JP2009284570A - Compact wind power generation charging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of energy conversion from wind power to electric power. <P>SOLUTION: The system 1a is constituted of: a wind turbine generator 2 of a rated output voltage 24 V which generates three-phase AC power by using a rotor which rotates by receiving wind power under each wind speed, and is constituted so as to be connectable to a 24 V battery via a smoothing circuit; a charging device 4a which charges the generated power of the wind turbine generator 2; and a load 8. The charging device 4a is constituted of: a chopper circuit 11a which increases and decreases a reactor current I2 of a reactor L fed from the wind turbine generator 2 by using a switching element Q which performs switching operation by a PWM drive signal; a reactor current control means 13a which controls the reactor current I2 so as to be increased and decreased by generating the PWM derive signal G; and the battery 21a of the rated charging voltage 24 V which charges the output power of the wind turbine generator 2 via the chopper circuit 11a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a small wind power charging device that charges generated power generated by a small wind power generator, and more particularly to a device capable of following a change in wind speed at high speed.

In a small wind power generation system, since the output of the wind power generator is constantly fluctuating and unstable, the wind power is temporarily charged into a battery, and stable power is supplied from the battery to the load. And as the charging method was disclosed by patent document 1, the method of connecting a wind power generator output to a battery directly after rectification was common.
In this charging method, the output voltage is fixed by the battery (the operating point at a certain wind speed = the number of revolutions is only one point at which the output voltage becomes equal to the battery voltage), and thus deviates from the maximum power point of the wind power generator. There was a problem that the operation at the operating point increased and the efficiency of converting wind energy into electric energy was low.
In addition, in a photovoltaic power generation system, it is common to add a maximum power point tracking function in order to increase energy conversion efficiency. However, a disclosure example of a technology that adds a maximum power point tracking function to a charging device for small wind power generation is as follows. There were very few, and it did not reach the completed technology.

  For example, when the hill-climbing method generally employed in the maximum power point tracking control of the solar power generation system is applied to wind power generation, the following control is performed. In the output characteristic diagrams of the wind power generators in FIGS. 4 (a) and 4 (b), on the higher rotation side than the maximum power point, the power increases when the voltage decreases, and the power decreases when the voltage increases. become. On the low rotation side from the maximum power point, when the voltage increases, the power increases, and when the voltage decreases, the power decreases. Note that the increasing and decreasing trends of voltage and current are always in reverse phase under a constant wind speed. For this reason, it is possible to determine whether the current operating point is on the high rotation side or the low rotation side with respect to the maximum power point by examining the increase / decrease tendency of the voltage and power at regular intervals. The current is increased during the next period, and if the operating point is on the low rotation side, the current is decreased during the next period so that the operating point is always close to the maximum power point.

  In the small wind power generator charging device 44 shown in FIGS. 5A and 5B, the reactor current value of the step-down chopper circuit 51 (or step-up chopper) is controlled (= adjusted) by the reactor current control means 53, so that the maximum power Although a point following function can be added, when the above-described hill-climbing method is applied, the determination cycle has to be made relatively long (for example, about 50 ms) in order to surely determine whether the voltage and power increase or decrease. Further, since the operation becomes unstable if the current change rate is made too fast, it has been necessary to control the current to change slowly.

JP 2000-116007 A

  In the case of this step-down chopper method, the secondary current I2 (reactor current) is controlled so as to maximize the secondary power and the maximum power point tracking control is performed (secondary power because secondary voltage V2 = battery voltage = constant). It can also be said that P2 is controlled). In this control process, the secondary current I2 is increased, the operating point is moved from the high rotation side toward the maximum power point, and after reaching the maximum power point, the current command value is set for the period until the next determination timing. If it becomes larger, the secondary power required by the control device becomes slightly larger than the maximum primary power in the current wind conditions (for example, the maximum power point is V1 = 48V, I1 = 1A, P1 = 48W). (For example, battery voltage 24V, command current I2 = 2.01 A, required secondary power P2 = 48.24 W). At this time, the reactor current control means 53 slightly increases the duty of the drive signal of the switching element Q, and flows the secondary current I2 equal to the secondary current command value m. For this reason, the primary current I1 increases, the primary voltage V1 and the primary power P1 decrease, and the operating point moves slightly to the low rotation side. Although the primary power P1 decreases, the secondary current command value m continues to increase slightly during the same period, so that a cycle in which the duty is further increased is repeated, causing a phenomenon in which the operating point moves to the low speed side at once. There was a case.

  Even if the secondary current command value m started to decrease during this cycle (by the hill-climbing method because of power increase and voltage decrease), it could not be stopped because the amount of change was small. Finally, when the primary-side voltage V1 drops to about the battery voltage, the primary-side voltage V1 is clamped by the battery voltage and becomes a constant voltage and becomes uncontrollable, and this state continues until the control is restored due to changes in wind power, etc. did. Even in this state, charging of the battery is continued. However, in the case of a wind speed at which the power is considerably lower than the maximum power, there is a problem that the energy conversion efficiency decreases during that time.

  In addition, when the wind power suddenly increases, the current changes slowly, so that the voltage suddenly rises as the generator powers up (current and power change slightly), and the operating point deviates significantly from the maximum power point. In addition, there is a problem that the energy conversion efficiency is lowered due to the phenomenon that the high rotation side occurs. When the wind power suddenly weakened, the power decreased due to the voltage drop, and the current command by the hill-climbing method was reduced, so that it was possible to realize good maximum power point tracking control.

  On the other hand, in the case of the step-up chopper method, the primary current (reactor current) I1 is directly controlled so that the primary power (generator output power) P1 is maximized, so that the primary current I1 increases rapidly and the primary voltage V1 as in the step-down chopper method. There is no sudden decline. However, when the wind power suddenly increased, a phenomenon in which the voltage suddenly increased occurred as in the step-down chopper method (current and voltage changes were small during this time). When the input voltage V1 becomes equal to or higher than the battery voltage, the input voltage V1 = battery voltage (constant) and the control becomes impossible, and this state continues until the control recovers due to a change in wind force or the like. Even in this state, charging of the battery is continued, but there is a problem in that the energy conversion efficiency (charging efficiency) is reduced in the case of a wind speed whose power is considerably lower than the maximum power.

  In view of the above problems, an object of the present invention is to provide a small wind power charging device that can improve the energy conversion efficiency from wind power to electric power.

  In order to solve the above-mentioned problem, a small wind power charging apparatus according to the invention of claim 1 is a chopper that increases or decreases the reactor current of a reactor supplied from a small wind power generator by a switching element that performs a switching operation by a predetermined PWM drive signal. A small wind power generator comprising: a circuit; power storage means for charging the output power of the small wind power generator via the chopper circuit; and a reactor current control means for generating the PWM drive signal to control the reactor current to be increased or decreased A charging device, wherein the reactor current control means determines a predetermined amount based on a hill-climbing method from output characteristics obtained by measuring in advance the relationship between the output power of the small wind power generator and the rotational speed of the rotor under each wind speed. Maximum power point tracking for generating a maximum power point tracking control signal for bringing the output power close to the maximum power point for each period. Reactor current command value generation for generating a current command value of the reactor current by adding a control signal generating means and a proportional component signal proportional to the detected output voltage of the small wind power generator to the maximum power point tracking control signal And a drive signal generating means for generating the PWM drive signal based on the generated reactor current command value and the detected reactor current.

  In the small wind power generator charging device according to the invention of claim 2, the maximum power point tracking control signal generating means shows the increasing / decreasing tendency of both values with respect to the detected output voltage and reactor current of the small wind generator. When both the values are determined to be the same increase / decrease by the increase / decrease trend determination means that is determined for each cycle, the negative reference value is output, but it is determined that the values are different. The reference value output switching means for switching so as to output a positive reference value, and the maximum power point tracking control signal by integrating the negative or positive reference value output from the reference value output switching means in the cycle. And a reference value integrating means for outputting as follows.

  According to a third aspect of the invention, the small-sized wind power charging apparatus includes a step-up or step-up chopper circuit, and the maximum power point tracking control signal generation unit includes the increase / decrease tendency determination unit. When at least the output voltage is determined to increase, when the output voltage rises to a preset first set voltage, the output power of the small wind power generator is set to a preset first set power. If below, the positive reference value output from the reference value output switching means is multiplied by a predetermined value and output to the reference value integrating means, while the output voltage is set in advance from the first set voltage. When the voltage drops to a set voltage of 2, the negative or positive reference value output from the reference value output switching means is switched to be output to the reference value integrating means without being multiplied by a predetermined value. Configured with a reference value predetermined multiple switching means.

  According to a fourth aspect of the present invention, there is provided a small wind power charging apparatus in which when the drive signal generating means increases the output voltage to the first set voltage, the output power of the small wind power generator is the first set. If the power is equal to or higher than the power, the switching element is turned off until the power becomes equal to or lower than the second set power.

  The small wind power charging device according to the invention of claim 5 is configured such that a rated charging voltage of the power storage means is larger than a rated output voltage of the small wind power generator.

  According to the first and second aspects of the invention, since the primary voltage component, which is the output voltage of the wind power generator, is added to the control amount, it is possible to control the sudden rise in voltage when the wind speed increases in the chopper circuit, and when the wind speed suddenly rises and falls rapidly The control responsiveness can be improved. Further, it is possible to prevent a sudden drop in voltage when the wind speed is constant in the step-down chopper method. As a result, a small wind power charging device with high control stability can be provided, and if used in a small wind power generation system, the energy conversion efficiency from wind power to electric power can be improved.

  According to the third and fourth aspects of the present invention, the reference value that is switched so that the negative or positive reference value output from the reference value output switching means is output to the reference value integrating means without being multiplied by a predetermined value. Since the predetermined multiple switching means is provided, it is possible to prevent the occurrence of a voltage clamping phenomenon outside the predetermined power range. In particular, according to the fourth aspect of the present invention, it is possible to eliminate the loss associated with the on / off operation of the switching element.

  According to the fifth aspect of the present invention, the power operating point can be brought close to the maximum power point during strong wind, and the charging efficiency of the power storage means can be improved.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings.
FIGS. 1A and 1B are circuit configuration diagrams of a wind power generation system 1a showing an embodiment of a small wind power charging apparatus according to the present invention. The system 1a generates a three-phase AC power by a rotor that rotates by receiving wind power at each wind speed, and is a small wind power generator (hereinafter referred to as a 24V rated output voltage) configured to be directly connected to a 24V battery via a smoothing circuit. 2), a small wind power charging device (hereinafter referred to as a charging device) 4a for charging the power generated by the wind power generator 2, and a load 8.

  The charging device 4a includes a chopper circuit 11a that increases / decreases a reactor current (secondary current) I2 of the reactor L supplied from the wind power generator 2 by a switching element Q that performs a switching operation according to a predetermined PWM drive signal, and a chopper circuit 11a. Reactor current control means 13a for generating an input PWM drive signal G to increase / decrease the reactor current I2 and a rated charge voltage 24V, which is a power storage means for charging the output power of the wind power generator 2 via the chopper circuit 11a. And a battery 21a.

The chopper circuit 11a is a step-down chopper circuit configured by connecting a MOSFET as a switching element Q and a reactor L in series to the positive output stage of the wind power generator 2 and grounding the output side of the switching element Q with a diode D. It is used.
Here, 61 is a voltage sensor for detecting the output voltage (primary voltage) V1 of the wind power generator 2, and 62 is a current sensor for detecting the reactor current (secondary current) I2 of the reactor L.

  As shown in FIG. 1 (b), the reactor current control means 13a is obtained by measuring in advance the relationship between the output power, output voltage, output current of the wind power generator 2 and the rotation speed of the rotor (wind turbine) at each wind speed. Based on the output characteristics (see FIGS. 4A and 4B), a maximum power point following control signal m for generating the output power of the wind power generator 2 close to the maximum power point is generated at predetermined intervals based on the hill-climbing method. And the proportional component signal v proportional to the detected output voltage of the wind power generator 2 is added to the maximum power point tracking control signal m, and the reactor current command value i of the reactor current is obtained. Reactor current command value generation means 17 to be generated, and drive signal generation means 19 to generate a PWM drive signal G of the chopper circuit based on the generated reactor current command value i and the detected reactor current I2. Ete is configured.

  The maximum power point tracking control signal generation means 15a determines the tendency of increase / decrease of both values for each predetermined period with respect to the output voltage V1 and the reactor current I2 of the wind power generator 2 detected by the voltage sensor 61 and the current sensor 62. When both the increase / decrease tendency determination means 23 and the increase / decrease tendency determination means 23 determine that both values have the same increase / decrease trend, a negative reference value (= −b) is output, while the increase / decrease trend is different. If determined, the reference value output switching means 24 for switching to output a positive reference value (= + a) and the negative or positive reference value output from the reference value output switching means 24 are integrated to obtain the maximum power point. Reference value integration means 26 that outputs as a follow-up control signal m is comprised.

  The reactor current command value generating means 17 generates a proportional component signal v proportional to the output voltage V1 of the wind power generator 2 detected by the voltage sensor 61, and the generated proportional component signal v and the maximum output from the preceding stage. The power point tracking control signal m is added and calculated, and adding means 28 is provided for outputting the calculation result as a reactor current command value i of the reactor current I2.

  The drive signal generating means 19 includes an addition / subtraction means 31 for calculating a difference between the reactor current command value i output from the addition means 28 and the reactor current I2, and a calculation for proportional and integral control with respect to the calculation result of the addition / subtraction means 31. And a comparator that compares the operation result of the proportional integration means 32 with a triangular wave having a preset frequency and outputs it as a PWM drive signal G having a predetermined frequency and pulse width that is input to the switching element Q. 33.

  Next, the charging operation by the charging device 4a when charging the output power of the wind power generator 2 directly connected to the 24V battery to the battery 21a having the rated charging voltage 24V in the system 1a having the above configuration will be described.

  In the maximum power point tracking control signal generation means 15a, the increase / decrease tendency determination means 23 shows the increase / decrease tendency of both values for the secondary current I2 (substitute for the secondary power P2) detected by the sensors 61 and 62 and the primary voltage V1. Examined at a fixed period of 50 ms. The reference value output switching means 24 outputs a negative reference value when the increase / decrease tendency determination means 23 determines that the increase / decrease tendency of both values is the same, while the increase / decrease trend is opposite (different). If it is determined, it is switched to output a positive reference value. The reference value integration means 26 obtains the maximum power point tracking control signal m based on the hill-climbing method by inputting the output of the reference value output switching means 24 for the next 50 ms. At this time, m is a signal waveform that changes linearly with respect to the time axis.

  The adding means 28 of the reactor current command value generating means 17 adds the proportional component signal v proportional to the primary voltage V1 to the m obtained in this way, and the reactor current command value (secondary current) which is the current command value of the reactor current. Command value) i is obtained.

  Here, FIG. 2 is a relationship diagram showing the relationship between m, v, and i during control execution in a constant wind force state. Since v has a time delay from m, i does not change linearly. Although m and v are in opposite phases, the ratio of v is set so that the change width of m is larger than v so that m and i are in phase. Further, if the primary voltage V1 is changed due to a change in wind speed or the like, i changes so as to cancel the voltage change due to the addition effect of v, and the control current increases or decreases, but from the first (cause) change amount of the primary voltage V1. However, the ratio of v is set so that the voltage change amount (result) for canceling it becomes larger.

  Next, in the drive signal generation means 19, the addition / subtraction means 31 compares i with the secondary current I2 and calculates the difference, and the proportional integration means 32 calculates the control amount for eliminating the difference, and the output and frequency 15 .6 kHz triangular wave is compared by the comparator 33, and the PWM drive signal G for driving the gate of the switching element Q to set the reactor current I2 to an appropriate value is obtained.

  By configuring the charging device 4a as described above, in the step-down chopper type chopper circuit 11a, even when the secondary current I2 that is larger than the primary power flows and the primary voltage V1 is slightly decreased, This is reflected in the next control cycle (the control period is 50 μs to 100 μs), the reactor current command value i decreases to a value sufficient to cancel the voltage change, and the drive signal generating means 19 responds immediately and the secondary current I2 Since the voltage starts to decrease, the rapid change of the voltage is suppressed, so that the phenomenon that the operating point rapidly moves to the low rotation side can be avoided.

  Further, in the chopper circuit 11a, when the wind force suddenly becomes strong, the sudden change of the primary voltage V1 is suppressed by the additional effect of v. Therefore, first, the operation of increasing the reactor current I2 and increasing the power starts ( When the primary voltage V1 continues to decrease), the increase in power is limited due to the voltage decrease. When the power finally starts decreasing, this is detected in the next judgment cycle, and m begins to decrease, and the reactor current I2 decreases. The electric power increases (the primary voltage V1 continues to increase during this time). Eventually, the increase in power is limited due to the decrease in current, and when the power finally starts decreasing, this is detected in the next judgment cycle, m starts increasing, and the reactor current I2 is increased again to increase the power. . As a result, it is possible to realize an operation of substantially following the maximum power point of the wind power generator 2 at each time point while avoiding a sudden increase in voltage.

  Note that when wind power is strengthened, it is ideal that the voltage and current increase at the same time to increase the power, but in the maximum power point tracking control of the above configuration, the current increase operation when the power increases due to the voltage decrease, This is not possible because the current decreases when the voltage increases and the power increases. However, when the wind power changes drastically and the wind power generator 2 rapidly shifts to a high output state, the voltage and current increase at the same time, so the maximum power point tracking operation is close to ideal.

  Next, another embodiment of the present invention will be described. FIG. 3 is a circuit configuration diagram of a wind power generation system showing another embodiment of the small wind power charging device according to the present invention. Similar to the system 1a of FIG. 1, the system 1b includes a wind power generator 2 for direct connection to a 24V battery, a charging device 4b for charging the generated power, and a load 8.

When the configuration of the charging device 4b is compared with that of the charging device 4a of FIG. 1, the following points are mainly different.
(1) As a chopper circuit 11b, a step-up chopper configured by connecting a reactor L and a diode D in series to the positive output stage of the wind power generator 2 and grounding the output side of the reactor L with a MOSFET as a switching element Q The point where the circuit is used.
Here, the chopper circuit 11b is configured to increase or decrease the reactor current I1 of the reactor L supplied from the wind power generator 2 by the switching element Q that performs a switching operation by a predetermined PWM drive signal.
(2) As the reactor current control means 13b, when the maximum power point tracking control signal generation means 15b determines that the output voltage V1 is increasing at least by the increase / decrease tendency determination means 23, the output voltage V1 is preset. If the output power P1 of the wind power generator 2 is equal to or lower than the preset first set power when the voltage rises to 1, the positive reference value output from the reference value output switching means 24 is multiplied by a predetermined value. While outputting to the reference value integrating means 26, when the output voltage V1 drops from the first set voltage to the preset second set voltage, the negative or positive reference value output from the reference value output switching means 24 is used. A reference value predetermined multiple switching unit 25 that switches to output to the reference value integrating unit 26 without performing a predetermined multiplication.
(3) The power storage means is a battery 21b having a rated charging voltage 48V that is approximately twice the rated output voltage of the wind power generator 2.
(4) The output power P1 is an output power calculation means 37 comprising a multiplication means 35 for multiplying the output voltage V1 and the reactor current I1, and a low-pass filter 36 which is a filtering means for filtering a predetermined frequency component contained in the multiplication result signal. The point computed by.

  The other structure of the charging device 4b is the same as that of the charging device 4a, and description thereof is omitted. Here, 63 is a current sensor for detecting the reactor current (primary current) I1 of the reactor L.

  By configuring the charging device 4b as described above, even in the step-up chopper type chopper circuit 11b, when the wind power suddenly becomes strong, the response is the same as that in the step-down chopper type, and therefore, a sudden increase in the output voltage V1 is avoided. However, it is possible to realize an operation that substantially follows the maximum power point of the wind power generator 2 at each time point.

  However, in the charging device 4a of FIG. 1, the wind power suddenly increases and the output power is increased by repeatedly increasing the secondary current I2 (decreasing the primary voltage V1) and decreasing the secondary current I2 (rising the primary voltage V1). Thus, in the secondary current I2 reduction (primary voltage V1 rise) mode, the primary voltage V1 rises above the rated charging voltage (= 24V) of the battery 21a, and the primary voltage V1 is clamped at the rated charging voltage of the battery 21a. The problem of the prior art cannot be completely solved by only adding the component v proportional to the primary voltage V1.

  For this reason, the reference value predetermined multiple switching means 25 is added as a voltage clamp prevention means to the step-up chopper type chopper circuit 11b to avoid the occurrence of the voltage clamp phenomenon when the wind power is not so strong and the generated power is low. Like to do.

  The voltage clamp avoiding operation by the reference value predetermined multiple switching means 25 is performed as follows. When the primary voltage V1 rises to the first set voltage (for example, 48V), if the primary power P1 is equal to or less than the first set power (for example, 40W), the maximum power point tracking control is stopped and the reference value integrating means 26, by inputting a positive reference value (= + A) several times the positive reference value and increasing the power point tracking control signal m rapidly, the primary current I1 is rapidly increased and the primary voltage V1 is rapidly decreased. When the primary voltage V1 drops to the second set voltage (for example, 40V), the normal maximum power point tracking control is restored.

  If the primary power P1 when the primary voltage V1 rises to the first set voltage (= 48V) is equal to or higher than the first set power (= 40W), the drive signal is generated so that the switching element Q is turned off. The PWM drive signal output from the means 19 is adjusted (or the output is stopped), and the operation is switched to the operation of directly charging the wind power generator 2 with the battery 21b until the primary power P1 becomes equal to or lower than the second set power (for example, 35 W). This state is maintained, and when the primary power P1 decreases to the second set power (= 35 W), the normal maximum power point tracking control is restored.

  This operation is to directly charge the battery according to the prior art when the wind is strong. However, since the rated charging voltage is larger than the rated output voltage of the wind power generator 2, the battery 21b having a rated charging voltage twice that of the wind generator 2 is charged. Combined with the point where the operating point is close to the maximum power point during strong wind and the loss of the switching element Q becomes zero, energy conversion with high efficiency can be realized.

  According to the configuration in this case, the reference value predetermined multiple switching means for switching so that the negative or positive reference value output from the reference value output switching means 24 is output to the reference value integrating means 26 without being multiplied by a predetermined value. 25, the occurrence of the voltage clamping phenomenon outside the predetermined power range can be prevented. In particular, when the output voltage V1 rises to 48V, which is the same as the battery 21b, if the output power P1 of the wind power generator 2 is 40 W or more, the switching element Q is turned off until it becomes 35 W or less. Loss associated with can be eliminated.

  Further, since the battery 21b having a rated charging voltage 48V that is larger than the rated output voltage 24V of the wind power generator 2 and almost twice that of the wind power generator 2 is provided, the power operating point can be brought close to the maximum power point in a strong wind. The charging efficiency of 21b can be improved.

In addition, this invention is not limited to the said embodiment, As shown below, it is also possible to change suitably the shape and structure of each part in the range which does not deviate from the meaning of this invention.
(1) The wind power generator may have a rated output voltage other than 24V.
(2) When the rated charging voltage of the battery is made larger than the rated output voltage of the wind power generator, it is not limited to twice, and may be a value indicated by other multiples.
(3) The reactor current control means is not limited to software, and may be configured entirely or partially by hardware.
(4) The filter is not limited to a low pass, and may be a high pass or a band pass.
(5) The chopper circuit only needs to include at least one of the step-down or step-up chopper circuit, and can be configured by providing both circuits.

One Embodiment of the small wind power generator charging device which concerns on this invention is shown, (a) is a circuit block diagram of a wind power generation system, (b) is a circuit block diagram of a reactor current control means. It is a relationship figure which shows the relationship of m, v, i during control execution in a wind force constant state. . 2 shows another embodiment of a small wind power charging device according to the present invention, where (a) is a circuit configuration diagram of a wind power generation system, (b) is a circuit configuration diagram of a reactor current control means, and (c) is an output power calculation means. FIG. The output characteristics of the wind power generator under each wind speed are shown. (A) is an output voltage-windmill rotational speed characteristic chart, and (b) is an output voltage / current-windmill rotational speed characteristic chart. One Embodiment of the conventional small wind power generator charging device is shown, (a) is a circuit block diagram of a wind power generation system, (b) is a circuit block diagram of a reactor current control means.

Explanation of symbols

  1a, 1b ... wind power generation system, 2. wind power generator, 4a, 4b ... charging device, 8 ... load, 11a, 11b ... chopper circuit, 13a, 13b ... reactor current control means, 15a, 15b ..Maximum power point tracking control signal generation means, 17 ... Reactor current command value generation means, 19 ... Drive signal generation means, 21a, 21b ... Battery, 23 ... Increase / decrease tendency judgment means, 24 ... Reference value output Switching means 25... Reference value predetermined multiplication switching means 26.. Reference value integration means 28.. Addition means 31.. Addition and subtraction means 32.. Proportional integration means 33 33 Comparator 35. 36 .... Filtering means 37 ... Output power calculation means 61 ... Voltage sensor 62,63 ... Current sensor D ... Diode L ... Reactor Q ... Switching element.

Claims (5)

A chopper circuit that increases or decreases the reactor current of the reactor supplied from the small wind power generator by a switching element that performs a switching operation according to a predetermined PWM drive signal, and an electric storage that charges the output power of the small wind power generator via the chopper circuit A small wind power charging apparatus comprising: and a reactor current control unit that generates and generates the PWM drive signal to control the reactor current to increase or decrease,
The reactor current control means is
Based on the output characteristics obtained by measuring the output power of the small wind power generator and the rotational speed of the rotor under each wind speed in advance, the output power is brought close to the maximum power point at predetermined intervals based on the hill-climbing method. Maximum power point tracking control signal generating means for generating a maximum power point tracking control signal of
A reactor current command value generating means for generating a current command value of the reactor current by adding a proportional component signal proportional to the detected output voltage of the small wind power generator to the maximum power point tracking control signal;
Drive signal generation means for generating the PWM drive signal based on the generated reactor current command value and the detected reactor current;
A small wind power charging device characterized by that. The maximum power point tracking control signal generating means is
With respect to the detected output voltage and reactor current of the small wind power generator, an increase / decrease tendency determination means for determining an increase / decrease tendency of both values for each cycle,
When both of the values are determined to be the same increase / decrease trend by the increase / decrease trend determining means, a negative reference value is output, whereas when it is determined that the values are different increase / decrease trends, a positive reference value is output. Reference value output switching means for switching to,
A reference value integration means for integrating the negative or positive reference value output from the reference value output switching means in the cycle and outputting it as the maximum power point tracking control signal.
The small wind power charging device according to claim 1. The chopper circuit has at least a step-up chopper circuit among step-down or step-up chopper circuits,
The maximum power point tracking control signal generating means is
When the increase / decrease tendency determination means determines that at least the output voltage is increasing, when the output voltage rises to a preset first set voltage, the output power of the small wind power generator is preset. If it is less than or equal to the first set power, the positive reference value output from the reference value output switching means is multiplied by a predetermined value and output to the reference value integrating means,
When the output voltage drops from the first set voltage to a preset second set voltage, the reference value without multiplying the negative or positive reference value output from the reference value output switching means by a predetermined value. A reference value predetermined multiple switching means for switching to output to the integrating means,
The small wind power charging device according to claim 2. The drive signal generation means includes
When the output voltage rises to the first set voltage, if the output power of the small wind power generator is equal to or higher than the first set power, the switching element is turned off until it becomes equal to or lower than the second set power. ,
The small wind power charging device according to claim 3. The power storage means is
The rated charging voltage is larger than the rated output voltage of the small wind power generator,
The small wind power charging device according to any one of claims 1 to 4.

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