WO2021017602A1 - Offshore wind power direct current grid-connected system platform - Google Patents

Abstract

An offshore wind power direct current grid-connected system platform used for an offshore wind farm, the system platform comprising a main system sub-platform (A), an auxiliary system sub-platform (B) and one or more covered bridges (C). The main system sub-platform (A) comprises a grid-connected system and a power delivery conversion device. The auxiliary system sub-platform (B) comprises a supportive auxiliary device. The covered bridges (C) physically and electrically connect the two platforms, and have a fireproof function. In the described solution, an original large-scale offshore platform is divided into two easy-to-construct sub-platforms by means of technology integration and optimization, which reduces the dimensions and size of a single offshore platform, reduces the weight of a single platform, and reduces the fabrication costs and difficulty of offshore construction. Additionally, living and working areas for personnel are provided on the grid-connected auxiliary system sub-platform (B), and isolation measures are set up between same and a grid-connected system main platform portion, which has better safety performance.

Description

Offshore wind power DC grid-connected system platform Technical field

This application belongs to the field of power system transmission, and mainly relates to a gallery bridge, and an offshore wind power DC grid-connected system platform for arranging wind power DC grid-connected systems using this bridge bridge.

Background technique

There are two ways to send electricity from offshore wind farms to the land grid: AC and DC. The AC transmission method uses power frequency AC submarine cables to send wind power to land. This kind of transmission scheme has simple structure and low cost, and is mainly suitable for transmission from offshore wind farms.

The offshore wind power resources are broader and more stable. In order to obtain more offshore wind energy resources, offshore wind farms are gradually developing in the direction of the deep sea. When the wind farm is more than 60km away from the shore and enters the broad open sea area, the AC transmission method of wind power will gradually lose its cost performance as the power loss, the difficulty of reactive power compensation and the overall cost increase, and the DC transmission method becomes the preferred option. The DC transmission method converts wind power AC power into DC power through a converter, and sends it to the shore converter station with low loss by means of DC submarine cable, and then converts DC to AC to the grid. In addition to low loss and large transmission capacity, the DC transmission method, especially the flexible DC transmission method, also has strong fault ride-through, fault isolation capabilities and better stability. It can also achieve voltage and frequency control of offshore wind farms. And other comprehensive controls to improve the quality of the entire wind power grid connection.

At present, the existing typical schemes of offshore wind power DC grid-connected system platforms all adopt single-platform design schemes. The existing technical schemes have the following defects: (1) Adopting single-platform scheme design, the platform is large and stable; (2) With With the further increase of system capacity, the volume of offshore platforms has increased sharply, and the cost and construction difficulty will increase significantly; (3) The distance between the platform and the shore is getting farther, and there will be people staying from time to time. The single-platform design cannot physically remove the personnel. The activity area is separated from the equipment area. There is a risk of fire or explosion in the converter valve transformer and oil-containing equipment of the AC field, which poses a threat to the personal safety of operators.

Summary of the invention

This application aims to provide a wind power DC grid-connected system platform. The platform is divided into a main system sub-platform and an auxiliary system sub-platform, and is electrically and physically connected through a gallery bridge. Set up the personnel living and working area on the grid-connected auxiliary system sub-platform, and establish isolation measures between the grid-connected system main platform part. Can achieve improved safety.

This application provides an offshore wind power DC grid-connected system platform, including: a main system sub-platform, including a grid-connected system and power transmission and conversion equipment; an auxiliary system sub-platform, which is independent of the main system sub-platform and includes supporting auxiliary Equipment; one or more bridges connecting the main system sub-platform and the auxiliary system sub-platform, and the bridge bridges physically and electrically connect the main system sub-platform and the auxiliary system sub-platform.

The covered bridge includes: a pedestrian passage; fire doors, installed at both ends of the pedestrian passage, for blocking the pedestrian passage and the main system sub-platform, the pedestrian passage and the auxiliary system sub-platform, and pipeline passages , Installed below the pedestrian passage to connect the main system sub-platform and the auxiliary system sub-platform; cable channel installed below the pedestrian passage to electrically connect the main system sub-platform and the auxiliary system sub-platform; There is a fireproof partition between the cable channel and the pedestrian channel and the pipeline channel respectively.

According to some embodiments of the present application, the fire door includes a temperature sensor and/or a smoke sensor, and is connected in communication with the switch of the fire door, and the temperature sensor senses a preset threshold temperature or the smoke sensor When a preset threshold smoke concentration is sensed, a closing signal is sent to the fire door switch to close the fire door.

According to some embodiments of the present application, the fire door further includes a fire sprinkler, and the fire sprinkler is installed on the top of the fire door.

According to some embodiments of the present application, the fire sprinkler is in communication connection with the temperature sensor and/or the smoke sensor, and the temperature sensor senses a preset threshold temperature or the smoke sensor senses a preset threshold temperature. When the threshold smoke concentration is reached, a trigger signal is sent to the fire sprinkler to open the fire sprinkler.

According to some embodiments of the present application, the auxiliary system sub-platform and the aforementioned pipeline are connected to each other through a detachable flange.

According to some embodiments of the present application, the auxiliary system sub-platform is connected with the detachable steel cable of the above-mentioned pedestrian passage and connected with the detachable aviation plug of the above-mentioned cable passage.

The grid-connected system and the electric power transmission and conversion equipment bring the electric power collected by the offshore wind farm to a high-voltage stable DC state, and transmit it to the underground cable for transmission.

The grid-connected system in the main system sub-platform includes: a direct current submarine cable, an alternating current submarine cable, a direct current bus and a confluence bus.

The power transmission conversion equipment includes: a connecting transformer, a voltage source converter, and system safety auxiliary equipment.

Optionally, the connecting transformer is a three-winding transformer or a four-winding transformer, and one winding of the three-winding transformer or the four-winding transformer passes through the cable channel of the bridge to be all on the auxiliary system sub-platform. Said supporting auxiliary equipment provides power.

Optionally, the grid-connected system platform includes an AC switchgear and a DC switchgear. The AC switchgear and the DC switch are located at the bus bar and the DC bus, respectively.

Optionally, the AC switchgear and the DC switchgear are air-insulated open-type devices or gas-insulated metal-enclosed switchgear.

The supporting auxiliary equipment includes: seawater treatment and cooling equipment, auxiliary power supply equipment, HVAC equipment, maintenance equipment, human pods, and escape equipment. These devices can be used by working candidates for work and life.

According to some embodiments, although the offshore DC grid-connected wind power system has a variety of equipment connection methods according to different usage conditions, no matter which method, the grid-connected system with high risk factor set in this invention can be used. The main platform is separated from the personnel living and working area, and isolation measures are set up between the two platforms to achieve lower cost, lower construction difficulty and ensure personnel safety on the basis of completing the original wind power generation current conversion and transportation purpose the goal.

Description of the drawings

The specific embodiments of the present invention will be described below with reference to the drawings. The accompanying drawings of the specification are used to provide a further understanding of the present invention and constitute a part of the application. The exemplary embodiments of the present invention and the description thereof are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Fig. 1 is a schematic diagram of the plan layout of the first layer equipment in the first embodiment.

Fig. 2 is a schematic diagram of the plan layout of the second layer equipment in the first embodiment.

Fig. 3 is a schematic diagram of the plan layout of the third layer equipment in the first embodiment.

Fig. 4 is a front sectional view of the first embodiment.

Fig. 5 is a left sectional view of the first embodiment.

Fig. 6 is a schematic diagram of the gallery bridge in the first embodiment.

Fig. 7 is an A-A sectional view of the gallery bridge in the first embodiment.

Detailed ways

The specific implementations of the present application will be described in more detail below with reference to the accompanying drawings and embodiments, so as to better understand the solutions of the present invention and the advantages of various aspects. However, the specific embodiments and examples described below are for illustrative purposes only, and are not intended to limit the application.

First embodiment

Figures 1, 2, 3, 4, and 5 are schematic diagrams of the offshore wind power DC grid-connected system platform according to the first embodiment of the present application. Among them, FIG. 1, FIG. 2, and FIG. 3 are schematic top views of the planar layout of the first, second, and third layer devices in the first embodiment of the present application, respectively. Fig. 4 is a front sectional view of the first embodiment. Fig. 5 is a left sectional view of the first embodiment. 6 and 7 are schematic diagrams of the gallery bridge, in which Fig. 6 is a schematic diagram of the gallery bridge, and Fig. 7 is a cross-sectional view of the gallery bridge A-A.

As shown in Figure 4, the offshore wind power DC grid-connected system platform disclosed in this embodiment includes a main system sub-platform A, an auxiliary system sub-platform B, and a bridge C. The main system sub-platform A includes grid-connected systems and power transmission and conversion equipment. The auxiliary system sub-platform is independent of the main system sub-platform and includes the equipment required for the life and work of the personnel. One or more bridges connect the main system sub-platform and the auxiliary system sub-platform, that is, in this embodiment, the main system sub-platform A and the auxiliary system sub-platform B are connected by two bridges C. The bridge connects the main system sub-platform and the auxiliary system sub-platform physically and electrically. The number of bridges can be determined according to the actual system platform conditions, and it is not a limitation of this embodiment here.

As shown in Figure 4 and Figure 5, the main system sub-platform A is for easy wiring, and can be composed of multiple layers of equipment planes. The figure shows a three-layer equipment plane and is designed for unmanned use. The offshore grid-connected auxiliary system sub-platform B is designed for manned personnel, that is, the personnel working and living areas are set on the offshore grid-connected auxiliary system sub-platform. Among them, the "multi-layer device plane" mentioned in the main system sub-platform A is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed in a specific orientation, and Therefore, it cannot be understood as a limitation of the present invention.

As shown in Figure 1 and Figure 5, the first layer of equipment includes 220kv AC submarine cable A1 and DC cable A7. The 220kv AC submarine cable A1 is installed in two parts: one is installed on the side of the main system sub-platform A, and the wind power Field connection, for the collected initial current to pass; part of it is installed on the first-layer equipment platform for the AC current in the system to pass. The DC cable A7 needs to be installed on the other side of a certain distance from the 220kv AC submarine cable A1 to facilitate the laying of the system circuit. The AC cable A1 and the DC cable A7 can provide AC and DC currents respectively.

As shown in Figure 2 and Figure 5, the second layer equipment of the sub-platform A of the offshore grid-connected main system includes a voltage source converter A5 and a DC bus A6. The voltage source converter A5 is a device for AC and DC conversion composed of single or multiple converter bridges. The DC bus A6 can be used to collect and pass DC current. The voltage source converter A5 and the DC bus A6 can be arranged side by side. The figure shows two each.

As shown in Figures 3 and 5, the third-tier equipment of the sub-platform A of the offshore grid-connected main system includes AC busbar A2, high-voltage shunt reactor A3, transformer A4, and control protection and auxiliary equipment A8. The return bus A2 has a large flux and can be used as the main circuit in the parallel circuit to collect current. The high-voltage shunt reactor A3 has multiple functions to improve the reactive power-related operating conditions of the power system. Transformer A4 is a commonly used device that uses the principle of electromagnetic induction to change the AC voltage. The control protection and auxiliary equipment A8 mainly plays the role of protecting the normal operation of auxiliary equipment.

The operating principle of the system is as follows. This embodiment is a 1000MW+ scale offshore wind power DC grid-connected system platform, and its AC end is connected to three 300MW offshore wind farms. During operation, the power of these three offshore wind farms is respectively sent to the sub-platform A of the offshore grid-connected main system through a 220kV AC submarine cable A1, and is boosted and converged to the confluence bus A2 through the transformer A4. After the voltage source converter A5 takes power from the AC bus A2 and converts it to DC, it passes through the high-voltage shunt reactor A3 and control protection and auxiliary equipment A8 to make the current reach a stable state, and then sends it out through the DC bus A6 and the DC submarine cable A7 To land. Among them, the high-voltage shunt reactor A3 can improve the operating state of the reactive power of the power system, that is, play the role of reactive power compensation and stabilize current, and control protection and auxiliary equipment A8 can provide over-current protection.

It should be noted that the AC busbar A2 and DC busbar A6 on the sub-platform A of the offshore grid-connected main system can be equipped with AC field switchgear and DC field switchgear to realize system input, exit, state conversion, isolation, and maintenance functions; Air-insulated open equipment or gas-insulated metal-enclosed switchgear can be used to ensure that the switch is not corroded and safe.

The transformer A4 uses a two-winding transformer or a three-winding transformer or a four-winding transformer. Except for the third winding as a backup power source, the others are all used for wind power generation current transmission. And the transformer A4 and the voltage source converter A5 use oil-immersed air cooling or seawater cooling to ensure safe temperature. The connection between the busbar A2 and the voltage source converter A5 adopts a cable or a gas insulated metal enclosed power transmission line.

As shown in Figure 1 and Figure 4, the offshore grid-connected auxiliary system sub-platform B includes seawater treatment and cooling equipment B1, auxiliary power equipment B2, HVAC equipment B3, maintenance equipment B4, manned pod B5, escape equipment B6, and escape equipment B7. The above equipment can provide certain daily necessities for the staff on the auxiliary system sub-platform B, such as drinking water, power supply and heating needs. It also provides equipment necessary for maintenance and at least three escape devices. The auxiliary power supply of the auxiliary power supply device B2 can be obtained from the third winding of the transformer A4, or by setting a separate auxiliary power supply transformer on the busbar A2. The facilities on the auxiliary system sub-platform B can be changed as needed according to the number of staff.

As shown in Figure 6 and Figure 7, there are two gallery bridges C. Each gallery bridge includes pedestrian passage C1, fire door C2, fire sprinkler equipment C3, pipeline passage C4, cable passage C5, and at least one layer of fire isolation Device C6.

As shown in Figures 6 and 7, the bridge C and the auxiliary system sub-platform B adopt a detachable connection. In this embodiment, the cable is a prefabricated cable, and the cable connector is a prefabricated plug. The cable is transferred at the disconnect point through the aviation plug. When the cable needs to be disconnected when a fire occurs, quickly disconnect the aviation plug of the cable. Pedestrian passage C1 and auxiliary system sub-platform B are physically fixed and detachably connected with steel cables. Flange connection at pipe joints. When a fire occurs, untie the fixed connection between the pedestrian passage C1 and the auxiliary system sub-platform B, disconnect the pipe flanges, and separate the gallery bridge C and the auxiliary system sub-platform B. Of course, there can also be multiple connection methods between the bridge C and the auxiliary system sub-platform B, as long as the two can be separated when a fire occurs, and no examples are given here.

As shown in Figures 6 and 7, the pipeline channel C4 and the cable channel C5 are located below the pedestrian channel C1. There is a fire partition C6 between the pedestrian passage C1 and the cable passage C5. In this embodiment, the pipeline channel C4 and the cable channel C5 are parallel, with a fire partition C6 in the middle. The cable channel C5 is used to connect the electrical connection of the two platforms. For example, the auxiliary power supply on the sub-platform of the auxiliary system needs to be obtained from the transformer on the sub-platform of the main system. In this case, a cable channel needs to be set on the bridge. The pipeline channel C4 is used for circulating cooling water. As long as the positions of the pipeline channel C4 and the cable channel C5 are below the pedestrian channel, the electrical connection and pipeline connection of the two platforms are sufficient, and the specific positions should not be used as a limitation to this embodiment.

As shown in Figure 6, fire doors C2 are located at both ends of the pedestrian passage C1, and are used to block the pedestrian passage C1 and the main system sub-platform A, and the pedestrian passage C1 and the auxiliary system sub-platform B. The fire door C2 includes a temperature sensor and a smoke sensor (at least one of the two types of sensors), and is connected to the switch of the fire door C2 in communication. The fire door C2 can be controlled manually or automatically. The specific automatic control method is as follows. When the temperature sensor senses a preset threshold temperature or the smoke sensor senses a preset threshold smoke concentration, it sends a close signal to the fire door C2 switch to close the fire door. Wherein, the predetermined threshold temperature and threshold smoke concentration are both values well known to those skilled in the art when a fire occurs.

As shown in Figure 7, the top of the fire door also includes a fire sprinkler C3, which is connected to the temperature sensor and the smoke sensor in communication. When a fire occurs, the temperature sensor senses the preset threshold temperature, or the smoke sensor senses the preset threshold smoke concentration, it will automatically start the fire sprinkler C3 and spray water to the fire door C2. To prevent the fire door C2 from failing due to high temperature, it has the effect of extinguishing fire and cooling. This setting can ensure that personnel on the auxiliary system sub-platform are not injured when the main system sub-platform experiences an oil fire accident.

This embodiment isolates the main platform of the oil-containing grid-connected system with a high risk factor from the living and working area of the personnel, and sets up isolation measures between the two platforms to ensure better safety on the basis of completing the original collection of wind power currents .

It should be noted that the offshore DC grid-connected wind power system has a variety of equipment connection methods depending on the use situation, but no matter which method, the personnel working and living area set in this invention can be separated from the oil-containing main system platform. In order to achieve lower cost, lower difficulty and guarantee the purpose of personnel arrangement.

Finally, it should be noted that: Obviously, the above-mentioned embodiments are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is unnecessary and impossible to list all the implementation methods here. And the obvious changes or alterations derived from this are still within the protection scope of the present invention.

Claims (15)

1. An offshore wind power DC grid-connected system platform, including:

   Main system sub-platform, including grid-connected system and power transmission and conversion equipment;

   The auxiliary system sub-platform is independent of the main system sub-platform and includes supporting auxiliary equipment;

   One or more bridges connect the main system sub-platform and the auxiliary system sub-platform, and the bridge bridges physically and electrically connect the main system sub-platform and the auxiliary system sub-platform.
2. The offshore wind power DC grid-connected system platform according to claim 1, wherein the bridge includes:

   Pedestrian crossing;

   Fire doors, installed at both ends of the pedestrian passage, used to block the pedestrian passage and the main system sub-platform, and the pedestrian passage and the auxiliary system sub-platform;

   The pipeline channel is installed below the pedestrian channel and connects the main system sub-platform and the auxiliary system sub-platform;

   The cable channel is installed below the pedestrian channel to electrically connect the main system sub-platform and the auxiliary system sub-platform, and the cable channel is separated from the pedestrian channel and the pipeline channel with fire protection.
3. The offshore wind power DC grid-connected system platform of claim 2, wherein the fire door includes a temperature sensor and/or a smoke sensor, and is connected to the switch of the fire door in communication, and the temperature sensor detects When the preset threshold temperature or the smoke sensor senses the preset threshold smoke concentration, it sends a closing signal to the fire door switch to close the fire door.
4. The offshore wind power DC grid-connected system platform according to claim 3, wherein the fire door further comprises a fire sprinkler, and the fire sprinkler is installed on the top of the fire door.
5. The offshore wind power DC grid-connected system platform according to claim 4, wherein the fire sprinkler is in communication connection with the temperature sensor and/or the smoke sensor, and the temperature sensor senses a preset threshold temperature Or, when the smoke sensor senses a preset threshold smoke concentration, it sends a trigger signal to the fire sprinkler to open the fire sprinkler.
6. The offshore wind power DC grid-connected system platform according to any one of claims 2-5, wherein the auxiliary system sub-platform and the pipeline are connected to each other through a detachable flange.
7. The offshore wind power DC grid-connected system platform according to claim 6, wherein the auxiliary system sub-platform is physically detachably connected to the pedestrian passage and connected to the cable passage detachable aviation plug.
8. The offshore wind power DC grid-connected system platform of claim 1, wherein the grid-connected system and the power transmission and conversion equipment bring the power collected by the offshore wind farm to a high-voltage stable DC state, and transmit it to an underground cable for transmission .
9. The offshore wind power DC grid-connected system platform according to claim 8, wherein the grid-connected system includes: the grid-connected system includes: a DC submarine cable, an AC submarine cable, a DC bus, and a confluence bus.
10. The offshore wind power DC grid-connected system platform according to claim 8, wherein the power transmission and conversion equipment includes: a connecting transformer, a voltage source converter, and system safety auxiliary equipment.
11. The offshore wind power DC grid-connected system platform according to claim 10, wherein the connecting transformer is a three-winding transformer or a four-winding transformer.
12. The offshore wind power DC grid-connected system platform according to claim 11, wherein one winding of the three-winding transformer or the four-winding transformer through the cable channel of the bridge is the auxiliary system sub-platform Supporting auxiliary equipment provides power.
13. The offshore wind power DC grid-connected system platform according to claim 8, wherein the grid-connected system platform includes an AC switchgear and a DC switchgear, and the AC switchgear and the DC switch are located at the busbar and the bus bar respectively.述DC bus.
14. The offshore wind power DC grid-connected system platform according to claim 13, wherein the AC switchgear and the DC switchgear are air-insulated open-type equipment or gas-insulated metal-enclosed switchgear.
15. The offshore wind power DC grid-connected system platform according to claim 1, wherein the supporting auxiliary equipment includes: seawater treatment and cooling equipment, auxiliary power supply equipment, HVAC equipment, maintenance equipment, human pods, and escape equipment.

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