Wide-area protection method for power transformation and distribution substation

Abstract

The invention relates to the technical field of power systems, and provides a wide-area protection method for a power transformation and distribution substation, and the method comprises the steps: (1) carrying out the grading of circuit breaker equipment in the power transformation and distribution substation according to a power supply relation; (2) establishing a topological relation of static circuit breaker equipment according to grading; (3) uploading the protection starting state and the opening and closing position state of the circuit breaker equipment through a communication network; and (4) when superior protection is started, judging whether the circuit breaker equipment performs locking control action or not according to a protection rule, and timely cutting off a subordinate fault line. According to the method, the circuit breaker equipment is graded, and when protection is started, whether the circuit breaker equipment locks the control action or not is judged according to the protection rule, so that a lower-level fault line is cut off in time, the power failure range is reduced, and reliable operation of a lower-level non-fault line is protected.

Description

Technical Field

[0001] The invention relates to the technical field of power systems, and in particular to a wide area protection method for railway substations. Background Art

[0002] Railway substation integrated automation protection is an important line of defense for the safe and stable operation of the railway system. The development and application of its technology is directly related to the reliability and safety of the railway.

[0003] When a high current fault occurs in the feeder of the substation, the feeder and the incoming line reach the quick-break current setting at the same time. In this way, the quick-breaks are simultaneously actuated, and the protection loses selectivity, which will cause the upper power incoming line switch to trip, causing unnecessary expansion of the power outage range, causing more non-fault lines to be out of power, and affecting power supply reliability. If this situation occurs frequently or at important power system nodes, it may have an adverse effect on the stability of the entire power system, and even cause serious accidents such as system oscillation or collapse.

[0004] Therefore, it is necessary for those skilled in the art to design a wide area protection method for a substation to solve the above problems. Summary of the invention

[0005] In view of the defects existing in the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a wide-area protection method for a substation, by grading the circuit breaker equipment. When the protection is started, it is judged according to the protection rules whether the circuit breaker equipment is locked and controlled, so as to timely cut off the lower-level fault line, reduce the scope of power outage, and protect the lower-level non-fault line from operating reliably.

[0006] In order to solve the above technical problems, the present invention provides a wide area protection method for a substation, the wide area protection method comprising:

[0007] (1) Classify the circuit breaker equipment in the substation according to the power supply relationship;

[0008] (2) Establishing static topological relationships of circuit breaker devices based on the hierarchy;

[0009] (3) Upload the protection start-up status and the opening and closing position status of the circuit breaker equipment to the superior through the communication network;

[0010] (4) When the upper level protection is activated, determine whether the circuit breaker equipment is locked and controlled according to the protection rules, and cut off the lower level fault line in time.

[0011] Furthermore, the classification standard of the circuit breaker equipment is:

[0012] The circuit breaker between the incoming line and the high-voltage busbar is defined as level 1;

[0013] The circuit breaker between the low voltage bus and the high voltage bus is defined as level 2;

[0014] All circuit breakers between the low voltage bus and the feeder are defined as level 3;

[0015] The bus tie breaker of the high voltage bus is defined as level 4;

[0016] The bus tie circuit breaker of the low voltage bus is defined as level 5;

[0017] Among them, level 1 is set as the superior of levels 2-5, level 2 is set as the superior of levels 3-5, level 3 is set as the superior of levels 4 and 5, and level 4 is set as the superior of level 5.

[0018] Furthermore, the steps for constructing the topological relationship in step (2) are:

[0019] (21) Close all circuit breakers of level 1, level 2 and level 3, separate all busbar circuit breakers of level 4 and level 5, detect the topological relationship of the physical network, and record the topological relationship of the connected circuit breakers as U(i, j), where i represents the divided level, 1≤i≤2; j represents the topological relationship of the jth circuit breaker in level i, and j is a positive integer; specifically, U(1, j), which is the topological relationship of the jth circuit breaker of level 1, is a set containing all connected circuit breakers of level 2; U(2, j), which is the topological relationship of the jth circuit breaker of level 2, is a set containing all connected circuit breakers of level 3;

[0020] (22) Close all circuit breakers at levels 1 and 4, separate all circuit breakers at levels 2, 3, and 5, detect the topological relationship of the physical network, and record the topological relationship of the circuit breakers at level 4 that are still connected as Ub(1, j). Ub(1, j) is a set of all connected bus tie circuit breakers at level 4, indicating the topological relationship of the j-th circuit breaker at level 1;

[0021] (23) Close all circuit breakers at levels 2 and 5, separate all circuit breakers at levels 1, 3, and 4, detect the physical network topology, and record the topology of the still connected circuit breakers at level 5 as Ub(2, j). Ub(2, j) is a set of all connected busbar circuit breakers at level 5, representing the topology of the j-th circuit breaker at level 2.

[0022] Preferably, the communication network information transmission time delay is less than 5ms.

[0023] Furthermore, in step (3),

[0024] The setting rule of the protection start state of the circuit breaker is: when any protection of the circuit breaker meets the set conditions, the protection start state is set to 1; when all protections do not meet the conditions, the protection start state is set to 0;

[0025] The setting rule of the opening and closing position state of the circuit breaker is: when the circuit breaker is closed, the opening and closing position state is set to 1, and when the circuit breaker is open, the opening and closing position state is set to 0.

[0026] Furthermore, the protection rule judgment logic in step (4) is:

[0027] The following logical judgment is performed on the protection of level 1~level 2 circuit breaker equipment:

[0028]

[0029] Where i represents the level of division, 1≤i≤2;

[0030] The protection start-up state of any circuit breaker representing the topological relationship U(i, j) of the j-th circuit breaker of level i;

[0031] The opening and closing state of any circuit breaker representing the topological relationship Ub(1, j) of the j-th circuit breaker of level i;

[0032] Represents the protection start-up state of any circuit breaker in the topological relationship U(i, j) of level i non-j circuit breakers;

[0033] If the value of Idex(i) is 1, the i-level circuit breaker control is locked; otherwise, the i-level circuit breaker control is not locked.

[0034] The present invention has the following beneficial effects:

[0035] (1) The present invention classifies the circuit breaker devices. When the protection is started, it is determined whether the circuit breaker device is locked and controlled according to the protection rules, so as to timely cut off the lower-level fault line, reduce the scope of power outage, and protect the lower-level non-fault line for reliable operation.

[0036] (2) The present invention realizes the coordinated protection action of multiple feeders and incoming lines by setting the protection rule judgment logic, thereby reducing the scope of power outage. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but this embodiment is not intended to limit the present invention. All similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The commas in the present invention represent the relationship of and, and the English letters in the present invention are case-sensitive.

[0038] The present invention provides a wide area protection method for a transformer substation, the wide area protection method comprising:

[0039] S1, classify the circuit breaker equipment in the substation according to the power supply relationship;

[0040] The classification standards of the circuit breaker equipment are:

[0041] The circuit breaker between the incoming line and the high-voltage busbar is defined as level 1;

[0042] The circuit breaker between the low voltage bus and the high voltage bus is defined as level 2;

[0043] All circuit breakers between the low voltage bus and the feeder are defined as level 3;

[0044] The bus tie breaker of the high voltage bus is defined as level 4;

[0045] The bus tie circuit breaker of the low voltage bus is defined as level 5;

[0046] Among them, level 1 is set as the superior of levels 2-5, level 2 is set as the superior of levels 3-5, level 3 is set as the superior of levels 4 and 5, and level 4 is set as the superior of level 5.

[0047] S2, establish the static topological relationship of the circuit breaker equipment according to the classification, the construction steps are:

[0048] S21, close all circuit breakers of level 1, level 2 and level 3, separate all busbar circuit breakers of level 4 and level 5, detect the topological relationship of the physical network, and record the topological relationship of the connected circuit breakers as U(i, j), where i represents the divided level, 1≤i≤2; j represents the topological relationship of the jth circuit breaker in level i, and j is a positive integer; specifically, U(1, j), which is the topological relationship of the jth circuit breaker of level 1, and is a set containing all connected circuit breakers of level 2; U(2, j), which is the topological relationship of the jth circuit breaker of level 2, and is a set containing all connected circuit breakers of level 3;

[0049] S22, close all circuit breakers of level 1 and level 4, separate all circuit breakers of level 2, level 3 and level 5, detect the topological relationship of the physical network, and record the topological relationship of the still connected circuit breakers of level 4 as Ub(1, j), where Ub(1, j) is a set of all connected bus tie circuit breakers of level 4, indicating the topological relationship of the j-th circuit breaker of level 1;

[0050] S23, close all circuit breakers at levels 2 and 5, separate all circuit breakers at levels 1, 3 and 4, detect the topological relationship of the physical network, and record the topological relationship of the still connected circuit breakers at level 5 as Ub(2, j). Ub(2, j) is a set of all connected busbar circuit breakers at level 5, representing the topological relationship of the j-th circuit breaker at level 2.

[0051] S3, uploading the protection start-up status and the opening and closing position status of the circuit breaker device through the communication network;

[0052] The setting rule of the protection start state of the circuit breaker is: when any protection of the circuit breaker meets the set conditions, the protection start state is set to 1; when all protections do not meet the conditions, the protection start state is set to 0;

[0053] The setting rule of the opening and closing position state of the circuit breaker is: when the circuit breaker is closed, the opening and closing position state is set to 1, and when the circuit breaker is open, the opening and closing position state is set to 0.

[0054] Preferably, the communication network information transmission time delay is less than 5ms.

[0055] S4, when the upper protection is activated, the circuit breaker device is judged according to the protection rules to determine whether the control action is locked, and the lower fault line is cut off in time;

[0056] Among them, the protection rule judgment logic is:

[0057] The following logical judgment is performed on the protection of level 1~level 2 circuit breaker equipment:

[0058]

[0059] Where i represents the level of division, 1≤i≤2;

[0060] The protection start-up state of any circuit breaker representing the topological relationship U(i, j) of the j-th circuit breaker of level i;

[0061] The opening and closing state of any circuit breaker representing the topological relationship Ub(1, j) of the j-th circuit breaker of level i;

[0062] Represents the protection start-up state of any circuit breaker in the topological relationship U(i, j) of level i non-j circuit breakers;

[0063] If the value of Idex(i) is 1, the i-level circuit breaker control is locked; otherwise, the i-level circuit breaker control is not locked.

[0064] Example

[0065] Taking the substation with only one incoming circuit breaker and one feeder circuit breaker as an example, the circuit breaker equipment in the substation is classified according to the power supply relationship and is divided into:

[0066] Level 1: incoming circuit breaker;

[0067] Level 3: Feeder circuit breaker.

[0068] The topological relationship of the static circuit breaker equipment established according to the classification is U(1, 1), U(1, 2), and the rest are empty;

[0069] When the 3rd level feeder circuit breaker protection is activated, Star[U(1,2)]=1, then the value of Idex(1) is 1, and the 1st level circuit breaker control is locked.

[0070] The present invention classifies the circuit breaker equipment. When the protection is started, it is judged according to the protection rules whether the circuit breaker equipment is locked and controlled, so as to timely cut off the lower fault line, reduce the power outage scope, and protect the lower non-fault line for reliable operation; by setting the protection rule judgment logic, the protection coordination action of multiple feeders and incoming lines is realized, and the power outage scope is reduced.

[0071] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

Claims

1. A wide area protection method for a substation, characterized in that: The wide area protection method comprises: (1) Classify the circuit breaker equipment in the substation according to the power supply relationship; (2) Establishing static topological relationships of circuit breaker devices based on the hierarchy; (3) Upload the protection start-up status and the opening and closing position status of the circuit breaker equipment to the superior through the communication network; (4) When the upper level protection is activated, determine whether the circuit breaker equipment is locked and controlled according to the protection rules, and cut off the lower level fault line in time.

2. A wide area protection method for a substation according to claim 1, characterized in that: The classification standards of the circuit breaker equipment are: The circuit breaker between the incoming line and the high-voltage busbar is defined as level 1; The circuit breaker between the low voltage bus and the high voltage bus is defined as level 2; All circuit breakers between the low voltage bus and the feeder are defined as level 3; The bus tie breaker of the high voltage bus is defined as level 4; The bus tie breaker of the low voltage bus is defined as level 5; Among them, level 1 is set as the superior of levels 2-5, level 2 is set as the superior of levels 3-5, level 3 is set as the superior of levels 4 and 5, and level 4 is set as the superior of level 5.

3. A wide area protection method for a substation according to claim 2, characterized in that: The steps for constructing the topological relationship in step (2) are: (21) Close all circuit breakers at levels 1, 2, and 3, separate all busbar circuit breakers at levels 4 and 5, detect the topological relationship of the physical network, and record the topological relationship of the connected circuit breakers as U(i, j), where i represents the divided level, 1≤i≤2; j represents the topological relationship of the jth circuit breaker in level i, and j is a positive integer; (22) Close all circuit breakers at levels 1 and 4, separate all circuit breakers at levels 2, 3, and 5, detect the topological relationship of the physical network, and record the topological relationship of the circuit breakers at level 4 that are still connected as Ub(1, j); (23) Close all circuit breakers at levels 2 and 5, separate all circuit breakers at levels 1, 3, and 4, detect the topological relationship of the physical network, and record the topological relationship of the circuit breaker at level 5 that is still connected as Ub(2, j).

4. A wide area protection method for a substation according to claim 1, characterized in that: In step (3), The setting rule of the protection start state of the circuit breaker is: when any protection of the circuit breaker meets the set conditions, the protection start state is set to 1; when all protections do not meet the conditions, the protection start state is set to 0; The setting rule of the opening and closing position state of the circuit breaker is: when the circuit breaker is closed, the opening and closing position state is set to 1, and when the circuit breaker is open, the opening and closing position state is set to 0.

5. A wide area protection method for a substation according to claim 1, characterized in that: The protection rule judgment logic in step (4) is: The following logical judgment is performed on the protection of level 1~2 circuit breaker equipment: Where i represents the level of division, 1≤i≤2; The protection start-up state of any circuit breaker representing the topological relationship U(i, j) of the j-th circuit breaker of level i; The opening and closing state of any circuit breaker representing the topological relationship Ub(1, j) of the j-th circuit breaker of level i; Represents the protection start-up state of any circuit breaker in the topological relationship U(i, j) of level i non-j circuit breakers; If the value of Idex(i) is 1, the i-level circuit breaker control is locked; otherwise, the i-level circuit breaker control is not locked.

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