Electric pulse deicing control method for wind turbine blade

Abstract

The electric pulse deicing control method for the wind turbine blade comprises the following steps that S1, deicing points are arranged on the windward side of the wind turbine blade, each deicing point is provided with an electric pulse deicing device, and each electric pulse deicing device comprises a magnet exciting coil and a skin, the skin is fixed on the surface of the fan blade at a deicing point, the excitation coil is completely covered with the skin, and the electric pulse deicing device is controlled by a deicing control module; wherein the deicing control module adjusts the magnitude of excitation current input to the excitation coil by adjusting the duty ratio of a PWM control signal; s2, environment parameters of the environment where the wind turbine blade is located and icing thickness detection information of the wind turbine blade are obtained, the environment parameters are input into a deicing control module, and the deicing control module determines the duty ratio of a PWM control signal according to the corresponding relation between the environment parameters and the icing thickness and the duty ratio of the PWM control signal; and S3, the deicing control module works according to the determined duty ratio of the PWM control signal, and outputs a corresponding excitation current to the excitation coil.

Description

Technical Field

[0001] The invention relates to an electric deicing method, in particular to an electric pulse deicing control method for wind turbine blades. Background Art

[0002] As a clean and renewable energy source, wind energy has received widespread attention around the world. As a result, the wind power industry has been able to develop rapidly, with its cumulative installed capacity increasing year by year and its proportion in total power generation also increasing.

[0003] As a device that converts wind energy into electrical energy, wind turbines require good wind energy as a driving force, and there are considerable wind speed conditions in high altitude and cold areas. However, the power generation can be increased by about 10% in this environment, but the blades will be threatened by icing. On the one hand, it affects the aerodynamic performance of the blades. Even slight icing will greatly change the original aerodynamic characteristics of the blades, causing the active output of the wind turbine to drop sharply or even shut down; on the other hand, when the blades are covered with ice, the mechanical load increases, which can easily shorten the service life of the wind turbine. In severe cases, it may even cause the blades to break or the wind turbine to collapse.

[0004] In the prior art, electric pulse vibration deicing is generally used to de-ice the blades of wind turbines. However, the existing electric pulse vibration deicing is difficult to completely remove ice from the wind turbine blades.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide an electric pulse de-icing control method for wind turbine blades, by arranging an excitation coil and a skin on the wind turbine blades, and then determining the duty cycle of the excitation current pulse of the excitation coil in combination with the environmental parameters of the actual operating environment of the wind turbine and the thickness of the ice coating, thereby generating a large transient electromagnetic force between the pulse coil and the skin, so that the ice coating on the wind turbine blades is broken, and the ice is effectively and thoroughly de-iced. In addition, in combination with the actual environmental parameters and the thickness of the ice coating, it can also avoid increased energy consumption, and effectively ensure the power generation efficiency and operating stability of the wind turbine.

[0007] The present invention provides a wind turbine blade electric pulse deicing control method, comprising the following steps:

[0008] S1. Deicing points are set on the windward surface of the wind turbine blades, and an electric pulse deicing device is set at each deicing point. The electric pulse deicing device includes an excitation coil and a skin. The skin is fixed to the surface of the wind turbine blade at the deicing point and the excitation coil is completely covered by the skin. The electric pulse deicing device is controlled by a deicing control module; wherein the deicing control module adjusts the magnitude of the excitation current input to the excitation coil by adjusting the duty cycle of the PWM control signal;

[0009] S2. Obtaining environmental parameters of the environment in which the wind turbine blades are located and ice thickness detection information of the wind turbine blades, the environmental parameters are input into the deicing control module, and the deicing control module determines the duty cycle of the PWM control signal according to the corresponding relationship between the environmental parameters and the ice thickness and the duty cycle of the PWM control signal;

[0010] S3. The de-icing control module operates according to the determined duty cycle of the PWM control signal and outputs the corresponding excitation current to the excitation coil.

[0011] Furthermore, the environmental parameters include wind speed, liquid water content in the air, and median diameter of supercooled water droplets.

[0012] Further, the de-icing control module includes a control unit, a voltage doubling circuit, an energy storage circuit and an excitation circuit;

[0013] The input end of the voltage doubler circuit is connected to the power supply, the output end of the voltage doubler circuit is connected to the input end of the energy storage circuit, the output end of the energy storage circuit is connected to the excitation circuit, and the excitation circuit supplies power to the excitation coil; the control input ends of the energy storage circuit and the excitation circuit are connected to the control unit;

[0014] The energy storage circuit includes an electronic switch Q1, a resistor R1 and a capacitor CR;

[0015] The input end of the electronic switch Q1 is connected to the output end of the voltage doubling circuit, the output end of the electronic switch Q1 is connected to ground via a resistor R1 and a capacitor CR in series, the common connection point between the resistor R1 and the capacitor CR serves as the output end of the energy storage charging circuit, and the control end of the electronic switch Q1 is connected to the control unit;

[0016] The excitation circuit includes an electronic switch Q2 and a resistor R2;

[0017] The input end of the electronic switch Q2 is connected to the output end of the energy storage charging circuit, the output end of the electronic switch Q2 is connected to one end of the resistor R2 through the excitation coil L1, the other end of the resistor R2 is grounded, and the control end of the electronic switch Q2 is connected to the control unit.

[0018] Furthermore, the control unit controls the charging time of the capacitor CR and the duty cycle of the control signal of Q2 according to the environmental parameter information and the ice thickness:

[0019] The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is d>2mm, the charging time is: 0.5RC≤t<1.2RC, and the duty cycle is: 70%~85%

[0020] The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is 0≤d≤2mm, the charging time is: 1.2RC≤t≤2.2RC, and the duty cycle is: >85%

[0021] The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is d>3mm, the charging time is 2RC≤t<3RC, and the duty cycle is: 88%~92%

[0022] The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is 0≤d≤3mm, the charging time is: 3RC≤t<4.5RC, and the duty cycle is: >92%

[0023] The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 , when the median diameter of supercooled water droplets is 1-20 μm and the ice thickness of the fan blades is d>4 mm, the charging time is 4.2RC≤t<5RC, and the duty cycle is: 90%~95%

[0024] The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 When the median diameter of the supercooled water droplets is between 1 and 20 μm and the ice thickness of the fan blades is 0 ≤ d ≤ 4 mm, the charging time is t ≥ 5 RC and the duty cycle is: > 95%; where RC is the set time coefficient.

[0025] Furthermore, the deicing points are arranged on the windward side of the fan blades and the distance between adjacent deicing points is 1 meter, and the distance between the deicing points and the edge of the windward side of the fan blades is 0.5 m.

[0026] Furthermore, the ice coating thickness d is the average of the ice coating thicknesses of the current deicing point and the areas covered by the four adjacent deicing points.

[0027] Beneficial effects of the present invention: Through the present invention, by arranging an excitation coil and a skin on the wind turbine blade, and then determining the duty cycle of the excitation current pulse of the excitation coil in combination with the environmental parameters of the actual operating environment of the wind turbine and the thickness of the ice coating, a large transient electromagnetic force is generated between the pulse coil and the skin, so that the ice coating on the wind turbine blade is broken, and the ice is effectively and thoroughly removed. In addition, in combination with the actual environmental parameters and the thickness of the ice coating, it is also possible to avoid an increase in energy consumption, and effectively ensure the power generation efficiency and operating stability of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0029] Figure 1 It is a flow chart of the present invention.

[0030] Figure 2 It is a schematic diagram of the voltage doubling circuit structure of the present invention.

[0031] Figure 3 It is a schematic diagram of the structure of the energy storage charging circuit of the present invention.

[0032] Figure 4 It is a schematic diagram of the structure of the excitation coil control circuit of the present invention.

[0033] Figure 5 It is a schematic diagram of the electrical structure of the present invention.

[0034] Figure 6 It is a schematic diagram of the deicing point arrangement structure of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below:

[0036] The present invention provides a wind turbine blade electric pulse deicing control method, comprising the following steps:

[0037] S1. Deicing points are set on the windward surface of the wind turbine blades, and an electric pulse deicing device is set at each deicing point. The electric pulse deicing device includes an excitation coil and a skin. The skin is fixed to the surface of the wind turbine blade at the deicing point and the excitation coil is completely covered by the skin. The electric pulse deicing device is controlled by a deicing control module; wherein the deicing control module adjusts the magnitude of the excitation current input to the excitation coil by adjusting the duty cycle of the PWM control signal;

[0038] S2. Obtain environmental parameters of the environment in which the wind turbine blades are located and ice thickness detection information of the wind turbine blades, and input the environmental parameters into the de-icing control module. The de-icing control module determines the duty cycle of the PWM control signal according to the corresponding relationship between the environmental parameters, the ice thickness and the duty cycle of the PWM control signal; the ice parameter detection information is an image collected by a high-definition camera, and the control unit estimates the ice thickness of the blades according to the image. The estimation process is a prior art and will not be elaborated here;

[0039] S3. The de-icing control module works according to the determined duty cycle of the PWM control signal, and outputs the corresponding excitation current to the excitation coil. Through the above, by setting the excitation coil and the skin on the wind turbine blade, and then determining the duty cycle of the excitation current pulse of the excitation coil in combination with the environmental parameters of the actual operating environment of the wind turbine and the ice thickness, a large transient electromagnetic force is generated between the pulse coil and the skin, so that the ice on the wind turbine blade breaks, effectively and thoroughly de-icing, and combined with the actual environmental parameters and ice thickness, it can also avoid increased energy consumption, effectively ensuring the power generation efficiency and operating stability of the wind turbine. Among them, the skin can be made of aluminum material, which has a relatively small mass and can reduce the load on the blade. The skin is fixed to the surface of the wind turbine blade by rivets.

[0040] In this embodiment, the environmental parameters include wind speed, liquid water content in air, and median diameter of supercooled water droplets.

[0041] The de-icing control module includes a control unit, a voltage doubling circuit, an energy storage circuit and an excitation circuit;

[0042] The input end of the voltage doubling circuit is connected to the power supply, the output end of the voltage doubling circuit is connected to the input end of the energy storage circuit, the output end of the energy storage circuit is connected to the excitation circuit, and the excitation circuit supplies power to the excitation coil; the control input ends of the energy storage circuit and the excitation circuit are connected to the control unit; wherein the control unit adopts an existing single-chip microcomputer, which is not described in detail here.

[0043] The energy storage circuit includes an electronic switch Q1, a resistor R1 and a capacitor CR;

[0044] The input end of the electronic switch Q1 is connected to the output end of the voltage doubling circuit, the output end of the electronic switch Q1 is connected to ground via a resistor R1 and a capacitor CR in series, the common connection point between the resistor R1 and the capacitor CR serves as the output end of the energy storage charging circuit, and the control end of the electronic switch Q1 is connected to the control unit;

[0045] The excitation circuit includes an electronic switch Q2 and a resistor R2;

[0046] The input end of the electronic switch Q2 is connected to the output end of the energy storage charging circuit, the output end of the electronic switch Q2 is connected to one end of the resistor R2 through the excitation coil L1, the other end of the resistor R2 is grounded, and the control end of the electronic switch Q2 is connected to the control unit. The electronic switch can be implemented by existing NMOS switches, triodes, etc. The on and off of Q2 and Q1 are: when charging Cr, Q1 is turned on and Q2 is turned off. After Cr is charged, Q1 is turned off, and Q2 works according to the PWM signal duty cycle determined by the control unit. Specifically:

[0047] The control unit controls the charging time of the capacitor CR and the duty cycle of the control signal of Q2 according to the environmental parameter information and the ice thickness:

[0048] The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is d>2mm, the charging time is: 0.5RC≤t<1.2RC, and the duty cycle is: 70%~85%

[0049] The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is 0≤d≤2mm, the charging time is: 1.2RC≤t≤2.2RC, and the duty cycle is: >85%

[0050] The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is d>3mm, the charging time is 2RC≤t<3RC, and the duty cycle is: 88%~92%

[0051] The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is 0≤d≤3mm, the charging time is: 3RC≤t<4.5RC, and the duty cycle is: >92%

[0052] The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 , when the median diameter of supercooled water droplets is 1-20 μm and the ice thickness of the fan blades is d>4 mm, the charging time is 4.2RC≤t<5RC, and the duty cycle is: 90%~95%

[0053] The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 When the median diameter of the supercooled water droplets is between 1 and 20 μm and the ice thickness of the fan blades is 0 ≤ d ≤ 4 mm, the charging time is t ≥ 5 RC and the duty cycle is: > 95%; where RC is the set time coefficient.

[0054] In this embodiment, the deicing points are arranged on the windward side of the fan blades and the distance between adjacent deicing points is 1 meter, and the distance between the deicing points and the windward edge of the fan blades is 0.5m;

[0055] Wherein: the ice thickness d is the average of the ice thickness of the current deicing point and the areas covered by the four adjacent deicing points. Figure 6 As shown, the circle represents the de-icing point. If Figure 6 The ice thickness d of the leftmost deicing point shown is determined as the average ice thickness of the area covered by the five deicing points on the left. Since there is no ice point further to the left of the leftmost point, the average is calculated by the thickness of the four nearest deicing points on the right.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A wind turbine blade electric pulse deicing control method, characterized in that: The following steps are involved: S1. Deicing points are set on the windward surface of the wind turbine blades, and an electric pulse deicing device is set at each deicing point. The electric pulse deicing device includes an excitation coil and a skin. The skin is fixed to the surface of the wind turbine blade at the deicing point and the excitation coil is completely covered by the skin. The electric pulse deicing device is controlled by a deicing control module; wherein the deicing control module adjusts the magnitude of the excitation current input to the excitation coil by adjusting the duty cycle of the PWM control signal; S2. Obtaining environmental parameters of the environment in which the wind turbine blades are located and ice thickness detection information of the wind turbine blades, the environmental parameters are input into the deicing control module, and the deicing control module determines the duty cycle of the PWM control signal according to the corresponding relationship between the environmental parameters and the ice thickness and the duty cycle of the PWM control signal; S3. The de-icing control module operates according to the determined duty cycle of the PWM control signal and outputs the corresponding excitation current to the excitation coil.

2. The electric pulse deicing control method for wind turbine blades according to claim 1 is characterized in that: The environmental parameters include wind speed, liquid water content in air, and median diameter of supercooled water droplets.

3. The electric pulse deicing control method for wind turbine blades according to claim 2 is characterized in that: The de-icing control module includes a control unit, a voltage doubling circuit, an energy storage circuit and an excitation circuit; The input end of the voltage doubler circuit is connected to the power supply, the output end of the voltage doubler circuit is connected to the input end of the energy storage circuit, the output end of the energy storage circuit is connected to the excitation circuit, and the excitation circuit supplies power to the excitation coil; the control input ends of the energy storage circuit and the excitation circuit are connected to the control unit; The energy storage circuit includes an electronic switch Q1, a resistor R1 and a capacitor CR; The input end of the electronic switch Q1 is connected to the output end of the voltage doubling circuit, the output end of the electronic switch Q1 is connected to ground via a resistor R1 and a capacitor CR in series, the common connection point between the resistor R1 and the capacitor CR serves as the output end of the energy storage charging circuit, and the control end of the electronic switch Q1 is connected to the control unit; The excitation circuit includes an electronic switch Q2 and a resistor R2; The input end of the electronic switch Q2 is connected to the output end of the energy storage charging circuit, the output end of the electronic switch Q2 is connected to one end of the resistor R2 through the excitation coil L1, the other end of the resistor R2 is grounded, and the control end of the electronic switch Q2 is connected to the control unit.

4. The electric pulse deicing control method for wind turbine blades according to claim 3 is characterized in that: The control unit controls the charging time of the capacitor CR and the duty cycle of the control signal of Q2 according to the environmental parameter information and the ice thickness: The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is d>2mm, the charging time is: 0.5RC≤t<1.2RC, and the duty cycle is: 70%~85% The ambient wind speed is 3-20m / s, the ambient temperature is -5-0℃, and the air liquid water content is 0.6-3.0g / m 3 , when the median diameter of supercooled water droplets is 10-80μm and the ice thickness of the fan blades is 0≤d≤2mm, the charging time is: 1.2RC≤t≤2.2RC, and the duty cycle is: >85% The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is d>3mm, the charging time is 2RC≤t<3RC, and the duty cycle is: 88%~92% The ambient wind speed is 1~15m / s, the ambient temperature is -5~-15℃, and the liquid water content in the air is 0.4~2.0g / m 3 , when the median diameter of supercooled water droplets is 5-35μm and the ice thickness of the fan blades is 0≤d≤3mm, the charging time is: 3RC≤t<4.5RC, and the duty cycle is: >92% The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 , when the median diameter of supercooled water droplets is 1-20 μm and the ice thickness of the fan blades is d>4 mm, the charging time is 4.2RC≤t<5RC, and the duty cycle is: 90%~95% The ambient wind speed is 1 to 10 m / s, the ambient temperature is -5 to -25°C, and the air liquid water content is 0.05 to 0.60 g / m 3 When the median diameter of the supercooled water droplets is between 1 and 20 μm and the ice thickness of the fan blades is 0 ≤ d ≤ 4 mm, the charging time is t ≥ 5 RC and the duty cycle is: > 95%; where RC is the set time coefficient.

5. The electric pulse deicing control method for wind turbine blades according to claim 1 is characterized in that: The deicing points are arranged on the windward side of the fan blades and the distance between adjacent deicing points is 1 meter, and the distance between the deicing points and the edge of the windward side of the fan blades is 0.5m.

6. The electric pulse deicing control method for wind turbine blades according to claim 4 is characterized in that: The ice thickness d is the average of the ice thickness of the current deicing point and the areas covered by the four adjacent deicing points.

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