A high voltage electrical wiring system suitable for high capacity medium voltage electrical equipment

Abstract

A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment relates to large power plant and power grid distribution technology field. It includes 500kV distribution device interval, 500kV / 35kV transformer, 35kV distribution device, 35kV / 10kV transformer and 10kV distribution device; the 500kV / 35kV transformer is connected with 35V distribution device through 35kV insulated tubular bus; the 35kV / 10kV transformer is connected with 35kV distribution device and 10kV distribution device through 35kV insulated tubular bus and 10kV insulated tubular bus respectively, and the 10kV distribution device is connected to electrical equipment through 10kV closed bus, and one branch is T-connected with power supply for factory load. The utility model significantly reduces the rated working current and short-circuit current level of electrical equipment, and the 10kV electrical equipment can select conventional products in the market, the equipment selection is easy, the equipment cost is reduced, the manufacturing difficulty of 500kV transformer is reduced, the relay protection configuration and operation maintenance are simple, and the technical difficulty and construction cost of the project are obviously reduced.

Description

Technical Field

[0001] This utility model relates to the field of power plant and power grid distribution technology, specifically to a high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment. Background Technology

[0002] In response to national policies on the flexible transformation of thermal power plants and the needs of regional heating development, a large thermal power plant has installed six 50MW electrode boilers to convert electrical energy into heat during off-peak hours and supply it to the heating network, thereby achieving deep peak shaving. The electrode boilers are powered by a single 360MVA / 500kV step-down transformer at the power plant. The voltage difference between the power source and the electrical equipment is significant, and the large capacity of each boiler makes the selection of the 500kV step-down transformer and 10kV electrical equipment a challenge. Optimizing the main electrical wiring to ensure the project not only selects equipment with the required electrical parameters but also significantly reduces investment is a pressing issue for the project.

[0003] Conventional electrical wiring configurations include two main approaches: First, connecting a 10kV busbar to a 500kV / 10kV split-winding transformer to supply power to each electric boiler and auxiliary equipment. This configuration presents significant challenges in transformer manufacturing, as the transformer's 10kV outlet rated operating current reaches 14434A and its short-circuit current reaches 103kA. No 10kV switchgear on the market meets these parameters, leading to substantial increases in wiring investment. Second, installing a 66kV–220kV step-down transformer between the 500kV power supply and the 10kV equipment, which then supplies power to each electric boiler and auxiliary equipment. While conventional equipment can be selected for this configuration, equipment costs and relay protection configurations are significantly increased. Utility Model Content

[0004] The purpose of this utility model is to solve the problems existing in the prior art and provide a high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment. The intermediate voltage between the 500kV power supply and the 10kV electrical equipment adopts 35kV medium-voltage power distribution. The maximum operating current of the selected electrical equipment does not exceed 4000A and the 10kV short-circuit current does not exceed 36kA.

[0005] The technical solution adopted by this utility model to achieve the above objectives is as follows: A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment includes a 500kV distribution unit bay, a 500kV / 35kV transformer, a 35kV distribution unit, a 35kV / 10kV transformer, and a 10kV distribution unit. The 500kV distribution unit bay steps down to a 10kV voltage level through the 500kV / 35kV transformer and the 35kV / 10kV transformer, and supplies power to the electrical equipment through the 10kV distribution unit. The 500kV / 35kV transformer is connected to the 35kV distribution unit through a 35kV insulated tubular busbar. The 35kV / 10kV transformer is connected to the 35kV distribution unit and the 10kV distribution unit through 35kV insulated tubular busbars and 10kV insulated tubular busbars, respectively. The 10kV distribution unit is connected to the electrical equipment through a 10kV enclosed busbar, with one branch connected to the plant auxiliary power supply to provide power to the plant auxiliary load.

[0006] Both the 500kV / 35kV transformer and the 35kV / 10kV transformer are selected as double-split transformers, which can better limit short-circuit current.

[0007] The 500kV power distribution equipment bay adopts a one-and-a-half circuit breaker connection form and a directly grounded system, including an ultra-high voltage power distribution equipment bay composed of circuit breakers, disconnecting switches, current transformers, voltage transformers and surge arresters.

[0008] A 500kV disconnect switch is installed between the 500kV distribution equipment bay and the 500kV / 35kV transformer to ensure that the 35kV distribution equipment and the 35kV insulated tubular busbar between the 500kV distribution equipment bay and the 500kV / 35kV transformer can be safely inspected and maintained while the 500kV distribution equipment bay is energized.

[0009] The 35kV power distribution unit adopts a line transformer group connection form and is an ungrounded system. It includes TPY-level current transformers, 35kV P-level measuring and metering current transformers, 35kV circuit breakers, 35kV voltage transformers, 35kV surge arresters, and high-voltage live-line display devices. The 35kV surge arresters, 35kV voltage transformers, high-voltage live-line display devices, 35kV circuit breakers, 35kV P-level measuring and metering current transformers, and TPY-level current transformers are connected sequentially via connecting wires. The 35kV surge arresters are connected to a 500kV / 35kV transformer, and the TPY-level current transformers are connected to a 35kV / 10kV transformer.

[0010] The 10kV power distribution device adopts a line transformer group connection form and is an ungrounded system, including a 10kV medium-voltage switch cabinet, which is equipped with circuit breakers, current transformers, voltage transformers, surge arresters and high-voltage live display devices.

[0011] This utility model provides a high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment. Compared with the prior art, the advantages of this utility model are: significantly reducing the rated operating current and short-circuit current levels of electrical equipment; allowing the use of conventional products on the market for 10kV electrical equipment, making equipment selection easier and reducing equipment costs; reducing the manufacturing difficulty of 500kV transformers; simplifying relay protection configuration and operation and maintenance; significantly reducing the technical difficulty and construction cost of the project; and enabling its widespread application in electrical fields with high power supply voltage and large-capacity electrical equipment. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model.

[0013] Figure 2 This is a schematic diagram of the 35kV power distribution device of this utility model.

[0014] In the diagram: 1 is a 500kV distribution equipment bay, 2 is a 500kV bay end disconnect switch, 3 is a 500kV / 35kV transformer, 4 is a 35kV insulated tubular busbar, 5 is a 35kV distribution equipment, 6 is a 35kV / 10kV transformer, 7 is a 10kV insulated tubular busbar, 8 is a 10kV distribution equipment, 9 is a 10kV enclosed busbar, 10 is electrical equipment, 11 is plant auxiliary load, 12 is a TPY-class current transformer, 13 is a 35kV P-class measuring and metering current transformer, 14 is a connecting conductor, 15 is a 35kV circuit breaker, 16 is a high-voltage live display device, 17 is a 35kV voltage transformer, and 18 is a 35kV surge arrester. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The accompanying drawings are incorporated in and form a part of this specification. It will be apparent to those skilled in the art that other drawings can be obtained from these drawings without any inventive effort.

[0016] Example

[0017] like Figure 1As shown, a high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment includes a 500kV distribution unit bay 1, a 500kV / 35kV transformer 3, a 35kV distribution unit 5, a 35kV / 10kV transformer 6, and a 10kV distribution unit 8. The 500kV distribution unit bay 1 steps down the voltage to 10kV through the 500kV / 35kV transformer 3 and the 35kV / 10kV transformer 6, and supplies power to the electrical equipment 10 through the 10kV distribution unit 8. The 35kV / 35kV transformer 3 is connected to the 35kV power distribution device 5 via a 35kV insulated tubular busbar 4; the 35kV / 10kV transformer 6 is connected to the 35kV power distribution device 5 and the 10kV power distribution device 8 via 35kV insulated tubular busbar 4 and 10kV insulated tubular busbar 7 respectively. The 10kV power distribution device 8 is connected to the electrical equipment 10 via a 10kV enclosed busbar 9. One branch is connected to the plant auxiliary power supply to provide power to the plant auxiliary load 11. In this embodiment, the electrical equipment 10 is an electrode boiler.

[0018] Both the 500kV / 35kV transformer 3 and the 35kV / 10kV transformer 6 are selected as double-split transformers, which can better limit short-circuit current.

[0019] The 500kV power distribution equipment bay 1 adopts a one-and-a-half circuit breaker connection form and a directly grounded system, including an ultra-high voltage power distribution equipment bay composed of circuit breakers, disconnecting switches, current transformers, voltage transformers and surge arresters.

[0020] A 500kV end disconnect switch 2 is installed between the 500kV distribution equipment bay 1 and the 500kV / 35kV transformer 3 to ensure that the 35kV distribution equipment 5 and the 35kV insulated tubular busbar 4 between the 500kV distribution equipment bay 1 and the 35kV distribution equipment 5 can be safely inspected and maintained while the 500kV distribution equipment bay 1 is energized.

[0021] like Figure 2 As shown, the 35kV power distribution device 5 adopts a line transformer group connection form and is an ungrounded system. It includes a TPY-level current transformer 12, a 35kV P-level measuring and metering current transformer 13, a 35kV circuit breaker 15, a 35kV voltage transformer 17, a 35kV surge arrester 18, and a high-voltage live display device 16. The 35kV surge arrester, 35kV voltage transformer, high-voltage live display device, 35kV circuit breaker, 35kV P-level measuring and metering current transformer, and TPY-level current transformer are connected sequentially by connecting wires. The 35kV surge arrester is connected to a 500kV / 35kV transformer, and the TPY-level current transformer is connected to a 35kV / 10kV transformer.

[0022] The 10kV power distribution device 8 adopts a line transformer group connection form and is an ungrounded system. It includes a 10kV medium-voltage switch cabinet, which is equipped with circuit breakers, current transformers, voltage transformers, surge arresters, and high-voltage live display devices.

[0023] This utility model provides a high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment such as electrode boilers, which adapts to and meets the operational needs of large thermal power plants. Under the premise of ensuring safe and reliable operation, it reduces the difficulty of engineering construction and saves engineering construction costs.

[0024] Obviously, the above embodiments are merely one example of this utility model and are not intended to limit the implementation and scope of this utility model. Any technical solutions that are the same as or equivalent to the contents described in the claims of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment, characterized in that, It includes a 500kV distribution equipment bay, a 500kV / 35kV transformer, a 35kV distribution device, a 35kV / 10kV transformer, and a 10kV distribution device. The 500kV distribution equipment bay is stepped down to 10kV voltage level through the 500kV / 35kV transformer and the 35kV / 10kV transformer, and supplies power to the electrical equipment through the 10kV distribution device. The 500kV / 35kV transformer is connected to the 35kV distribution device through a 35kV insulated tubular busbar. The 35kV / 10kV transformer is connected to the 35kV distribution device and the 10kV distribution device through 35kV insulated tubular busbar and 10kV insulated tubular busbar, respectively. The 10kV distribution device is connected to the electrical equipment through a 10kV enclosed busbar, and one branch is connected to the plant auxiliary power supply to provide power to the plant auxiliary load.

2. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment according to claim 1, characterized in that, Both the 500kV / 35kV transformer and the 35kV / 10kV transformer are selected as double-split transformers, which can better limit short-circuit current.

3. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment according to claim 1, characterized in that, The 500kV power distribution equipment bay adopts a one-and-a-half circuit breaker connection form and a directly grounded system, including an ultra-high voltage power distribution equipment bay composed of circuit breakers, disconnecting switches, current transformers, voltage transformers and surge arresters.

4. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment according to claim 1, characterized in that, A 500kV bay end isolating switch is installed between the 500kV power distribution equipment bay and the 500kV / 35kV transformer.

5. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment according to claim 1, characterized in that, The 35kV power distribution unit adopts a line transformer group connection form and is an ungrounded system. It includes TPY-level current transformers, 35kV P-level measuring and metering current transformers, 35kV circuit breakers, 35kV voltage transformers, 35kV surge arresters, and high-voltage live display devices. The 35kV surge arresters, 35kV voltage transformers, high-voltage live display devices, 35kV circuit breakers, 35kV P-level measuring and metering current transformers, and TPY-level current transformers are connected sequentially by connecting wires. The 35kV surge arresters are connected to a 500kV / 35kV transformer, and the TPY-level current transformers are connected to a 35kV / 10kV transformer.

6. A high-voltage electrical wiring system suitable for large-capacity medium-voltage electrical equipment according to claim 1, characterized in that, The 10kV power distribution device adopts a line transformer group connection form and is an ungrounded system, including a 10kV medium-voltage switch cabinet, which is equipped with circuit breakers, current transformers, voltage transformers, surge arresters and high-voltage live display devices.

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