the anti-overpass blocking function is activated. The anti-overpass tripping line protection device sends an anti-overpass GOOSE input abnormal signal.

[0092] The fault information is output by combining the starting relay with the transient first half-wave energy selection principle.

[0093] The mathematical expression for the starting relay is as follows:

[0094] Δu0(t)>u 0set +k1Δu0T (1)

[0095] Δi0(t)>I 0set +k1Δi0T (2)

[0096] Where: u 0set i 0set These are the zero-sequence voltage change setpoint and the zero-sequence current change setpoint, respectively.

[0097] Δi0(t) is the sudden change in current, expressed by the following formula:

[0098] Δi0(t)=||i0(t)-i0(tT)|-|i0(tT)-i0(t-2T)|| (3)

[0099] Δu0(t) is the voltage surge, expressed by the following formula:

[0100] Δu0(t)=||u0(t)-u0(tT)|-|u0(tT)-u(t-2T)|| (4)

[0101] In equation (3), Δi0T is the zero-sequence current mutation threshold, which is taken as the zero-sequence current mutation of the previous cycle; in equation (4), Δu0T is the zero-sequence voltage mutation threshold, which is taken as the zero-sequence voltage mutation of the previous cycle.

[0102] In equations (1) and (2), k1 is the reliability coefficient of the floating threshold, which is taken as 1.25; T is the sampling period of the protection device.

[0103] If N out of M consecutive sampling points of the zero-sequence current mutation Δi0(t) satisfy equation (2), the zero-sequence current mutation triggers the element to operate. If N out of M consecutive sampling points of the zero-sequence voltage mutation Δu0(t)) satisfy equation (1), the zero-sequence voltage mutation triggers the element to operate. If the element is triggered when any mutation occurs, it is considered that a fault has been detected.

[0104] The transient first half-wave energy line selection principle includes:

[0105] Define parameter variable q k (t) is

[0106] q k (t)=i0(t)*du0(t) / dt (5)

[0107] For non-faulty line q k (t) is greater than 0, the faulty line has q k (t) is less than 0;

[0108] For parameter variable q k (t) Integrating from the moment of fault initiation, we obtain the parameter variable E. q for

[0109]

[0110] Where: T1 is the time when the integration ends, which can be set to T / 2;

[0111] Non-faulty line E q Greater than 0, faulty line E q If the value is less than 0, to prevent misjudgments caused by errors in the protection device program calculation process, the protection judgment can be defined as follows:

[0112] E q <E z (7)

[0113] Among them: E z A fixed threshold value is set for the protection device.

[0114] This embodiment embeds the anti-overpass module and protection module into the anti-overpass tripping line protection device, providing anti-overpass and protection functions. It can achieve overcurrent protection and leakage current protection against overpass tripping, ensuring the reliability of multi-level power supply systems. The anti-overpass tripping line protection device supports GOOSE communication according to the IEC61850 standard, prioritizing the transmission of GOOSE signals. It possesses comprehensive anti-overpass functions such as anti-overpass blocking and switch failure detection, providing overcurrent and low-current grounding protection. No additional setting configuration is required; each device is configured with 20 anti-overpass GOOSE inputs to meet future expansion needs.

[0115] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A line protection device for preventing over-tripping based on GOOSE, characterized in that... Includes voltage transformers, current transformers, Ethernet communication interfaces, anti-overrate modules, and protection modules. There are multiple anti-over-level tripping line protection devices in a distributed configuration, which are connected to the switches at each level of the multi-level power supply system. The lower-level anti-over-level tripping line protection device transmits the GOOSE signal to the upper-level anti-over-level tripping line protection device in the form of GOOSE message. The GOOSE message is transmitted through the Ethernet communication interface. The anti-overstepping module receives the GOOSE signal uploaded by the lower-level anti-overstepping tripping line protection device, processes the GOOSE signal, and drives the connected switch to perform protection. The protection module outputs fault information based on the voltage and current sample values ​​collected by the voltage transformer and current transformer. The GOOSE signal processing includes: Based on the structure of the multi-level power supply system, determine the hierarchical relationship of the anti-over-level tripping line protection device; When a small current ground fault occurs in the power supply system, all anti-overcurrent tripping line protection devices that sense the small current ground fault information activate leakage protection and send a GOOSE signal to the corresponding upstream anti-overcurrent tripping line protection device. The GOOSE signal transmission delay is less than 10ms. If the anti-overcurrent tripping line protection device closest to the fault point does not receive the GOOSE signal, after the leakage protection delay, the anti-overcurrent tripping line protection device closest to the fault point will activate and drive the switch to disconnect the fault. After the anti-overlapping trip line protection device operates for 200ms, it continues to detect leakage fault information. If the fault information still exists, it is considered that the switch has failed to operate, and the GOOSE signal is stopped. The upstream anti-overlapping trip line protection device then operates to clear the fault. If the anti-overlapping trip line protection device receives the GOOSE signal for more than 400ms and detects that the fault still exists, it determines that the secondary switch has failed to operate. The anti-overlapping trip line protection device's blocking signal is enabled, and the anti-overlapping trip line protection device immediately operates to clear the fault. The anti-overpass tripping line protection device receives the GOOSE signal from the lower-level anti-overpass tripping line protection device and transmits the status, quality, and maintenance information carried by the GOOSE signal to the corresponding GOOSE input of the current-level anti-overpass tripping line protection device. The anti-over-level tripping line protection device handles each GOOSE input separately. When the GOOSE input quality is valid and the maintenance information is consistent, the GOOSE input status is 1. After an interrupt Δt delay, the GOOSE input is judged to be valid and the blocking logic judgment is performed. If the time for setting the GOOSE input to 1 in the anti-over-trip line protection device is greater than 15 seconds, the protection device will determine whether any of the GOOSE inputs are set to 1, have valid quality, consistent maintenance information, and no blocked GOOSE signal. In this case, the anti-over-trip line protection device will block the leakage protection function.

2. The anti-over-tripping line protection device based on GOOSE according to claim 1, characterized in that, The GOOSE signal includes an overcurrent protection blocking signal and a leakage current protection blocking signal. The Ethernet communication interface includes an overcurrent protection GOOSE input and a leakage current protection GOOSE input. The overcurrent protection blocking signal is transmitted to the upper-level protection circuit breaker through the overcurrent protection blocking GOOSE input, and the leakage current protection blocking signal is transmitted to the upper-level protection circuit breaker through the leakage current protection blocking GOOSE input.

3. The anti-over-tripping line protection device based on GOOSE according to claim 1, characterized in that, The circuit protection device for preventing overcurrent tripping is equipped with overcurrent protection control words and leakage current protection control words. When the overcurrent protection level control word or the leakage current protection level control word is activated, the minimum action delay of the protection line protection device against overcurrent tripping is automatically set to 20ms.

4. The anti-over-tripping line protection device based on GOOSE according to claim 1, characterized in that, Determining the hierarchical relationship of the anti-over-tripping line protection device includes: On a busbar, the anti-overpass tripping line protection device connected to the busbar outgoing line is the lower level, and the anti-overpass tripping line protection device connected to the busbar incoming line is the upper level. The anti-overpass line protection device for the two separately operating busbars is a lower-level protection device of the anti-overpass line protection device connected to the busbar inlet and an upper-level protection device of the anti-overpass line protection device connected to the busbar outlet. On the two busbar connection lines, the anti-overpass tripping line protection device connected to the busbar outgoing line is the superior protection device connected to the busbar incoming line.

5. The anti-over-tripping line protection device based on GOOSE according to claim 1, characterized in that, The output fault information is obtained by combining the starting relay with the transient first half-wave energy selection principle.

6. The anti-over-tripping line protection device based on GOOSE according to claim 5, characterized in that, The mathematical expression for the starting relay is as follows: (1) (2) in: , These are the zero-sequence voltage change setpoint and the zero-sequence current change setpoint, respectively. The sudden change in current is expressed by the following formula: (3) The voltage change is expressed by the following formula: (4) In equation (2), The zero-sequence current mutation threshold is taken as the zero-sequence current mutation of the previous cycle; in equation (1), The zero-sequence voltage mutation threshold is set as the zero-sequence voltage mutation value of the previous cycle. In equations (1) and (2), The reliability coefficient for the floating threshold is set to 1.25; T is the sampling period of the protection device. Zero-sequence current mutation N out of M consecutive sampling points satisfy equation (2), the zero-sequence current mutation triggers the element to operate; the zero-sequence voltage mutation If N out of M consecutive sampling points satisfy equation (1), the zero-sequence voltage mutation triggers the element to operate. If the element is triggered by any mutation, it is considered that a fault has been detected.

7. The anti-over-tripping line protection device based on GOOSE according to claim 5, characterized in that, The transient first half-wave energy line selection principle includes: Define parameter variables for (5) For non-faulty lines Greater than 0, faulty lines have Less than 0; For parameter variables Integrating from the moment the fault begins, we obtain the parameter variables. for (6) in: The time at which integration ends can be set to T / 2; Non-faulty lines Greater than 0, faulty circuit If the value is less than 0, to prevent misjudgments caused by errors in the protection device program calculation process, the protection judgment can be defined as follows: (7) in: A fixed threshold value is set for the protection device.

8. A protection system for preventing over-level tripping, characterized in that, include: The GOOSE-based anti-over-trip line protection device and SCD visual configuration tool according to any one of claims 1-7; The SCD visualization configuration tool is used to visualize the power supply system structure.

9. The anti-over-trip protection system according to claim 8, characterized in that, The SCD visualization configuration tool includes a GOOSE signal virtual terminal and a visualization configuration display. The input terminal of the GOOSE signal virtual terminal is connected to the anti-overpass tripping line protection device, and the output terminal is connected to the visualization configuration display. The visualization configuration display provides a global visualization of the lower and upper levels of each anti-overpass tripping line protection device, as well as the names of the GOOSE signals sent and received between the devices.

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