Intelligent selective trip protection system for full-through traction power supply network

Abstract

The application discloses an intelligent trip protection system of a full-through traction power supply network, which mainly applies to the full-through traction power supply network and is composed of a protection device, a satellite clock and a communication network.The system supports comparing the relevant current information of the phase of the power supply arm on the side and the phase of the power supply arm on the opposite side through an algorithm, determining the corresponding fault interval in the full line, determining the locking condition through a power direction discrimination method based on a GOOSE communication mode, and accurately and quickly completing the isolation of the fault interval.When the topological structure of the full-through traction power supply network changes, there is no need to switch the setting value, the system has better applicability than a traditional wide-area protection trip network, and supports the double-end power supply condition.The system has certain engineering applicability and better solves some problems in the protection process of the full-through traction power supply network.

Description

Technical Field

[0001] This invention belongs to the field of relay protection for traction power supply systems, and in particular relates to an intelligent tripping protection system for a fully continuous traction power supply network. Background Technology

[0002] The continuous traction power supply network maintains the same angle at both power supply ends, minimizing its impact on power quality and offering unique advantages over current traction power supply systems, thus possessing significant potential for future adoption. Given the synchronicity of power supply angles, the continuous traction power supply network allows for flexible topology changes, such as supporting simultaneous power supply from both ends and diverse combinations of station activation / deactivation. Traditional wide-area protection and control systems and integrated automation systems can no longer meet relay protection requirements. When the structure of the fully continuous traction power supply network changes, such as during cross-area support power supply, switching of setting groups is necessary. Theoretically, the activation / deactivation of stations can cause numerous structural changes, and combining these various scenarios results in a number and complexity of setting zones that are difficult to quantify and adapt to the requirements of operation and maintenance departments. Therefore, considering the future widespread adoption of fully continuous traction power supply systems, it is urgent to address the aforementioned issues at the relay protection level. Summary of the Invention

[0003] In view of this, the present invention aims to propose an intelligent trip protection system for a fully continuous traction power supply network, so as to provide a scientific, reasonable, fast and accurate protection system. The intelligent trip protection system for a fully continuous traction power supply network can achieve fault isolation and is applicable to various flexible and complex operating conditions.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] The intelligent trip protection system for the fully continuous traction power supply network includes protection devices, satellite clocks, and inter-station fiber optic channels;

[0006] Three stations with a continuous traction power supply topology are selected and designated from left to right as station A, station B, and station C, respectively.

[0007] Each of the three power supply arms—the right power supply arm of station A, the left power supply arm of station B, and the left power supply arm of station C—is equipped with a protection device. These three protection devices are connected to a satellite clock to synchronize time and are also connected via an inter-station fiber optic channel.

[0008] Furthermore, the intelligent trip protection system collects the analog quantities of the up and down fault currents and the analog quantities of the bus voltage for each power supply arm, and normalizes the angle of each analog quantity based on the angle of the up current of the A arm.

[0009] Furthermore, the intelligent tripping protection system supports two topologies: cross-zone power supply and non-cross-zone power supply. It completes fault isolation of the fully continuous traction power supply network based on the criteria of each protection device, as detailed below:

[0010] S51. When the fully continuous traction power supply network topology of station B is put into operation, the intelligent selective trip protection system is used to select the devices of station A and station B to complete the fault isolation between the two stations.

[0011] S52. When the fully continuous traction power supply network topology at station B is not in operation, the intelligent selective trip protection system selects the devices at stations A and C to complete the fault isolation between the two stations.

[0012] Furthermore, the specific criteria for each protection device are as follows:

[0013] When a fault occurs, the intelligent tripping system selects the analog quantities of the two already put into operation as the research object. Taking S51 as the research object, the principle of S52 is the same. When the maximum voltage value is less than the threshold voltage and the maximum current value is greater than the threshold current value, it enters the fault isolation state.

[0014] When there is no current in either the up or down direction of the right power supply arm of station A, and the up or down current of the left power supply arm of station B is between -90° and 90°, the intelligent trip protection system will automatically trip the circuit breaker on the corresponding left power supply arm of station B.

[0015] If the upward current of the right power supply arm of station A is 0° and the upward current of the left power supply arm of station B is between -90° and 90°, then the selective trip protection system can automatically trip the circuit breakers of the upward current of the right power supply arm of station A and the upward current of the left power supply arm of station B.

[0016] If there is a first-generation and second-generation power supply arm on the right side of station A, and the upward or downward current of the power supply arm on the left side of station B is between -90° and 90°, then all circuit breakers in the section between station A and station B will be tripped.

[0017] Furthermore, the intelligent selective trip protection system supports power direction blocking based on GOOSE communication, which can distinguish between the non-faulty section at the far end and the long fault section at the near end, and complete selective blocking.

[0018] Furthermore, the power direction blocking based on the GOOSE communication method is specifically as follows:

[0019] Let the line impedance angle be α. When the angle difference between the vector sum of the up and down feeder currents on the right side of A and the bus voltage is between -(-90-α)° and (90+α)°, it is judged as positive. After determining that the corresponding opposite power supply arm is reversed through the GOOSE communication channel, the blocking flag is set.

[0020] Compared with existing technologies, the intelligent trip protection system for the fully continuous traction power supply network described in this invention has the following advantages:

[0021] (1) This system solves the protection of the fully continuous traction power supply network under dual-end power supply conditions;

[0022] (2) The system is suitable for various complex and flexible working conditions. Its protection function is not affected when the fully connected network topology changes.

[0023] (3) The system does not need to switch the set value when dealing with different network topologies. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 This is a basic structural diagram of an intelligent selective trip protection system;

[0026] Figure 2 A network diagram of two intelligent selective protection systems in a fully connected network topology;

[0027] Figure 3 Name and orientation diagram of the intelligent selective trip protection system;

[0028] Figure 4 An example of power direction blocking function in GOOSE communication mode;

[0029] Figure 5 Functional logic diagram of the intelligent trip protection system; Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0031] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] The intelligent trip protection system for a fully continuous traction power supply network of the present invention includes the following steps:

[0033] An intelligent trip protection system for a fully continuous traction power supply network is characterized by comprising the following steps:

[0034] (1) The intelligent tripping system mainly completes fault isolation of the fully continuous traction power supply network topology, and consists of protection devices, satellite clocks, and inter-station fiber optic channels, such as... Figure 1 As shown.

[0035] (2) Arbitrarily select three stations with a continuous traction power supply topology, and designate them as station A, station B and station C from left to right.

[0036] (3) The intelligent tripping system mainly consists of three protection devices, respectively installed on the right power supply arm of station A, the left power supply arm of station B, and the left power supply arm of station C. These three devices are connected to the satellite for time synchronization and are also connected via inter-station fiber optic cables. Figure 1 As shown.

[0037] (4) The intelligent tripping system supports the collection of six fault currents and six bus voltages for each power supply arm. The angles of each analog quantity are normalized based on the angle of the upward current of the A-arm (assuming the angle of the A-arm is 0°).

[0038] (5) The intelligent tripping system adaptively supports both cross-zone and non-cross-zone power supply topologies, and completes fault isolation of the full-connection traction power supply network according to the criteria of each protection device.

[0039] (6) The intelligent selective tripping system supports power direction blocking based on GOOSE communication, which can distinguish between the non-faulty section at the far end and the long fault section at the near end, and complete selective blocking.

[0040] The three stations selected in (1) for the continuous traction power supply topology refer to the minimum components that this system can support. The topology of the continuous traction power supply network varies greatly, and the number and location of traction stations and substations are quite flexible. The minimum components selected for analysis are for clarity of description, but in principle, they have the same applicability to all stations along the line.

[0041] As stated in (3), when selecting the power supply arm within the facility, the left and right directions must strictly correspond. Furthermore, the intelligent trip protection system requires a high-precision clock.

[0042] When normalization is completed in step (4), each protection device in the intelligent trip protection system transmits the original sampling points through optical fiber, which ensures that the reference in the system is consistent. The angle of the upward current of A is rotated to 0°, and the other analog quantities are rotated accordingly to complete the normalization.

[0043] The six analog currents collected represent the up and down feeder currents of the right power supply arm at station A, the left power supply arm at station B, and the left power supply arm at station C. The six voltages collected represent the two bus voltages at station A, the two bus voltages at station B, and the two bus voltages at station C. Figure 2 As shown

[0044] The optical transmission points represent the sampling points of each protection device. Given that the speed of light in optical fiber is on the order of 10^8 m / s, the communication time difference between stations is ignored. After receiving data from the neighboring station, the device at this station calculates new sampling points using the Lagrange quadratic difference method, and then uses the Fourier algorithm to obtain fault data for both the local and adjacent stations. The intelligent tripping system resolves the angle difference between stations.

[0045] During the normalization process, the current value of A is used as the reference. According to the following formula, the angles of each analog quantity are rotated to complete the normalization. The normalization of B and C is similar and will not be elaborated further. In the formula, angle is the angle function.

[0046]

[0047]

[0048] When the fully connected traction power supply network topology B is put into operation, the intelligent selective trip protection system can autonomously select the device of station A and station B to complete the fault isolation between the two stations; when the fully connected traction power supply network topology B is not put into operation, the intelligent selective trip protection system can autonomously select the device of station A and station C to complete the fault isolation between the two stations.

[0049] Furthermore, the criteria for each protection device in (5) are as follows, and the specific flowchart is as follows: Figure 3 As shown.

[0050] When a fault occurs, the intelligent tripping system selects the analog quantities of the two already put into operation as the research object. Taking the S51 case as the research object, the principle of the S52 case is the same and need not be repeated. When the maximum voltage value is less than the threshold voltage and the maximum current value is greater than the threshold current value, it enters the fault isolation state.

[0051] When there is no current in either the up or down direction of the right power supply arm of station A, and the up or down current of the left power supply arm of station B is between -90° and 90°, the intelligent trip protection system will automatically trip the circuit breaker on the corresponding left power supply arm of station B.

[0052] If the upward current of the right power supply arm of station A is 0° and the upward current of the left power supply arm of station B is between -90° and 90°, then the selective trip protection system can automatically trip the circuit breakers of the upward current of the right power supply arm of station A and the upward current of the left power supply arm of station B.

[0053] If there is a first-generation and second-generation power supply arm on the right side of station A, and the upward or downward current of the power supply arm on the left side of station B is between -90° and 90°, then all circuit breakers in the section between station A and station B will be tripped.

[0054] The power direction blocking function supported by (6) in the GOOSE communication mode refers to: setting the line impedance angle as α, and using the vector sum of the up and down feeder currents on the right side of A and the two parameters of the bus voltage when calculating the power direction.

[0055] When a fault occurs, in the remote non-faulty section, there must be a situation where the maximum voltage value is less than the threshold voltage and the maximum current value is greater than the threshold current value. The locomotive may not have been disconnected, satisfying the above action criteria. At this time, the intelligent trip protection system calculates the angle between the voltage and current on one side of the non-faulty section and then obtains the angle relationship between the voltage and current on the other side through GOOSE communication. When the angle difference is between -(-90-α)° and (90+α)°, it is judged as positive. If the comparison results on both sides are opposite, the intelligent trip protection system is in a blocked state in this non-faulty section.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent trip protection system for a fully continuous traction power supply network, characterized in that, This includes protection devices, satellite clocks, and inter-station fiber optic channels; Three stations with a continuous traction power supply topology are selected and designated from left to right as station A, station B, and station C, respectively. Each of the right power supply arm of station A, the left power supply arm of station B, and the left power supply arm of station C is equipped with a protection device. The three protection devices are connected to the satellite clock to complete time synchronization and are connected through the inter-station fiber optic channel. The intelligent tripping protection system supports two topologies: cross-zone power supply and non-cross-zone power supply. It completes fault isolation of the fully continuous traction power supply network based on the criteria of each protection device, as detailed below: S51. When the fully continuous traction power supply network topology of station B is put into operation, the intelligent selective trip protection system is used to select the devices of station A and station B to complete the fault isolation between the two stations. S52. When the fully continuous traction power supply network topology B is not in operation, the intelligent selective trip protection system selects the devices of substations A and C to complete the fault isolation between the two substations. The specific criteria for each protection device are as follows: When a fault occurs, the intelligent tripping system selects the analog quantities of the two already put into operation as the research object. Taking S51 as the research object, the principle of S52 is the same. When the maximum voltage value is less than the threshold voltage and the maximum current value is greater than the threshold current value, it enters the fault isolation state. When there is no current in either the up or down direction of the right power supply arm of station A, and the up or down current of the left power supply arm of station B is between -90° and 90°, the intelligent trip protection system will automatically trip the circuit breaker on the corresponding left power supply arm of station B. If the upward current of the right power supply arm of station A is 0° and the upward current of the left power supply arm of station B is between -90° and 90°, then the selective trip protection system can automatically trip the circuit breakers of the upward current of the right power supply arm of station A and the upward current of the left power supply arm of station B. If there is a first-generation and second-generation situation in the right power supply arm of station A, and the upward or downward current of the left power supply arm of station B is between -90° and 90°, then all circuit breakers in the section between station A and station B will be tripped.

2. The intelligent trip protection system for a fully continuous traction power supply network according to claim 1, characterized in that: The intelligent trip protection system collects the analog quantities of the up and down fault currents and the analog quantities of the bus voltage for each power supply arm. The angle of each analog quantity is normalized based on the angle of the up current of the A arm.

3. The intelligent trip protection system for a fully continuous traction power supply network according to claim 1, characterized in that: The intelligent selective trip protection system supports power direction blocking based on GOOSE communication, which can distinguish between the non-faulty section at the far end and the long fault section at the near end, and complete selective blocking.

4. The intelligent trip protection system for a fully continuous traction power supply network according to claim 3, characterized in that: The power direction blocking based on the GOOSE communication method is as follows: Let the line impedance angle be... When the angle difference between the vector sum of the up and down feeder currents on the right side of A and the bus voltage is within -(-90- )° and (90+ If the angle is between 0° and 10°, it is considered positive. After determining that the corresponding opposite power supply arm is in reverse through the GOOSE communication channel, a lockout flag is set.

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