KR20200003582A - Wind turbine system and method for controlling the same - Google Patents

Abstract

Provided are a wind power generation system which efficiently uses an installation space, reduces an installation cost, increases a lifetime of an energy storage system (ESS), and increases energy storage efficiency and a controlling method thereof. According to an aspect of the present invention, the wind power generation system comprises: a wind power generator; a main ESS connected between the wind power generator and a power grid; a sub ESS provided at the wind power generator and selectively connected to the main ESS or the power grid; and a control unit controlling charging and discharging of the sub ESS and the main ESS.

Description

Wind power generation system and its control method {WIND TURBINE SYSTEM AND METHOD FOR CONTROLLING THE SAME}

The present invention relates to a wind power generation system and a control method thereof, and more particularly, to a wind power generation system including an ESS and a control method thereof.

Wind power generation refers to a power generation method in which wind energy is converted into mechanical energy (rotary power) using a windmill, and the mechanical energy is converted into electrical energy by driving a generator to obtain electric power.

Wind power generation is not only the most economical among the renewable energy sources developed so far, but also has been actively invested not only in Europe but also in the Americas and Asia due to the advantages of being able to generate power by using wind, which is an infinite clean energy source for uninterrupted energy. to be.

Renewable energy sources, such as wind power and solar power, have inherently intermittent characteristics in which power production varies greatly depending on environmental factors such as seasons and weather. This intermittence leads to rapid fluctuations in power generation output, resulting in poor power quality. As a classic method for overcoming such intermittence, instead of installing a single device of high capacity, a method of installing a plurality of devices of low capacity or distributing power generation facilities over a wide area has been applied.

Recently, power generated from renewable energy sources is stored in an energy storage system (ESS) and used when needed, thereby expanding renewable energy and improving the efficiency of the power industry.

The energy storage system (ESS) is composed of various operating systems such as a power storage source, a power converter (PCS), and a power management system (PMS).

Among them, the power management system controls the ESS, which is very important for efficiently operating the power storage sources and power conversion devices developed to date to improve power quality and optimize energy efficiency.

Republic of Korea Patent No. 10-1141047

The present invention is to provide a wind power generation system that can efficiently use the installation space and reduce the installation cost by efficiently deploying the wind turbine and the energy storage system.

In addition, the present invention is to provide a control method of a wind power generation system that can increase the life of the ESS and increase the energy storage efficiency by efficiently controlling the charging and discharging of the ESS according to the magnitude of the generated power and load power.

According to an aspect of the present invention, there is provided a wind power generation system, a wind generator, a main ESS connected between the wind turbine and the power grid, a sub ESS provided to the wind generator and selectively connected to the main ESS or the power grid, and the sub It may include a control unit for controlling the charge and discharge of the ESS and the main ESS.

The controller may be configured to supply and store the generated power of the wind generator to the sub ESS and to supply and store power to the main ESS when there is remaining power.

The controller may be configured to supply and store the generated power of the wind generator to the sub ESS and to supply power to the electric power grid when there is no remaining power.

A plurality of wind turbines may be installed and each sub ESS may be connected, and the main ESS may be connected to each sub ESS.

The sub ESS may be stacked and installed inside the tower of the wind turbine.

The sub ESS may be configured of a lithium secondary battery.

In a control method of a wind power generation system according to another aspect of the present invention, in a control method of a wind power generation system comprising a wind generator, a sub ESS provided in the wind generator, and a main ESS connected between the sub ESS and the electric power grid. And supplying and charging the power generated by the wind generator to the sub ESS, and supplying and charging the sub ESS to the main ESS when there is power remaining compared to the load.

The method may further include supplying and charging the generated power of the wind power generator to the sub ESS and supplying power from the sub ESS to the electric power grid when there is no power remaining compared to the load.

The sub ESS may be stacked and installed inside the tower of the wind turbine.

A plurality of wind turbines may be installed and each sub ESS may be connected, and the main ESS may be connected to each sub ESS.

The sub ESS may be configured of a lithium secondary battery.

As described above, according to an aspect of the present invention, by efficiently disposing the wind power generator and the energy storage system, it is possible to efficiently use the installation space and reduce the installation cost.

In addition, by efficiently controlling the charging and discharging of the ESS according to the magnitude of the generated power and the load power, the life of the ESS can be increased and the energy storage efficiency can be increased.

1 is a schematic diagram showing a wind power generation system according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating that power is directly supplied from a sub ESS to a power grid in the wind power generation system of FIG. 1.
3 is a view showing that the sub ESS is installed inside the tower of the wind turbine.
4 is a flowchart illustrating a control method of a wind power generation system according to an embodiment of the present invention.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, the terms 'comprise' or 'have', etc., are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present disclosure does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or combinations thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it is noted that the same components in the accompanying drawings are represented by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present invention will be omitted. For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated.

Hereinafter, a wind power generation system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 is a schematic diagram showing a wind power generation system according to an embodiment of the present invention, Figure 2 is a schematic diagram showing that power is directly supplied from the sub ESS to the power grid in the wind power generation system of Figure 1, Figure 3 is a wind turbine The drawing shows that the sub ESS is installed inside the tower.

The wind power generation system according to an embodiment of the present invention includes a wind generator 10, a sub ESS 20, a main ESS 30, and a controller.

The wind turbine 10 includes a tower 12, a nacelle 14, and a plurality of blades 16. The tower 12 is installed at a constant height from the ground, and can support the nacelle 14 and the plurality of blades 16 and the like. The tower 12 may have a tubular shape in which the diameter increases from the top to the bottom. Inside the tower 12 may be installed a staircase, conveyor or elevator for transporting a worker or work tool for maintenance of the generator.

The nacelle 14 is a housing installed on the top of the tower 12, and is generally made in a hexahedral shape, but may also be formed in a cylindrical shape or the like. Inside the nacelle 14, a shaft (not shown), a speed increaser (not shown), a brake (not shown), a generator (not shown) may be installed.

In front of the nacelle 14, a hub (not shown) coupled to the front end of the shaft is rotatably installed. A plurality of blades 16 are coupled to the outer circumferential surface of the hub so as to be spaced apart from each other at predetermined intervals along the circumferential direction.

The hub may consist of a conical protrusion that protrudes forward to reduce wind resistance. The blade 16 is rotated about the central axis of the hub by the wind. The blade 16 has a streamlined cross section in the width direction, and a space portion may be formed therein.

The shaft transmits the rotational force of the rotor consisting of the hub and the plurality of blades 16 to the speed increaser. The shaft may be rotatably supported by the bearing.

The speed increaser is a device for converting a rotational speed of a shaft rotated by a rotor into a suitable rotational speed by using a gear, and an speed increase gear part including a plurality of gears may be provided inside the speed increaser. In addition, in order to lubricate and cool a plurality of gears in the gearbox, the gearbox may be provided with a gearbox oil.

The brake may be disposed in a position adjacent to the speed increaser to control the rotational force of the shaft. This brake can mainly use a disk method.

The generator is a device for generating electric power by using the input rotational energy, the rotor and stator connected to the rotating shaft is provided therein. Electric power is generated by the rotor rotating at high speed around the stator.

The sub ESS 20 is installed adjacent to each wind turbine 10 to receive and charge the power produced by each wind turbine 10, and discharge the power if necessary.

The main ESS 30 is connected between the sub ESS 20 and the power grid 50, and a plurality of sub ESSs 20 are connected to the main ESS 30. The main ESS 30 may receive power from the sub ESS 20 to charge or discharge to supply power to the electric power grid 50.

Charge and discharge of the sub ESS 20 and the main ESS 30 are controlled by a controller (not shown). The controller charges the sub ESS 20 by first supplying the power produced by the wind turbine 10 to the sub ESS 20. When the sub ESS 20 is fully charged, the control unit controls to supply power to the main ESS 30 or the electric power grid 50. The controller may control to supply power to the electric power grid 50 when a power load occurs even when the sub ESS 20 is not fully buffered.

Energy Storage System (ESS) is a system that maximizes energy efficiency by storing electricity produced in each linked system including power plants, substations and transmission lines, and then using power efficiently and efficiently when power is needed. to be.

With ESS, load and leveling can be achieved, especially in response to environmental changes, charging and discharging of renewable energy power. In addition, Smart Grid ESS can establish a two-way power supply system using information and communication technology, improve the flexibility of transmission and distribution power system, prevent power outages, and improve the efficiency of power management in economic terms. have.

Looking at the type of ESS by storage capacity, the large-capacity ESS is located on the power plant, has a capacity of several hundred MW, and can store several hours of power every day. The small-capacity ESS is located on the transmission and distribution point and directly connected to the power consumer. The capacity is kW and can store power in minutes.

In addition to the pumped hydro, the power storage device for storing the power used in the ESS includes a lithium secondary battery, a redox flow battery, a sodium-sulfur (NaS) battery, and a compressed battery. Compressed Air Energy Storage, flywheel batteries and the like.

Pump generators and flywheel batteries are physical energy storage systems that can quickly store high output energy.

Lee? Secondary cells, NaS cells and redox flow cells are chemical energy storage systems, particularly Li? Secondary batteries and NaS batteries can be suitably used for both power plants and consumer ESSs.

Especially, Lee? The secondary battery has a power conversion efficiency of 96%, a lifespan of nearly 10 years, and a discharge duration of about 15 minutes to 2 hours. Lee? Secondary batteries are easy to commercialize, environmentally friendly, and efficient.

In the present invention, both the sub ESS 20 and the main ESS 30 may be configured of the same type of battery. For example, the sub ESS 20 and the main ESS 30 are referred to as? It may be composed of a secondary battery. On the other hand, the sub ESS 20 and the main ESS 30 may be composed of different kinds of batteries. In this case, the capacity of the main ESS 30 may be larger than that of the sub ESS 20.

The wind power generation system of the present invention can reduce the size of the main ESS by installing a sub ESS in each wind generator in addition to the main ESS. Therefore, the installation area and space for installing the main ESS can be reduced, and the system installation space can be efficiently utilized. In addition, since the generated power is distributed and stored in the main ESS or the sub ESS, the generated power can be efficiently stored and used.

The control unit controls to supply and store the power produced by the wind power generator 10 to the sub ESS 20 and to supply power to the main ESS 30 when there is remaining power.

The power produced by the wind turbine 10 varies with time, and the load power required by the electric grid 50 may also vary with time. The controller supplies power generated by the wind power generator 10 to the sub ESS 20 and charges it. If there is power remaining in preparation for the load power, the controller supplies power to the main ESS 30 as shown in FIG. 1. Control to charge the main ESS (30). The controller may control to discharge power from the main ESS 30 and supply the power to the power grid 50 when a necessary load is generated in the power grid 50. Of course, if there is a required load in the power grid 50, the controller may control to supply power to the main ESS (30) to charge and at the same time to supply power from the main ESS (30) to the power grid (50). .

The control unit controls to supply power to the electric power grid 50 as shown in FIG. 2 when there is no remaining power by supplying and storing the generated power of the wind power generator 10 to the sub ESS 20. In this case, since the load power is so large that power generation power is supplied to the electric power grid 50, there is not enough power left to charge the main ESS 30, so that the controller directly supplies power from the sub ESS 20 to the electric power grid 50. To control. Of course, when the sum of the generated power and the charging power of the sub ESS 20 is smaller than the load power, the controller discharges the power charged in the sub ESS 20 together with the generated power to the electric power grid 50 together with the generated power. Can be controlled to supply.

In addition, when the generated power is smaller than the load power, it may be controlled to supply power previously charged to the main ESS 30 to the electric power grid 50. Accordingly, even if the generated power fluctuates in real time, power can be stably supplied to the electric power grid 50.

On the other hand, the wind turbine 10 has a plurality of (10-1. 10-2, 10-3, 10-4) is installed and each sub ESS (20-1, 20-2, 20-3, 20-4)) The main ESS 30 may be connected to each sub ESS 20-1, 20-2, 20-3, and 20-4.

1 and 2, four wind generators 10-1, 10-2, 10-3, and 10-4 are installed, and each sub-ESS 20-1, 20-2, 20-3, 20 is installed in each wind generator. An embodiment in which -4) is connected is shown. The number of wind power generators may be installed in the range of 1 to several dozen depending on the site situation, one or more sub-ESS may be installed for each wind power generator.

In an embodiment in which a plurality of wind generators 10-1. 10-2, 10-3, 10-4 and a plurality of sub ESSs 20-1, 20-2, 20-3, 20-4 are connected, Since the generated power of the wind generator is different from each other, where the power is supplied from each sub ESS (20-1, 20-2, 20-3, 20-4) can be controlled differently.

For example, in a state where a predetermined load power is present, the sum of the generated powers of the three wind turbines 10-1, 10-2, and 10-3 is produced larger than the load power, and one wind turbine ( 10-4, when no power is produced, the generated power is supplied to each sub ESS (20-1, 20-2, 20-3), and then to the main ESS (30), and at the same time remaining power is supplied to the power grid (50). ) Can be supplied.

If the sum of the generated powers of the three wind turbines 10-1, 10-2, 10-3 is produced smaller than the load power, the generated power is transferred to each sub ESS 20-1, 20-2, 20-3. And then directly to the grid 50.

As shown in FIG. 3, the sub ESS 20 is preferably stacked and installed inside the tower 12 of the wind power generator 10.

As described above, a staircase, a conveyor, or an elevator is installed inside the tower 12, and the sub ESS 20 may be stacked and installed so as not to interfere with the stairs, the conveyor, or the elevator.

In this case, an air-cooled cooling device (not shown) for blowing air at room temperature to the sub ESS 20 that is generated during charging and discharging by the driving force of the shaft rotated by the wind can be provided. It may be provided with a water-cooled cooling device for cooling the sub ESS (20) with cooling water by driving the pump with the drive force.

The sub ESS 20 is preferably composed of a lithium secondary battery. The sub ESS 20 is an energy storage device having a smaller capacity than that of the main ESS 30. When the sub ESS 20 is configured as a lithium secondary battery, the sub ESS 20 has a good power conversion efficiency and is easily miniaturized, and thus, the sub ESS 20 is advantageously installed inside the tower 12.

A lithium secondary battery is a battery that uses the principle of generating a potential difference between lithium ions between a positive electrode and a negative electrode, and has an advantage of high energy density and energy efficiency.

Next, a control method of the wind power generation system of the present invention will be described with reference to FIG. 4.

As shown in Figure 4, by operating the wind power generator 10 generates power, that is, power (S10). When the wind blows above a certain speed, the blade of the wind turbine will rotate and generate power.

When the wind power generator 10 generates power, the generated power is supplied to the sub ESS 20 and charged (S20). Even when electric power is supplied to the sub ESS 20, when the battery is discharged at the same time, the sub ESS 20 may be charged or discharged depending on the magnitude of the charge power and the discharge power.

At this time, the control unit charges the sub ESS 20 and determines whether there is power remaining compared to the load (S30). Here, the remaining power relative to the load refers to the power remaining after subtracting the load power from the generated power when the generated power larger than the load power required by the power grid 50 is produced. In addition, the remaining power is first charged in the sub ESS 20, and when the power remains even after the sub ESS 20 is fully charged, it is supplied to the main ESS 30 and charged.

If the sub ESS 20 is charged in step S30 and there is more power remaining than the load, the sub ESS 20 supplies the power from the sub ESS 20 to the main ESS 30 to be charged, and if there is a load from the main ESS 30. Discharge to supply power to the power grid 50 (S40).

In step S30, when charging to the sub ESS 20 and there is no remaining power compared to the load, the power is directly supplied from the sub ESS 20 to the power grid 50 (S50).

According to the present invention, by efficiently deploying the wind turbine and the energy storage system, it is possible to efficiently use the installation space and reduce the installation cost.

In addition, by efficiently controlling the charging and discharging of the ESS according to the magnitude of the generated power and the load power, the life of the ESS can be increased and the energy storage efficiency can be increased.

As mentioned above, although an embodiment of the present invention has been described, those of ordinary skill in the art may add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention may be modified and changed in various ways, etc., which will also be included within the scope of the present invention.

10: wind power generator
12: tower
14: nacelle
16: blade
20: Sub ESS
30: Main ESS
50: power grid

Claims (11)

Wind power generator;
A main ESS connected between the wind turbine and the power grid;
A sub ESS provided to the wind turbine and selectively connected to the main ESS or the electric power grid; And
A controller for controlling charging and discharging of the sub ESS and the main ESS;
Wind power generation system comprising a. The method of claim 1,
The control unit supplies and stores the generated power of the wind power generator to the sub ESS and controls to supply and store power to the main ESS when there is remaining power. The method of claim 2,
The control unit supplies and stores the generated power of the wind generator to the sub ESS and controls to supply power to the power grid when there is no remaining power. The method according to any one of claims 1 to 3,
The wind generator is provided with a plurality of sub-ESS is connected to each other,
The main ESS is a wind power generation system, characterized in that connected to each sub ESS. The method of claim 4, wherein
The sub ESS is a wind power generation system, characterized in that is installed stacked inside the tower of the wind turbine. The method of claim 4, wherein
The sub ESS is a wind power generation system, characterized in that consisting of a lithium secondary battery. In the control method of the wind power generation system comprising a wind power generator, a sub ESS provided in the wind generator, and a main ESS connected between the sub ESS and the power grid,
Supplying and charging the power generated by the wind power generator to the sub ESS; And
Charging the sub ESS and supplying and charging the main ESS when there is power remaining relative to the load;
Control method of a wind power generation system comprising a. The method of claim 7, wherein
And supplying and charging the generated power of the wind generator to the sub ESS, and supplying power from the sub ESS to the electric power grid when there is no power remaining compared to the load. The method of claim 8,
The sub ESS is a control method of a wind power generation system, characterized in that is installed stacked inside the tower of the wind generator. The method according to any one of claims 7 to 9,
The wind generator is provided with a plurality of sub-ESS is connected to each other,
The control method of the wind power generation system, characterized in that the main ESS is connected to each sub ESS. The method of claim 10,
The sub ESS is a control method of a wind power generation system, characterized in that consisting of a lithium secondary battery.

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