JP6048173B2 - Maximum power point tracking control device, maximum power point tracking control method, and photovoltaic power generation system - Google Patents

Description

  The present invention relates to an apparatus and method for maximum power point tracking control that draws the current maximum power based on the output of a photovoltaic power generation panel.

  The output characteristics of the photovoltaic power generation panel change depending on the amount of solar radiation. Maximum power point tracking control (MPPT control) is performed by a power converter such as a DC / DC converter so that the power generation capability of such a solar power generation panel is always maximized at that time (for example, (See Patent Documents 1 and 2.)

  In such MPPT (Maximum Power Point Tracking) control, the operating point on the output characteristics is moved little by little on the voltage side to see whether the power increases or decreases. Then, the maximum power point is searched by changing the voltage in the direction in which the power increases. In the vicinity of the maximum power point, the amount of change in voltage is reduced to search for the maximum power point with high accuracy. When passing through the maximum power point, the change in power changes from increasing to decreasing. Therefore, by detecting this and reversing the direction of change, it is prevented from leaving the maximum power point.

JP-A-6-83465 (Claim 1) Japanese Patent No. 2804718 (Claim 1)

However, in the conventional MPPT control as described above, two elements of voltage and current are necessary for the calculation of electric power for detecting the variation of the solar radiation amount. May be larger. In such a case, even if the amount of solar radiation changes in the vicinity of the maximum power point, a change in power cannot be detected, and finding a new maximum power point is delayed.
In view of such conventional problems, an object of the present invention is to realize MPPT control that is less susceptible to noise and that quickly captures the maximum power point even when the amount of solar radiation changes.

  (1) The present invention is a maximum power point tracking control device that draws the current maximum power based on the output of the photovoltaic power generation panel, the power converter connected to the photovoltaic power generation panel, and the power A control unit that controls the converter, and the control unit is capable of coarse adjustment and fine adjustment according to the step width for changing the current flowing through the power converter, and approaches the maximum power point by the coarse adjustment. When the voltage change with respect to the current change exceeds a threshold value, the maximum power point is captured by fine adjustment, and when the voltage value exceeds the threshold value by fine adjustment, the coarse adjustment is restored.

  In the maximum power point tracking control device configured as described above, the switching timing of the coarse adjustment / fine adjustment can be determined only by whether or not the voltage change exceeds the threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner. In addition, if the amount of solar radiation is constant, the voltage change does not exceed the threshold when entering fine adjustment, but if the threshold is exceeded again due to change in the amount of solar radiation, the adjustment returns to rough adjustment and the characteristic after the change in solar radiation is reached. The maximum power point can be approached quickly. In this way, the maximum power point can always be captured at high speed.

(2) Also, in the maximum power point tracking control device of (1) above, when the amount of solar radiation suddenly decreases, the voltage corresponding to the current at the current characteristic falls below a predetermined value. Voltage control may be performed using the voltage at the maximum power point as a target value, and current control may be performed so that the current corresponding to the voltage approaches the maximum power point.
When the amount of solar radiation decreases rapidly, if the maximum power point tracking control is restarted from the beginning, it will take time to reach the maximum power point. However, if the voltage is controlled so that it becomes the voltage at the previous maximum power point and the current corresponding to it is approached to the maximum power point, the maximum power point can be set more quickly even if the amount of solar radiation decreases rapidly. Can be caught.

(3) Moreover, the solar power generation system of this invention is equipped with a solar power generation panel and the maximum power point tracking apparatus of said (1).
Since such a solar power generation system is excellent in maximum power point tracking performance, power generation efficiency is improved.

  (4) On the other hand, the present invention is a maximum power point tracking control method for extracting the current maximum power by controlling the power converter connected to the photovoltaic power generation panel by the control unit, and the control unit includes: , Coarse adjustment and fine adjustment are possible by the magnitude of the step width for changing the current flowing through the power converter, and when the maximum power point is approached by the coarse adjustment and the change in voltage with respect to the change in current exceeds a threshold value, The maximum power point is captured by fine adjustment, and on the other hand, when the threshold is exceeded by fine adjustment, the adjustment returns to coarse adjustment.

  In the maximum power point tracking control method as described above, the switching timing of the coarse adjustment / fine adjustment can be determined only by whether or not the voltage change exceeds the threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner. In addition, if the amount of solar radiation is constant, the voltage change does not exceed the threshold when entering fine adjustment, but if the threshold is exceeded again due to change in the amount of solar radiation, the adjustment returns to rough adjustment and the characteristic after the change in solar radiation is reached. The maximum power point can be approached quickly. In this way, the maximum power point can always be captured at high speed.

  (5) On the other hand, the present invention is a maximum power point tracking control device that draws the current maximum power based on the output of the photovoltaic power generation panel, and a power converter connected to the photovoltaic power generation panel; A control unit for controlling the power converter, the control unit is capable of coarse adjustment and fine adjustment according to the step width for changing the input voltage to the power converter, The maximum power point is captured by fine adjustment when the current change with respect to the change in the input voltage exceeds a threshold value, and the coarse adjustment is returned when the threshold value is exceeded by fine adjustment. .

  In the maximum power point tracking control device configured as described above, it is possible to determine the timing of switching between coarse adjustment / fine adjustment only based on whether or not the change in current exceeds a threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner. In addition, if the amount of solar radiation is constant, the change in current will not exceed the threshold when fine adjustment is entered, but if the threshold is exceeded again due to a change in the amount of solar radiation, the adjustment will return to rough adjustment and The maximum power point can be approached quickly. In this way, the maximum power point can always be captured at high speed.

(6) Moreover, the solar power generation system of this invention is equipped with a solar power generation panel and the maximum power point tracking apparatus of said (5).
Since such a solar power generation system is excellent in maximum power point tracking performance, power generation efficiency is improved.

  (7) Moreover, this invention is the maximum electric power point tracking control method which draws out the maximum electric power at this time by controlling the power converter connected to the photovoltaic power generation panel by a control part, Comprising: The said control part is , Coarse adjustment and fine adjustment are possible depending on the step width to change the input voltage to the power converter, the coarse adjustment makes it approach the maximum power point, and the change of the current with respect to the change of the input voltage sets the threshold value. When it exceeds, the maximum power point is captured by fine adjustment, and when it exceeds the threshold value by fine adjustment, it returns to coarse adjustment.

  In the maximum power point tracking control method as described in (7) above, the switching timing of the coarse adjustment / fine adjustment can be determined only by whether or not the change in current exceeds the threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner. In addition, if the amount of solar radiation is constant, the change in current will not exceed the threshold when fine adjustment is entered, but if the threshold is exceeded again due to a change in the amount of solar radiation, the adjustment will return to rough adjustment and The maximum power point can be approached quickly. In this way, the maximum power point can always be captured at high speed.

  According to the maximum power point tracking control device and the maximum power point tracking control method of the present invention, it is possible to realize MPPT control that is less susceptible to noise and that quickly captures the maximum power point even when the amount of solar radiation changes. Moreover, if such a maximum power point tracking control apparatus is provided in a solar power generation system, it contributes to the improvement of power generation efficiency.

It is a connection diagram of a photovoltaic power generation system including a maximum power point tracking control device according to an embodiment of the present invention. It is a flowchart which shows operation | movement of MPPT control (current control) performed by a control part. It is a graph which shows the output which can be drawn out from a photovoltaic power generation panel in a fixed amount of solar radiation by the relationship between a voltage and an electric current. It is a graph when the amount of solar radiation changes a little from the graph shown with a dashed-two dotted line, (a) has shown the case where the amount of solar radiation increases, (b) has each shown the case where the amount of solar radiation decreases. It is a graph when the amount of solar radiation decreases rapidly. It is a flowchart which shows operation | movement of MPPT control (voltage control) performed by a control part. It is a graph when the amount of solar radiation changes a little from the graph shown with a dashed-two dotted line, (a) has shown the case where the amount of solar radiation increases, (b) has each shown the case where the amount of solar radiation decreases.

  FIG. 1 is a connection diagram of a photovoltaic power generation system 100 including a maximum power point tracking control device 10 according to an embodiment of the present invention. In the figure, a photovoltaic power generation system 100 supplies power to a load 4 from a photovoltaic power generation panel 1 via a DC / DC converter 2 as a power converter and an inverter 3 that performs conversion from direct current to alternating current. Can do.

  Switching control of the DC / DC converter 2 and the inverter 3 is performed by the control unit 5. The voltage output from the photovoltaic power generation panel 1, that is, the input voltage to the DC / DC converter 2 is input to the control unit 5 as voltage information. Further, the current output from the photovoltaic power generation panel 1, that is, the input current to the DC / DC converter 2, is detected by the current sensor 6, and is input to the control unit 5 as current information.

<< MPPT control by current control >>
FIG. 2 is a flowchart showing an MPPT control operation (also a maximum power point tracking control method) executed by the control unit 5. First, the control unit 5 calculates the current power P based on the input voltage and current (step S1), and performs counter addition (step S2). This counter counts the number of electric powers P obtained for averaging later. Next, the control part 5 determines whether the count value of a counter is a predetermined value (step S3). Here, if it is assumed to be a predetermined value, for example, the control unit 5 obtains an average value P _ave (I _i ) for a predetermined number of powers P (step S4).

Next, the control unit 5 determines whether or not the average value P _ave (I _i ) is larger than the maximum value P _max stored so far (step S5). Here, for example, the average value _P ave _{(I i)} is, when greater than the maximum value _{P max,} the maximum value _{P max,} is updated to the latest average value _P ave _{(I i)} (step S6). Subsequently, the control unit 5 checks whether or not the flag (Flag_on) is 0 (step S7). This flag is for viewing the direction history. If it is 0, the immediately preceding current is increasing, and if it is not 0, the immediately preceding current is decreasing. Therefore, if it is 0, the controller 5 adds the next current I _{i + 1} with the step width dI (step S15). If it is not 0, the controller 5 subtracts the next current I _{i + 1} by the step width dI (step S8). There are two types of values for the step width dI: coarse adjustment for large values and fine adjustment for small values.

On the other hand, if the average value P _ave (I _i ) is equal to or less than the maximum value P _max in step S5, the maximum value P _max is left as the previous value (P _max ) (step S10). Subsequently, the control section 5, the average value _P ave _{(I i) is} whether the apparent to _{P max} small, to see if slight variations about a the maximum value _{P max} for the coefficient _{K R} (for example, 0. 98) It is determined whether or not the average value P _ave (I _i ) is smaller than the value multiplied by (step S11). If this determination result is yes, it is understood that the maximum power point has been passed, so the direction of current change is reversed (step S13), and if no, the direction is maintained (step S12). Subsequently, the control unit 5 checks whether or not the flag (Flag_on) is 0 (step S14). If 0, the controller 5 adds the next current I _{i + 1} with the step width dI (step S15). If it is not 0, the controller 5 subtracts the next current I _{i + 1} by the step width dI (step S8).

  Next, the control part 5 determines whether the variation | change_quantity of the voltage (denoted as PV voltage) which the photovoltaic power generation panel 1 outputs is more than a threshold value (step S9). If it is less than the threshold value, the process returns to step S1. If it is equal to or greater than the threshold value, the control unit 5 determines whether or not the amount of solar radiation has sharply decreased depending on whether or not the amount of change is a sharp decrease level that greatly exceeds the threshold value (step S16). If not suddenly decreased, the controller 5 determines whether coarse adjustment or fine adjustment is being performed (step S17). When the step width dI is a larger value, coarse adjustment is being performed. At this time, the control unit 5 sets the step width dI to a smaller value (step S18). When the step width dI is a smaller value, that is, when fine adjustment is being performed, the control unit 5 sets the step width dI to a larger value (step S19).

On the other hand, if the amount of change is less than the threshold value in step S9, the process returns to step S1. When the counter does not reach the predetermined value in step S3, the process proceeds to step S9, and the control unit 5 determines whether or not the amount of change in the voltage output from the photovoltaic power generation panel 1 is equal to or greater than a threshold value. If it is less than the threshold value, the process returns to step S1. If the amount of change in voltage is greater than or equal to the threshold value in step S9, the processes in steps S16 to S19 described above are performed. The process from step S16 to step S20 will be described later.
Next, a specific description will be given while comparing the flowchart and the graph.

FIG. 3 is a graph showing the output that can be extracted from the photovoltaic power generation panel 1 in a certain amount of solar radiation in relation to voltage and current. The voltage and current are also an input voltage and an input current (current flowing through the DC / DC converter 2) to the DC / DC converter 2, respectively. For example, when the current is I _1, the voltage is V ₁ , and when the current is I ₂ , the voltage is V ₂ . Supposing the maximum power point is P, the maximum power is V _P · I _P. When the current is gradually increased from 0 by a constant step width dI by controlling the switching of the DC / DC converter 2 (PWM control), the voltage change amount dV with respect to dI gradually increases. First, coarse adjustment is performed, and the value of dI is set to a larger value. Then, the amount of change dV _th at the position estimated to have approached the maximum power point P to some extent is set as a threshold value. This threshold is mainly based on experience values. When the voltage change amount is equal to or greater than the threshold value (step S9), the current step width dI is set to a smaller value to make a fine adjustment state (step S18).

  If the amount of solar radiation is constant, when fine adjustment is started, the voltage change amount dV with respect to dI does not exceed the threshold value, and the fine adjustment state is maintained. Then, when the maximum power point is passed, the direction is reversed and returned, and when it is returned too much, the direction is reversed again (steps S1 to S15). Thus, control is performed so as to move back and forth between the maximum power points without leaving the maximum power point. Thus, the state where the maximum power point is captured is substantially maintained.

On the other hand, FIG. 4 is a graph when the amount of solar radiation changes slightly from the graph shown by a dashed-two dotted line, (a) shows the case where the amount of solar radiation increases, (b) shows the case where the amount of solar radiation decreases, respectively. Show. In (a), when the position of the current I ₂ and voltage V ₂ on the two-dot chain line changes to the characteristic indicated by the solid line, the position of the current I ₂ and voltage V _x is obtained, and the amount of voltage change (V _x −V ₂ ). Exceeds the threshold. Accordingly, the MPPT control is changed from fine adjustment to rough adjustment (steps S9, S17, S19). Thus, on the new characteristics, the maximum power point is approached at high speed by coarse adjustment. When the amount of change in voltage again becomes equal to or greater than the threshold, the MPPT control is changed to fine adjustment (steps S9, S17, S18).

In the case of FIG. 4B, when the current I ₂ and the voltage V ₂ on the two-dot chain line change from the position indicated by the solid line, the current I ₂ and the voltage V _y become positions, and the voltage change amount ( V ₂ -V _y) becomes equal to or higher than the threshold. Accordingly, the MPPT control is changed from fine adjustment to rough adjustment (steps S9, S17, S19). Thus, on the new characteristics, the maximum power point is approached at high speed by coarse adjustment. Then, when the amount of change in voltage becomes equal to or greater than the threshold value again, the MPPT control changes to fine adjustment (steps S9, S17, S18).

  As described above, in the maximum power point tracking control device (or control method) described above, the switching timing of the coarse adjustment / fine adjustment can be determined only by whether or not the voltage change exceeds the threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner.

In addition, if the amount of solar radiation is constant, the voltage change does not exceed the threshold when the MPPT control enters fine adjustment, but if the threshold is exceeded again due to the change in the amount of solar radiation, the MPPT control returns to the coarse adjustment. It is possible to quickly approach the maximum power point in the characteristics after the change in solar radiation. In this way, the maximum power point can always be captured at high speed.
Moreover, since the solar power generation system 100 equipped with such a maximum power point tracking device 10 is excellent in the maximum power point tracking performance, the power generation efficiency is improved.

FIG. 5 is a graph when the amount of solar radiation decreases rapidly. In the figure, if the immediately preceding position is, for example, the current I ₂ and the voltage V ₂ and is almost the maximum power point, the voltage value corresponding to the current I ₂ does not exist on the new graph due to the sudden decrease in the amount of solar radiation. The voltage becomes zero. Thus, when the amount of solar radiation decreases rapidly and the voltage corresponding to the current current falls below a predetermined value (for example, 0), the voltage at the previous maximum power point is targeted. Voltage control is performed as a value (step S20), and current control is performed so as to approach the maximum power point from the current _Iz corresponding to the voltage.

  When the amount of solar radiation decreases rapidly, if the MPPT control is restarted from the beginning, it takes time to reach the maximum power point. However, if the voltage is controlled so that it becomes the voltage at the previous maximum power point and the current corresponding to it is approached to the maximum power point, the maximum power point can be set more quickly even if the amount of solar radiation decreases rapidly. Can be caught.

<< MPPT control by voltage control >>
Next, MPPT control by voltage control, which is different from the above, will be described with reference to FIGS.
FIG. 6 is a flowchart showing an MPPT control operation (also a maximum power point tracking control method) executed by the control unit 5. First, the control unit 5 calculates the current power P based on the input voltage and current (step S1), and performs counter addition (step S2). This counter counts the number of electric powers P obtained for averaging later. Next, the control part 5 determines whether the count value of a counter is a predetermined value (step S3). Here, if it is assumed to be a predetermined value, for example, the control unit 5 obtains an average value P _ave (V _i ) of the predetermined number of powers P (step S4).

Next, the control unit 5 determines whether or not the average value P _ave (V _i ) is larger than the maximum value P _max stored so far (step S5). Here, for example, the average value _P ave _{(V i)} is, when greater than the maximum value _{P max,} the maximum value _{P max,} is updated to the latest average value _P ave _{(V i)} (Step S6). Subsequently, the control unit 5 checks whether or not the flag (Flag_on) is 0 (step S7). This flag is for viewing the direction history. If it is 0, the immediately preceding voltage is increasing, and if it is not 0, the immediately preceding voltage is decreasing. Therefore, if 0, the control unit 5 adds the next voltage V _{i + 1} with the step width dV (step S15). If it is not 0, the controller 5 subtracts the next voltage V _{i + 1} by the step width dV (step S8). There are two types of values for the step width dV: coarse adjustment for large values and fine adjustment for small values.

On the other hand, if the average value P _ave (V _i ) is equal to or less than the maximum value P _max in step S5, the maximum value P _max is left as the previous value (P _max ) (step S10). Subsequently, the control section 5, the average value _P ave _{(V i) is} whether the apparent to _{P max} small, to see if slight variations about a the maximum value _{P max} for the coefficient _{K R} (for example, 0. 98) It is determined whether or not the average value P _ave (V _i ) is smaller than the value multiplied by (step S11). If the determination result is yes, it is understood that the maximum power point has been passed, so the direction of voltage change is reversed (step S13), and if no, the direction is maintained (step S12). Subsequently, the control unit 5 checks whether or not the flag (Flag_on) is 0 (step S14). If 0, the control unit 5 adds the next voltage V _{i + 1} with the step width dV (step S15). If it is not 0, the controller 5 subtracts the next voltage V _{i + 1} by the step width dV (step S8).

  Next, the control part 5 determines whether the variation | change_quantity of the electric current which the solar power generation panel 1 outputs is more than a threshold value (step S9). If it is less than the threshold value, the process returns to step S1. If it is equal to or greater than the threshold value, the control unit 5 determines whether coarse adjustment or fine adjustment is being performed (step S17). When the step width dV is a larger value, coarse adjustment is being performed. At this time, the control unit 5 sets the step width dV to a smaller value (step S18). When the step width dV is a smaller value, that is, during fine adjustment, the control unit 5 sets the step width dV to a larger value (step S19).

On the other hand, if the amount of change is less than the threshold value in step S9, the process returns to step S1. When the counter does not reach the predetermined value in step S3, the process proceeds to step S9, and the control unit 5 determines whether or not the amount of change in the current output from the solar power generation panel 1 is equal to or greater than the threshold value. If it is less than the threshold value, the process returns to step S1. If the amount of change in current is greater than or equal to the threshold value in step S9, the processes in steps S17 to S19 described above are performed.
Next, a specific description will be given while comparing the flowchart and the graph.

FIG. 3 (the same diagram as in the case of current control) is a graph showing the output that can be extracted from the photovoltaic power generation panel 1 in a certain amount of solar radiation in relation to voltage and current. The voltage and current are also an input voltage and an input current (current flowing through the DC / DC converter 2) to the DC / DC converter 2, respectively. For example, when the voltage is V _1, the current is I ₁ , and when the voltage is V ₂ , the current is I ₂ . Supposing the maximum power point is P, the maximum power is V _P · I _P. When the voltage is gradually increased from 0 by a constant step width dV by controlling the switching of the DC / DC converter 2 (PWM control), the current change amount dI with respect to dV gradually increases. First, coarse adjustment is performed, and the value of dV is set to the larger value. Then, the amount of change dI _th at the position estimated to have approached the maximum power point P to some extent is set as a threshold value. This threshold is mainly based on experience values. When the amount of change in current becomes equal to or greater than the threshold value (step S9), the voltage step width dV is set to a smaller value to enter a fine adjustment state (step S18).

  If the amount of solar radiation is constant, when the fine adjustment is started, the current change amount dI with respect to dV does not exceed the threshold value, and the fine adjustment state is maintained. Then, when the maximum power point is passed, the direction is reversed and returned, and when it is returned too much, the direction is reversed again (steps S1 to S15). Thus, control is performed so as to move back and forth between the maximum power points without leaving the maximum power point. Thus, the state where the maximum power point is captured is substantially maintained.

On the other hand, FIG. 7 is a graph when the amount of solar radiation slightly changes from the graph indicated by the two-dot chain line, (a) shows a case where the amount of solar radiation increases, and (b) shows a case where the amount of solar radiation decreases, Show. In (a), when the position of the voltage V ₂ and current I ₂ on the two-dot chain line changes to the characteristic indicated by the solid line, the position of the voltage V ₂ and current I _x is obtained, and the amount of change in current (I _x −I ₂ ). Becomes greater than or equal to the threshold. Accordingly, the MPPT control is changed from fine adjustment to rough adjustment (steps S9, S17, S19). Thus, on the new characteristics, the maximum power point is approached at high speed by coarse adjustment. Then, when the amount of change in current again becomes equal to or greater than the threshold value, the MPPT control is changed to fine adjustment (steps S9, S17, S18).

In the case of FIG. 7B, when the position of the voltage V ₂ and current I ₂ on the two-dot chain line changes to the characteristic indicated by the solid line, the position of the voltage V ₂ and current I _y is obtained, and the amount of change in current ( I ₂ −I _y ) is greater than or equal to the threshold value. Accordingly, the MPPT control is changed from fine adjustment to rough adjustment (steps S9, S17, S19). Thus, on the new characteristics, the maximum power point is approached at high speed by coarse adjustment. Then, when the amount of change in voltage becomes equal to or greater than the threshold value again, the MPPT control changes to fine adjustment (steps S9, S17, S18).

  As described above, in the maximum power point tracking control device (or control method) described above, the switching timing of the coarse adjustment / fine adjustment can be determined only by whether or not the change in current exceeds the threshold value. That is, since the amount to be determined is one, it is hardly affected by noise, and accurate determination is possible. Therefore, switching can be performed in a timely manner.

In addition, if the amount of solar radiation is constant, the change in the current does not exceed the threshold when the MPPT control enters fine adjustment, but if the threshold is exceeded again due to the change in the amount of solar radiation, the MPPT control returns to the coarse adjustment. It is possible to quickly approach the maximum power point in the characteristics after the change in solar radiation. In this way, the maximum power point can always be captured at high speed.
Moreover, since the solar power generation system 100 equipped with such a maximum power point tracking device 10 is excellent in the maximum power point tracking performance, the power generation efficiency is improved.

  According to the voltage control as described above, when the amount of solar radiation decreases abruptly (see FIG. 5), the amount of change in voltage is smaller than the amount of change in current. The amount is less than the amount away from the maximum power point on the current axis. Therefore, the speed of reapproach to the maximum power point can be made faster than in the case of current control.

  In the above embodiment, the control unit 5 in FIG. 1 is an independent entity different from the DC / DC converter 2, but as an apparent form, it can be integrated with the DC / DC converter 2. It is. Moreover, although the example which the control part 5 also controls the inverter 3 was shown in FIG. 1, you may provide a dedicated control part separately for inverter control.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Solar power generation panel 2 DC / DC converter 5 Control part 10 Maximum power point tracking apparatus 100 Solar power generation system

Claims (7)

It is a maximum power point tracking control device that draws the current maximum power based on the output of the photovoltaic panel,
A power converter connected to the photovoltaic panel;
A control unit for controlling the power converter,
The control unit is capable of coarse and fine adjustments depending on the step width for changing the current flowing through the power converter. A maximum power point tracking control device that captures the maximum power point by fine adjustment when a threshold value is exceeded and returns to coarse adjustment when the threshold value is exceeded by fine adjustment.   If the voltage corresponding to the current at the present time falls below a predetermined value due to a sudden decrease in the amount of solar radiation, voltage control is performed with the voltage at the previous maximum power point as the target value, and the voltage is The maximum power point tracking control device according to claim 1, wherein current control is performed so as to approach the maximum power point from a corresponding current.   A solar power generation system comprising the solar power generation panel and the maximum power point tracking device according to claim 1. By controlling the power converter connected to the photovoltaic power generation panel by the control unit, it is a maximum power point tracking control method for extracting the current maximum power,
The control unit is capable of coarse and fine adjustment by the magnitude of the step width to change the current flowing through the power converter, approaching the maximum power point by coarse adjustment,
When the change in voltage with respect to the change in current exceeds a threshold, the maximum power point is captured by fine adjustment, and on the other hand, when the threshold is exceeded by fine adjustment, the adjustment returns to rough adjustment.
Maximum power point tracking control method. It is a maximum power point tracking control device that draws the current maximum power based on the output of the photovoltaic panel,
A power converter connected to the photovoltaic panel;
A control unit for controlling the power converter,
The control unit is capable of coarse and fine adjustment according to the step width for changing the input voltage to the power converter, and approaches the maximum power point by the coarse adjustment, and the current for the change in the input voltage is adjusted. A maximum power point tracking control device that captures the maximum power point by fine adjustment when the change exceeds a threshold value, and returns to coarse adjustment when the threshold value is exceeded by fine adjustment.   A solar power generation system comprising the solar power generation panel and the maximum power point tracking device according to claim 5. By controlling the power converter connected to the photovoltaic power generation panel by the control unit, it is a maximum power point tracking control method for extracting the current maximum power,
The control unit is capable of coarse adjustment and fine adjustment by the magnitude of the step width for changing the input voltage to the power converter, approaching the maximum power point by coarse adjustment,
When the change in current with respect to the change in the input voltage exceeds a threshold value, the maximum power point is captured by fine adjustment, and on the other hand, when the threshold value is exceeded by fine adjustment, the coarse adjustment is returned.
Maximum power point tracking control method.

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