A method and system for segmented fault identification in the bilateral power supply traction network of urban railways

Abstract

This invention provides a method and system for fault segment identification in a dual-powered traction network of an urban railway, comprising the following steps: obtaining the voltage phasor of the cross-connector HLn at time t and the voltage phasor at time t+Δt; calculating the voltage change of the cross-connector HLn based on the voltage phasor of the cross-connector HLn at time t and the voltage phasor at time t+Δt; calculating the fault voltage component matrix of the traction network based on the voltage change of all cross-connectors HLn; and determining the fault segment s based on the fault voltage component matrix; obtaining the current phasor of the first cross-connector HLs and the current phasor of the last cross-connector HLs+1 at time t+Δt; and calculating the power flow direction φ of the cross-connectors at both ends of the fault segment s based on the angle of the cross-connector current phasor. s With φ s+1 The fault power flow direction matrix {φ} of the transverse connecting lines on both sides of segment s is obtained. s ,φ s+1}; Based on the fault power flow direction matrix {φ} of the transverse connecting lines at both ends of the fault segment s s ,φ s+1 The algorithm determines whether the fault is located in the uplink or downlink segment. This invention's algorithm is simple, reliable, and easy to implement.

Description

Technical Field

[0001] This invention relates to the field of AC electrified railway power supply technology, specifically to a method and system for identifying fault segments in the traction network of a suburban railway with bilateral power supply. Background Technology

[0002] Existing fault identification schemes are only applicable to existing single-sided power supply traction networks. However, for urban railway double-sided power supply systems, due to changes in the distribution and synthesis of power supply and power consumption (power flow), it is impossible to identify fault segments in the traction network at the feeder of the traction substation, nor can it provide a reliable fault tripping scheme for the traction network. Therefore, it is necessary to propose a new method to identify fault segments in double-sided power supply traction networks. This new identification method is not only applicable to fault segment identification in double-sided power supply traction power supply systems, but also provides a basis for fault tripping and fault location in double-sided power supply traction power supply systems. Summary of the Invention

[0003] One of the objectives of this invention is to provide a fault segmentation identification system for a dual-powered traction network of urban railways, which can effectively solve the technical problems of fault segmentation identification and fault identification in both directions of dual-powered traction networks.

[0004] One of the objectives of this invention is achieved through the following technical solution:

[0005] A method for segmented fault identification in a dual-powered traction network of an urban railway includes the following steps:

[0006] For crossbar HL n Using the cross-connection line voltage phasor As a reference phasor, assume the current phasor of the cross-connector flows from the upper line to the lower line and is positive. Obtain the HL of the cross-connector at time t. n Voltage phasor and voltage phasor at time t+Δt According to voltage phasor and voltage phasor Calculate the cross line HL n voltage change According to all cross braces HL of the line n voltage change Calculate the fault voltage component matrix of the traction network Based on the identification function of the fault segmentation identification unit, and according to the fault voltage component matrix of the traction network... Determine the faulty segment s;

[0007] Obtain the phasor current of the HLs current at the beginning of the fault segment s at time t+Δt. Current phasor of the end cross-connection HLs+1 Based on the phasor angle of the cross-connecting line current and Calculate the power flow direction of the cross-connection at both ends of the fault segment s. and If the phasor angle of the current in the horizontal connecting line HLs at the beginning of segment s is... Then record the fault direction of the cross-connector HLs at the beginning of segment s. like but If the phasor angle of the current in the transverse line HLs at the end of segment s is... Then record the fault flow direction of the transverse connecting line HLs at the end of segment s. like but Based on the power flow direction of the cross-connecting lines at both ends of the fault segment s. and Obtain the fault power flow direction matrix of the transverse connecting lines on both sides of segment s. Based on the judgment function of the fault uplink and downlink identification unit, and according to the fault power flow direction matrix of the cross-connecting lines at both ends of the fault segment s, Determine whether the fault is located in the upstream or downstream segment.

[0008] As a further improvement of the present invention, the fault segmentation identification unit FIU is based on the traction network fault voltage component matrix. The steps to determine the faulty segment s include the following:

[0009] Find the fault voltage component matrix of the traction network Maximum value of elements Compare Adjacent elements and Size. If Let s = max - 1; if Let s = max; the fault segmentation identification unit FIU determines that the fault occurs in segment s.

[0010] As a further improvement of the present invention, the fault power flow direction matrix of the transverse connecting lines at both ends of the fault segment s is described. The steps to determine whether a fault is located in the uplink or downlink segment include the following:

[0011] If the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s The fault occurs at the upstream traction network of segment s. If the fault flow direction matrix is ​​located on both sides of the faulty segment s... The fault occurred at the downlink traction network of segment s.

[0012] The second objective of this invention is to provide a fault segmentation identification system for a dual-power supply traction network of a suburban railway, used to implement a fault segmentation identification method for a dual-power supply traction network of a suburban railway. In this system, a traction substation SS1 is located at the beginning of a dual-power supply section of a suburban double-track railway, and a traction substation SS2 is located at the end. Switching stations, denoted as KB1, KB2, ..., KB2, are installed on the traction network between SS1 and SS2. m The area between adjacent substations is recorded as a segment, and each segment includes an upstream traction network and a downstream traction network; the feature is that: at the beginning of the traction network, the busbar B1 of traction substation SS1 is connected to the beginning of the upstream traction network of segment 1 through feeder F1, the busbar B2 of SS1 is connected to the downstream traction network of segment 1 through feeder F2, and the busbar B1 and the busbar B2 are connected through the cross link HL1;

[0013] Switching Station KB1 Busbar B 11 via feeder F 11 Connected to the end of the uplink traction network of segment 1, and via feeder F 13 Connected to the first end of the uplink traction network of section 2, switch station KB1 busbar B 12 via feeder F 12 Connected to the end of the downlink traction network of segment 1, and via feeder F 14 Connected to the first end of the downlink traction network of segment 2, busbar B 11 With busbar B 12 Connected via crossbar HL2; Switching station KB m Busbar B m1 via feeder F m1 Connected to the end of the uplink traction network of segment m, and via feeder F m3 With segment m+1 upward traction network UN m+1 Header connection, switch station KB m Busbar B m2 via feeder F m2 Connected to the end of the downlink traction network of segment m, and via feeder F m4 Connected to the first end of the downlink traction network of segment 2, busbar B m1 With busbar B m2 via the crossbar HL m+1 connect;

[0014] At the end of the traction network, busbar B3 of traction substation SS2 is connected to the end of the upward traction network of section m+1 via feeder F3, and busbar B4 of SS2 is connected to the end of the downward traction network of section m+1 via feeder F4. Busbar B3 and busbar B4 are connected by cross link HL. m+1 connect;

[0015] The traction substation SS and the switching station KB are equipped with a data measurement unit DMn. The data measurement unit DMn is connected to the fault segmentation identification unit FIU via fiber optic FO. The fault segmentation identification unit FIU is connected to the fault uplink and downlink identification unit DIU via fiber optic FO. The data measurement unit DMn is used for the cross-connection line HL. n Current phasor and voltage phasor The measurement, where m+1≥n≥1; the fault segmentation identification unit FIU is used to calculate the voltage change of each cross-connection line. And based on the fault voltage component matrix of the traction network The fault was determined to occur in segment s;

[0016] The fault uplink / downlink identification unit (DIU) is used to calculate the current flow of the cross-connected lines at both ends of the fault segment s. and And based on the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s. Determine whether the fault is located in the upstream or downstream segment.

[0017] As a further improvement of the present invention, the cross-connector HL1 is provided with a voltage transformer PT1, the cross-connector HL2 is provided with a voltage transformer PT2, ..., the cross-connector HL n A voltage transformer (PT) is provided. n The cross-connector HL1 is equipped with a current transformer CT1, the cross-connector HL2 is equipped with a current transformer CT2, ..., the cross-connector HL... n Equipped with current transformers (CTs) n .

[0018] As a further improvement of the present invention, the fault segmentation identification unit FIU has the function of identifying fault segments.

[0019] As a further improvement of the present invention, the fault uplink / downlink identification unit (DIU) has the function of determining whether the fault is located in the segmented uplink or downlink.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The fault voltage matrix of the traction network cross-connection line can be obtained, thereby identifying the fault segment.

[0022] 2. It can obtain the power flow direction of the cross-connector and determine the upstream or downstream direction of the fault.

[0023] 3. By determining the fault segment and the upstream and downstream directions of the traction network, a basis is provided for calculating fault distance and location.

[0024] 4. The principle is correct, the algorithm is simple and reliable, and it is easy to implement. It can be directly applied to existing measurement and control systems, which is convenient for engineering practice. Attached Figure Description

[0025] Figure 1 This is a flowchart of the fault segmentation identification method for the bilateral power supply traction network of urban railways described in Example 1.

[0026] Figure 2 This is a schematic diagram of the distribution of the fault segmentation identification system for the dual-sided power supply traction network of the urban railway described in Example 2.

[0027] Figure 3 This is a structural block diagram of the fault segmentation identification system for the dual-sided power supply traction network of urban railways described in Example 2. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] This embodiment provides a method for segmented fault identification in the bilateral power supply traction network of urban railways, such as... Figure 1 As shown, the steps include:

[0031] A1: Regarding the horizontal crossbar HL n Using the cross-connection line voltage phasor As a reference phasor, assume the current phasor of the cross-connector flows from the upper line to the lower line and is positive. Obtain the HL of the cross-connector at time t. n Voltage phasor and voltage phasor at time t+Δt

[0032] A2: Based on the horizontal line HL at time t n Voltage phasor and voltage phasor at time t+Δt Calculate the cross line HL n voltage change

[0033] A3: Based on all cross braces HL of the line n voltage change Calculate the fault voltage component matrix of the traction network

[0034] A4: Based on the fault voltage component matrix of the traction network Determine the faulty segment s.

[0035] A5: Obtain the current phasor of the transverse connecting line HLs at the beginning of the fault segment s at time t+Δt. Current phasor of the end cross-connection HLs+1

[0036] A6: Based on the phasor angle of the cross-connecting line current. and Calculate the power flow direction of the cross-connection at both ends of the fault segment s. and Obtain the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s.

[0037] If the phasor angle of the current in the horizontal connecting line HLs at the beginning of segment s is... Then record the fault direction of the cross-connector HLs at the beginning of segment s. like but If the phasor angle of the current in the transverse line HLs at the end of segment s is... Then record the fault flow direction of the transverse connecting line HLs at the end of segment s. like but Based on the power flow direction of the cross-connecting lines at both ends of the fault segment s. and

[0038] A7: Based on the fault flow direction matrix of the transverse connecting lines on both sides of fault segment s Determine whether the fault is located in the upstream or downstream segment.

[0039] Preferably, in this embodiment, the step of basing the fault voltage component matrix of the traction network... Determining the fault segment s, i.e., step A4, includes:

[0040] (1) Locate the fault voltage component matrix of the traction network Maximum value of elements Compare

[0041] Adjacent elements and size.

[0042] (2) If Let s = max - 1;

[0043] (3) If Let s = max;

[0044] (4) The fault segment identification unit FIU determines that the fault occurs in segment s.

[0045] Preferably, in this embodiment, the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s is used. Determining whether the fault is located in the segment's uplink or downlink, step A5 includes:

[0046] (1) If the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s The fault occurred at the upstream traction network of segment s.

[0047] (2) If the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s The fault occurred at the downlink traction network of segment s.

[0048] Preferably, the method provided in this embodiment further includes the following steps:

[0049] A0: When it is determined that a fault has occurred in the traction network, proceed to step A1.

[0050] Example 2

[0051] like Figure 2 and Figure 3 As shown, this embodiment provides a bilateral power supply traction power supply system for urban railways. In the bilateral power supply section of the urban double-track railway, a traction substation SS1 is set at the beginning of the traction network, and a traction substation SS2 is set at the end. Switching stations are set on the traction network between traction substations SS1 and SS2, denoted as switching stations KB1, KB2, ..., KB1. m Adjacent substations are categorized as a segment, each segment comprising an upstream traction network and a downstream traction network. The characteristic feature is that at the beginning of the traction network, busbar B1 of traction substation SS1 is connected to the beginning of the upstream traction network of segment 1 via feeder F1, and busbar B2 of SS1 is connected to the downstream traction network of segment 1 via feeder F2. Busbars B1 and B2 are connected via a cross-connector HL1. Switching station KB1 busbar B... 11 via feeder F 11 Connected to the end of the uplink traction network of segment 1, and via feeder F 13 Connected to the first end of the uplink traction network of section 2, switch station KB1 busbar B 12 via feeder F 12 Connected to the end of the downlink traction network of segment 1, and via feeder F 14 Connected to the first end of the downlink traction network of segment 2, busbar B 11 With busbar B 12 Connected via cross bracing HL2. And so on, for the switching station KB. m Busbar B m1 via feeder F m1 Connected to the end of the uplink traction network of segment m, and via feeder F m3 With segment m+1 upward traction network UN m+1 Header connection, switch station KB m Busbar B m2 via feeder F m2 Connected to the end of the downlink traction network of segment m, and via feeder F m4 Connected to the first end of the downlink traction network of segment 2, busbar B m1 With busbar B m2 via the crossbar HLm+1 Connection. At the end of the traction network, busbar B3 of traction substation SS2 is connected to the end of the upward traction network of section m+1 via feeder F3, and busbar B4 of SS2 is connected to the end of the downward traction network of section m+1 via feeder F4. Busbar B3 and busbar B4 are connected by cross link HL. m+2 connect.

[0052] Specifically, the functions of each unit are as follows:

[0053] Data measurement unit DMn: used to acquire the cross-connection HL at time t. n Voltage phasor and voltage phasor at time t+Δt Obtain the phasor current of the HLs current at the beginning of the fault segment s at time t+Δt. Current phasor of the end cross-connection HLs+1

[0054] Fault Segmentation Identification Unit (FIU): Based on the cross-connection line HL at time t n Voltage phasor and voltage phasor at time t+Δt Calculate the cross line HL n voltage change According to all cross braces HL of the line n voltage change Calculate the fault voltage component matrix of the traction network Based on the identification function of the fault segmentation identification unit, and according to the fault voltage component matrix of the traction network... The faulty segment s can be determined;

[0055] Fault Uplink / Downlink Identification Unit (DIU): Based on the power flow direction of the cross-connecting lines at both ends of the fault segment s. and Obtain the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s. Based on the judgment function of the fault uplink and downlink identification unit, and according to the fault power flow direction matrix of the cross-connecting lines on both sides of the fault segment s, Determine whether the fault is located in the upstream or downstream segment.

[0056] Furthermore, the cross-connector HL1 is equipped with a voltage transformer PT1, the cross-connector HL2 is equipped with a voltage transformer PT2, ..., the cross-connector HL... n A voltage transformer (PT) is provided. n The cross-connector HL1 is equipped with a current transformer CT1, the cross-connector HL2 is equipped with a current transformer CT2, ..., the cross-connector HL... n Equipped with current transformers (CTs) n .

[0057] It should also be noted that the traction network of the bilateral power supply section has a total of 2 traction substations and m switching stations. Correspondingly, the traction network has m+1 segments, and the fault segment s of the traction network, where m+1≥s≥1. Each segment has a cross-connecting line at both ends. Taking the cross-connecting line HLn as an example (m+2≥n≥1), as follows... Figure 2 As shown, in step A1, the voltage phasor of the cross-connector HLn at time t is obtained through the voltage transformer PTn. and voltage phasor at time t+Δt In step A4 of the embodiment, after determining the fault segment s, the current phasor of the cross-connector HLs at the beginning of the fault segment s at time t+Δt is obtained through the current transformer CTs. Current phasor of the end cross-connection HLs+1

[0058] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope 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 method for segmented fault identification in a bilateral power supply traction network of an urban railway, characterized in that, Including the following steps: Obtain the voltage phasor of the cross-connector HLn at time t. and voltage phasor at time t+Δt Based on the voltage phasor of the transverse line HLn at time t and voltage phasor at time t+Δt Calculate the voltage change of the cross-connector HLn. Based on the voltage changes of all cross-connectors HLn in the line Calculate the fault voltage component matrix of the traction network According to the fault voltage component matrix of the traction network Determining the fault segment s includes the following steps: finding the fault voltage component matrix of the traction network. Maximum value of elements Compare Adjacent elements and Size; if Let s = max - 1; if Let s = max; determine if the fault occurs in segment s; Obtain the phasor current of the HLs current at the beginning of the fault segment s at time t+Δt. Current phasor of the end cross-connection HLs+1 Based on the phasor angle of the cross-connecting line current and Calculate the power flow direction φ of the cross-connection line at both ends of the fault segment s. s With φ s+1 The fault power flow direction matrix of the transverse connecting line on both sides of segment s is obtained. The steps include: if the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s The fault occurs at the upstream traction network of segment s; if the fault flow direction matrix of the cross-connecting lines on both sides of the faulty segment s... The fault occurred at the downlink traction network of segment s; Based on the fault flow direction matrix of the transverse connecting lines at both ends of fault segment s. Determine whether the fault is located in the upstream or downstream segment.

2. A fault segmentation identification system for a dual-power supply traction network of a suburban railway, used to implement the fault segmentation identification method for a dual-power supply traction network of a suburban railway as described in claim 1, wherein, The first end of the double-track railway section with bilateral power supply is equipped with traction substation SS1, and the last end is equipped with traction substation SS2. Switching stations are set up on the traction network between traction substations SS1 and SS2, and are denoted as switching stations KB1, KB2, ..., KBm. Adjacent stations are denoted as a segment, and each segment includes an up-line traction network and a down-line traction network. The feature is that at the first end of the traction network, the busbar B1 of traction substation SS1 is connected to the first end of the up-line traction network of segment 1 through feeder F1, and the busbar B2 of SS1 is connected to the down-line traction network of segment 1 through feeder F2. The busbars B1 and B2 are connected by a cross link HL1. Busbar B11 of switchgear KB1 is connected to the end of the uplink traction network of section 1 via feeder F11, and to the beginning of the uplink traction network of section 2 via feeder F13. Busbar B12 of switchgear KB1 is connected to the end of the downlink traction network of section 1 via feeder F12, and to the beginning of the downlink traction network of section 2 via feeder F14. Busbars B11 and B12 are connected by cross-connector HL2. Busbar Bm1 of switchgear KBm is connected to the end of the uplink traction network of section m via feeder Fm1, and to the beginning of the uplink traction network UNm+1 of section m+1 via feeder Fm3. Busbar Bm2 of switchgear KBm is connected to the end of the downlink traction network of section m via feeder Fm2, and to the beginning of the downlink traction network of section 2 via feeder Fm4. Busbars Bm1 and Bm2 are connected by cross-connector HLm+1. At the end of the traction network, busbar B3 of traction substation SS2 is connected to the end of the upward traction network of section m+1 through feeder F3, and busbar B4 of SS2 is connected to the end of the downward traction network of section m+1 through feeder F4. Busbar B3 and busbar B4 are connected through cross link HLm+1. The traction substation SS and the switching station KB are equipped with a data measurement unit DMn. The data measurement unit DMn is connected to the fault segmentation identification unit FIU via fiber optic FO. The fault segmentation identification unit FIU is connected to the fault uplink and downlink identification unit DIU via fiber optic FO. The data measurement unit DMn is used for the current phasor of the cross-connecting line HLn. and voltage phasor The measurement, where m+1≥n≥1; the fault segmentation identification unit FIU is used to calculate the voltage change of each cross-connector. And based on the fault voltage component matrix of the traction network The fault was determined to occur in segment s; The fault uplink / downlink identification unit (DIU) is used to calculate the current flow φ of the cross-connection lines at both ends of the fault segment s. s With φ s+1 And based on the fault power flow direction matrix of the transverse connecting lines on both sides of the fault segment s. Determine whether the fault is located in the upstream or downstream segment.

3. The fault identification system for the bilateral power supply traction network of urban railways according to claim 2, characterized in that: The horizontal connecting line HL1 is equipped with a voltage transformer PT1, the horizontal connecting line HL2 is equipped with a voltage transformer PT2, ..., the horizontal connecting line HLn is equipped with a voltage transformer PTn; the horizontal connecting line HL1 is equipped with a current transformer CT1, the horizontal connecting line HL2 is equipped with a current transformer CT2, ..., the horizontal connecting line HLn is equipped with a current transformer CTn.

4. The bilateral power supply traction network fault segmentation identification system according to claim 2, characterized in that, The fault segmentation identification unit (FIU) has the function of identifying fault segments.

5. The bilateral power supply traction network fault segmentation identification system according to claim 2, characterized in that, The fault uplink / downlink identification unit (DIU) has the function of determining whether the fault is located in the segmented uplink or downlink.

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