KR101622689B1 - Small wind generation system and method for sensorless fuzzy maximum power point tracking using SMR circuit - Google Patents

Abstract

A small wind power generation system that performs sensorless fuzzy maximum power point tracking control using an SMR circuit is disclosed. A diode rectifier receiving a three-phase alternating current from the permanent magnet synchronizer, a switch connected to both ends of the diode rectifier, and a current switched-mode-rectifier (SMR) circuit including a diode connected to one end of the switch, And a fuzzy controller for performing a fuzzy control based on a difference between the value of the previous power value of the permanent magnet synchronous machine and the previous power value of the permanent magnet synchronous machine to vary the duty ratio of the switch to follow the maximum power point.

Description

Technical Field [0001] The present invention relates to a small wind turbine generation system and method for performing sensorless fuzzy maximum power point tracking control using an SMR circuit,

The present invention relates to a small wind power generation system, and more particularly, to a small wind power generation system and method that performs maximum power point follow-up control using a sensorless fuzzy algorithm based on an SMR circuit.

Since the use of fossil fuels such as petroleum and coal is causing environmental pollution and global warming problems, the world's energy demand has been increasing. Some reports expect the world's energy consumption to triple by 2050.

Recently, wind energy and photovoltaic power generation systems are attracting attention as an alternative energy source for depletion of fossil energy.

In particular, wind power is a pollution-free energy source in the natural state, and it is the most economical energy source among alternative energy sources. The wind power generation system is a power generation system that converts wind energy into mechanical energy using various types of windmills and drives the generators with this mechanical energy to obtain electric power. The wind power generation system is a pollution-free power generation system that does not have problems such as heat emission due to heat generation, air pollution, and radiation leakage, unlike the conventional fossil fuel or uranium power generation system, by making the wind which is an infinite clean energy as a power source.

Such wind power generation has been recognized as the most promising alternative energy source. Such a wind power generation system is easy to structure and install, and can be operated and managed easily. .

However, existing wind turbine systems require high-priced equipment because they use MPPT control method using rotational speed information of conventional wind speed and generator, and there is a problem of reliability due to failure of wind speed sensor and rotational speed measuring sensor of generator There is the disadvantage that there is.

In order to overcome such disadvantages, a sensorless MPPT control technique which does not require wind velocity and rotational speed information of a generator has been proposed. The sensorless MPPT control can compare the relationship between the output power of the generator and the output voltage to make it possible to output the maximum power. Among the sensorless MPPT control methods, the P & O (Perturb and Observe) algorithm has a problem that the rotational speed of the generator continues to vibrate around the maximum power point in a steady state with a slow follow-up speed. This results in a problem of degrading the quality of the voltage supplied to the simple system, and research is underway to remedy these problems at present.

Japanese Patent Application Laid-Open Publication No. 10-2013-0103909 relates to a power conversion apparatus, and more particularly, to a power conversion apparatus that is capable of transmitting maximum power to a load through a maximum power point estimation control based on voltage and current generated in a wind power generation system using wind power The present invention relates to a power conversion apparatus employing sensorless MPPT control of a wind power generation system.

Open No. 10-2013-0099479 relates to a wind power generation control system, and more particularly to a wind power generation control system for developing a new control technique capable of reducing installation and operation burden, The present invention relates to a method of controlling a sensorless on-line neural network.

The present invention is directed to a small wind turbine power generation system that performs sensorless fuzzy maximum power point follow-up control using an SMR circuit that removes LC passive elements by using a synchronous inductance of a permanent magnet synchronous machine instead of a conventional boost converter wind power generation system And method.

According to another aspect of the present invention, there is provided a method for controlling a duty ratio of a permanent magnet synchronous machine in a variable step size using a fuzzy control so that a permanent magnet synchronous machine has an optimum duty ratio based on a difference between a current power value and a previous power value of the permanent magnet synchronous machine This paper proposes a small wind power generation system and method for sensorless fuzzy maximum power point tracking control using SMR circuit.

A small wind power generation system for performing sensorless fuzzy maximum power point tracking control using an SMR circuit according to the present invention includes a diode rectifier for receiving three-phase alternating current from a permanent magnet synchronous machine, a switch connected to both ends of the diode rectifier, A switched-mode-rectifier (SMR) circuit including a diode connected to one end of the switch, and a fuzzy control based on a difference between a current power value of the permanent magnet synchronous machine and a previous power value of the permanent magnet synchronous machine, And a fuzzy controller for varying the duty ratio of the fuzzy controller to follow the maximum power point.

And the permanent magnet synchronous machine includes a role of a three-phase boost converter through an internal synchronous impedance.

And the fuzzy controller calculates the power of the permanent magnet synchronous machine on the basis of the measured values of the current and voltage output according to the duty ratio.

Wherein the fuzzy controller includes a fuzzy logic unit for converting an input variable and an output variable into a membership function, a rule base table based on the converted input variable and the output variable, An inference engine for calculating a fuzzy value by using the calculated fuzzy value, and an observer for converting the calculated fuzzy value to an actual value to calculate a duty ratio on which the fuzzy control is performed.

The fuzzy controller performs fuzzy control on the duty ratio so as to generate a maximum power of the permanent magnet synchronous machine to add or subtract the weight of the variable step size.

Wherein the purge control unit adds a weight of the variable step size to the duty ratio if the difference value is positive and the duty ratio has a tendency to increase and if the difference value is positive and the duty ratio has a tendency to decrease, The weight of the step size is subtracted.

Wherein the fuzzy controller subtracts the weight of the variable step size from the duty ratio if the difference value is negative and the duty ratio tends to increase, and if the difference value is negative and the duty ratio tends to decrease, And adds a weight value of the size.

The fuzzy controller may follow a maximum point of the characteristic curve based on a characteristic curve of the turbine and a differential chain rule, while varying the duty ratio.

A small wind power generation method for performing sensorless fuzzy maximum power point follow-up control using an SMR circuit according to the present invention includes the steps of: calculating a difference between a current power value of a permanent magnet synchronous machine and a previous power value of the permanent magnet synchronous machine; And varying a duty ratio of the switch to follow a maximum power point, wherein the step of following the maximum power point comprises the steps of: and a fuzzy controller for calculating a fuzzy value using a predetermined rule base based on the converted input variable and the output variable, converting the calculated fuzzy value to an actual value, And the duty ratio is calculated.

The small wind power generation system and method for performing the sensorless fuzzy maximum power point follow-up control using the SMR circuit according to the present invention is characterized in that in the conventional boost converter wind power generation system, the LC inductive elements of the permanent magnet synchronous machine are used instead, Saving, and easy maintenance.

Further, by controlling the duty ratio in a variable step size using the fuzzy control so that the permanent magnet synchronous machine has the optimum duty ratio based on the difference between the current power value and the previous power value of the permanent magnet synchronous machine, The steady state response characteristic becomes more stable and the response speed becomes faster.

1 is a view for explaining a configuration of a small wind power generation system according to an embodiment of the present invention.
2 is a view for explaining driving of the SMR circuit according to an embodiment of the present invention.
3 is a diagram for explaining a maximum power point tracking control according to an embodiment of the present invention.
4 is a block diagram illustrating a fuzzy controller according to an embodiment of the present invention.
5 is a block diagram illustrating a fuzzy controller according to another embodiment of the present invention.
6 is a diagram illustrating an input membership function according to an embodiment of the present invention.
7 is a diagram illustrating an output membership function according to an embodiment of the present invention.
8 is a diagram illustrating a table of fuzzy inference rules according to an embodiment of the present invention.
9 is a diagram for comparing a fixed step size P & O maximum power point tracking control and a variable step size fuzzy maximum power point tracking control according to an embodiment of the present invention.
10 is a diagram for comparing experiments of fixed step size P & O maximum power point tracking control and variable step size fuzzy maximum power point tracking control according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather obvious or understandable to those skilled in the art.

1 is a view for explaining a configuration of a small wind power generation system according to an embodiment of the present invention.

Referring to FIG. 1, the small wind power generation system 1 compares power calculated according to a duty ratio of a switch of a SMR (Switched-Mode Rectifier) circuit to follow a maximum power point. That is, since the small wind power generation system 1 does not require a sensor for measuring the rotational speed of the wind speed and the permanent magnet synchronous machine, the cost can be reduced and maintenance can be facilitated.

Also, the small wind power generation system 1 performs fuzzy control based on the difference value between the current power value and the previous power value of the permanent magnet synchronous generator (PMSG) so that the permanent magnet synchronous machine has a speed The duty ratio is controlled to be a variable step size. As a result, the small wind power generation system 1 is more stable in the steady-state response characteristic than the conventional fixed step size control, and the response speed can be increased.

The small wind power generation system 1 includes a blade 110, a permanent magnet synchronous machine 120, an SMR circuit 130, a capacitor 140, a system side converter 150, a three-phase inductor 160, a system 170, And a purge control unit 180.

The blade 110 is a wing that converts wind energy into mechanical energy. The mechanical energy may be energy generated while rotating. The blade 110 can be designed to effectively rotate the wind. That is, the blade 110 can be designed by dynamically computing the number of blades and the blade angle that can achieve the highest efficiency.

The permanent magnet synchronizer 120 converts the mechanical energy converted in the blade 110 into electrical energy. The permanent magnet synchronous machine 120 can generate a three-phase alternating current. Particularly, the permanent magnet synchronous machine 120 may be constituted by a permanent magnet and an armature alternately arranged with N poles and S poles, and may generate electrical energy through the frequency of the alternating current generated by the revolution speed (RPM) .

The SMR circuit 130 converts an alternating current into a direct current. The SMR circuit 130 includes a diode rectifier, a switch, and a diode.

More specifically, the SMR circuit 130 includes a diode rectifier that receives the three-phase alternating current of the permanent magnet synchronizer 120 and includes a switch connected across the diode rectifier. The SMR circuit 130 also includes a diode whose node is connected to one end of the switch.

The SMR circuit 130 may be similar in form and operation to a three-phase boost rectifier. That is, the SMR circuit 130 is composed of fewer passive elements compared to a conventional wind power generation system using a boost converter. The SMR circuit 130 can reduce the cost and the volume by removing the inductor L and the capacitor C. [

Therefore, the small wind power generation system 1 can be downsized using the above-described characteristics of the SMR circuit 130. [

The capacitor 140 temporarily stores electrical energy as a smoothing capacitor. That is, the capacitor 140 smoothes the AC to convert it into DC, and temporarily stores electric energy.

The capacitor 140 is also provided between the SMR circuit 130 and the system side converter 150. More specifically, the capacitor 140 has one end connected to the cathode of the diode and the other end connected to the other end of the switch. Both ends of the capacitor 140 are connected to the system side converter 150.

The system side converter 150 can control the active power and the reactive power by respectively controlling the direct axis current and the quadrature axis current. The system side converter 150 includes two controllers, namely, an inside and an outside.

The inner controller of the system side converter 150 is a PI (Proportional Integral) controller. The PI controller controls the d and q axis currents, respectively. The outer controller of the system side converter 150 controls the reactive power and the DC link voltage to a constant duty ratio value for unit power factor control and maximum power transfer.

The three-phase inductor 160 filters the current entering the system 170. Through which the system 170 receives electrical energy.

The fuzzy controller 180 calculates the power of the permanent magnet synchronizer 120 which varies according to the wind based on the measured values of the current and voltage output according to the duty ratio of the switch of the SMR circuit 130. The fuzzy controller 180 performs fuzzy control on the duty ratio of the switch of the SMR circuit 130 so that the maximum power of the permanent magnet synchronous machine 120 is generated so as to add or subtract the weight of the variable step size, do.

That is, if the power difference value of the permanent magnet synchronous machine 120 is positive and the duty ratio of the switch tends to increase, the fuzzy controller 180 adds the weight of the variable step size to the duty ratio. If the power difference value is positive and the duty ratio is The weight of the variable step size is subtracted from the duty ratio.

Also, if the power difference value of the permanent magnet synchronous machine 120 is negative and the duty ratio of the switch tends to increase, the purge control unit 180 subtracts the weight of the variable step size from the duty ratio. If the power difference value is negative and the duty ratio is decreased The weight of the variable step size is added to the duty ratio.

2 is a view for explaining driving of the SMR circuit according to an embodiment of the present invention.

Referring to FIG. 2, the small wind power generation system 1 uses the SMR circuit 130 through the permanent magnet synchronous machine 120. The SMR circuit 130 includes a diode rectifier 230 for receiving the three-phase alternating current of the permanent magnet synchronizer 120 and includes a switch connected across the diode rectifier 230. The SMR circuit 130 also includes a diode 250 whose eNode is coupled to one end of the switch.

The permanent magnet synchronous machine 120 can serve as a three-phase boost converter through an internal synchronous impedance. The permanent magnet synchronous machine 120 is equivalent to a circuit in which the three-phase inductors 222, 224, and 226 are connected to the three-phase voltage sources 212, 214, and 216, respectively. The three-phase inductors 222, 224, and 226 can perform voltage boosting on the energy received from the blade 110. That is, the three-phase inductors 222, 224, and 226 generate a synchronous impedance, and a boost effect can be obtained based on the generated synchronous impedance.

The three-phase inductors 222, 224, and 226 store and supply energy by turning on and off the switch 240. When the switch 240 is switched on, the three-phase inductors 222, 224, and 226 can momentarily store energy with an increase in the applied current. When the switch 240 is switched off, the three-phase inductors 222, 224, and 226 can be energized by adding stored energy and the energy of the three-phase voltage sources 212, 214, and 216.

Thus, the three-phase inductors 222, 224, and 226 can perform the boost effect. The respective voltages corresponding to the three-phase inductors 222, 224, and 226 are calculated by the fuzzy controller 180 based on the voltage equation.

The SMR circuit 130 expresses the relationship between the voltage and the current by Equations (1) and (2).

는 스위치(240)의 듀티비를 의미하고,

는 다이오드 정류기에 인가되는 전압을 의미하며,

는 커패시터(140)에 인가되는 전압으로 DC링크 전압을 의미하고,

는 다이오드 정류기에 출력되는 전류를 의미하며,

는 다이오드(250)에서 출력되는 전류를 의미한다.
here,

Quot; means the duty ratio of the switch 240,

Quot; means a voltage applied to the diode rectifier,

The voltage applied to the capacitor 140 means a DC link voltage,

Means the current output to the diode rectifier,

Quot; current " means the current output from the diode 250.

The DC link voltage, which is the output voltage of the SMR circuit 130, is constantly controlled by DC link constant voltage control of the system side inverter. Therefore, when the DC link voltage is constant, the average value of the DC link current is equal to the average value of the diode current as shown in Equation (3).

는 DC링크 전류를 의미한다.here,

Means the DC link current.

Also, if the duty ratio of the SMR circuit 130 is adjusted, the diode average current can be varied. Using Equation (2), the diode average current becomes smaller as the duty ratio becomes larger, and the diode average current becomes larger as the duty ratio becomes smaller.

That is, when the duty ratio of the SMR circuit 130 varies according to the change in the wind speed, the small wind power generation system 1 can adjust the magnitude of the power transmitted to the system 170.

3 is a diagram for explaining a maximum power point tracking control according to an embodiment of the present invention.

Referring to FIG. 3, the purge controller 180 follows the relationship between the duty ratio and the power based on the characteristic curve of the turbine and the differential cascade rule.

The fuzzy controller 180 can express the relationship between the power and the duty ratio in terms of power and the number of rotations as expressed by Equation (4) using a differential cascade rule.

는 전력을 의미하고,

는 스위치(240)의 듀티비를 의미하며,

는 영구자석 동기기기(120)의 회전수를 의미한다.here,

Means power,

Quot; means the duty ratio of the switch 240,

Means the number of revolutions of the permanent magnet synchronous machine 120.

That is, the duty ratio of the switch 240 is a value that is applied in reverse to the number of revolutions of the permanent magnet synchronous machine 120.

When the duty ratio of the switch 240 is reduced, the number of revolutions of the permanent magnet synchronous machine 120 increases. When the duty ratio of the switch 240 increases, the number of revolutions of the permanent magnet synchronous machine 120 decreases.

The fuzzy controller 180 can express a power curve according to the duty ratio change by using the characteristic curve of the turbine and Equation (4). The maximum power point may be a maximum point of the power curve.

FIG. 3 shows that power increases when the duty ratio increases in a low speed region at a specific wind speed and increases when the duty ratio decreases, but increases when the duty ratio decreases in a high speed region and increases when the duty ratio increases . The purge control unit 180 may control the duty ratio by increasing or decreasing the weight of the variable step size to a predetermined initial duty ratio or a predetermined duty ratio.

That is, the fuzzy controller 180 controls the duty ratio of the switch 240 to follow the maximum power point.

4 is a block diagram illustrating a fuzzy controller according to an embodiment of the present invention.

Referring to FIG. 4, the purge control unit 180 optimizes the duty ratio of the switch 240 through the purge control. That is, the fuzzy controller 180 calculates the duty ratio of the switch 240 that outputs the maximum power through the fuzzy control.

The purge control unit 180 includes a purge unit 410, an inference engine unit 420, a purge unit 430, and a storage unit 440.

The fuzzification unit 410 converts an input variable and an output variable into a membership function. The fuzzification unit 410 fuzzles the membership function in the form of a triangle. The membership function of the triangle is set as shown in Equation (5) and Equation (6).

는 영구자석 동기기(120)의 전력 변동값을 의미하고,

는 스위치(240)의 듀티비 변동값을 의미한다.
here,

Means a power fluctuation value of the permanent magnet synchronous machine 120,

Quot; duty ratio "

The inference engine unit 420 generates a rule base table based on the input variables and the output variables converted in the fuzzification unit 410 and calculates a fuzzy value using the generated rule base table. The rule-based table may be a rule table for fuzzy inference.

The inference engine unit 420 establishes a relation with the fuzzy inference rule by the logical operator AND as shown in Equation (6), based on the membership function converted in the fuzzy unit 410. In particular, the computation of the fitness for input fuzzy sets of input variables and output variables is performed by minimum computation.

Accordingly, the inference engine 420 calculates the inference result of each rule based on the calculated fitness, and calculates the final inference result from the inference result of each rule to generate the fuzzy inference rule table.

The defuzzification unit 430 converts the fuzzy value calculated by the reasoning engine unit 420 into an actual value to calculate the duty ratio at which the fuzzy control is performed.

The de-fuzzification unit 430 uses a center of gravity method for de-fuzzing. That is, the non-fuzzing unit 430 controls the SMR circuit 130 with the duty ratio optimized based on the duty ratio variation obtained through the non-fuzzification as in Equation (8) . ≪ / RTI >

는 최적화 듀티비를 의미한다.
here,

Means the optimum duty ratio.

The storage unit 440 stores a fuzzy inference rule table, which is a rule-based table generated on the basis of the input variables and the output variables converted by the fuzzification unit 410. The storage unit 440 stores the fuzzy value calculated using the predetermined fuzzy inference rule table.

5 is a block diagram illustrating a fuzzy controller according to another embodiment of the present invention.

Referring to FIG. 5, the fuzzy controller 180 performs fuzzy control based on fuzzy inference rules.

The purge control unit 180 receives the reference duty ratio and the system side converter output power. The purge control unit 180 applies the reference duty ratio and the system side converter output power to the reverse impedances 520 and 530 and the adder / subtracter, respectively. The purging control unit 180 calculates a variation value of the reference duty ratio and a variation value of the system side converter output power, respectively.

The fuzzy controller 180 calculates the optimized duty ratio by performing the fuzzy control 540 on the calculated variation values and applies the calculated optimized duty ratio and the reverse impedance 510 to the adder to calculate a duty ratio .

FIG. 6 is a diagram illustrating an input membership function according to an embodiment of the present invention. FIG. 7 is a diagram illustrating an output membership function according to an embodiment of the present invention. Fig. 8 is a diagram illustrating a table of fuzzy inference rules according to the present invention; Particularly, FIG. 6 (a) shows the input belonging function of the output power variation value, and FIG. 6 (b) shows the input belonging function of the duty ratio variation value.

6 to 8, the fuzzy controller 180 fuzes the input membership function and the output membership function.

The fuzzy control unit 180 selects a belonging function as a triangle. The output voltage variation value of the permanent voltage synchronizer 120 which is the difference between the present value and the previous value of the output power of the permanent voltage synchronizer 120 is 7, the duty ratio variation value which is the difference between the present value of the reference duty ratio and the previous value is 5 , The duty ratio at which the fuzzy control, which is the output of the fuzzy controller 180, is performed is selected to have seven fuzzy sets.

It is to be understood that this is merely an embodiment and other embodiments are possible.

와

에 대해 출력

는 35개의 규칙을 갖는다. 즉, 퍼지 제어부(180)는 도 6 및 도 7을 기초로 퍼지추론규칙에 대한 테이블을 생성할 수 있다.
The fuzzy controller 180 generates a table for fuzzy inference rules. The fuzzy controller 180 receives the input

Wow

Output for

Has 35 rules. That is, the fuzzy controller 180 can generate a table for the fuzzy inference rule based on FIGS. 6 and 7. FIG.

9 is a diagram for comparing a fixed step size P & O maximum power point tracking control and a variable step size fuzzy maximum power point tracking control according to an embodiment of the present invention. FIG. 8A shows an example of the fixed step size P & O maximum power point follow-up control proposed in the conventional small wind power system, and FIG. 8B shows an example of the variable step size fuzzy maximum This is an embodiment of power point tracking control.

Referring to FIG. 9, the small wind power system 1 can verify an algorithm for performing maximum power point tracking control by performing fuzzy control through an embodiment.

(Example)

Hereinafter, the present invention will be described more specifically with reference to Examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[Table 1] shows the constants of the wind turbine system, and [Table 2] shows the constants of the permanent magnet synchronous machine and power system.

Here, an embodiment was performed using a PSIM simulator to verify the algorithm of the small wind turbine system (1). The examples were carried out under the conditions of [Table 1] and [Table 2] based on actual experimental constants. In addition, the performance and stability of the fixed step size P & O maximum power point tracking control algorithm and the variable step size fuzzy maximum power point tracking control algorithm are compared and verified.

The embodiment is at an air speed of 9 (m / s), and the switching frequency of the entire system is 10 (kHz).

The results of the embodiment show that both the maximum power point follow-up control method and the maximum power point follow-up control follow the optimum value with a power coefficient of 0.48 and a main speed ratio of 8.1. Also, it can be seen that the duty ratio of the SMR circuit is controlled to the optimum value through the maximum power point tracking control.

However, in the case of fixed step size P & O maximum power point follow-up control, the operation time of the permanent magnet synchronous machine at the maximum power point is about 6 seconds, and the proposed maximum fuzzy maximum power point follow- It can be confirmed that the follow-up time is slow.

10 is a diagram for comparing experiments of fixed step size P & O maximum power point tracking control and variable step size fuzzy maximum power point tracking control according to an embodiment of the present invention. FIG. 9A is an experimental example of the fixed step size P & O maximum power point follow-up control proposed in the conventional small wind power system. FIG. 9B is a graph showing an example of the variable step size fuzzy maximum This is an experimental example of power point tracking control.

Referring to FIG. 10, the small wind turbine system 1 can verify an algorithm for performing maximum power point tracking control by performing fuzzy control through an experimental example.

(Experimental Example)

In order to verify the validity of the algorithm of the small wind power system (1), experiments were conducted based on the constants shown in [Table 1] and [Table 2].

As in the case of the embodiment of FIG. 8, the two systems follow the optimal power factor, the main speed ratio and the duty ratio due to the maximum power point tracking control and can be confirmed to operate at the maximum power point.

However, it can be confirmed that the fixed step size P & O maximum power point follow-up control is about 24 seconds, and the variable step size fuzzy maximum power point follow-up control follows the maximum power point after about 12 seconds.

The small wind turbine system (1) is not complicated in control, and is designed with the highest priority in terms of price and efficiency. In other words, the small wind power generation system (1) can be advantageous in cost competitiveness by using the SMR circuit which does not use the speed sensor and the passive element, and the stability and the response speed can be secured through the fuzzy control.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation in the embodiment in which said invention is directed. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

1: Small Wind Power System 110: Blade
120: permanent magnet synchronizer 130: SMR circuit
140: Capacitor 150: System side converter
160: Three-phase inductor 170: System
180: purge controller 212, 214, 216: three-phase voltage source
222, 224, 226: Three-phase inductor 230: Diode rectifier
240: switch 250: diode
410: purge unit 420: reasoning engine unit
430: non-fuzzification unit 440: storage unit
510, 520, 530: reverse impedance 540: fuzzy logic controller

Claims (9)

A diode rectifier for receiving a three-phase alternating current from the permanent magnet synchronous machine, a switch connected to both ends of the diode rectifier, and a diode connected to one end of the switch, and a switched-mode-rectifier (SMR) circuit. And
A fuzzy controller for performing a fuzzy control based on a difference between a current power value of the permanent magnet synchronous machine and a previous power value of the permanent magnet synchronous machine to vary a duty ratio of the switch to follow a maximum power point; Lt; / RTI >
Wherein the fuzzy controller comprises:
If the difference value is positive and the duty ratio tends to increase, the duty ratio is added to the weight of the variable step size,
If the difference value is positive and the duty ratio tends to decrease, the duty ratio is subtracted from the weight of the variable step size,
Subtracting the weight of the variable step size from the duty ratio if the difference value is negative and the duty ratio tends to increase,
Wherein the weight value of the variable step size is added to the duty ratio when the difference value is negative and the duty ratio tends to decrease.
The method according to claim 1,
The permanent magnet synchronous machine comprising:
Phase boost converter through the internal synchronous impedance of the small wind turbine. The present invention relates to a small-sized wind turbine generator with a sensorless fuzzy maximum power point follow-up control using an SMR circuit.
The method according to claim 1,
Wherein the fuzzy controller comprises:
And the power of the permanent magnet synchronous machine is calculated on the basis of the measured values of the current and voltage output according to the duty ratio.
The method according to claim 1,
Wherein the fuzzy controller comprises:
A fuzzy unit for converting an input variable and an output variable into a membership function;
An inference engine unit for generating a rule base table based on the converted input variables and output variables and calculating a fuzzy value using the generated rule base table; And
And a non-fuzzy unit for converting the calculated fuzzy value into an actual value to calculate a duty ratio on which the fuzzy control is performed. The small wind power generation system according to claim 1, .
5. The method of claim 4,
Wherein the fuzzy controller comprises:
Wherein the duty ratio is controlled so as to generate the maximum power of the permanent magnet synchronous machine so that the weight of the variable step size is added to or subtracted from the duty ratio of the permanent magnet synchronous machine.
delete delete The method according to claim 1,
Wherein the fuzzy controller comprises:
Wherein the maximum point of the characteristic curve is tracked based on a characteristic curve of the turbine and a differential cascade rule while the duty ratio is variable.
A diode rectifier for receiving a three-phase alternating current from the permanent magnet synchronous machine, a switch connected to both ends of the diode rectifier, and a diode connected to one end of the switch, and a switched-mode-rectifier (SMR) circuit. And
A fuzzy controller for performing a fuzzy control based on a difference between a current power value of the permanent magnet synchronous machine and a previous power value of the permanent magnet synchronous machine to vary a duty ratio of the switch to follow a maximum power point; , Wherein the sensorless fuzzy maximum power point follow-up control is performed using an SMR circuit,
Calculating a difference between a current power value of the permanent magnet synchronous machine and a previous power value of the permanent magnet synchronous machine;
And performing fuzzy control based on the calculated difference value to vary the duty ratio of the switch to follow the maximum power point,
Wherein the step of following the maximum power point comprises:
A fuzzy value is calculated using a predetermined rule base based on the converted input variable and the output variable, and the calculated fuzzy value is converted into a membership function, The duty ratio obtained by performing the fuzzy control is calculated,
If the difference value is a positive number and the duty ratio tends to increase, the duty ratio is added to the weight of the variable step size, and if the difference value is positive and the duty ratio tends to decrease, However,
If the difference value is negative and the duty ratio tends to increase, the weight of the variable step size is subtracted from the duty ratio. If the difference value is negative and the duty ratio tends to decrease, Wherein the sensorless fuzzy maximum power point follow-up control is performed using an SMR circuit.

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