A distributed switching and locking busbar structure and operation method

Abstract

The present invention discloses a distributed switching lockout small busbar structure and an operating method, comprising a switching lockout small busbar, a terminal box in an outgoing line interval, a terminal box in a main transformer interval, and a terminal box in a busbar interval. The four are interconnected and used in combination. This structure is suitable for a "small busbar + distributed start" electrical locking circuit of an AIS isolating knife in a 110kV / 220kV double busbar with bypass wiring mode, meeting the electrical locking guarantee of all intervals and theoretically enabling unlimited expansion. It reduces the installation of control cables in the busbar interval and the auxiliary contacts of the busbar isolating knife and busbar circuit breaker. In practice, only one 2-core 4 square millimeter low-voltage power cable and one set of auxiliary contacts required for the busbar isolating knife and busbar circuit breaker are installed. This solution reduces construction investment while achieving inherent safety in operation, effectively ensuring the safe and stable operation of power equipment.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment, and in particular to a distributed switching and locking small busbar structure and an operating method. Background Art

[0002] Currently, in an AIS substation with 110kV / 220kV double busbar with bypass connection, the isolation switches of the line and main transformer bays are generally locked against misoperation during main and auxiliary busbar switching operations or bypass busbar switching operations in the following two ways:

[0003] Type A method directly utilizes the "isolating switch position signal + circuit breaker position signal (in series)" of the mutually independent bus-tie bays, which are respectively routed to the corresponding line and main transformer bays (to prevent power mixing and parasitic circuits) as the electrical locking condition for the isolating switch. However, due to the large number of auxiliary contacts and cables required for the bus-tie bay isolating switches and circuit breakers, this method is only applicable to smaller 110kV (or 220kV) substations, where the line and main transformer bays typically have fewer than eight circuits.

[0004] Category B: For larger 110kV (or 220kV) substations, where the line and main transformer intervals are typically greater than eight, or even as many as 12 to 16, independent electrical interlocking circuits are clearly unsuitable. This is because the installation of numerous control cables is difficult, and the number of disconnect switches and circuit breaker auxiliary contacts is insufficient. Operation and maintenance units typically adopt organizational procedures, which define switching procedures.

[0005] In summary, the existing technology and actual operation still have the following defects:

[0006] ① In existing 110kV / 220kV double-busbar with bypass AIS substations, the above-mentioned Class A method requires multiple busbar isolation switches and circuit breaker auxiliary contacts and cables, and has a limited scope of application. It is generally only suitable for substations with smaller 110kV (or 220kV) system scales, where the lines and main transformer bays are generally less than 8 circuits.

[0007] ② The above-mentioned Class B method is not suitable for using independent electrical interlocking circuits because the installation of a large number of control cables is difficult, and the number of isolation switches and circuit breaker auxiliary contacts cannot meet the requirements. The operation and maintenance unit generally adopts organizational procedures, that is, it stipulates from the switching operation procedures;

[0008] ③ Regardless of Class A or Class B methods, there is either a lack of scalability or loss of intrinsically safe electrical locking protection. Summary of the Invention

[0009] In view of the deficiencies in the prior art, the present invention provides a distributed switching and locking busbar structure and an operating method to solve the above problems.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0011] A distributed switching lockout busbar structure includes a switching lockout busbar, an outgoing line bay terminal box, a main transformer bay terminal box, and a busbar bay terminal box. The switching lockout busbar is sequentially connected to the outgoing line bay terminal box, the main transformer bay terminal box, and the busbar bay terminal box. The busbar bay terminal box includes a 1M busbar side isolation knife auxiliary contact 1LG (which can be simplified as isolation knife 1LG), a 2M busbar side isolation knife auxiliary contact 2LG (which can be simplified as isolation knife 2LG), a busbar bay circuit breaker auxiliary contact MDL (which can be simplified as circuit breaker MDL), and a switching operation permission start signal relay JJ. The 1M busbar side isolation knife auxiliary contact 1LG, the 2M busbar side isolation knife auxiliary contact 2LG, and the busbar bay circuit breaker auxiliary contact MD L three can be connected in series to start the switching and locking of the small busbar. The terminal box in the outgoing line interval and the terminal box in the main transformer interval both include the intermediate relay 1ZJ, the switching handle QK, the 1M busbar side isolation knife auxiliary contact 1G (which can be simplified as isolation knife 1G), the 2M busbar side isolation knife auxiliary contact 2G (which can be simplified as isolation knife 2G), the line side isolation knife auxiliary contact 3G (which can be simplified as isolation knife 3G), and the circuit breaker auxiliary contact DL (which can be simplified as circuit breaker DL). The six can be interconnected to control the 1G opening and closing circuit and the 2G opening and closing circuit respectively. This structure is suitable for the "small busbar + distributed start" electrical locking circuit of the AIS isolation knife under the 110kV / 220kV double busbar with bypass wiring mode, which meets the electrical locking protection of all intervals and can achieve theoretically unlimited expansion.

[0012] Preferably, the intermediate relay 1ZJ is connected to the switching and locking busbar through the switching handle QK.

[0013] Preferably, the switching locking busbar includes +BLM and -BLM.

[0014] Preferably, the -BLM is normally charged with negative voltage -110V, and the +BLM is not charged (or has a virtual negative voltage) to indicate that the line bay and the main transformer bay are prohibited from performing switching operations.

[0015] Preferably, the +BLM is negatively charged with -110V before the locking condition is met, and is positively charged with +110V after the locking condition is met. The positive charge (+110V) of +BLM indicates that the main busbars 1M and 2M of the primary electrical system have been closed (the busbar intervals 1LG, DL, and 2LG are all closed), allowing the line intervals and main transformer intervals to perform reverse operations.

[0016] Preferably, the switching locking busbar is a low-voltage power cable, and the low-voltage power cable is 2-core and 4 square millimeters.

[0017] Preferably, the 1G opening and closing circuit is composed of the 1M busbar side isolating knife auxiliary contact 1G, the 2M busbar side isolating knife auxiliary contact 2G, the circuit breaker auxiliary contact DL, the line side isolating knife auxiliary contact 3G, the intermediate relay 1ZJ, and the switching handle QK. The above six are connected in sequence, and the 1G opening and closing circuit is connected with the 1M busbar side isolating knife auxiliary contact 1G closed, the 2M busbar side isolating knife auxiliary contact 2G closed, the circuit breaker auxiliary contact DL closed, the line side isolating knife auxiliary contact 3G closed, the intermediate relay 1ZJ closed, and the switching handle QK closed.

[0018] Preferably, another group of 1M busbar side isolating knife auxiliary contacts 1G and 2M busbar side isolating knife auxiliary contacts 2G are set in parallel with the 1M busbar side isolating knife auxiliary contacts 1G and 2M busbar side isolating knife auxiliary contacts 2G of the 2G opening and closing circuit, and the 2G opening and closing circuit is connected with the 1M busbar side isolating knife auxiliary contact 1G of the circuit closed, the 2M busbar side isolating knife auxiliary contact 2G closed, the circuit breaker auxiliary contact DL closed, the line side isolating knife auxiliary contact 3G closed, the intermediate relay 1ZJ closed, and the switching handle QK closed.

[0019] An operating method for a distributed switching lockout busbar structure: ① The switching lockout busbar allows switching operation: the precondition is that the 1M busbar side isolation knife auxiliary contact 1LG is closed, and at the same time the busbar bay circuit breaker auxiliary contact MDL is closed, and the 2M busbar side isolation knife auxiliary contact 2LG is also closed, and then operated in parallel, forming a switching lockout busbar on-site with the busbar bay terminal box, wherein -BLM is normally charged with negative -110V, and +BLM is charged with negative -110V before the locking condition of the busbar bay terminal box is met, and is charged with positive +110V after the locking condition of the busbar bay terminal box is met;

[0020] ② Lead the switching lock busbar to the terminal box in the outgoing line bay and the terminal box in the main transformer bay respectively, and use a 2-core 4mm2 low-voltage power cable for connection;

[0021] ③ In all outgoing line bay terminal boxes and main transformer bay terminal boxes, one intermediate relay 1ZJ is configured. When the blocking conditions are met, any outgoing line bay terminal box or main transformer bay terminal box is blocked, and the switching handle QK is used to connect to the switching blocking busbar of the bay, thus realizing distributed starting under parallel operation conditions across bays;

[0022] ④ By connecting the normally open contact of the intermediate relay 1ZJ in series with the locking conditions of the terminal box in the outgoing line bay and the terminal box in the main transformer bay, an overall distributed operation logic method can be formed.

[0023] Preferably, the locking condition of the busbar bay terminal box is as follows: the auxiliary contact 1LG of the isolating knife on the 1M busbar side is closed, the auxiliary contact MDL of the busbar bay circuit breaker is closed, and the auxiliary contact 2LG of the isolating knife on the 2M busbar side is also closed;

[0024] There are two locking conditions for any terminal box in the outgoing line bay or the main transformer bay: 1G opening and closing circuit is connected, 2G opening and closing circuit is connected,

[0025] 1G opening and closing circuit is connected: the auxiliary contact 1G of the isolating knife on the 1M bus side of the circuit is closed, the auxiliary contact 2G of the isolating knife on the 2M bus side is closed, the auxiliary contact DL of the circuit breaker is closed, and the auxiliary contact 3G of the isolating knife on the line side is closed;

[0026] The 2G opening and closing circuit is connected: the auxiliary contact 1G of the isolating knife on the 1M bus side of the circuit is closed, the auxiliary contact 2G of the isolating knife on the 2M bus side is closed, the auxiliary contact DL of the circuit breaker is closed, and the auxiliary contact 3G of the isolating knife on the line side is closed.

[0027] Compared with the prior art, the present invention discloses a distributed switching and locking busbar structure and operation method, comprising a switching and locking busbar, an outgoing line bay terminal box, a main transformer bay terminal box, and a busbar bay terminal box, which are interconnected and used in combination to function.

[0028] ① This structure is applicable to the "small busbar + distributed start" electrical interlocking circuit of the AIS isolating switch in the 110kV / 220kV double busbar with bypass wiring mode, meeting the electrical interlocking guarantee of all intervals and can achieve theoretically unlimited expansion;

[0029] ② Reduce the number of control cables installed in the busbar interval and the auxiliary contacts of the busbar isolation switch and busbar circuit breaker. In fact, only one 2-core 4 square millimeter low-voltage power cable and one set of auxiliary contacts requiring the busbar isolation switch and busbar circuit breaker are installed;

[0030] ③This solution reduces construction investment while achieving inherent safety in operation, effectively ensuring the safe and stable operation of power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of a distributed switching and locking busbar structure of the present invention;

[0032] Figure 2 This is a structural diagram of the prior art solution A of the present invention;

[0033] Figure 3 This is a structural diagram of a busbar compartment terminal box according to the prior art of the present invention;

[0034] Figure 4 This is a structural diagram of a main transformer bay terminal box according to the prior art of the present invention;

[0035] Figure 5 It is a structural schematic diagram of the terminal box for the outgoing line interval in the prior art of the present invention. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] A distributed switching lockout busbar structure includes a switching lockout busbar, an outgoing line bay terminal box, a main transformer bay terminal box, and a busbar bay terminal box. The switching lockout busbar is sequentially connected to the outgoing line bay terminal box, the main transformer bay terminal box, and the busbar bay terminal box. The busbar bay terminal box includes a 1M busbar side isolation knife auxiliary contact 1LG, a 2M busbar side isolation knife auxiliary contact 2LG, a busbar bay circuit breaker auxiliary contact MDL, and a switching operation permission start signal relay JJ. The 1M busbar The side isolating knife auxiliary contact 1LG, the 2M busbar side isolating knife auxiliary contact 2LG, and the busbar interval circuit breaker auxiliary contact MDL can be connected in series to start the switching and locking of the small busbar. The outgoing line interval terminal box and the main transformer interval terminal box both include the intermediate relay 1ZJ, the switching handle QK, the 1M busbar side isolating knife auxiliary contact 1G, the 2M busbar side isolating knife auxiliary contact 2G, the line side isolating knife auxiliary contact 3G, and the circuit breaker auxiliary contact DL, and the six can be connected to each other to control the 1G opening and closing circuit and the 2G opening and closing circuit respectively. The intermediate relay 1ZJ is connected to the switching lock busbar through the switching handle QK. The switching lock busbar includes +BLM and -BLM. The -BLM is usually negatively charged -110V. The +BLM is not charged (or virtual negative) to indicate that the line interval and the main transformer interval are prohibited from performing reverse operation. The +BLM is negatively charged -110V before the locking condition is met and positively charged +110V after the locking condition is met. The +BLM is positively charged (+110V) to indicate that the power is on. The main busbars 1M and 2M of the gas primary system are closed (busbar intervals 1LG, DL, and 2LG are all closed), allowing reverse operation in the line interval and main transformer interval. The switching lock small busbar is a low-voltage power cable, which is a 2-core 4-square-millimeter low-voltage power cable. The 1G opening and closing circuit is the 1M busbar side isolation knife auxiliary contact 1G, the 2M busbar side isolation knife auxiliary contact 2G, the circuit breaker auxiliary contact DL, and the line side isolation knife auxiliary contact 3G. , intermediate relay 1ZJ, switching handle QK, the above six are connected in sequence, and the 1G opening and closing circuit is connected as follows: the 1M bus side isolation knife auxiliary contact 1G of the circuit is closed, the 2M bus side isolation knife auxiliary contact 2G is closed, the circuit breaker auxiliary contact DL is closed, the line side isolation knife auxiliary contact 3G is closed, the intermediate relay 1ZJ is closed, the switching handle QK is closed, the 2G opening and closing circuit and the 1G opening and closing circuit 1M bus side isolation knife auxiliary contact Another group of 1M busbar side isolation knife auxiliary contacts 1G and 2M busbar side isolation knife auxiliary contacts 2G are set in parallel, and the 2G opening and closing circuit is connected with the 1M busbar side isolation knife auxiliary contact 1G of the circuit closed, the 2M busbar side isolation knife auxiliary contact 2G closed, the circuit breaker auxiliary contact DL closed, the line side isolation knife auxiliary contact 3G closed, the intermediate relay 1ZJ closed, and the switching handle QK closed.

[0038] The specific contents of the anti-mistaken locking principle of the 1M busbar side isolation knife auxiliary contact 1G and the 2M busbar side isolation knife auxiliary contact 2G of all the outgoing line bay terminal boxes and the main transformer bay terminal boxes during the switching lockout of the small busbar switching operation are as follows: the 1M busbar side isolation knife auxiliary contact 1LG, the 2M busbar side isolation knife auxiliary contact 2LG and the bus tie bay circuit breaker auxiliary contact MDL are all closed, the switching lockout of the small busbar is in operation, and the 1M busbar side isolation knife auxiliary contact 1G and the 2M busbar side isolation knife auxiliary contact 2G of all the line and main transformer bay terminal boxes can be used for switching operations as needed. When operating, the staff can also choose to open the outgoing line bay terminal box or the main transformer bay terminal box according to their needs. In addition, a lock can be set on the switching handle QK, and the lock can be unlocked according to the corresponding key and the next operation can be carried out (the setting principle of one lock per bay).

[0039] The locking conditions of the terminal box in the busbar bay are as follows: the auxiliary contact 1LG of the isolating knife on the 1M busbar side is closed, the auxiliary contact MDL of the busbar bay circuit breaker is closed, and the auxiliary contact 2LG of the isolating knife on the 2M busbar side is also closed;

[0040] There are two locking conditions for any terminal box in the outgoing line bay or the main transformer bay: 1G opening and closing circuit is connected, and 2G opening and closing circuit is connected.

[0041] 1G opening and closing circuit is connected: the auxiliary contact 1G of the isolating knife on the 1M bus side of the circuit is closed, the auxiliary contact 2G of the isolating knife on the 2M bus side is closed, the auxiliary contact DL of the circuit breaker is closed, and the auxiliary contact 3G of the isolating knife on the line side is closed;

[0042] The 2G opening and closing circuit is connected: the auxiliary contact 1G of the isolating knife on the 1M bus side of the circuit is closed, the auxiliary contact 2G of the isolating knife on the 2M bus side is closed, the auxiliary contact DL of the circuit breaker is closed, and the auxiliary contact 3G of the isolating knife on the line side is closed.

[0043] The improved circuit operation method of the switching operation lockout of the small busbar is mainly based on "small busbar + distributed starting", as follows:

[0044] ① Set the preconditions for the switching operation of the switching lock small busbar to be allowed (the auxiliary contact 1LG of the isolating knife on the 1M busbar side is closed, and the auxiliary contact MDL of the busbar bay circuit breaker is closed, and the auxiliary contact 2LG of the isolating knife on the 2M busbar side is also closed, and the "switching lock small busbar (+BLM, -BLM, where -BLM is usually negatively charged -110V, +BLM is negatively charged -110V before the locking conditions of the busbar bay terminal box are met, and is positively charged +110V after the locking conditions of the busbar bay terminal box are met)" is formed locally (busbar bay terminal box);

[0045] ② Lead the switching locking busbar (+BLM, -BLM) to the terminal box in the outgoing line bay and the terminal box in the main transformer bay respectively (use 2-core 4 square millimeter low-voltage power cable for connection).

[0046] ③ An intermediate relay 1ZJ is configured in all outgoing line bay terminal boxes and main transformer bay terminal boxes. When the blocking conditions are met, the relay is connected to the switching blocking busbar (+BLM, -BLM) of the bay through the switching handle QK, achieving "distributed start" of cross-bay parallel operation conditions. The switching handle QK is mainly used to activate during operation and deactivate during non-operation time, which can achieve circuit energy saving and extend equipment operation time.

[0047] ④ By connecting the normally open contact of the "distributed start" relay 1ZJ in series with the electrical locking conditions in the line or main transformer interval, an overall distributed operation logic method can be formed.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0049] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0050] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A distributed switching and locking busbar structure, characterized by: It includes a switching lockout busbar, an outgoing line bay terminal box, a main transformer bay terminal box, and a busbar coupling bay terminal box. The switching lockout busbar is connected in parallel to the outgoing line bay terminal box, the main transformer bay terminal box, and the busbar coupling bay terminal box. The busbar coupling bay terminal box includes an isolating knife 1LG, an isolating knife 2LG, a circuit breaker MDL, and a switching operation start signal relay JJ. The isolating knife 1LG, the isolating knife 2LG, and the circuit breaker MDL can be connected in series to start the switching lockout busbar. The outgoing line bay terminal box and the main transformer bay terminal box both include an intermediate relay 1ZJ, a switching handle QK, an isolating knife 1G, an isolating knife 2G, an isolating knife 3G, and a circuit breaker DL, and the six can be connected to each other to control the 1G opening and closing circuit and the 2G opening and closing circuit respectively. The intermediate relay 1ZJ is connected to the switching lock busbar through the switching handle QK. The switching lock busbar includes +BLM and -BLM. The 1G opening and closing circuit is composed of the isolating knife 1G, the isolating knife 2G, the circuit breaker DL, the isolating knife 3G, the intermediate relay 1ZJ, and the switching handle QK. The above six are connected in sequence, and the 1G opening and closing circuit is connected when the isolating knife 1G of the circuit is closed, the isolating knife 2G is closed, the circuit breaker DL is closed, the isolating knife 3G is closed, the intermediate relay 1ZJ is closed, and the switching handle QK is closed. The 2G opening and closing circuit is connected in parallel with the isolation knife 1G and isolation knife 2G of the 1G opening and closing circuit, and the 2G opening and closing circuit is connected with the isolation knife 1G of the circuit closed, the isolation knife 2G closed, the circuit breaker DL closed, the isolation knife 3G closed, the intermediate relay 1ZJ closed, and the switching handle QK closed.

2. The distributed switching and locking busbar structure according to claim 1 is characterized in that: The -BLM is usually negatively charged at -110V.

3. The distributed switching and locking busbar structure according to claim 2 is characterized in that: The +BLM is negatively charged with -110V before the locking condition of the terminal box in the busbar interval is met, and is positively charged with +110V after the locking condition of the terminal box in the busbar interval is met.

4. The distributed switching and locking busbar structure according to claim 1 is characterized in that: The switching locking busbar is a low-voltage power cable, and the low-voltage power cable is 2 cores and 4 square millimeters.

5. An operating method for a distributed switching and locking busbar structure according to any one of claims 1 to 4, characterized in that: ① The switching lockout busbar allows switching operation: after the precondition isolation knife 1LG is closed, the circuit breaker MDL is closed, and the isolation knife 2LG is also closed, a switching lockout busbar is formed locally with the busbar bay terminal box. Among them, -BLM is usually charged with negative voltage -110V, and +BLM is charged with negative voltage -110V before the locking condition of the busbar bay terminal box is met, and is charged with positive voltage +110V after the locking condition of the busbar bay terminal box is met; ② Lead the switching lock busbar to the terminal box in the outgoing line bay and the terminal box in the main transformer bay respectively, and use a 2-core 4mm2 low-voltage power cable for connection; ③ In all outgoing line bay terminal boxes and main transformer bay terminal boxes, one intermediate relay 1ZJ is configured. When the blocking conditions are met, any outgoing line bay terminal box or main transformer bay terminal box can be connected to the switching blocking busbar of the bay through the switching handle QK, realizing distributed starting under parallel operation conditions across bays; ④ By connecting the normally open contact of the intermediate relay 1ZJ in series with the locking conditions of the terminal box in the outgoing line bay and the terminal box in the main transformer bay, an overall distributed operation logic method can be formed.

6. The method for operating a distributed switching and locking busbar structure according to claim 5, characterized in that: The locking conditions of the busbar bay terminal box are: the isolating switch 1LG is closed, the circuit breaker MDL is closed, and the isolating switch 2LG is also closed; There are two locking conditions for any terminal box in the outgoing line bay or the main transformer bay: 1G opening and closing circuit is connected, 2G opening and closing circuit is connected, 1G opening and closing circuit is connected: the circuit isolating knife 1G is closed, the isolating knife 2G is closed, the circuit breaker DL is closed, and the isolating knife 3G is closed; The 2G opening and closing circuit is connected: the circuit's isolation knife 1G is closed, the isolation knife 2G is closed, the circuit breaker DL is closed, and the isolation knife 3G is closed.

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