Novel wind power plant emergency standby power supply system based on compressed air energy storage

Abstract

The invention discloses a novel wind power plant emergency standby power supply system based on compressed air energy storage, which comprises a compressed air energy storage module, a power generation module and a control module, and is characterized in that the compressed air energy storage module comprises an air compressor and a high-pressure air storage tank, and the power generation module comprises an air expansion machine and a power generator; the control module comprises a storage battery and an intelligent controller, compressed air is stored in the high-pressure air storage tank through off-peak electricity, under the emergency operation working condition, the variable-pitch control system of the wind turbine generator set sends out an instruction to conduct emergency variable pitch, at the moment, the control module sends out the instruction, the compressed air energy storage module and the power generation module sequentially work and start to discharge, and the compressed air energy storage module and the power generation module start to conduct emergency variable pitch. The variable pitch system controls feathering of the blades so as to achieve the purpose of safe shutdown, and meanwhile, the system can provide illumination for each section of tower drum and a cabin when dispatching is in power failure but the tower drum still needs to work on a machine so as to ensure that the work of field personnel is completed in time.

Description

Technical Field

[0001] The invention relates to a wind farm backup power supply system, in particular to a novel wind farm emergency backup power supply system based on compressed air energy storage. Background Art

[0002] With the rapid development of renewable energy power generation, installed capacity has increased significantly. Traditional wind turbines use supercapacitors as backup power sources for wind turbines. The working principle is: the grid inputs power to supply wind turbines while charging the supercapacitor group through the charger controlled by the intelligent management unit. Charging stops when the rated voltage is reached. Under emergency operating conditions, the wind turbine pitch control system issues a command to perform emergency pitch change. At this time, the supercapacitor begins to discharge, and the pitch system controls the blades to straighten to achieve the purpose of safe shutdown. However, supercapacitors are expensive, and the capacitance is easy to decay. They need to be inspected and replaced regularly. Each wind turbine must be installed at the bottom of the tower, which increases the cost of the site. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a new wind farm emergency backup power supply system based on compressed air energy storage. The system can directly store gas in the station, and the electricity does not need to be connected to the grid. When the electricity utilization is low, the wind turbines can be directly used to generate electricity and store gas. When necessary, the necessary electricity required for the safety chain and lighting of the wind turbines in the entire station can be provided, so as to achieve the purpose of improving the cabin operation and maintenance efficiency and reducing the workload of the staff.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A novel wind farm emergency backup power supply system based on compressed air energy storage, comprising a compressed air energy storage module, a power generation module and a control module, wherein the compressed air energy storage module comprises a compressor 1 and a high-pressure air storage tank 2, the power generation module comprises an expander 3 and a generator 4, and the control module comprises a battery 5 and an intelligent controller 6;

[0006] The compressed air energy storage module, when the electricity consumption is low, the station wind turbine generates electricity to drive the module to operate, the electric valve at the inlet of the high-pressure air storage tank 2 is closed, the compressor 1 compresses the air into the high-pressure air storage tank 2, and the compression is stopped when the pressure in the high-pressure air storage tank 2 reaches the set value, and the electric valve at the inlet of the high-pressure air storage tank 2 is disconnected;

[0007] In the power generation module, the expander 3 drives the generator 4 to generate electricity. When the wind turbine safety chain needs to run, the wind turbine safety chain issues a command. After receiving the command, the intelligent controller 6 controls the electric valve at the outlet of the high-pressure air storage tank 2 to close. The high-pressure air in the high-pressure air storage tank 2 performs work through the expander 3, the generator 4 generates electricity, and the wind turbine safety chain starts to work after receiving power.

[0008] In the control module, when electricity consumption is low, the station wind turbine charges the battery 5, which is mainly used to power the intelligent controller 6 and the inlet and outlet solenoid valves of the high-pressure air storage tank 2. The main function of the intelligent controller 6 is to receive the wind turbine safety chain instructions and control the power supply of the compressed air energy storage module and the power generation module.

[0009] When a power outage is scheduled but machine operations are required, the intelligent controller 6 controls the outlet electric valve of the high-pressure air storage tank 2 to release compressed air, drives the expander 3 to work, and the generator 4 to generate electricity. The generated electricity is supplied to the wind turbine tower base, tower and cabin lighting systems at all levels through the voltage stabilizer.

[0010] The system mainly provides power supply for wind farms in plain areas. Wind turbines are relatively concentrated in plain areas, and the construction cost of the system is relatively low. One set of equipment can provide backup power for the entire station. When the wind turbines in the wind farm are more dispersed, it is not suitable to deploy this system due to cost issues.

[0011] The present invention has the following advantages:

[0012] The present invention provides a novel wind farm emergency backup power supply system based on compressed air energy storage. The system combines a novel energy storage method and directly uses wind turbines to generate electricity and store air during low electricity consumption, replacing traditional supercapacitors as the backup power supply for wind farms, reducing the pressure of daily inspections and scheduled inspections, and having high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flow chart of a new type of wind farm emergency backup power supply system based on compressed air energy storage according to the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0015] With the rapid development of the economy and society, the demand for electricity is becoming more and more vigorous. Traditional thermal power generation can no longer meet the needs of the economy and society for production and life. Therefore, in recent years, a large number of new energy power stations have been put into operation, which not only meet the demand for electricity, but also meet the low-carbon requirements. At present, the mainstream new energy sources include wind power, solar energy and hydropower. Traditional wind turbines need to be equipped with backup power sources such as supercapacitors and batteries to ensure the safe operation of the wind turbine safety chain in an emergency. However, supercapacitors and batteries are expensive and require regular maintenance. The maintenance time is long, and it is necessary to test whether the degree of power attenuation meets the operating conditions of the safety chain. At the same time, the tower bottom, tower barrel and cabin lighting of traditional wind turbines all need to be dispatched for power supply. Once the power is off, the lighting system will lose power, which will bring more inconvenience to daily inspections.

[0016] When the wind turbine is connected to the grid, the main control sends position instructions to the variable pitch system through the communication bus. The variable pitch system uses the control technology and power system to adjust the angle between the windward surface of the blade and the longitudinal rotation axis, that is, the pitch angle, so that the blade reaches the position given by the wind turbine main control, so that the output power of the wind turbine generator reaches the set value of the main control smoothly. When the wind turbine is shut down normally or in an emergency, the safety chain system drives the variable pitch system to control the blades to the predetermined safe position, realize aerodynamic braking, and ensure the safe shutdown of the wind turbine. When the wind turbine is connected to the grid, the 400VAC sent to the variable pitch system fails (non-LVRT). In the case of loss of main power, the variable pitch system relies on the backup power supply to provide energy, drive the blades back to a safe position, and ensure the safe shutdown of the wind turbine. It can be seen that the backup power supply of the wind turbine plays an extremely important role in ensuring the safety of the wind turbine.

[0017] In order to solve the problems mentioned above, the present invention provides a new wind farm emergency backup power supply system based on compressed air energy storage. The system can directly store gas in the station without the need to access the grid. When electricity consumption is at low levels, wind turbines can be directly used to generate electricity and store gas. When necessary, the necessary electricity required for safety chains and lighting for wind turbines in the entire station can be provided, so as to improve the cabin operation and maintenance efficiency and reduce the workload of staff.

[0018] The compressed air energy storage module (including a compressor 1 and a high-pressure air storage tank 2), the power generation module (including an expander 3 and a generator 4) and the control module (including a battery 5 and an intelligent controller 6) together constitute a new wind farm emergency backup power supply system based on compressed air energy storage.

[0019] Compressor 1 and high-pressure air storage tank 2 constitute the compressed air energy storage module of the system. When electricity consumption is low, the station wind turbine generates electricity to drive the module to operate, the electric valve at the inlet of high-pressure air storage tank 2 is closed, and compressor 1 compresses the air into high-pressure air storage tank 2. When the pressure in high-pressure air storage tank 2 reaches the set value, compression stops, and the electric valve at the inlet of high-pressure air storage tank 2 is disconnected.

[0020] The power generation module consists of an expander 3 and a generator 4. The expander 3 drives the generator 4 to generate electricity. When the wind turbine safety chain needs to run, the wind turbine safety chain issues a command. After receiving the command, the intelligent controller 6 controls the electric valve at the outlet of the high-pressure air storage tank 2 to close. The high-pressure air in the high-pressure air storage tank 2 performs work through the expander 3, the generator 4 generates electricity, and the wind turbine safety chain starts working after receiving power.

[0021] The control module consists of a battery 5 and an intelligent controller 6. When electricity consumption is low, the station wind turbine charges the battery 5. The battery 5 requires less electricity and is mainly used to power the intelligent controller 6 and the inlet and outlet solenoid valves of the high-pressure air storage tank 2. The main function of the intelligent controller 6 is to receive wind turbine safety chain instructions and control the power supply of the compressed air energy storage module and the power generation module.

[0022] When a power outage is scheduled but machine operations are required, the intelligent controller 6 controls the outlet electric valve of the high-pressure air storage tank 2 to release compressed air, drives the expander 3 to work, and the generator 4 to generate electricity. The generated electricity is supplied to the wind turbine tower base, tower and cabin lighting systems at all levels through the voltage stabilizer.

[0023] The system is mainly provided for wind farms in plain areas. Wind turbines are more concentrated in plain areas, and the construction cost of the system is relatively low. One set of equipment can provide backup power for the entire station. When the wind turbines in the wind farm are more dispersed, it is not suitable to deploy this system due to cost issues.

[0024] The basic working principle of traditional supercapacitors is: the power grid inputs electrical energy to supply the wind turbine operation, while the charger controlled by the intelligent management unit charges the supercapacitor group. Charging stops when the rated voltage is reached. Under emergency operating conditions, the wind turbine pitch control system issues a command to perform emergency pitch change. At this time, the supercapacitor begins to discharge, and the pitch control system controls the blades to achieve safe shutdown.

[0025] The system of the present invention can directly store gas in the station without the need to connect to the grid. When electricity consumption is low, wind turbines can be used to generate electricity and store gas. When necessary, the necessary electricity for safety chains and lighting can be provided for wind turbines throughout the station, thereby reducing the installation cost of the entire station and achieving the goal of improving cabin operation and maintenance efficiency and reducing the workload of staff.

[0026] The above is the complete working process of a new wind farm emergency backup power supply system based on compressed air energy storage in the present invention.

Claims

1. A new wind farm emergency backup power supply system based on compressed air energy storage, characterized in that: It comprises a compressed air energy storage module, a power generation module and a control module, wherein the compressed air energy storage module comprises a compressor (1) and a high-pressure air storage tank (2), the power generation module comprises an expander (3) and a generator (4), and the control module comprises a storage battery (5) and an intelligent controller (6); The compressed air energy storage module, when electricity consumption is low, the station wind turbine generates electricity to drive the module to operate, the electric valve at the inlet of the high-pressure air storage tank (2) is closed, the compressor (1) compresses air into the high-pressure air storage tank (2), and the compression stops when the pressure in the high-pressure air storage tank (2) reaches a set value, and the electric valve at the inlet of the high-pressure air storage tank (2) is disconnected; In the power generation module, the expander (3) drives the generator (4) to generate electricity. When the wind turbine safety chain needs to be operated, the wind turbine safety chain issues an instruction. After receiving the instruction, the intelligent controller (6) controls the electric valve at the outlet of the high-pressure air storage tank (2) to close. The high-pressure air in the high-pressure air storage tank (2) performs work through the expander (3), the generator (4) generates electricity, and the wind turbine safety chain starts to work after receiving power. In the control module, when electricity consumption is low, the station wind turbine charges the battery (5), which is mainly used to supply power to the intelligent controller (6) and the inlet and outlet solenoid valves of the high-pressure air storage tank (2). The intelligent controller (6) mainly receives wind turbine safety chain instructions and controls the power supply of the compressed air energy storage module and the power generation module.

2. A novel wind farm emergency backup power supply system based on compressed air energy storage as claimed in claim 1, characterized in that: When the power outage is scheduled but the machine needs to be operated, the intelligent controller (6) controls the outlet electric valve of the high-pressure air storage tank (2) to release compressed air, drives the expander (3) to work, and the generator (4) to generate electricity. The generated electricity is supplied to the wind turbine tower base, tower and cabin lighting systems at all levels through the voltage stabilizer.

3. A novel wind farm emergency backup power supply system based on compressed air energy storage as claimed in claim 1, characterized in that: The system mainly provides power supply for wind farms in plain areas.

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