Single CT current acquisition device applied to main transformer equipment of power plant unit

Abstract

The utility model discloses a single current transformer (CT) current acquisition device applied to main transformer equipment of a power plant unit, which relates to the technical field of substation acquisition and comprises a main power supply line, a first current transformer and a second current transformer. The first current transformer is connected in series with the first current acquisition loop, the second current transformer is arranged on the first current acquisition loop, the second current transformer is connected in series with the main transformer cooler cabinet acquisition loop, the main transformer cooler cabinet is connected with the main transformer cooler cabinet acquisition loop, and the main transformer cooler cabinet is connected with the main transformer cooler cabinet acquisition loop. The unit protection cabinet is connected with the first current acquisition loop. The utility model aims to provide the single CT current acquisition device which is compact in structure and accurate in monitoring, current data acquisition of a main transformer of a power plant unit and a cooling system and a protection system of the main transformer can be completed only through a set of current transformer system, and monitoring efficiency and system reliability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of substation acquisition, and specifically relates to a single CT current acquisition device applied to the main transformer equipment of a power plant unit. Background Art

[0002] In modern power systems, as a key device, the operation status of the main transformer of a power plant unit directly affects the stability and security of the entire power network. Traditional current acquisition devices often require multiple sets of current transformers to monitor different lines respectively, which not only increases the equipment cost, but also may cause difficulties in maintenance due to installation space limitations.

[0003] The existing main transformer cooler and unit protection share a set of current transformer (CT) circuits, which may cause some potential problems, mainly including:

[0004] 1. Increased load: When designing current transformers, a certain load capacity is usually considered, including the total impedance of devices such as measuring instruments and relays. When the main transformer cooler control circuit and the unit protection circuit share the same set of CTs, their loads will act on the CTs together. If the load of the cooler control equipment is large, it may cause the voltage on the secondary side of the CT to drop, affecting the accuracy of the protection equipment, and even may cause the protection to malfunction or refuse to operate.

[0005] 2. Interference problem: The start-stop operation of the cooler, especially the cooling fan with a motor, etc., may generate electromagnetic interference. This interference may be transmitted to the electronic equipment of the unit protection through the shared CT circuit, causing misjudgment of the protection device or increasing the measurement error, especially more significant in sensitive microcomputer protection systems.

[0006] 3. Maintenance and repair risks: Sharing CT means that when maintaining or repairing the cooler control circuit, it may be necessary to temporarily interrupt the unit protection, and vice versa. This not only increases the operation complexity, but also may affect the timeliness and effectiveness of the protection in case of emergency.

[0007] 4. Fault chain reaction: If a fault occurs in the cooler control system, such as a short circuit or an open circuit, it may directly affect the protection circuit passing through the same CT, resulting in misoperation of the protection, and then may unnecessary cut off the main transformer or other key equipment, affecting the stable operation of the power system.

[0008] Therefore, it is necessary to develop a current acquisition device with high integration and wide monitoring range. Summary of the Utility Model

[0009] The technical problem to be solved by the present utility model is to address the deficiencies in the prior art, and design a single CT current acquisition device applied to the main transformer equipment of a power plant unit. The aim is to achieve efficient and accurate current monitoring of the main transformer and its auxiliary equipment by optimizing the configuration and connection mode of the current transformer, and improve the safe operation level of the power system.

[0010] The technical solution adopted by the present utility model to solve its technical problem is as follows:

[0011] A single CT current acquisition device applied to the main transformer equipment of a power plant unit, comprising:

[0012] A main power supply line, a first current transformer, and a second current transformer. The first current transformer is arranged on the main power supply line, the first current transformer is connected in series to a first current acquisition loop, the second current transformer is arranged on the first current acquisition loop, the second current transformer is connected in series to a main transformer cooler cabinet acquisition loop, wherein the main transformer cooler cabinet is connected to the main transformer cooler cabinet acquisition loop, and the unit protection cabinet is connected to the first current acquisition loop.

[0013] As a further technical solution of the present invention, it further comprises a third current transformer. The third current transformer is arranged on the first current acquisition loop, the third current transformer is connected in series to a unit protection cabinet acquisition loop, wherein the unit protection cabinet acquisition loop is connected to the unit protection cabinet.

[0014] As a further technical solution of the present invention, the main power supply line is an ABC three-phase power supply line, and the first current transformer is arranged on the C-phase line.

[0015] As a further technical solution of the present invention, a first ammeter is connected in series to the main transformer cooler cabinet acquisition loop.

[0016] As a further technical solution of the present invention, a second ammeter is connected in series to the unit protection cabinet acquisition loop.

[0017] As a further technical solution of the present invention, the second current transformer is a 300 / 5A current transformer.

[0018] As a further technical solution of the present invention, the third current transformer is a 300 / 5A current transformer.

[0019] Compared with the prior art, the present utility model has the following beneficial effects:

[0020] 1. The purpose of the present utility model is to provide a single CT current acquisition device with a compact structure and accurate monitoring. Only through a set of current transformer systems can the current data acquisition of the main transformer of the power plant unit, its cooling system, and protection system be completed, improving the monitoring efficiency and system reliability.

[0021] 2. The second current transformer and the third current transformer are both arranged on the first current acquisition loop, and are respectively connected in series to the acquisition loop of the main transformer cooler cabinet and the acquisition loop of the unit protection cabinet, so as to monitor the current conditions of the cooling system and the protection system respectively, achieving a comprehensive monitoring of the operating state of the main transformer.

[0022] 3. A first ammeter is installed in series on the acquisition loop of the main transformer cooler cabinet, and a second ammeter is installed in series on the acquisition loop of the unit protection cabinet, so as to intuitively display the current values of each part and facilitate the on-site operators to timely understand the operating conditions of the equipment.

[0023] 4. The second current transformer and the third current transformer adopt the specification of 300 / 5A, ensuring the measurement accuracy in a high-current environment, and at the same time being compatible with the existing electrical equipment standards, facilitating installation and replacement.

[0024] 5. The current monitoring functions of the main transformer and its important auxiliary equipment are integrated through a single CT system in the present utility model, simplifying the equipment configuration and reducing the installation and maintenance costs. At the same time, high-precision current transformers are adopted to ensure the accuracy of current data, providing reliable data support for the safety monitoring of the power system. In addition, the design of this device is easy to integrate into the existing power facilities, enhancing the scalability and flexibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of a single CT current acquisition device applied to the main transformer equipment of a power plant unit proposed by the present utility model;

[0026] Figure 2 It is a circuit control structure diagram of another embodiment proposed by the present utility model;

[0027] Figure 3 It is a structural diagram of the current input loop proposed by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following describes the specific embodiments of the present utility model in conjunction with the drawings and embodiments:

[0029] It should be noted that the structures, colors, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementable conditions of the present utility model. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed by the present utility model.

[0030] Meanwhile, terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope of implementation of the present utility model. Changes or adjustments to their relative relationships, without substantial changes in technical content, should also be regarded as the scope of implementation of the present utility model.

[0031] As Figure 1 shown, the present utility model provides a single CT current acquisition device applied to the main transformer equipment of a power plant unit, including: a main power supply line, a first current transformer, and a second current transformer. The first current transformer is arranged on the main power supply line, the first current transformer is connected in series to a first current acquisition circuit, the second current transformer is arranged on the first current acquisition circuit, and the second current transformer is connected in series to a main transformer cooler cabinet acquisition circuit, where the main transformer cooler cabinet is connected to the main transformer cooler cabinet acquisition circuit, and the unit protection cabinet is connected to the first current acquisition circuit.

[0032] In an embodiment of the present utility model, by setting the first current transformer and the second current transformer, the current acquisition of the main transformer cooler cabinet and the unit protection cabinet is separated. Among them, the first current transformer uses the current of the main power supply line, the second current transformer acquires the current information of the main transformer cooler cabinet, and the difference between the acquisition currents of the first current transformer and the second current transformer is the current value of the unit protection cabinet, thus avoiding the influence caused by sharing a set of current transformers between the main transformer cooler cabinet and the unit protection cabinet.

[0033] See Figure 2 and Figure 3 , the present utility model also provides another implementation manner. Specifically, a unit protection cabinet acquisition circuit is connected to the unit protection cabinet, a third current transformer is arranged on the first current acquisition circuit, and the third current transformer is connected in series to the unit protection cabinet acquisition circuit, where the unit protection cabinet acquisition circuit is connected to the unit protection cabinet.

[0034] The second current transformer and the third current transformer respectively acquire the currents of the main transformer cooler cabinet and the unit protection cabinet. The acquisition circuits are independently set and will not interfere with each other, improving the acquisition accuracy.

[0035] In an embodiment of the present utility model, the main power supply line is an ABC three-phase power supply line, and one path is selected as the acquisition power supply line. Specifically, the first current transformer is arranged on the C-phase line.

[0036] The purpose of the present utility model is to provide a single CT current acquisition device with a compact structure and accurate monitoring. Only through a set of current transformer systems can the current data acquisition of the main transformer of the power plant unit, its cooling system, and protection system be completed, improving the monitoring efficiency and system reliability.

[0037] The first current transformer is arranged on one phase line of the main power supply line and is directly connected in series to the first current acquisition circuit to achieve the preliminary measurement of the current in the main power supply line.

[0038] The second current transformer and the third current transformer are both arranged on the first current acquisition circuit and are respectively connected in series to the main transformer cooler cabinet acquisition circuit and the unit protection cabinet acquisition circuit to respectively monitor the current conditions of the cooling system and the protection system, thus achieving the comprehensive monitoring of the operating status of the main transformer. A first ammeter is installed in series on the main transformer cooler cabinet acquisition circuit, and a second ammeter is installed in series on the unit protection cabinet acquisition circuit to intuitively display the current values of each part, facilitating on-site operators to timely understand the equipment operating conditions.

[0039] The second current transformer and the third current transformer adopt the 300 / 5A specification, ensuring the measurement accuracy in a high-current environment and being compatible with existing electrical equipment standards, which is convenient for installation and replacement.

[0040] The utility model integrates the current monitoring functions of the main transformer and its important auxiliary equipment through a single CT system, simplifies the equipment configuration, and reduces the installation and maintenance costs. At the same time, high-precision current transformers are adopted to ensure the accuracy of current data, providing reliable data support for the safety monitoring of the power system. In addition, the design of this device is easy to integrate into existing power facilities, enhancing the scalability and flexibility of the system.

[0041] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A single CT current acquisition device applied to the main transformer equipment of a power plant unit, characterized by: include: A main power supply line, a first current transformer and a second current transformer, wherein the first current transformer is arranged on the main power supply line, the first current transformer is connected in series to a first current collection loop, the second current transformer is arranged on the first current collection loop, the second current transformer is connected in series to a main transformer cooler cabinet collection loop, wherein the main transformer cooler cabinet is connected to the main transformer cooler cabinet collection loop, and the unit protection cabinet is connected to the first current collection loop.

2. According to claim 1, a single CT current acquisition device applied to the main transformer equipment of a power plant unit is characterized in that: It also includes a third current transformer, which is arranged on the first current collection loop and is connected in series to the unit protection cabinet collection loop, wherein the unit protection cabinet collection loop is connected to the unit protection cabinet.

3. The single CT current acquisition device applied to the main transformer equipment of a power plant unit according to claim 1 is characterized in that: The main power supply line is an ABC three-phase power supply line, wherein a first current transformer is arranged on the C phase line.

4. The single CT current acquisition device applied to the main transformer equipment of a power plant unit according to claim 1 is characterized in that: The first ammeter is connected in series to the main transformer cooler cabinet collection circuit.

5. The single CT current acquisition device applied to the main transformer equipment of a power plant unit according to claim 2 is characterized in that: A second ammeter is connected in series to the collection circuit of the unit protection cabinet.

6. The single CT current acquisition device applied to the main transformer equipment of a power plant unit according to claim 1 is characterized in that: The second current transformer is a 300 / 5A current transformer.

7. The single CT current acquisition device applied to the main transformer equipment of a power plant unit according to claim 2 is characterized in that: The third current transformer is a 300 / 5A current transformer.

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