TWM380389U - A novel sensorless maximum power point tracking controller for small-scale wind power generation systems - Google Patents

Abstract

To improve the dynamic response of the wind turbine to the rapidly changing wind velocity, a novel maximum power point tracking controller is proposed in this apparatus. By adaptively adjusting the virtual inertia of the mechanical system, the dynamic response of the wind turbine can be greatly improved for capturing more wind energy during wind velocity variations. Moreover, both the anemometer and encoder are not required in the proposed apparatus, the cost of the mechanical system is reduced and reliability of the wind power generation system is enhanced as well. The proposed controller is composed of a rotating angular speed estimator, a input torque estimator, a torque command calculator with adjustable virtual inertia, and a current controller.

Description

V. New description: f There is no new technology field. This is a maximum power tracking controller for wind power generation system. It uses electric energy conversion circuit and adaptive adjustment of virtual moment of inertia to effectively improve the mechanical system. The dynamic response, which in turn increases the efficiency of the wind turbine's ability to extract wind energy as the wind speed changes. [Prior Art] In recent years, wind power generation systems have become an alternative energy system developed by all countries because of their zero pollution, inexhaustible and economic efficiency. Among them, small-scale wind power generation systems are more suitable for installation in urban buildings and have lower R&D thresholds. Basically, the small wind power generation system is composed of a small wind turbine with a fixed blade angle, a permanent magnet generator 2, a two-phase AC/DC converter 5, a battery module, a group 6 and a DC load 7. The overall structure can be Refer to the figure - figure. Tenth, the DC load can also be replaced by a constant AC converter to provide AC power to the AC load. In order to enable the wind turbine to capture the wind, the system needs to use a maximum power tracker 8 to control the speed of the wind turbine. Basically, in the existing literature, the maximum power tracking controller can be roughly formed into the following four-sided speed ratio control method, disturbance observation control method, power mapping control method, and optimal torque control method. In the tip speed ratio control method, an anemometer must be used to achieve maximum power tracking control, so the cost is relatively high. As far as the scrambling method is concerned, although the control law is simple, but this

The method causes a disturbance near the maximum power point and a rate of drop. The basic principle of the power mapping method and the optimal torque method is to use the best curve obtained from a pre-measurement and then determine the control command of the system by the speed of the wind turbine to converge the operating point of the wind turbine to the maximum power point. . However, in the current literature, the influence of the moment of inertia of the system on the wind age efficiency is considered when the wind speed changes. In view of this, this creation proposes a new maximum power tracking control method to improve the wind turbine's response by adapting the system's virtual moment of inertia to improve the wind speed. The efficiency of the wind turbine's extraction of wind energy. [New content] In order to make the content of this creation easy to understand, the following is a detailed description of the maximum power of the wind power generation system. The relationship between the power and the wind speed from the system towel wind turbine is as follows (1): (1)

Pw=\pCpAvl In the above formula (1), p: air density A: equivalent force area when the wind turbine rotates vw: wind speed: power factor of the wind turbine

The power factor c of the wind turbine is expressed by the following approximate polynomial: CP=C0+ ^ + c2S2 + + c^A δ νω_ ν. Ίί^/( 疋 wind turbine tip speed ratio function and can be (2) (3) (2) and (3), δ: the tip ratio of the wind turbine is wide: the equivalent radius of the wind turbine ^: the angular velocity of the wind turbine rotation C〇~C4: the real number can be earned by the equation (2) The maximum value is the ratio of the optimum tip speed to the subtraction. And the formula (1) shows that when the wind turbine's tip speed ratio is better than the control, it can be transferred to the maximum. Power: (4) (5) ^w.rnax — ^w,opt " ω„ι = ko)^

, pAr'C _ £___P, max ~ 2δ3 opt In the formula (4), the maximum torque of the wind input. The dynamic equation of the mechanical system composed of the moth machine and the generator can be expressed as follows (6).

v B〇)m m (6) In the above formula (6), rw : input torque by the wind turbine

The output electromagnetic torque of the generator J: the moment of inertia of the mechanical system B: the equivalent friction coefficient of the mechanical system The output torque of the generator and its output current are expressed by the following equation (7): (7) Γβ». = ^Λ=| Γν« where ρ : the number of poles of the generator λ ϊ : the magnetic flux linkage of the generator, the amplitude of the output current of the generator is known from equation (7). The optimum torque tracking rate control is followed by the wind turbine. The best input torque '7:=W' is directly used as the generator's wheel electromagnetic torque command. When the wind speed changes rapidly, the wind turbine can't quickly reach the maximum power working point because the wind turbine's moment of inertia is slow. Moreover, if the optimal torque control method is adopted, the acceleration and deceleration of the wind turbine depends only on the torque difference between the input torque of the wind turbine and the optimal torque curve, so that when operating at low wind speed, the wind turbine is operated. The dynamic response is slower and the maximum wind energy cannot be effectively captured when the wind speed changes. In order to effectively improve the dynamic response of the wind turbine when the wind speed changes, the main purpose of this creation is to reveal a new non-sensing maximum power tracking controller that adapts the dynamic moment of inertia of the mechanical system to improve the dynamic response of the wind turbine. In turn, the wind energy obtained by the wind turbine when the wind speed changes is increased, and the structure is as shown in the second figure. Firstly, use the speed and phase wire _ 9 to estimate the force of the ship, and then estimate the torque of the wind wheel, and then calculate the output electromagnetic torque command of the generator through the adaptive difficult virtual inertia power chasing wheel (4) 1G. (4) The current control (4) 12 controls the generator wheel current to achieve the required output contact. The following implementations of the frequency-fighting implementation, together with the accompanying drawings, are more versatile, to further explain the technical know-how, characteristics and effects of the creation. [Embodiment] The torque command of the new maximum power tracking system proposed by this creation is calculated according to the following formula: 疋T^=(t~kSl)^kv + kS2m (8) It can be known from the above formula (8) 'When the wind turbine When the operating point converges to the maximum point, the torque command will be the same as the command for the best torque control method. However, in the transient situation when the wind speed changes, it will introduce people - to adjust the correction amount of the virtual inertia to accelerate the riddle of the wind turbine. After determining the output torque command, calculate according to the formula (7). The output current amplitude command is used as a reference to the wheel (4) power electronic converter for current (4). For the money domain (4), the speed should be much faster than the response speed of the mechanical system. @ @此(第) and (8) , ^

Άω^ dt ^Βνωη (9) Month ρι令巧天^ In the above formula, JK=J/(1_蚌) is the virtual moment of inertia and eight is the virtual friction coefficient. It can be seen from equation (9) that when & is set to a negative real number, the virtual moment of inertia of the system is reduced, thereby accelerating the dynamic response speed of the mechanical system. Next, in order to analyze the dynamic characteristics of the proposed system, we assume that the system is stable, as shown in the following equations (10) and (11): (10) There is a small signal perturbation near the operating point ωηι = ωη〇 + A〇 ?w ^-V^+AV^ ((1) In the previous equation, %. and \. respectively, the wind turbine speed and wind speed at the steady-state operating point, and the small signal disturbance amount for the wind turbine speed and wind speed. (2), (9), (1〇), and (11) are available (8) Ν Δν^(5) s + M (12) N = {\-kv)k^mo (13) M = (\- Kv)kMamo+j (14) kN = :i[, +1CApt+C". t· -c4〇(15) 2J5^ ^C〇c^opt ^c^〇pt ~ ^ opt 3cA;) + y (16) From equations (12) and (14), the speed of the wind turbine is The 3dB bandwidth of the wind speed response speed is μ, and the bandwidth is known as %. The function. In the optimal torque control method, the response speed of the wind turbine is also reduced when the wind speed is low, thereby reducing the wind energy drawn by the wind turbine. In this creation, the bandwidth of the wind turbine can be changed by adjusting the knowledge. If the bandwidth of the wind turbine at different wind speeds is M380389 Ι^ΨΜ will be the same, then this adaptive adjustment factor should be adjusted according to the speed of the wind (7) with the wind speed: Κ-ί{ωη ) = \-

M-b/J

(17) The second figure shows the adaptive optimal torque control method and the adaptive tunable virtual habits proposed in this work. 1. The trajectory of the command to control the A torque command when the wind speed changes. When the wind speed changes from a low wind speed step to a high wind speed, the optimal working point changes from point A to point.

B. In the conventional maximum power tracking control method, the wind turbine only accelerates by the torque input of the input torque and the optimal torque of the custom torque, and the control method proposed by the present invention adds to the moment when the wind speed becomes faster. The output torque command is reduced to the compensation amount to temporarily increase the difference between the input torque and the output torque for accelerating the wind turbine. Therefore, the response speed of the wind turbine can be effectively improved. Similarly, when the wind speed is slow, the torque command of the controller proposed by this creation is temporarily higher than the torque command of the controller to achieve a faster speed. Riding a wind turbine to the best

When making a point, the appropriate ship will turn to the ride and the amount will be hidden. (4) The control method will be the same as the torque command of the conventional control method. The fourth figure and the first are the actual measurement results used to verify the feasibility of the authoring device. The fourth figure shows that when the wind speed is step change, the new maximum power tracking proposed by this creation is used to earn a fine-grained tracking controller. As can be seen from the fourth figure (4), the control ^' wind _ _ _ _ fast. The fourth picture (6) is not the change of the new (four) surface. The fourth picture (〇10 M380389 shows that the power factor of the wind turbine can be faster and maintained at the maximum when using the new controller. The fifth figure shows the transient state of the system when the wind speed is periodically changed as follows Change. ^=6.25^0.093^), 0.153^)] ((8) It can be seen from the fifth figure (4) that when the optimal torque control method is used, the change of the speed of the wind turbine is less than that of the Wei. Na's new control method's bottle force machine relies on the response day _ change the new can keep up with the wind speed change. As can be seen from the fifth picture (6), using the new control method proposed by this creation, it can be more lenient The power factor of the wind turbine is controlled to the maximum value. When the wind speed is changed as above (18), the wind turbine's total output energy is 4. when the wind turbine is used, the wind turbine is used. The adaptive adjustment of the virtual inertia control is carried out, and the total energy of the wind turbine is 4. (10) watt-hours.

It can be seen that the new maximum power tracking (4) proposed by this creation can effectively improve the dynamic response of the wind turbine and increase the wind energy extracted by the wind turbine. Based on this, the content, characteristics and effects of the creative technology are reviewed below. The new maximum power chasing of this creation (4) On the small wind power generation system, the two voltage sensors and the two current sensors at the output of the generator respectively measure the line and current of the generator wheel. The generated electric current signal is estimated by the = and phase angle estimator to calculate the generator speed and the electrical phase angle, and can also calculate the amplitude of the generator output current. Then the input torque estimator can estimate the speed from the wind turbine to the generator by the speed estimation value and the current amplitude.

The power tracking control _ is a direct-^, and to improve the wind turbine input variable torque value in the wind-adjustable virtual inertia method. The best torque method is used to calculate the maximum torque of the generator to calculate the torque command of the phase. When the speed changes, the dynamic invention should be added to the torque command of the controller. One is used to adjust the amount of virtual women. The _ 剌 剌 赖 轻 • • • • • • • • • • • • • • 大 大 大 • • • • • • • • • • • • • • • • • • • • • • • • • • • • can. In summary, the solution has the following two contribution points: 1. No need to use any mechanical H, which effectively reduces the cost of the crane system and enhances the reliability of the system. 2. An adaptive adjustment method for virtual moment of inertia is proposed to improve the dynamic response of the wind turbine when the wind speed changes, and then increase the wind of the wind turbine. The above embodiment is only for explaining the technical idea and characteristics of the creation. The purpose is to enable those skilled in the art to understand the content of this creation and implement it accordingly. When it is not possible to limit the scope of the patent of this creation, that is, the equivalent changes and modifications made by the spirit of this creation should still be covered. Within the scope of this creation patent. 12 M380389 [Simple description of the diagram] Fig.: A block diagram showing a small wind power generation system. Figure: Block diagram showing the preferred embodiment of the new non-sensing maximum power tracking control proposed in this work. The third figure: indicates the output torque command trace map of the author controller and the conventional controller when the wind speed changes.

The positive paving device is compared with the fourth graph: it indicates that when the wind speed step changes, the system of the author controller and the conventional controller respectively adopts (a) wind turbine observation change, (6) generator output torque variation, (c) Wind turbine power factor changes. Figure 5: shows the (a) wind turbine speed change and (b) power factor change of the system using the author controller and the conventional controller when the wind speed continuity changes. [Main component symbol description] 1 : Small vertical axis wind turbine 2 : Permanent magnet generator 31, 32 : Current sensor 41, 42 : Voltage sensor 5 : Three-phase AC/DC conversion 6 : Battery module 7 : DC Load or single-phase AC/DC converter 8: Maximum power tracking controller for wind power generation system M380389 9 10 11 12 : Generator speed and phase angle estimator: Generator output torque command calculator: Wind turbine input torque estimation : Generator output current controller

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Claims (1)

:1 M380389 僧: 1. A new non-sensing maximum power tracking controller for small wind power generation systems. The controller includes: Speed and phase estimation H 'received by the sensed H sense Generator voltage and current signal 'and estimate the speed of the wind turbine and (4) and the amplitude value of the generator current; Input torque estimator, receiving the wind turbine speed estimated by the speed and phase angle estimator and the generator current Na County to the torque input by the wind input 适应-adaptive adjustment virtual maximum solution control (four) disk phase Corner Na broken _ side butterfly (four) paste speed: torque to calculate the output torque command of the generator; white current control receives the generator output command calculated by the largest god chasing (four) and calculates the money flow current Amplitude life Sixth, apply for a patent scope order, and then adjust the duty cycle ratio of the switch according to the error value between the generator current amplitude calculated by the current command wire to control the generator current vibration cap to indirectly reach the required output torque. The main spirit is to use the best torque control in the case of not using any mechanical sense. In addition, the compensation speed of the compensation control wire plus the thief force machine calculated by the adaptive adjustment virtual inertia method lies. Improve the efficiency of wind turbines in extracting wind energy when wind speed changes.