Logic simplification method for four-source power supply single-bus sectionalizing wiring substation backup power supply automatic switching device

Abstract

The application discloses a four-power-supply single-bus sectional wiring substation backup automatic switching logic simplification method, which is applied to a four-power-supply single-bus sectional wiring substation of 110kV voltage grade power transmission and distribution network, simplifies the backup automatic switching configuration of the four-power-supply single-bus sectional substation into several simple wiring backup automatic switching, and the logic algebra expression of the four-power-supply single-bus sectional wiring substation backup automatic switching is: the configuration operation of the four-power-supply single-bus sectional wiring substation backup automatic switching is realized, and the correctness of the wiring backup automatic switching operation mode is verified by using the logic algebra.

Description

TECHNICAL FIELD

[0001] The application relates to a four-power-supply single-bus sectional wiring substation automatic backup-throw-in logic simplification method, and belongs to the control technology of a power transmission and distribution network. BACKGROUND

[0002] With the continuous construction of a power system, some substations represented by 110kV voltage grades adopt more than two power supply wiring, in order to optimize the power supply capacity resources of the 110kV substation, some 110kV voltage grade substations have four power supply lines, for example, a network architecture in a chain structure is adopted, the substation lines can be taken from multiple different power sources, forming a chain structure of "two-end power supply and two-line multi-station", and the operation mode is flexible and changeable, and the 110kV single-bus sectional wiring substation therein theoretically has four power sources. If the operation mode of a single substation in the wiring mode is "exhausted", there are as many as 27 kinds, and at present, there is no corresponding backup power automatic throw-in device protection scheme (hereinafter referred to as backup throw-in) that can meet the wiring mode. Engineering examples prove that the backup throw-in device of a complex wiring can be simplified into several simple wiring backup throw-ins to form. However, how to configure and simplify the backup throw-in of the four-power-supply single-bus sectional wiring substation, and how to verify the correctness of the operation mode of the backup throw-in, the existing technology has not yet solved. Therefore, it is a technical problem urgently needed to be researched and solved in the field at present to study the configuration and simplification method of the backup throw-in of the four-power-supply single-bus sectional wiring substation, and to verify the correctness of the operation mode of the backup throw-in by using the method of logic algebra. SUMMARY

[0003] The application aims to provide a four-power-supply single-bus sectional wiring substation automatic backup-throw-in logic simplification method, which is applied to a 110kV voltage grade transmission and distribution network, and simplifies the backup throw-in of the four-power-supply single-bus sectional wiring substation into several simple wiring backup throw-ins, so as to realize the configuration and operation of the backup throw-in of the four-power-supply single-bus sectional wiring substation, and verify the correctness of the operation mode of the wiring backup throw-in by using logic algebra.

[0004] The application is achieved by the following technical scheme:

[0005] A four-power-supply single-bus sectional wiring substation automatic backup-throw-in logic simplification method simplifies the backup throw-in of the four-power-supply single-bus sectional wiring substation into four single-bus sectional wiring backup throw-ins and two single-bus wiring backup throw-ins;

[0006] The circuit breakers QF1, QF2 and QF3 of the four-power-supply single-bus sectional wiring substation line form a single-bus sectional wiring backup throw-in of double-power-supply three-circuit breakers, which is referred to as backup throw-in 1;

[0007] The double power supply three-circuit breaker single mother segment wiring backup power supply is composed of circuit breakers QF3, QF4 and QF5, and is referred to as backup power supply 2;

[0008] The double power supply three-circuit breaker single mother segment wiring backup power supply is composed of circuit breakers QF1, QF3 and QF5, and is referred to as backup power supply 3;

[0009] The double power supply three-circuit breaker single mother segment wiring backup power supply is composed of circuit breakers QF2, QF3 and QF4, and is referred to as backup power supply 4;

[0010] The double power supply two-circuit breaker single mother bus backup power supply is composed of circuit breakers QF1 and QF4, and is referred to as backup power supply 5;

[0011] The double power supply two-circuit breaker single mother bus backup power supply is composed of circuit breakers QF2 and QF5, and is referred to as backup power supply 6;

[0012] The backup power supply 1 operating mode meets the following logical algebraic expression:

[0013]

[0014] The backup power supply 2 operating mode meets the following logical algebraic expression:

[0015]

[0016] The backup power supply 3 operating mode meets the following logical algebraic expression:

[0017]

[0018] The backup power supply 4 operating mode meets the following logical algebraic expression:

[0019]

[0020] The backup power supply 5 operating mode meets the following logical algebraic expression:

[0021]

[0022] The backup power supply 6 operating mode meets the following logical algebraic expression:

[0023]

[0024] The logical relationship between the above backup power supplies is "or", and the logical algebraic expression of the backup power supply of the single mother bus segment wiring substation of four power supplies is:

[0025]

[0026] Wherein, A, B, C, D, E respectively represent the closing operation state of circuit breakers QF1, QF2, QF3, QF4, QF5, and are represented by logic algebra as 1 respectively; Respectively represent the opening operation state of circuit breakers QF1, QF2, QF3, QF4, QF5, namely the hot standby state, and are represented by logic algebra as 0 respectively.

[0027] In the above formula, the logic algebra expression of each 1 field represents one operation mode of the four-source power supply single-bus sectional wiring substation, and there are 27 operation modes in total.

[0028] The object of the application can also be further achieved by the following technical measures:

[0029] The aforementioned four-source power supply single-bus sectional wiring substation backup automatic switching logic simplification method, the control logic of the four-source power supply single-bus sectional wiring substation backup automatic switching is composed of six parts, i.e., the single-mother sectional wiring backup automatic switching logic composed of high-voltage side circuit breakers QF1, QF2 and QF3, the single-mother sectional wiring backup automatic switching logic composed of circuit breakers QF3, QF4 and QF5, the single-mother sectional wiring backup automatic switching logic composed of circuit breakers QF2, QF3 and QF4, the single-mother sectional wiring backup automatic switching logic composed of circuit breakers QF1, QF3 and QF5, the single-mother sectional wiring backup automatic switching logic composed of circuit breakers QF1 and QF4, and the single-mother sectional wiring backup automatic switching logic composed of circuit breakers QF2 and QF5, and the six parts are arranged in the same backup automatic switching device.

[0030] The aforementioned four-source power supply single-bus sectional wiring substation backup automatic switching logic simplification method, when more than one of the six backup automatic switchings satisfies the action condition, the selection is realized by setting the action delay between the six backup automatic switchings.

[0031] The aforementioned four-source power supply single-bus sectional wiring substation backup automatic switching logic simplification method, when more than one of the six backup automatic switchings satisfies the action condition, the selection is realized by increasing the judgment logic between the backup automatic switchings. For example, the longitudinal backup automatic switchings (backup automatic switching 5 and backup automatic switching 6) are preferentially used, or the backup automatic switchings related to the dedicated power supply are preferentially used according to the actual operation situation on site.

[0032] Compared with the prior art, the application has the following beneficial effects:

[0033] 1. The four-source power supply single-bus sectional wiring substation backup automatic switching is simplified into four double-source single-mother sectional primary main wiring backup automatic switchings and two double-source single-bus backup automatic switchings, which is simple and clear.

[0034] 2. The simplified four-source power supply single-bus sectional wiring substation backup automatic switching can automatically adapt to the input or exit according to the operation state of the primary equipment, and part of the backup automatic switching function can be enabled, so that the operation flexibility is strong.

[0035] 3. The simplified several simple backup power supply devices of the four power supply single bus sectional wiring substation are common backup power supply devices in the power grid, and do not need to be redesigned and produced.

[0036] 4. The simplified four power supply single bus sectional wiring substation backup power supply device operation mode of the logical algebraic calculation is clear and easy to understand. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is an example of the primary main wiring of the four power supply single bus sectional wiring substation to which the simplified method of the present application is applied;

[0038] Figure 2 is a high voltage side primary main wiring diagram of the four power supply single bus sectional wiring substation to which the simplified method of the present application is applied. DETAILED DESCRIPTION

[0039] The present application will be further described below in combination with the drawings and specific embodiments.

[0040] As shown in the drawings, Figure 1 In the four power supply single bus sectional wiring substation to which the method of the present application is applied, taking a chain wiring of three 110kV substations as an example, the four power sources of the substation 1, the substation 2 and the substation 3 are involved, and the four power sources of the substation 1 are S1, S2, S3 and S4. The power sources S1 and S2 supply power to the 110kV substation 1 through the line 1 and the line 2 respectively, and the power source S1 supplies power to the 110kV substation 1 through the line 1 via the circuit breaker QF1, and the power source S2 supplies power to the 110kV substation 1 through the line 2 via the circuit breaker QF2. The 110kV side of the substation 1 is in the form of "hand in hand", and the I section bus is connected to the 110kV substation 2 through the circuit breaker QF4 via the tie line 4, and the II section bus is connected to the 110kV substation 2 through the circuit breaker QF5 via the tie line 5, the line 4 is connected to the 110kV I section bus of the substation 2 via the circuit breaker QF6, and the line 5 is connected to the 110kV II section bus of the substation 2 via the circuit breaker QF7. Similarly, the 110kV side I section bus of the substation 2 is connected to the 110kV substation 3 through the circuit breaker QF9 via the tie line 6, and the 110kV side II section bus of the substation 2 is connected to the 110kV substation 3 through the circuit breaker QF10 via the tie line 7, the line 6 is connected to the 110kV I section bus of the substation 3 via the circuit breaker QF11, and the line 7 is connected to the 110kV II section bus of the substation 3 via the circuit breaker QF12. The power sources S3 and S4 supply power to the I section and II section buses of the substation 3 through the line 8 via the circuit breaker QF14 and the line 9 via the circuit breaker QF15 respectively.

[0041] 110kV substation 1, substation 2 and substation 3 110kV side wiring mode is consistent with single bus section wiring, section breaker is QF3, QF8 and QF13 respectively. Take 110kV substation 1 as an example (see Figure 2 ), in addition to the line branch, the I section bus of substation 1 is connected with No. 1 main transformer and bus voltage transformer TV1, and the II section bus is connected with No. 2 main transformer and bus voltage transformer TV2.

[0042] The simplified process of the application is implemented as follows:

[0043] 1. Simplification of four power supply single bus section wiring substation backup power supply

[0044] 1.1 Operation mode of four power supply single bus section wiring substation

[0045] Four power supply single bus section wiring substation adopts multi-path power supply, and each section bus is connected through one-in-one-out two-loop lines, and the primary main wiring diagram is shown in Figure 1 、 Figure 2 Each two power supplies cannot be parallel operated for a long time, and at least one circuit breaker in the loop between each two power supplies should be in hot standby state. The backup power supply of four power supply single bus section wiring substation can list 27 kinds of operation modes according to the "exhaustive method", which is shown in Table 1.

[0046] Table 1, possible operation mode of four power supply single bus section wiring substation backup power supply

[0047]

[0048]

[0049]

[0050] 1.2 Simplification of four power supply single bus section wiring substation backup power supply

[0051] 1.2.1 Primary main wiring of four power supply single bus section wiring substation

[0052] Figure 2 The primary main wiring of four power supply single bus section wiring substation, the high voltage side of the substation is single bus section wiring: the high voltage I section bus is connected with circuit breaker QF1, circuit breaker QF3 and circuit breaker QF4, the high voltage II section bus is connected with circuit breaker QF2, circuit breaker QF3 and circuit breaker QF5, wherein the circuit breaker QF3 is a section breaker.

[0053] 1.2.2 Simplification of four power supply single bus section wiring substation backup power supply

[0054] If considering the standby power supply by the whole substation, the operation mode is up to 27, which is not easy to remember and the operation is complex. For simple processing, the standby power supply of single bus section wiring substation with four power supply can be composed of four single bus section wiring standby power supply and two single bus standby power supply:

[0055] a. Single bus section wiring standby power supply composed of circuit breakers QF1, QF2, QF3 (referred to as standby power supply 1);

[0056] b. Single bus section wiring standby power supply composed of circuit breakers QF3, QF4, QF5 (referred to as standby power supply 2);

[0057] c. Single bus section wiring standby power supply composed of circuit breakers QF1, QF3, QF5 (referred to as standby power supply 3);

[0058] d. Single bus section wiring standby power supply composed of circuit breakers QF2, QF3, QF4 (referred to as standby power supply 4);

[0059] e. Single bus standby power supply composed of circuit breakers QF1, QF4 (referred to as standby power supply 5);

[0060] f. Single bus standby power supply composed of circuit breakers QF2, QF5 (referred to as standby power supply 6).

[0061] The possible operation mode of the simplified standby power supply of single bus section wiring substation with four power supply can be listed in 27 kinds of operation mode by "exhaustive method", see Table 2.

[0062] Table 2, possible operation mode of simplified standby power supply of single bus section wiring substation with four power supply

[0063]

[0064]

[0065]

[0066] 2 Verification of the correctness of the simplified operation mode of the standby power supply of single bus section wiring substation with four power supply

[0067] 2.1 Mathematical model of standby power supply

[0068] Whether the four power supply single bus sectional wiring substation backup power supply can be simplified as a combination of four single bus sectional wiring backup power supply and two single bus wiring backup power supply, the logical algebra method verifies that the six backup power supplies are applicable to the operation mode, which can meet the needs of all operation modes of the four power supply single bus sectional wiring substation, and the backup power supply of the fixed wiring mode can be realized by several of the six backup power supplies. The closing state and non-closing state of the circuit breaker can be represented by logical algebra, and the logical algebra 1 represents the closing state of the circuit breaker, and the logical algebra 0 represents the non-closing state of the circuit breaker (satisfying the reasonable premise of the operation mode). Use A, B, C, D, E to represent QF1, QF2, QF3, QF4, QF5 circuit breakers in the closing state, and use logical algebra to represent 1 respectively; use respectively represent the non-closing state of QF1, QF2, QF3, QF4, QF5 circuit breakers, and use logical algebra to represent 0 respectively.

[0069] 2.1.1 Mathematical model of backup power supply 1

[0070] Figure 2 The operation and non-operation of QF1, QF2 and QF3 in the single bus sectional wiring main wiring constitute six operation modes of the single bus sectional wiring backup power supply:

[0071] a. Circuit breaker QF1, QF2 operation, backup circuit breaker QF3. When the incoming line 1 loses power, open QF1 circuit breaker, and put on QF3 circuit breaker; when the incoming line 2 loses power, open QF2 circuit breaker, and put on QF3 circuit breaker. The logical algebra expression of the operation mode is:

[0072] b. Circuit breaker QF1, QF3 operation, backup circuit breaker QF2. When the incoming line 1 loses power, open QF1 circuit breaker, and put on QF2 circuit breaker. The logical algebra expression of the operation mode is:

[0073] c. Circuit breaker QF2, QF3 operation, backup circuit breaker QF1. When the incoming line 2 loses power, open QF2 circuit breaker, and put on QF1 circuit breaker. The logical algebra expression of the operation mode is:

[0074] d. Circuit breaker QF1 operation, backup circuit breaker QF2, QF3. When the incoming line 1 loses power, open QF1 circuit breaker, and put on QF2, QF3 circuit breakers. The logical algebra expression of the operation mode is:

[0075] e. Breaker QF2 is running, spare breaker QF1, QF3 is put into operation. When the incoming line 2 loses power, QF2 breaker is tripped, QF1, QF3 breakers are put into operation. The logic algebraic expression of its operation mode is:

[0076] Thus the logic algebraic expression that the spare power automatic switching 1 operation mode satisfies is formula (1):

[0077]

[0078] 2.1.2 Mathematical model of spare power automatic switching 2

[0079] Figure 2 The operation and non-operation of QF3, QF4, QF5 in the main wiring of the single bus section wiring constitute six operation modes of the single bus section wiring spare power automatic switching:

[0080] a. Breaker QF4, QF5 is running, spare breaker QF3 is put into operation. When the incoming line 4 loses power, QF4 breaker is tripped, QF3 breaker is put into operation; when the incoming line 5 loses power, QF5 breaker is tripped, QF3 breaker is put into operation. The logic algebraic expression of its operation mode is:

[0081] b. Breaker QF3, QF4 is running, spare breaker QF5 is put into operation. When the incoming line 4 loses power, QF4 breaker is tripped, QF5 breaker is put into operation. The logic algebraic expression of its operation mode is:

[0082] c. Breaker QF3, QF5 is running, spare breaker QF4 is put into operation. When the incoming line 5 loses power, QF5 breaker is tripped, QF4 breaker is put into operation. The logic algebraic expression of its operation mode is:

[0083] d. Breaker QF4 is running, spare breaker QF3, QF5 is put into operation. When the incoming line 3 loses power, QF4 breaker is tripped, QF3, QF5 breakers are put into operation. The logic algebraic expression of its operation mode is:

[0084] e. Breaker QF5 is running, spare breaker QF3, QF4 is put into operation. When the incoming line 4 loses power, QF5 breaker is tripped, QF3, QF4 breakers are put into operation. The logic algebraic expression of its operation mode is:

[0085] Thus the logic algebraic expression that the spare power automatic switching 2 operation mode satisfies is formula (2):

[0086]

[0087] 2.1.3 Mathematical model of backup power supply 3

[0088] Figure 2 The operation and non-operation of QF1, QF3 and QF5 in the main power supply of the single-bus sectionalization constitute six operation modes of the backup power supply of the single-bus sectionalization:

[0089] a. The circuit breaker QF1 and QF5 are operated, and the backup circuit breaker QF3 is operated. When the incoming line 1 loses power, the QF1 circuit breaker is tripped, and the QF3 circuit breaker is operated. When the incoming line 4 loses power, the QF5 circuit breaker is tripped, and the QF3 circuit breaker is operated. The logic algebraic expression of the operation mode is:

[0090] b. The circuit breaker QF1 and QF3 are operated, and the backup circuit breaker QF5 is operated. When the incoming line 1 loses power, the QF1 circuit breaker is tripped, and the QF5 circuit breaker is operated. The logic algebraic expression of the operation mode is:

[0091] c. The circuit breaker QF3 and QF5 are operated, and the backup circuit breaker QF1 is operated. When the incoming line 4 loses power, the QF5 circuit breaker is tripped, and the QF1 circuit breaker is operated. The logic algebraic expression of the operation mode is:

[0092] d. The circuit breaker QF1 is operated, and the backup circuit breaker QF3 and QF5 are operated. When the incoming line 1 loses power, the QF1 circuit breaker is tripped, and the QF3 and QF5 circuit breakers are operated. The logic algebraic expression of the operation mode is:

[0093] e. The circuit breaker QF5 is operated, and the backup circuit breaker QF1 and QF3 are operated. When the incoming line 4 loses power, the QF5 circuit breaker is tripped, and the QF1 and QF3 circuit breakers are operated. The logic algebraic expression of the operation mode is:

[0094] Thus, the logic algebraic expression satisfied by the operation mode of the backup power supply 3 is formula (3):

[0095]

[0096] 2.1.4 Mathematical model of backup power supply 4

[0097] Figure 2 The operation and non-operation of QF2, QF3 and QF4 in the main power supply of the single-bus sectionalization constitute six operation modes of the backup power supply of the single-bus sectionalization:

[0098] a. The circuit breaker QF2 and QF4 are operated, and the backup circuit breaker QF3 is operated. When the incoming line 2 loses power, the QF2 circuit breaker is tripped, and the QF3 circuit breaker is operated ；When the incoming line 3 loses power, the QF4 breaker is tripped and the QF3 breaker is put into operation. The logic algebraic expression of the operation mode is:

[0099] b. The breakers QF2 and QF3 are operated, and the backup breaker QF4 is put into operation. When the incoming line 2 loses power, the QF2 breaker is tripped and the QF4 breaker is put into operation. The logic algebraic expression of the operation mode is:

[0100] c. The breakers QF3 and QF4 are operated, and the backup breaker QF2 is put into operation. When the incoming line 3 loses power, the QF4 breaker is tripped and the QF2 breaker is put into operation. The logic algebraic expression of the operation mode is:

[0101] d. The breaker QF2 is operated, and the backup breakers QF3 and QF4 are put into operation. When the incoming line 2 loses power, the QF2 breaker is tripped and the QF3 and QF4 breakers are put into operation. The logic algebraic expression of the operation mode is:

[0102] e. The breaker QF4 is operated, and the backup breakers QF2 and QF3 are put into operation. When the incoming line 3 loses power, the QF4 breaker is tripped and the QF2 and QF3 breakers are put into operation. The logic algebraic expression of the operation mode is:

[0103] Thus, the logic algebraic expression satisfied by the backup automatic switching 4 operation mode is formula (4):

[0104]

[0105] 2.1.5 Mathematical model of backup automatic switching 5

[0106] Figure 2 The operation and non-operation of QF1 and QF4 in the main circuit of the single-bus sectional wiring constitute three operation modes of the single-bus backup automatic switching:

[0107] a. The breaker QF1 is operated, and the backup breaker QF4 is put into operation. When the incoming line 1 loses power, the QF1 breaker is tripped and the QF4 breaker is put into operation. The logic algebraic expression of the operation mode is:

[0108] b. The breaker QF4 is operated, and the backup breaker QF1 is put into operation. When the incoming line 3 loses power, the QF4 breaker is tripped and the QF1 breaker is put into operation. The logic algebraic expression of the operation mode is:

[0109] The logic algebraic expression satisfied by the backup automatic switching 5 operation mode is formula (5):

[0110]

[0111] 2.1.6 Mathematical model of backup power supply 6

[0112] Figure 2 The operation and non-operation of QF2 and QF5 in the main power supply of single bus sectionalization constitute three operation modes of backup power supply:

[0113] a. Circuit breaker QF2 is operated, and backup power supply QF5 is thrown. When power supply of incoming line 2 is lost, QF2 circuit breaker is tripped, and QF5 circuit breaker is thrown. The logical algebraic expression of the operation mode is:

[0114] b. Circuit breaker QF5 is operated, and backup power supply QF2 is thrown. When power supply of incoming line 4 is lost, QF5 circuit breaker is tripped, and QF2 circuit breaker is thrown. The logical algebraic expression of the operation mode is:

[0115] The logical algebraic expression satisfied by backup power supply 6 operation mode is formula (6):

[0116]

[0117] 2.2 Theoretical analysis of backup power supply of single bus sectionalization substation with four power supplies

[0118] Backup power supply 1 and other circuit breakers QF4 and QF5 are equivalent to the logical relationship of "and", and the logical algebraic expression of backup power supply 1 operation mode is:

[0119]

[0120] Operation of formula (7) can obtain

[0121]

[0122] Backup power supply 2 and other circuit breakers QF1 and QF2 are equivalent to the logical relationship of "and", and the logical algebraic expression of backup power supply 2 operation mode is:

[0123]

[0124] Operation of formula (9) can obtain

[0125]

[0126] Backup power supply 3 and other circuit breakers QF2 and QF4 are equivalent to the logical relationship of "and", and the logical algebraic expression of backup power supply 3 operation mode is:

[0127]

[0128] The operation (11) formula can be obtained

[0129]

[0130] The backup power supply 4 and other circuit breakers QF1, QF5 are equivalent to the logical relationship of "and" in the logical relationship, and the logical algebraic expression of the backup power supply 4 operation mode is obtained:

[0131]

[0132] The operation (13) formula can be obtained

[0133]

[0134] The backup power supply 5 and other circuit breakers QF2, QF3, QF5 are equivalent to the logical relationship of "and" in the logical relationship, and the logical algebraic expression of the backup power supply 5 operation mode is obtained:

[0135]

[0136] The operation (15) formula can be obtained

[0137]

[0138] The backup power supply 6 and other circuit breakers QF1, QF3, QF4 are equivalent to the logical relationship of "and" in the logical relationship, and the logical algebraic expression of the backup power supply 6 operation mode is obtained:

[0139]

[0140] The operation (17) formula can be obtained

[0141]

[0142] Arrange (8), (10), (12), (14), (16), (18) formula, merge repeated items, and consider that The operation mode does not exist, ABCDE, The backup power supply mode does not exist, and the formula (8), (10), (12), (14), (16), (18) becomes the formula (19):

[0143]

[0144] In formula (19), there are 27 operation modes.

[0145] 2.3 Operation mode comparison: the logical algebraic expression of each 1 field in formula (19) represents an operation mode of a four-source power supply single-bus sectional wiring substation, which is consistent with the "exhaustive" four-source power supply single-bus sectional wiring backup power supply operation mode, that is, the simplified four-source power supply single-bus sectional wiring substation backup power supply operation mode is the same as the "exhaustive method" four-source power supply single-bus sectional wiring substation backup power supply operation mode listed, indicating that the operation effect is the same.

[0146] Through the above steps, it is verified that the simplified four-source power supply single-bus sectional wiring substation backup power supply and the "exhaustive method" four-source power supply single-bus sectional wiring substation backup power supply have the same operation effect.

Claims

1. A method for simplifying the backup automatic switching logic of a single busbar sectionalized substation with four power supplies, characterized in that: The single busbar sectionalized connection substation with four power supplies is simplified to consist of four single busbar sectionalized connection substations and two single busbar connection substations. The circuit breakers QF1, QF2 and QF3 of the single busbar sectionalized substation line powered by four power supplies form a single busbar sectionalized standby automatic start-up with three circuit breakers of dual power supply, referred to as standby automatic start-up 1; The single-mother sectionalized wiring of the dual power supply three circuit breakers consisting of circuit breakers QF3, QF4 and QF5 is referred to as standby automatic transfer 2; The single busbar sectional wiring of the dual power supply three circuit breakers consisting of circuit breakers QF1, QF3 and QF5 is referred to as standby automatic transfer 3; The single mother sectional wiring of the dual power supply three circuit breakers consisting of circuit breakers QF2, QF3 and QF4 is referred to as standby automatic transfer 4; The single busbar standby automatic transfer of two circuit breakers with dual power supply composed of circuit breakers QF1 and QF4 is referred to as standby automatic transfer 5; The single busbar standby automatic transfer of two circuit breakers with dual power supply composed of circuit breakers QF2 and QF5 is referred to as standby automatic transfer 6; The operation mode of the standby automatic start-up 1 satisfies the following logical algebraic expression: The operation mode of the standby automatic start-up 2 satisfies the following logical algebraic expression: The operation mode of the standby automatic input 3 satisfies the following logical algebraic expression: The operation mode of the standby automatic start-up 4 satisfies the following logical algebraic expression: The operation mode of the standby automatic input 5 satisfies the following logical algebraic expression: The operation mode of the standby automatic start-up 6 satisfies the following logical algebraic expression: The logical relationship between the above-mentioned automatic switching switches is "OR". The logical algebraic expression for the automatic switching switch of a single-busbar sectionalized substation with four power supplies is: Among them, A, B, C, D, and E respectively represent the circuit breakers QF1, QF2, QF3, QF4, and QF5 in the closed operating state, and are respectively represented by 1 in logical algebra; Respectively indicate that the circuit breakers QF1, QF2, QF3, QF4, and QF5 are in the open operation state, that is, the hot standby state, and are represented by 0 in logical algebra; The logical algebraic expression of each field in the above formula represents an operating mode of a single-bus sectionalized substation powered by four power sources, with a total of 27 operating modes.

2. The method for simplifying the backup automatic switching logic of a single busbar sectionalized connection substation with four power supplies according to claim 1, characterized in that: The control logic of the standby automatic transfer of a single-busbar sectionalized substation powered by four power sources consists of six parts, namely the single-busbar sectionalized connection standby automatic transfer logic composed of high-voltage side circuit breakers QF1, QF2, and QF3, the single-busbar sectionalized connection standby automatic transfer logic composed of circuit breakers QF3, QF4, and QF5, the single-busbar sectionalized connection standby automatic transfer logic composed of circuit breakers QF2, QF3, and QF4, the single-busbar sectionalized connection standby automatic transfer logic composed of circuit breakers QF1, QF3, and QF5, the single-busbar sectionalized connection standby automatic transfer logic composed of circuit breakers QF1 and QF4, and the single-busbar sectionalized connection standby automatic transfer logic composed of circuit breakers QF2 and QF5. These six parts are set in the same standby automatic transfer device.

3. The method for simplifying the backup automatic switching logic of a single busbar sectionalized substation with four power supplies as claimed in claim 2, characterized in that: When more than one of the six standby automatic start-ups meets the action conditions, selection is achieved by setting the action delay between the six standby automatic start-ups.

4. The method for simplifying the backup automatic switching logic of a single busbar sectionalized connection substation with four power supplies as claimed in claim 2, characterized in that: When more than one of the six standby automatic start-ups meets the action conditions, selection is achieved by adding judgment logic between the standby automatic start-ups.

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