Integrated spare power automatic switching scheme of chained wiring transformer substation based on optical fiber communication interaction

Abstract

The invention discloses a comprehensive spare power automatic switching scheme of a chained wiring transformer substation based on optical fiber communication interaction, which innovatively solves the problem of remote spare power automatic switching planning in a structure that a multi-loop chained wiring four-path power supply supplies power to three transformer substations. The comprehensive spare power automatic switching scheme method for the chained wiring transformer substation based on optical fiber communication interaction comprises the following steps: determining a remote spare power automatic switching working line on the basis of erecting optical fiber communication, and analyzing a remote spare power automatic switching operation mode on the basis of the working line; the charging and discharging and the action and starting logic of the remote spare power automatic switching device under the working line are determined; in different operation modes of the power grid, the achievable remote spare power automatic switching operation modes are listed, and the action logic of the circuit breaker in the corresponding remote spare power automatic switching operation modes is analyzed.

Description

Technical Field

[0001] The invention relates to a chain-type wiring transformer substation comprehensive standby automatic switching scheme based on optical fiber communication interaction, belonging to the technical field of power system transmission and distribution network control. Background Art

[0002] Substation chain connection is a form of power grid structure in which substations are interconnected through two or more transmission lines to form a chain-like topology. In this connection mode, each substation is not only connected to the upstream substation, but also to at least one substation downstream, so that even if a certain section of the transmission line fails, electricity can still be transmitted through other paths, thereby ensuring the stability of the power grid and the continuity of power supply. In the context of a new power system with a high proportion of new energy access and a high proportion of power electronic equipment access, the promotion and application of chain connection can improve power supply reliability, enhance power grid flexibility, promote power grid modernization, and optimize the power grid operation structure. However, the chain connection structure is very likely to cause the scope of the fault to expand when a fault occurs during operation, and the power supply reliability is relatively insufficient. Therefore, in order to ensure the reliability, economy and operational flexibility of the power supply system, it is necessary to study the comprehensive standby automatic investment technology suitable for chain connection.

[0003] The existing research on chain-type automatic backup switch is mainly aimed at the power supply structure of four power supply lines to two 110kV substations (such as the document "A universal remote automatic backup switch method, Shao Zhenyu et al., Power System Protection and Control, 2014, 24(18)"), which has a relatively simple operation mode. However, this power supply structure lacks the analysis of the automatic backup switch action logic under the system N-1 operation mode, and the research is not complete. In addition, this power supply structure cannot give full play to the various advantages of chain connection due to the small number of substations involved.

[0004] In order to further reduce the investment in transmission line construction and improve the redundancy of the power grid, a four-way power supply line can be used to supply power to three 110kV substations. This power supply structure can further improve the reliability of power supply, enhance the redundancy of the power grid, greatly reduce line construction investment, optimize line corridors, and reduce economic costs. However, compared with the four-way power supply structure for two substations, the four-way power supply structure for three substations is relatively complex, and the number of remote standby automatic operation modes that need to be considered is growing exponentially, and the planning is difficult, so the relevant research field is blank. Summary of the invention

[0005] The purpose of the present invention is to provide a comprehensive automatic standby switching scheme for chain-type connected substations based on optical fiber communication interaction, and to propose an action logic that can be followed by remote automatic standby switching in a multi-circuit chain-type connected three-substation power grid structure. On the basis of setting up optical fiber communication between the substations, the present invention proposes an action logic scheme for remote automatic standby switching in a multi-circuit chain-type connected four-way power supply structure for three substations, innovatively solves the problem of remote automatic standby switching planning in a multi-circuit chain-type connected four-way power supply structure for three substations, and illustrates the correctness of various remote automatic standby switching operation logics through examples.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A comprehensive automatic backup scheme for chain-connected substations based on optical fiber communication interaction. On the basis of optical fiber communication, the main power supply line is used as the starting point. The line consisting of closed circuit breakers and serially connected busbars is called a remote automatic backup working line. One working line can be connected to three busbars in series at most. A comprehensive automatic backup network has multiple remote automatic backup working lines, and each has an independent automatic backup working logic.

[0008] 1. Remote standby automatic input to achieve operation mode

[0009] (1) For a three-substation network with four power supply lines connected in a chain, there are multiple operating modes for the remote backup automatic switch in normal operation. QFn, where n is 1 to 15, represents the circuit breaker. The action logic of the remote backup automatic switch is different in different operating modes. There are 16 remote backup automatic switch operating modes in total. Each operating mode has a maximum of four working lines. The 16 operating modes are summarized into 5 lines with specific differences in structure, including:

[0010] 1) Remote standby automatic action logic mode 1

[0011] a. Working line 1: QF2, bus 12, QF5, QF7, bus 22, QF10, QF12, bus 32;

[0012] b. Working line 2: QF1, bus 11, QF4, QF6, bus 21, QF9, QF11, bus 31;

[0013] 2) Remote standby automatic switching action logic method 2

[0014] a. Working line 1: QF2, bus 12, QF5, QF7, bus 22, QF10, QF12, bus 32;

[0015] b. Working line 2: QF14, bus 31, QF11, QF9, bus 21, QF6, QF4, bus 11;

[0016] 3) Remote standby automatic action logic mode 3

[0017] a. Working line 1: QF2, bus 12, QF5;

[0018] b. Working line 2: QF1, bus 11, QF4, QF6, bus 21;

[0019] c. Working line three: QF15, bus 32, QF12, QF10, bus 22;

[0020] d. Working line 4: QF14, bus 31, QF11;

[0021] 4) Remote standby automatic action logic mode 4

[0022] a. Working line 1: QF2, bus 12, QF5, QF7, bus 22;

[0023] b. Working line 2: QF1, bus 11, QF4, QF6, bus 21;

[0024] c. Working line three: QF15, bus 32, QF12;

[0025] d. Working line 4: QF14, bus 31, QF11;

[0026] 5) Remote standby automatic action logic mode 5

[0027] a. Working line 1: QF2, bus 12, QF5;

[0028] b. Working line 2: QF1, bus 11, QF4, QF6, bus 21, QF9, QF11, bus 31;

[0029] c. Working line three: QF15, bus 32, QF12, QF10, bus 22;

[0030] (2) When the substation working line is in N-1 operation (it can still operate normally when any component in the power system fails), it is also necessary to consider the standby automatic switching working line and the circuit breaker action logic during line maintenance. Different maintenance lines have different remote standby automatic switching operation modes. There are 8 remote standby automatic switching working modes. The situations considered during the maintenance of lines 1, 2, 8, and 9 are similar, and the situations considered during the maintenance of lines 4, 5, 6, and 7 are similar. Therefore, the circuit breaker action logic during the maintenance of lines 6 and 8 can be explained, including the following contents:

[0031] 1) Automatic backup mode during maintenance of line 8

[0032] a. Working line 1: QF2, bus 12, QF5, QF7, bus 22.

[0033] b. Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0034] c. Working line three: QF15, busbar 32, QF13, busbar 31.

[0035] 2) Automatic backup mode during maintenance of line 6

[0036] a. Working line 1: QF2, bus 12, QF5.

[0037] b. Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0038] c. Working line three: QF15, busbar 32, QF12, QF10, busbar 22.

[0039] d. Working line four: QF14, busbar 31.

[0040] 2. Remote backup logic implementation conditions

[0041] For the above remote standby automatic switching working mode, the following logical implementation conditions should be met:

[0042] (1) Remote standby automatic charging logic

[0043] 1) The three-phase busbar has voltage and is in normal operation.

[0044] 2) The relevant circuit breaker is in the predetermined state:

[0045] a. Only one busbar in the working circuit is connected to the main power supply;

[0046] b. There is at least one busbar with open-loop characteristics in the working line, and a closed loop is not formed between the incoming and outgoing lines of the busbar;

[0047] 3) The backup automatic switching function has been put into use, and at least one bus with open-loop characteristics has a backup power supply;

[0048] 4) The function of the standby automatic switching device has been activated through the operation interface or remote control;

[0049] When the above conditions are met at the same time, the standby automatic transfer device starts to enter the charging state;

[0050] (2) Remote standby automatic power supply logic

[0051] 1) When the working line status changes, the discharge is delayed when one of the following situations occurs:

[0052] a. More than one busbar in the working circuit is connected to the main power supply;

[0053] b. The busbar in the working line no longer has open-loop characteristics;

[0054] c. The backup power supply of all buses with open-loop characteristics in the working line disappears;

[0055] 2) The circuit breaker is in an abnormal opening or closing position. When one of the following situations occurs, discharge immediately:

[0056] a. After the command to cut off the main supply or the backup supply is issued, if the corresponding switch is not detected to be in the open position after the tripping waiting delay setting;

[0057] b. After the command to switch to the main supply or the standby supply is issued, if the corresponding switch is not detected to be in the closed position after the closing waiting delay setting;

[0058] 3) Exit the standby automatic switching function through the operation interface or remote control and discharge immediately;

[0059] 4) Immediately discharge upon receiving an external blocking signal;

[0060] 5) Related communication is abnormal, and discharge is delayed;

[0061] When any of the above conditions is met, the standby automatic transfer device will discharge. After discharge, the standby automatic transfer device will be locked and will no longer perform any action;

[0062] (3) Remote standby automatic start-up logic

[0063] 1) Any section of the busbar in the working line loses pressure;

[0064] 2) There is no current in the main power supply of the busbar in the voltage-loss section;

[0065] 3) There is voltage on the backup power supply side;

[0066] When the above three conditions are met at the same time, the standby automatic transfer device starts;

[0067] (4) Remote standby automatic operation process

[0068] 1) Cut off the main power supply corresponding to the voltage-losing busbar closest to the power supply side busbar;

[0069] 2) After confirming that the main power supply corresponding to the voltage-losing busbar is cut off, close the backup power supply corresponding to the open-loop side;

[0070] 3) The longitudinal circuit breaker is closed first. There is a step difference Δt between the transverse circuit breaker and the longitudinal circuit breaker.

[0071] The purpose of the present invention can also be further achieved by the following technical measures:

[0072] In the aforementioned chain-connected substation comprehensive backup automatic switching scheme based on optical fiber communication interaction, the step difference Δt between the transverse circuit breaker and the longitudinal circuit breaker is 0.3s to 0.5s.

[0073] The aforementioned chain-connected substation comprehensive standby automatic switching scheme based on optical fiber communication interaction is applied to normal operation and N-1 operation mode.

[0074] Compared with the prior art, the beneficial effects of the present invention are: it can further improve the reliability of power supply of the power grid, be applied to normal operation and N-1 operation mode, enhance the redundancy of the power grid, greatly reduce the investment in line construction, optimize the line corridor, and reduce economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 It is a primary main wiring diagram of a chain-type wiring substation to which the method of the present invention is applied;

[0076] Figure 2 This is the primary main wiring diagram of the high voltage side of the chain-type wiring 110kV substation to which the method of the present invention is applied;

[0077] Figure 3 It is a wiring diagram of the remote standby automatic switching action logic mode of the chain-type substation used in the method of the present invention;

[0078] Figure 4 It is the wiring diagram of the second logic mode of remote standby automatic switching action of the chain-type substation used in the method of the present invention;

[0079] Figure 5 It is a three-wire diagram of the logic mode of remote standby automatic switching action of the chain-type substation used in the method of the present invention;

[0080] Figure 6 It is a four-wire diagram of the remote standby automatic switching action logic mode of the chain-type substation used in the method of the present invention;

[0081] Figure 7 It is a five-wire diagram of the remote standby automatic switching action logic mode of the chain-type substation used in the method of the present invention;

[0082] Figure 8 It is a remote standby automatic switching wiring diagram when the chain substation line 8 is overhauled and repaired in the method of the present invention;

[0083] Fig. 9 This is a remote standby automatic switching wiring diagram when the chain substation line 6 is overhauled and repaired according to the method of the present invention. DETAILED DESCRIPTION

[0084] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0085] For multi-circuit chain-connected three-substation, Figure 1For example, 4 incoming power supplies can be configured, namely S1, S2, S3 and S4. The different power supplies on both sides (S1 and S2, S3 and S4) can come from the 110kV side of different 220kV substations, or different 110kV busbars of the same 220kV substation. Power sources S1 and S2 supply power to 110kV substation 1 through line 1 and line 2 respectively, and are connected to busbar 11 and busbar 12 of 110kV substation 1 through circuit breakers QF1 and QF2 respectively. The 110kV side of substation 1 is in a "hand-in-hand" form, with busbar 11 connected to 110kV substation 2 through interconnecting line 4 via circuit breaker QF4 and busbar 12 connected to 110kV substation 2 through interconnecting line 5 via circuit breaker QF5. Line 4 is connected to 110kV busbar 21 of substation 2 through circuit breaker QF6, and line 5 is connected to 110kV busbar 22 of substation 2 through circuit breaker QF7. Similarly, the 110kV bus 21 of substation 2 is connected to the 110kV substation 3 through the interconnection line 6 via the circuit breaker QF9, and the bus 22 is connected to the 110kV substation 3 through the interconnection line 7 via the circuit breaker QF10. The line 6 is connected to the 110kV bus 31 of substation 3 through the circuit breaker QF11, and the line 7 is connected to the 110kV bus 32 of substation 3 through the circuit breaker QF12. Power sources S3 and S4 supply power to substation 3 through lines 8 and 9, respectively, and are connected to bus 31 and bus 32 of substation 3 through circuit breakers QF14 and QF15, respectively.

[0086] The 110kV side wiring mode of 110kV substation 1, substation 2 and substation 3 all adopt single busbar segmented wiring, and the segmented circuit breakers are QF3, QF8 and QF13 respectively. Take 110kV substation 1 as an example (see Figure 2 ), in addition to the line branches, the substation 1 bus 11 is connected to the No. 1 main transformer and the bus voltage transformer TV1, and the bus 12 is connected to the No. 2 main transformer and the bus voltage transformer TV2.

[0087] Specific examples of the present invention are as follows:

[0088] 1. Standby automatic operation mode during normal operation

[0089] For a three-substation network with four power supply lines connected in a chain, there are multiple operation modes for the comprehensive automatic backup during normal operation. The possible automatic backup operation modes are listed in an arranged manner. There are a total of 16 automatic backup operation modes, and each operation mode has a maximum of four working lines. The specific 16 operation modes are shown in Table 1.

[0090] Table 1 Standby automatic operation mode during normal operation

[0091]

[0092]

[0093] The 16 remote standby automatic switching operation modes described in Table 1 are symmetrical or similar in structure. The above 16 operation modes can be summarized into 5 situations with specific differences in structure. A specific logical analysis is conducted on these 5 operation modes. Among them, Figure 3 to Figure 7 The rectangular graphic symbol corresponding to QFn (n is 1 to 15) represents a circuit breaker, the colored part represents that the circuit breaker is closed, and the blank part represents that the circuit breaker is open.

[0094] (1) Remote standby automatic action logic mode 1

[0095] 1) Working line 1: QF2, busbar 12, QF5, QF7, busbar 22, QF10, QF12, busbar 32.

[0096] a. Busbar 32 loses pressure, circuit breaker QF12 is tripped, and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF15 is disconnected and then circuit breaker QF13 is closed.

[0097] b. Busbar 22 and busbar 32 lose pressure, circuit breaker QF7 is tripped and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF15 is disconnected and then circuit breaker QF8 is closed.

[0098] c. Busbars 12, 22 and 32 all lose pressure, circuit breaker QF2 is tripped and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF15 is disconnected and then QF3 is closed.

[0099] 2) Working line two: QF1, busbar 11, QF4, QF6, busbar 21, QF9, QF11, busbar 31.

[0100] a. Busbar 31 loses pressure, circuit breaker QF11 trips, and circuit breaker QF14 closes; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF14 is disconnected and then circuit breaker QF13 is closed.

[0101] b. Busbar 21 and busbar 31 lose pressure, circuit breaker QF6 is tripped and circuit breaker QF14 is closed; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF14 is disconnected and then circuit breaker QF8 is closed.

[0102] c. Busbars 11, 21 and 31 all lose pressure, circuit breaker QF1 is tripped and circuit breaker QF14 is closed; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF14 is disconnected and then QF3 is closed.

[0103] (2) Remote standby automatic switching action logic method 2

[0104] 1) Working line 1: QF2, busbar 12, QF5, QF7, busbar 22, QF10, QF12, busbar 32.

[0105] a. Busbar 32 loses pressure, circuit breaker QF12 is tripped, and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF15 is disconnected and then circuit breaker QF13 is closed.

[0106] b. Busbar 22 and busbar 32 lose pressure, circuit breaker QF7 is tripped and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF15 is disconnected and then circuit breaker QF8 is closed.

[0107] c. Busbars 12, 22 and 32 all lose pressure, circuit breaker QF2 is tripped and circuit breaker QF15 is closed; if circuit breaker QF15 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF15 is disconnected and then QF3 is closed.

[0108] 2) Working line two: QF14, busbar 31, QF11, QF9, busbar 21, QF6, QF4, busbar 11.

[0109] a. Busbar 11 loses pressure, circuit breaker QF4 is tripped, and circuit breaker QF1 is closed; if circuit breaker QF1 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF3 is closed or circuit breaker QF1 is disconnected and then QF3 is closed.

[0110] b. Busbar 11 and busbar 21 lose pressure, circuit breaker QF9 is tripped and circuit breaker QF1 is closed; if circuit breaker QF1 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF1 is disconnected and then circuit breaker QF8 is closed.

[0111] c. Busbars 11, 21 and 31 all lose pressure, circuit breaker QF14 is tripped and circuit breaker QF1 is closed; if circuit breaker QF1 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF13 is closed or circuit breaker QF1 is disconnected and then circuit breaker QF13 is closed.

[0112] (3) Remote standby automatic action logic method 3

[0113] 1) Working line 1: QF2, bus 12, QF5.

[0114] Busbar 12 loses pressure, circuit breaker QF2 is tripped, and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF3 is closed.

[0115] 2) Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0116] a. Busbar 21 loses pressure, circuit breaker QF6 is tripped, and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF8 is closed.

[0117] b. Busbar 11 and busbar 21 lose pressure, circuit breaker QF1 is tripped and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF3 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF3 is closed.

[0118] 3) Working line three: QF15, busbar 32, QF12, QF10, busbar 22.

[0119] a. Busbar 22 loses pressure, circuit breaker QF10 is tripped, and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF8 is closed.

[0120] b. Busbar 32 and busbar 22 lose pressure, circuit breaker QF15 is tripped and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF13 is closed.

[0121] 4) Working line four: QF14, busbar 31, QF11.

[0122] Busbar 31 loses pressure, circuit breaker QF14 is tripped, and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF13 is closed.

[0123] (4) Remote standby automatic action logic mode 4

[0124] 1) Working line 1: QF2, bus 12, QF5, QF7, bus 22.

[0125] a. Busbar 22 loses pressure, circuit breaker QF7 is tripped, and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF8 is closed.

[0126] b. Busbars 12 and 22 lose pressure, circuit breaker QF2 is tripped, and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF3 is closed.

[0127] 2) Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0128] a. Busbar 21 loses pressure, circuit breaker QF6 is tripped, and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF8 is closed.

[0129] b. Busbar 11 and busbar 21 lose pressure, circuit breaker QF1 is tripped and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF3 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF3 is closed.

[0130] 3) Working line three: QF15, busbar 32, QF12.

[0131] When busbar 32 loses pressure, circuit breaker QF15 is tripped and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF13 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF13 is closed.

[0132] 4) Working line four: QF14, busbar 31, QF11.

[0133] Busbar 31 loses pressure, circuit breaker QF14 is tripped, and circuit breaker QF9 is closed; if circuit breaker QF9 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF9 is disconnected and then circuit breaker QF13 is closed.

[0134] (5) Remote standby automatic action logic mode 5

[0135] 1) Working line 1: QF2, bus 12, QF5.

[0136] Busbar 12 loses pressure, circuit breaker QF2 is tripped, and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF3 is closed.

[0137] 2) Working line two: QF1, busbar 11, QF4, QF6, busbar 21, QF9, QF11, busbar 31.

[0138] a. Busbar 31 loses pressure, circuit breaker QF11 trips, and circuit breaker QF14 closes; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF14 is disconnected and then circuit breaker QF13 is closed.

[0139] b. Busbar 21 and busbar 31 lose pressure, circuit breaker QF6 is tripped and circuit breaker QF14 is closed; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF14 is disconnected and then circuit breaker QF8 is closed.

[0140] c. Busbars 11, 21 and 31 all lose pressure, circuit breaker QF1 is tripped and circuit breaker QF14 is closed; if circuit breaker QF14 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF14 is disconnected and then QF3 is closed.

[0141] 3) Working line three: QF15, bus 32, QF12, QF10, bus 22

[0142] a. Busbar 22 loses pressure, circuit breaker 10 trips, and circuit breaker 7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF8 is closed.

[0143] b. Busbar 32 and busbar 22 lose pressure, circuit breaker 15 trips and circuit breaker 7 closes; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF13 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF13 is closed.

[0144] 2. Standby automatic operation mode during N-1 operation

[0145] When the substation working line is in N-1 operation, it is also necessary to consider the standby automatic switching working line and circuit breaker action logic during line maintenance. Different maintenance lines have different remote standby automatic switching operation modes. The specific remote standby automatic switching working lines that can be realized during N-1 operation are shown in Table 2.

[0146] Table 2N-1 Operation standby automatic switching working line

[0147]

[0148] The 8 remote backup automatic switching working modes described in Table 2 are similar to the situations considered when lines 1, 2, 8, and 9 are overhauled, and the situations considered when lines 4, 5, 6, and 7 are overhauled. Therefore, this article explains the circuit breaker action logic when lines 6 and 8 are overhauled. Figure 8-Figure 9 The rectangular graphic symbol corresponding to QFn (n is 1 to 15) represents a circuit breaker, the colored part represents that the circuit breaker is closed, and the blank part represents that the circuit breaker is open.

[0149] (1) Automatic switching operation mode during maintenance of line 8

[0150] 1) Working line 1: QF2, bus 12, QF5, QF7, bus 22.

[0151] a. Busbar 22 loses pressure, circuit breaker QF7 is tripped, and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF8 is closed.

[0152] b. Busbars 12 and 22 lose pressure, circuit breaker QF2 is tripped, and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF3 is closed.

[0153] 2) Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0154] a. Busbar 21 loses pressure, circuit breaker QF6 is tripped, and circuit breaker QF11 is closed; if circuit breaker QF11 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF8 is closed or circuit breaker QF11 is disconnected and then circuit breaker QF8 is closed.

[0155] b. Busbar 11 and busbar 21 lose pressure, circuit breaker QF1 is tripped and circuit breaker QF11 is closed; if circuit breaker QF11 refuses to operate or the backup power supply is not successfully put into use, circuit breaker QF3 is closed or circuit breaker QF11 is disconnected and then circuit breaker QF3 is closed.

[0156] 3) Working line three: QF15, busbar 32, QF13, busbar 31.

[0157] a. Circuit breaker QF13 fails, busbar 31 loses pressure, circuit breaker QF13 is tripped, and circuit breaker QF11 is closed.

[0158] b. Busbars 31 and 32 lose pressure, circuit breaker QF15 is tripped and circuit breaker QF10 is closed; if circuit breaker QF10 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF11 is closed or circuit breaker QF10 is disconnected and then circuit breaker QF11 is closed.

[0159] (2) Automatic switching operation mode during maintenance of line 6

[0160] 1) Working line 1: QF2, bus 12, QF5.

[0161] Busbar 12 loses pressure, circuit breaker QF2 is tripped, and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF3 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF3 is closed.

[0162] 2) Working line two: QF1, bus 11, QF4, QF6, bus 21.

[0163] a. Busbar 21 loses pressure, circuit breaker QF6 opens, and circuit breaker QF8 closes.

[0164] b. Busbar 11 and busbar 21 lose pressure, circuit breaker QF1 is tripped and circuit breaker QF3 is closed; if circuit breaker QF3 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF13 is closed or circuit breaker QF3 is disconnected and then circuit breaker QF8 is closed.

[0165] 3) Working line three: QF15, busbar 32, QF12, QF10, busbar 22.

[0166] When busbar 22 loses pressure, circuit breaker QF10 is tripped and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF8 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF8 is closed.

[0167] Busbar 32 and busbar 22 lose pressure, circuit breaker QF15 is tripped, and circuit breaker QF7 is closed; if circuit breaker QF7 refuses to operate or the backup power supply is not successfully put into operation, circuit breaker QF13 is closed or circuit breaker QF7 is disconnected and then circuit breaker QF13 is closed.

[0168] 4) Working line four: QF14, busbar 31.

[0169] Busbar 31 loses pressure, circuit breaker QF14 opens, and circuit breaker QF13 closes.

[0170] Through the analysis of the above specific examples, it can be shown that the chain-connected three-substation comprehensive backup automatic switching action logic scheme based on optical fiber communication interaction is feasible.

[0171] The above-described embodiments are only preferred embodiments of the present invention, and the protection scope thereof is not limited thereto. Any improvements and modifications made by those skilled in the art in accordance with the technical principles of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A comprehensive automatic backup scheme for chain-type substations based on optical fiber communication interaction. On the basis of optical fiber communication, the main power supply line is used as the starting point, and the line consisting of closed circuit breakers and serially connected busbars is called a remote automatic backup working line. A working line can be connected to three busbars in series at most; a comprehensive automatic backup network has multiple remote automatic backup working lines, and each has an independent automatic backup working logic; it is characterized in that: The following operation modes are included: (1) Remote standby automatic switching operation mode 1) For a three-substation network with a chain connection of four power supply lines, there are multiple operating modes for the comprehensive automatic switching of the remote standby switch in normal operation. QFn, where n is 1 to 15, represents the circuit breaker. The action logic of the remote standby switch is different in different operating modes. There are 16 remote standby switch operating modes in total, and each operating mode has a maximum of four working lines. The 16 operating modes are summarized into 5 lines with specific differences in structure, including: ① Remote standby automatic action logic mode 1 a. Working line 1: QF2, bus 12, QF5, QF7, bus 22, QF10, QF12, bus 32; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21, QF9, QF11, bus 31; ② Remote standby automatic switching action logic mode 2 a. Working line 1: QF2, bus 12, QF5, QF7, bus 22, QF10, QF12, bus 32; b. Working line 2: QF14, bus 31, QF11, QF9, bus 21, QF6, QF4, bus 11; ③ Remote standby automatic action logic mode 3 a. Working line 1: QF2, bus 12, QF5; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21; c. Working line three: QF15, bus 32, QF12, QF10, bus 22; d. Working line 4: QF14, bus 31, QF11; ④ Remote standby automatic action logic mode 4 a. Working line 1: QF2, bus 12, QF5, QF7, bus 22; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21; c. Working line three: QF15, bus 32, QF12; d. Working line 4: QF14, bus 31, QF11; ⑤ Remote standby automatic throw action logic mode 5 a. Working line 1: QF2, bus 12, QF5; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21, QF9, QF11, bus 31; c. Working line three: QF15, bus 32, QF12, QF10, bus 22; 2) When the substation working line is in N-1 operation, it includes the following working modes: ① The first line maintenance automatic backup working mode: a. Working line 1: QF2, bus 12, QF5, QF7, bus 22; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21; c. Working line three: QF15, bus 32, QF13, bus 31; ② The second line maintenance automatic backup working mode: a. Working line 1: QF2, bus 12, QF5; b. Working line 2: QF1, bus 11, QF4, QF6, bus 21; c. Working line three: QF15, bus 32, QF12, QF10, bus 22; d. Working line 4: QF14, busbar 31; (2) Remote backup logic implementation conditions For the above remote standby automatic switching working mode, the following logical implementation conditions should be met: 1) Remote standby automatic charging logic ① The three-phase busbar has voltage and is in normal operation; ②The relevant circuit breakers are in the predetermined state: a. Only one busbar in the working circuit is connected to the main power supply; b. There is at least one busbar with open-loop characteristics in the working line, and a closed loop is not formed between the incoming and outgoing lines of the busbar; ③ The backup automatic switching function has been put into use, and at least one bus with open-loop characteristics has a backup power supply; ④The function of the standby automatic switching device has been activated through the operation interface or remote control; When the above conditions are met at the same time, the standby automatic transfer device starts to enter the charging state; 2) Remote standby automatic power supply logic ① When the working line status changes, the discharge is delayed when one of the following situations occurs: a. More than one busbar in the working circuit is connected to the main power supply; b. The busbar in the working line no longer has open-loop characteristics; c. The backup power supply of all buses with open-loop characteristics in the working line disappears; ② The circuit breaker is abnormal in opening and closing positions. When one of the following situations occurs, discharge immediately: a. After the command to cut off the main supply or the backup supply is issued, if the corresponding switch is not detected to be in the open position after the tripping waiting delay setting; b. After the command to switch to the main supply or the standby supply is issued, if the corresponding switch is not detected to be in the closed position after the closing waiting delay setting; ③ Exit the standby automatic transfer function through the operation interface or remote control and discharge immediately; ④ Upon receiving an external locking signal, discharge immediately; ⑤Related communication is abnormal, delayed discharge; When any of the above conditions is met, the standby automatic transfer device will discharge. After discharge, the standby automatic transfer device will be locked and will no longer perform any action; 3) Remote standby automatic start-up logic ① Any section of the busbar in the working line loses pressure; ② There is no current in the main power supply of the busbar in the voltage-loss section; ③There is voltage on the backup power supply side; When the above three conditions are met at the same time, the standby automatic transfer device starts; 4) Remote standby automatic switching operation process ① Cut off the main power supply corresponding to the voltage-losing busbar closest to the power supply side busbar; ② After confirming that the main power supply corresponding to the voltage-losing busbar is cut off, close the corresponding standby power supply on the open-loop side; ③ Close the longitudinal circuit breaker first. There is a step difference Δt between the transverse circuit breaker and the longitudinal circuit breaker.

2. The chain-connected substation comprehensive backup and automatic switching scheme based on optical fiber communication interaction according to claim 1 is characterized in that: Applicable to normal operation and N-1 operation mode.

3. The chain-connected substation comprehensive backup and automatic switching scheme based on optical fiber communication interaction according to claim 1 is characterized in that: The step difference Δt between the transverse circuit breaker and the longitudinal circuit breaker is 0.3s to 0.5s.

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