WO2016015635A1

WO2016015635A1 - Control method and device for preventing mppt misjudgement

Info

Publication number: WO2016015635A1
Application number: PCT/CN2015/085357
Authority: WO
Inventors: 刘瑞; 孙丰涛; 陈洪涛; 程良意
Original assignee: 珠海格力电器股份有限公司
Priority date: 2014-07-29
Filing date: 2015-07-28
Publication date: 2016-02-04
Also published as: CN104133517A; CN104133517B

Abstract

A control method and device for preventing MPPT misjudgement, the method comprising: a first operating point, a second operating point and a third operating point are obtained, and the second operating point is moved to the third operating point according to a current movement direction; the power of the second operating point and the power of the third operating point are obtained, and when the power of the second operating point is greater than that of the third operating point, it is determined that misjudgement has occurred, and the operating point following the third operating point is moved in the reverse direction, so as to achieve the goal of adjusting the movement direction of the operating points of a photovoltaic cell in a timely manner. The control method has a simple principle, performs adjustment in a timely manner after misjudgement has occurred in the photovoltaic cell, and enables the solar energy utilisation rate to be increased.

Description

Control method and device for preventing MPPT misjudgment

Technical field

The present invention relates to the field of automatic control technologies, and in particular, to a control method and apparatus for preventing MPPT misjudgment.

Background technique

Nowadays, solar energy is one of the new energy sources. In order to convert solar energy into usable electrical energy, a circuit with maximum power point tracking (MPPT) function is needed, which uses photovoltaic cells to convert solar energy into electrical energy, photovoltaic cells. The PU characteristic curve when the intensity of sunlight is constant is shown in Fig. 1. The horizontal axis is the voltage U and the vertical axis is the power P. As can be seen from Fig. 1, there is a maximum power point in the entire PU characteristic curve of the photovoltaic cell, which is called MPP point, the greater the power of the photovoltaic cell, the more the output power, the higher the solar energy utilization rate. Therefore, in the working process of the photovoltaic cell, it is hoped that the photovoltaic cell will always work at the maximum power point.

In the prior art, the conductance increment method is generally used to keep the photovoltaic cell working at the maximum power point. The specific principle of the conductance increment method is as follows:

Taking FIG. 1 as an example, there is only one maximum power point in the PU characteristic curve, that is, the MPP point in the figure, and the slope on the left side of the maximum power point MPP is greater than zero, that is,

The slope to the right of the maximum power point is less than zero, ie

The slope is equal to zero at the point of maximum power, ie

Since the output power of the photovoltaic point is P=UI, the two sides of the formula are derived.

This leads to the following conclusions:

To the left of the maximum power point,

To the right of the maximum power point,

At the maximum power point,

Specifically, the sampled voltage values U(k), U(k-1) and current values I(k), I(k-1), let dU=U(k)-U(k-1), dI=I (k)-I(k-1), calculation formula If

Then, the output voltage of the photovoltaic cell is increased by the control circuit, so that the operating point moves to the right to approach the MPP point, if

The photovoltaic cell output voltage is reduced, so that the operating point moves to the left near the MPP point, if

Then keep its output voltage unchanged.

However, in reality, the PV characteristics of photovoltaic cells are inconsistent under different light intensities, and the maximum power points are also inconsistent. As shown in Figure 2, the PU characteristics of photovoltaic cells under two different light intensities, curves a represents the PU characteristic curve when the irradiation intensity is strong, and b represents the PU characteristic curve with weak irradiation intensity. When the light intensity is weakened, the PU characteristic curve of the photovoltaic cell changes from a to b, and the working point is changed by the illumination change Point A becomes point B. As shown in FIG. 3, it is an IU characteristic graph corresponding to FIG. 2.

Referring to Figure 2 and Figure 3, since the operating point A is on the left side of the MPP point of the maximum power point before the illumination changes, it should move to the right side to the MPP point. At this time, point A is taken as the previous moment of sampling. Sampling, after the light intensity changes after sampling, the PU characteristic curve changes. Point A moves to the right to point C, and point A becomes point B. At this time, the sampled value of point C is collected. In theory, it should be Calculated according to point B and point C

But now it is calculated according to point A and point C.

Referring to Fig. 3, I/U at point C is k1, dI/dU from point A to point C is k2, and dI/dU from point B to point C is k3, since point B is at the maximum power point left. side,

Should be greater than 0, but sampled

If k ₁ +k ₂ <0, a false positive phenomenon occurs.

In summary, the conductance increment method adopted in the prior art cannot accurately track the maximum power point of the photovoltaic cell when the illumination intensity changes, and may also cause a misjudgment phenomenon, resulting in low use efficiency of the photovoltaic cell. A new approach is needed to solve this problem.

Summary of the invention

The invention provides a control method and device for preventing misjudgment of an MPPT circuit. The invention can effectively solve the phenomenon that the MPPT circuit is misjudged, causing low use of the photovoltaic cell, thereby improving the solar energy utilization rate of the MPPT circuit.

According to an aspect of the present invention, a control method for preventing MPPT misjudgment is provided, the method comprising:

Obtaining a first working point and a second working point of the MPPT, where the first working point and the second working point are working points obtained by adjacent sampling moments;

Calculating the first working point and the second working point according to a conductance increment algorithm, obtaining a current moving direction, and moving the second working point to a third working point according to a current moving direction;

Obtaining the power of the second working point and the power of the third working point;

When the power difference of the second operating point is greater than the power of the third operating point, it is determined that a misjudgment occurs, and the next operating point of the third operating point is moved in a direction opposite to the current moving direction.

Preferably, the process of determining that the power of the second working point is greater than the power of the third working point comprises:

Obtaining the power of the first working point;

Subtracting the power of the first operating point by the difference of the power of the third operating point as a first difference, subtracting the power of the first operating point from the power of the second operating point a value, as the second difference, calculating a power difference of the first difference minus the second difference;

When the power difference is greater than zero, it is determined that the power of the second operating point is greater than the power of the third operating point.

Calculating a difference between the power of the second operating point minus the power of the third operating point, and determining that the power of the second operating point is greater than the power of the third operating point when the difference is greater than zero.

Preferably, moving the next working point of the third working point in a direction opposite to the current moving direction comprises:

When the third operating point is to the left of the maximum power point and the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the next operating point of the third operating point is controlled to move to the right.

When the third operating point is to the right of the maximum power point and the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the next operating point of the third operating point is controlled to move to the left.

Preferably, moving the second working point to the third working point in the current moving direction comprises:

When the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the second operating point is controlled to move to the right to the third working point.

When the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the second operating point is controlled to move to the left to the third working point.

Preferably, the MPPT circuit state change comprises:

The light intensity changes, increases the output voltage of the photovoltaic cell, or lowers the output voltage of the photovoltaic cell.

Preferably, the method further comprises:

When the power of the second working point is less than the power of the third working point, it is determined that no misjudgment occurs;

The second working point and the third working point are calculated according to a conductance increment algorithm to obtain a current moving direction, and the third working point is moved to a next working point according to a current moving direction.

According to another aspect of the present invention, a control apparatus for preventing a misjudgment of an MPPT circuit is provided, the apparatus comprising:

An acquiring unit, configured to acquire a first working point and a second working point of the MPPT circuit;

a moving unit, configured to calculate the first working point and the second working point according to a conductance increment algorithm, obtain a current moving direction, and move the second working point to a third working point according to a current moving direction ;

a first acquiring power unit, configured to acquire power of the second working point and power of the third working point;

An execution unit, configured to: when the power of the second working point is greater than the power of the third working point, determine that a misjudgment occurs, and then the next working point of the third working point is pressed in a direction opposite to the current moving direction. Move.

Preferably, the execution unit comprises:

a second acquiring power unit, configured to acquire power of the first working point;

Obtaining a power difference unit, configured to subtract a power of the first operating point from a power of the third operating point as a first difference, and subtract the power of the first operating point from the Calculating, by the difference of the power of the second working point, as the second difference, calculating a power difference of the first difference minus the second difference;

The first determining unit is configured to determine that the power of the second operating point is greater than the power of the third working point when the power difference is greater than zero.

Preferably, the execution unit comprises:

a calculating unit, configured to calculate a difference between a power of the second working point and a power of the third working point;

The second determining unit is configured to determine that the power of the second working point is greater than the power of the third working point when the difference is greater than zero.

The present invention provides a control method for preventing MPPT misjudgment. The present invention first obtains a first working point before a state change, and then acquires a second working point after a state change, and calculates according to an existing conductance increment algorithm. Move direction and move to get the third working point.

Since the characteristic curve of the photovoltaic cell determines the maximum power of the maximum power point, the power of the remaining positions is less than the power of the maximum power point. If the current moving direction is correct, the third working point should be closer to the maximum power point than the second working point, that is, the first The power of the three working points is greater than the power of the second working point, so when the power of the second working point is greater than the power of the third working point, it is proved that a misjudgment occurs, and when the power of the second working point is less than the power of the third working point, It proves that no misjudgment has occurred.

After the misjudgment occurs, the next working point of the third working point is moved in the opposite direction to achieve the purpose of timely adjusting the moving direction of the working point of the photovoltaic cell. The judgment principle of the present invention is simple, quick and easy to implement, thereby causing the photovoltaic cell to appear. After misjudgment, it can be adjusted in time to improve solar energy utilization.

DRAWINGS

The accompanying drawings, which are incorporated in the claims In the drawing:

Figure 1 is a PU characteristic curve of a photovoltaic cell;

2 is a PU characteristic curve of a photovoltaic cell under different light intensities;

Figure 3 is a IU characteristic curve of a photovoltaic cell at different light intensities;

4 is a flowchart of a control method for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention;

FIG. 5 is a flowchart of still another method for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention;

6 is a schematic diagram of a misjudgment in the case where the illumination intensity is weakened in the control method for preventing the MPPT circuit from being misjudged according to the embodiment of the present invention;

FIG. 7 is a schematic diagram of the occurrence of a false positive in the case where the illumination intensity is weakened in the control method for preventing the MPPT circuit from being misjudged according to the embodiment of the present invention;

FIG. 8 is a schematic diagram of a misjudgment in the case where the illumination intensity is enhanced in the control method for preventing the MPPT circuit from being misjudged according to the embodiment of the present invention; FIG.

FIG. 9 is a schematic diagram of a method for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a control apparatus for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention; FIG.

FIG. 11 is a schematic structural diagram of another control apparatus for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of another control device for preventing misjudgment of an MPPT circuit according to an embodiment of the present invention.

detailed description

It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments.

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. It is an embodiment of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope shall fall within the scope of the application.

It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or Post-order. It should be understood that the data so used may be interchanged where appropriate to facilitate the embodiments of the present application described herein. In addition, the terms "comprises" and "comprises" and "the" and "the" are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

As shown in FIG. 4, an embodiment of the present invention provides a control method for preventing MPPT misjudgment, and the method includes:

The MPPT state change includes a change in the illumination intensity or a change in the output voltage of the photovoltaic cell, and the illumination intensity changes, including an increase in the illumination intensity and a slight decrease in the illumination. The change in the output voltage of the photovoltaic cell includes an increase in the output voltage of the photovoltaic cell or a decrease in the output voltage of the photovoltaic cell. The change of the output voltage of the photovoltaic cell does not lead to misjudgment, but the method of the present invention is improved on the basis of the original, so it can be applied to the situation where the illumination intensity is constant.

Step S101: Acquire a first working point and a second working point of the MPPT, where the first working point and the second working point obtain working points for adjacent sampling moments.

The method embodiment can be applied to a controller. The controller continuously collects the working point of the photovoltaic cell according to a certain frequency. After collecting the first working point, the first working point is stored first, and then the next working point is collected according to a certain frequency. , that is, the second working point, after obtaining two working points, the calculation is performed by the conductance increment method.

Step S102: Calculate the first working point and the second working point according to a conductance increment algorithm, obtain a current moving direction, and move the second working point to a third working point according to a current moving direction.

Obtaining the I/U at the second operating point on the current IU characteristic curve of the photovoltaic cell, obtaining the slope of the straight line formed by the first working point and the second working point, that is, obtaining dI/dU, and then calculating

when

When the current direction of movement is moving to the right, when

When the current direction of movement is to the left.

As shown in Fig. 2, the photovoltaic characteristic curve shows that the operating point of the photovoltaic cell is directly related to the output voltage of the photovoltaic cell. When the output voltage increases, the operating point moves to the right, and when the output voltage decreases, the operating point moves to the left. Move the second work point in the current direction of movement, including two cases:

The first case: the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the second operating point is controlled to move to the right to the third working point.

The second case: the current moving direction is leftward, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the second operating point is controlled to move to the left to the third working point.

Step S103: Acquire the power of the second working point and the power of the third working point.

The controller itself does not know whether the environment in which the MPPT is located has changed. Therefore, after calculating according to the original conductance increment algorithm, it is necessary to make a judgment. If the current moving direction is correct, the third working point should be more than the second working point. Close to the maximum power point, that is, the power of the third working point is greater than the power of the second working point, so when the power of the second working point is greater than the power of the third working point, it is determined that a misjudgment occurs, and the controller is judged after the misjudgment occurs. Knowing that the current MPPT status has changed, it is necessary to adjust the current moving direction in time.

Step S104: When the power of the second working point is greater than the power of the third working point, it is determined that a misjudgment occurs, and the next working point of the third working point is moved in a direction opposite to the current moving direction.

After the misjudgment, that is, the third working point has deviated from the maximum power point, in order to keep the photovoltaic cell working at the maximum power point, it is necessary to immediately adjust the moving direction of the working point, and the controller will move the next working point of the photovoltaic cell to the current Move in the opposite direction of movement to bring the working point of the photovoltaic cell as close as possible to the maximum power point.

Preferably, when the power of the second operating point is less than the power of the third operating point, it is determined that no false positive has occurred. The second working point and the third working point are calculated according to a conductance increment algorithm to obtain a current moving direction, and the third working point is moved to a next working point according to a current moving direction.

When a misjudgment occurs, the next work point is moved in the opposite direction to the current one, including:

When the third operating point is to the left of the maximum power point and the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the next operating point of the third operating point is controlled. move to the right.

The embodiment of the invention provides a control method for preventing misjudgment of the MPPT circuit. The invention can quickly and conveniently determine whether the current moving direction has a misjudgment. When a misjudgment occurs, the next working point of the third working point is reversed. The direction is moved to achieve the purpose of timely adjusting the moving direction of the working point of the photovoltaic cell. The judgment principle of the invention is simple, fast and easy to implement, so that after the solar cell is misjudged, it can be adjusted in time, so that the solar energy utilization rate is improved.

Preferably, in the step S104 of the foregoing embodiment, the process of determining that the power of the second working point is greater than the power of the third working point includes the following two methods:

As shown in Figure 5, the first method includes the following steps:

Step S501: Acquire the power of the first working point of the power of the first working point.

Step S502: Subtract the power of the first working point from the power of the first working point minus the power of the third working point as the first difference, and firstly power the first working point. The power of the point minus the difference of the power of the second operating point is used as the second difference, and the power difference of the first difference minus the second difference is calculated.

Step S503: When the power difference is greater than zero, determine that the power of the second operating point is greater than the power of the third operating point.

The power difference between the first working point and the third working point is a first difference dp1, and the power difference between the first working point and the second working point is a second difference dp2, and the power difference dp=dp1 -dp2, under normal circumstances, dp1 <dp2, that is, dp1-dp2<0, when dp1-dp2>0, it is considered that a misjudgment occurs, and when dp1-dp2<0, it is considered that no misjudgment occurs.

The first way is to use the power difference between the two differences to determine whether a misjudgment occurs. This method can be implemented but the implementation of the method is more complicated. The second method is provided below, and the second method is simpler.

The second type: calculating the difference between the power of the second working point minus the power of the third working point, and determining that the power of the second working point is greater than the power of the third working point when the difference is greater than zero. The second way is simpler and more convenient.

According to the study by the inventor of the present application, the conductance increment method may cause misjudgment when the external irradiation intensity changes, and is mainly divided into the following two cases:

The first type: when the irradiation intensity changes before and the working point is on the same side of the maximum power point, if the irradiation intensity is weakened, the misjudgment phenomenon will occur. The second type: when the irradiation intensity changes, the working point is at the maximum power. When the point is on the opposite side, if the irradiation intensity is enhanced, a misjudgment phenomenon may occur, and specific embodiments of the present invention will be described below for different situations:

The first type: the irradiation intensity is weakened, and the working point before and after the change of the irradiation intensity is on the same side of the maximum power point.

The PU characteristic curve of the photovoltaic cell is shown in Fig. 6 and Fig. 7. Fig. 6 is a schematic diagram of the judgment when the misjudgment phenomenon occurs, and Fig. 7 is a working principle diagram when the misjudgment phenomenon does not occur. When the light intensity is weakened, the PU characteristic curve changes from a to b, and the working point is moved to point C according to the moving direction before the irradiation intensity is weakened. If a false positive phenomenon occurs, the working point will continue to move to the left to point D, and the calculation will be performed. The power difference between point A and point C is dp2 and the power difference between point A and point D is dp1, so that dp=dp1-dp2. If dp is greater than 0, the misjudgment occurs. The next operating point of point D should be reversed. If the movement is less than 0, there is no false positive phenomenon, and the working point is moved in the original direction.

The second type: the irradiation intensity increases, and the working point before and after the change of the irradiation intensity is located at the opposite side of the maximum power point.

As shown in Fig. 8, when the illumination intensity is increased, the PU characteristic curve changes from b to a, and the working point is moved to point C according to the moving direction before the irradiation intensity is enhanced. If a misjudgment occurs, the working point will continue to the left. Move to point D, calculate the power difference dp2 between point A power and point C, and the power difference dp1 between point A power and point D, so that dp=dp1-dp2. If dp is greater than 0, the misjudgment phenomenon occurs, and the point D should be If a working point moves in the opposite direction if it is less than 0, there is no false positive phenomenon, and the working point is continuously moved in the original direction.

The method provided by the embodiment of the invention can be applied to the case when the illumination intensity is unchanged, so an embodiment in which the illumination intensity is unchanged is given.

As shown in Figure 9, when there is no change in the intensity of the irradiation, the working point should continue to be disturbed according to the original direction, point A is the original working point, point C is the working point to join the first disturbance, and point D is the second disturbance. The working point, the disturbance is to increase the output voltage of the photovoltaic cell or reduce the output voltage of the photovoltaic cell, calculate A Point power and point C power difference dp2 and point A power and point D power difference dp1, let dp = dp1 - dp2, if dp is greater than 0, misjudgment occurs, should move the operating point in the opposite direction if less than 0, then No false positive phenomenon, continue to move the working point according to the original direction, because the irradiation intensity has not changed, no false positive phenomenon occurs, dp should be less than 0, as can also be seen from Figure 9, the actual work dp is less than 0, so the moving direction is just normal In the case where the moving direction is the same, the method provided by the present invention can also be applied to the case where the light intensity is not changed, and the application range is wider.

As shown in FIG. 10, the embodiment of the present invention further provides a control device for preventing a misjudgment of an MPPT circuit, and the device may be used to perform a control method for preventing a misjudgment of an MPPT circuit according to an embodiment of the present invention. The method includes:

The obtaining unit 100 is configured to acquire a first working point and a second working point of the MPPT circuit.

The mobile unit 200 is configured to calculate the first working point and the second working point according to a conductance increment algorithm, obtain a current moving direction, and move the second working point to a third working position according to a current moving direction. point.

The first acquiring power unit 300 is configured to acquire power of the second working point and power of the third working point.

The executing unit 400 is configured to: when the power of the second working point is greater than the power of the third working point, determine that a misjudgment occurs, and then the next working point of the third working point is reversed from the current moving direction. Move in the direction.

As shown in FIG. 11, the execution unit 400 includes:

The second acquisition power unit 401 is configured to acquire power of the first working point.

Obtaining a power difference unit 402, configured to subtract a power of the first operating point from a power of the third operating point as a first difference, and subtract the power of the first working point from the And calculating, as the second difference, a power difference value of the first difference value minus the second difference value.

The first determining unit 403 is configured to determine that the power of the second operating point is greater than the power of the third operating point when the power difference is greater than zero.

As shown in FIG. 12, the execution unit 400 includes:

The calculating unit 404 is configured to calculate a difference between the power of the second working point and the power of the third working point.

The second determining unit 405 is configured to determine that the power of the second working point is greater than the power of the third working point when the difference is greater than zero.

The execution unit 400 in FIG. 10 is also used to:

When the third operating point is to the left of the maximum power point and the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the next operating point of the third operating point is controlled to move to the right. When the third operating point is to the right of the maximum power point and the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the next operating point of the third operating point is controlled to move to the left.

The mobile unit 200 in FIG. 10 is also used to:

When the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the second operating point is controlled to move to the right to the third working point. When the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the second operating point is controlled to move to the left to the third working point.

The embodiment of the invention provides a control device for preventing the MPPT from being misjudged. In the embodiment of the present invention, the first working point before the state change is first obtained, and then the second working point after the state change is obtained, according to the existing conductance increment algorithm. The calculation is performed to obtain the current moving direction, and after moving, the third working point is obtained.

The functions described in the method of the present embodiment can be stored in a computing device readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on this It is understood that portions of the embodiments of the present invention that contribute to the prior art or portions of the technical solutions may be embodied in the form of a software product stored in a storage medium, including instructions for causing a calculation The device (which may be a personal computer, server, mobile computing device or network device, etc.) performs all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same or similar parts of the respective embodiments may be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims

A control method for preventing MPPT misjudgment, characterized in that it comprises:

Obtaining a first working point and a second working point of the MPPT, where the first working point and the second working point are working points obtained by adjacent sampling moments;

Calculating the first working point and the second working point according to a conductance increment algorithm, obtaining a current moving direction, and moving the second working point to a third working point according to a current moving direction;

Obtaining the power of the second working point and the power of the third working point;

When the power difference of the second operating point is greater than the power of the third operating point, it is determined that a misjudgment occurs, and the next operating point of the third operating point is moved in a direction opposite to the current moving direction.
The method according to claim 1, wherein the process of determining that the power of the second operating point is greater than the power of the third operating point comprises:

Obtaining the power of the first working point;

Comparing the power of the first operating point minus the power of the third operating point as a first difference, and subtracting the power of the first operating point from the power of the second operating point Calculating, as the second difference, a power difference value of the first difference minus the second difference;

When the power difference is greater than zero, it is determined that the power of the second operating point is greater than the power of the third operating point.
The method according to claim 1, wherein the process of determining that the power of the second operating point is greater than the power of the third operating point comprises:

Calculating a difference between a power of the second operating point minus a power of the third operating point, and determining that a power of the second operating point is greater than a power of the third operating point when the difference is greater than zero.
The method according to claim 1, wherein moving the next operating point of the third operating point in a direction opposite to the current moving direction comprises:

When the third operating point is to the left of the maximum power point and the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the next operating point of the third operating point is controlled to move to the right.
The method according to claim 1, wherein moving the next operating point of the third operating point in a direction opposite to the current moving direction comprises:

When the third operating point is to the right of the maximum power point and the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the next operating point of the third operating point is controlled to move to the left.
The method of claim 1 wherein moving the second operating point to the third operating point in the current direction of movement comprises:

When the current moving direction is to the right, the output voltage of the photovoltaic cell controlling the MPPT circuit is increased, and the second operating point is controlled to move to the right to the third working point.
The method of claim 1 wherein moving the second operating point to the third operating point in the current direction of movement comprises:

When the current moving direction is to the left, the output voltage of the photovoltaic cell controlling the MPPT circuit is decreased, and the second operating point is controlled to move to the left to the third working point.
The method of claim 1 wherein said MPPT circuit state change comprises:

The light intensity changes, increases the output voltage of the photovoltaic cell, or lowers the output voltage of the photovoltaic cell.
The method of claim 1 further comprising:

When the power of the second operating point is less than the power of the third operating point, determining that no misjudgment occurs;

The second working point and the third working point are calculated according to a conductance increment algorithm to obtain a current moving direction, and the third working point is moved to a next working point according to a current moving direction.
A control device for preventing misjudgment of an MPPT circuit, comprising:

An acquiring unit, configured to acquire a first working point and a second working point of the MPPT circuit;

a moving unit, configured to calculate the first working point and the second working point according to a conductance increment algorithm, obtain a current moving direction, and move the second working point to the third moving direction according to a current moving direction Working point

a first acquiring power unit, configured to acquire power of the second working point and power of the third working point;

An execution unit, configured to determine that a misjudgment occurs when the power of the second working point is greater than the power of the third working point, and press the next working point of the third working point in a direction opposite to the current moving direction. Move.
The apparatus according to claim 10, wherein the execution unit comprises:

a second acquiring power unit, configured to acquire power of the first working point;

Obtaining a power difference unit, configured to subtract a power of the first operating point from a power of the third operating point as a first difference, and subtract the power of the first operating point from the Calculating, by the difference of the power of the second working point, as the second difference, calculating a power difference of the first difference minus the second difference;

The first determining unit is configured to determine that the power of the second operating point is greater than the power of the third operating point when the power difference is greater than zero.
The apparatus according to claim 10, wherein the execution unit comprises:

a calculating unit, configured to calculate a difference between a power of the second working point and a power of the third working point;

a second determining unit, configured to determine that the power of the second working point is greater than the power of the third working point when the difference is greater than zero.