Methods for controlling electrical power and voltage converters for this purpose in a maximum power point tracking control system

Abstract

The aim is to provide a method for controlling electrical power and a voltage converter for this purpose in maximum power point tracking (MPPT) control, which can be used in conjunction with an optimizer that can be connected to most commercially available PCSs.Referring to a voltage value of an MPPT maximum power point, which is defined as the peak of a voltage-power curve 1, an optimal operating point, at which the power of solar cell panels is maximized, is maintained at a constant power value by inducing an operating voltage of the power converter to fall into a flat sub-region of a plateau shape 2, which has a step formed by straight lines that drop perpendicularly on both the low-voltage and high-voltage sides of the voltage-power curve 1 and meet the slopes of the voltage-power curve, with the operating voltage of the power conditioner then being maintained in a constant fixed range and output externally.

Description

Technical area

[0001] The present invention relates to an electric power control method and a voltage converter therefor in a maximum power point tracking controller used to obtain the generated power of a solar module formed of a plurality of solar cell panels with maximum efficiency. State of the art

[0002] Photovoltaic power generation (also referred to as solar power generation) has been put into practice as a means of securing energy supply toward the realization of a low-carbon society. Solar power generation is designed to generate a predetermined electrical output using one or more solar cell panels (photovoltaic panels (PV panels): hereinafter also referred to simply as solar cell panels) arranged in a plane.

[0003] Solar power generation systems are widespread and range from small household systems to large-scale installations that replace existing power generation facilities such as thermal or nuclear power plants. Large-scale systems, in particular, which fall under the term power plants, are also referred to as mega-solar plants (mega-solar power plants).

[0004] With thousands to tens of thousands or more panels arranged as arrays on the ground, water, or similar surfaces, Mega Solar converts the electromagnetic wave energy of sunlight into electrical energy and transmits it to customers. To maximize the power output from a large number of panels, the connections between the modules can use either a series or parallel configuration.

[0005] Fig. Figure 7 is an explanatory diagram of a parallel plate connection scheme in a solar module as used in the present invention. Fig. 7, a large number of panels 3 are arranged as a single solar module (hereinafter also referred to simply as a module) 60 at a power generation site. A module outputs a required voltage by interconnecting the power outputs of a large number of panels 3, e.g., 10 or 20 panels, via module-internal parallel connection lines 21. Note that such a solar module is sometimes referred to as a string. While in Fig. 7 only a single solar module 60 is shown, other solar modules are connected to a power conditioning system (PCS; also referred to as power conditioner) 7 via parallel connecting lines between the modules, not shown.

[0006] In the Fig. In the parallel plate connection diagram shown in Figure 7, each plate 3 contains an optimizer 4, which includes an optimizer (OP) circuit with a boost converter function. The optimizer 4 has a function of connecting to other plates and other modules not shown. If the voltage at a maximum power point of a single plate is, for example, 40 V (DC), the optimizer circuit increases the voltage through a boost converter, for example, to 800 V (the target voltage is set to a desired value by the power conditioner). In parallel connection, the 800 V output of the optimizer 4 of each plate is connected to the module's internal parallel connection line 21. Therefore, the voltage of the solar module 60 is 800 V. The output is adjusted to a desired AC voltage or the like by a power conditioner 7 and supplied to customer loads via a system line 8.

[0007] In this type of solar power system, which uses sunlight as an energy source, the amount of sunlight reaching the panel surfaces varies greatly depending on the season and time of day, the location of the power generation system, the shade of trees and the like, weather conditions, the adhesion of foreign objects, and so on, leading to fluctuations in power generation. Maximum power point tracking (MPPT) control is used as a technique to reduce these fluctuations. MPPT (Maximum Power Point Tracking) automatically finds an operating point that maximizes the product of voltage and current, thereby maximizing the power generated by the panels.

[0008] There is a large amount of prior art that discloses conventional techniques relevant to MPPT control in the present invention. Patent Literature 1 and Patent Literature 2 can be cited as examples. Citation listPatent literature Patent Literature 1: Japanese Translation of PCT International Application Publication No. 2009-540419 Patent Literature 2: Japanese Patent Laid-Open No. 2018-195225 Summary of the inventionTechnical problem

[0009] As described above, to extract power output from a large number of panels, the connections between the panels in the module can use either a series or parallel scheme. With a series scheme, the failure of a single panel or shadowing (fluctuations in the amount of light received) affects the entire module, reducing or losing the module's electrical output. This poses a problem in that the electrical energy generated by the other modules is wasted. This waste is a problem that must be addressed, even from the perspective of the SDGs.

[0010] To solve the above problems, the inventors developed a scheme in which an optimizer is provided on a single-plate basis, MPPT (Maximum Power Point Tracking) control is performed on a single-plate basis, and the power is delivered to a power conditioner by connecting the panels subject to MPPT control in parallel. Thus, by using the parallel connection scheme in which an optimizer is provided on a single-plate basis and the outputs of the panels are connected in parallel to the power conditioner, the effect of a reduction in generated power (local reduction in the amount of light irradiating the module) caused by panel failure or shadows can be limited on the panels in the module. However, it is assumed that the power conditioner has the function of setting a constant voltage maintenance.

[0011] However, many commercially available power conditioners have an MPPT function but not a constant voltage maintenance function. Therefore, some power generation systems that use a commercially available power conditioner cannot use an optimizer. This is also a problem that needs to be addressed.

[0012] The Fig. 4(a) to 4(c) are explanatory diagrams for explaining MPPT, where Fig. 4(a) shows a voltage-power curve (PV curve) of a plate, Fig. 4(b) a constant voltage maintenance power conditioner (constant voltage PCS) and Fig. 4(c) shows a power conditioner with only an MPPT function (MPPT PCS).

[0013] The Fig. 5(a) and Fig. 5(b) are explanatory diagrams of a voltage-power curve classified by optimization function, where Fig. 5(a) is an explanatory diagram of a voltage-power curve of a full-voltage optimizer of the OP-MPPT type, which Fig. 4(a), and Fig. 5(b) is an explanatory diagram of a voltage-power (PV) curve of an optimizer having a control function mentioned below with a plateau shape relevant to the present invention (where the "plateau shape" means a relatively flat, stable, plateau-like interval and not a "trapezoid" in the geometric sense).

[0014] Possible power conditioners are a Fig. 4(b), which can maintain a constant voltage (e.g. 800 V) in addition to an original MPPT control function, and a Fig. 4(c) shows a power conditioner that only has an MPPT function. Fig. The PCS (Constant Voltage PCS) of the constant voltage maintenance type shown in Figure 4(b) is designed to maintain a constant voltage (A) determined by the Fig. 4(a) is shown as the voltage-power curve (PV curve).

[0015] In actual operation, the constant voltage (A) is suitably set to a value close to the MPPT voltage of the panels that make up the module (e.g. 800 V when using 20 panels of 40 V each).

[0016] However, as described above, many commercially available power conditioners are equipped with an MPPT function but lack a constant voltage maintenance function. Consequently, some sites (e.g., power plants) that use a commercially available power conditioner cannot use an optimizer.

[0017] It is an object of the present invention, which relates to a technique related to an optimizer that can be connected to most commercially available power conditioners, to solve the above-mentioned problems, and in particular to provide a novel electric power control method and a voltage converter therefor in the maximum power point tracking (MPPT) control. Solution to the problem

[0018] Next, configurations of the main features of the electric power control method and the voltage converter therefor in the maximum power point tracking controller according to the present invention made to achieve the above-mentioned object will be described.

[0019] First, an electric power control method for maximum power point tracking control, which is intended to efficiently extract the generated power of a solar module composed of a large number of solar cell panels, is designed as follows.

[0020] The present invention provides an electric power control method for maximum power point tracking control intended to efficiently extract the generated power of a solar module formed from a large number of solar cell panels, wherein: the solar module comprises an optimizer configured to increase the power output of the solar module to a predetermined voltage and a power conditioner equipped with a MPPT function; and (1) The optimizer inductively controls an operating voltage of the power conditioner to set a MPPT target voltage of the power conditioner based on a voltage-power characteristic curve of the optimizer. (2) The optimizer inductively controls the operating voltage of the power conditioner as described under 1. and 2. 1. If the power conditioner voltage is below a target value (on the left side of Fig. 1), the optimizer increases the output power when the power conditioner increases its voltage, and the optimizer decreases the output power when the power conditioner decreases its operating voltage. 2. If the voltage of the power conditioner is higher than the target value (on the right side of Fig. 1), the optimizer decreases the output power when the power conditioner increases its voltage, and the optimizer increases the output power when the power conditioner decreases its voltage.

[0021] The present invention provides a voltage converter for maximum power point tracking control intended to efficiently extract the generated power of a solar module formed from a large number of solar cell panels, the voltage converter comprising: an optimizer configured to increase the power output of a solar module to a predetermined voltage, and a power conditioner equipped with a MPPT function, wherein (3) each of the solar cell panels comprises an optimizer and a power conditioner provided with a maximum power point tracking control circuit, and the maximum power point tracking control circuit comprises a controller configured to maintain the power of the solar module at a constant power value with respect to a voltage value of a maximum power point provided as a peak of a voltage-power curve at which the voltage of the solar module is maximum, so that the voltage-power curve forms a plateau shape having a step formed by straight lines that vertically descend on a low-voltage side and a high-voltage side, respectively, and adjacent to slopes of the voltage-power curve, and Using the electric power control method described in (1) or (2) above, the controller induces an operating voltage of the power conditioner in a constant fixed range in a flat portion of the plateau shape, then maintains the operating voltage of the power conditioner in the constant fixed range, and outputs the operating voltage as generated output power. (4) If a voltage at the point of maximum power in the voltage-power curve D T (V) is a voltage that matches the voltage-power curve on the low-voltage side of the plateau shape, D L (V) and a voltage on the high voltage side of the plateau form D H (V) is; D L < D H , are the values ​​of power at a point of D L (V) and the power at a point of D Hso that the circuits that make up the optimizer and the power conditioner can detect the power difference more clearly than a value of the power at a point of D T (V) in the performance tracking control, and that D L and D H Have power values ​​that are slightly lower than a plateau-shaped power value. In fact, the power difference is a design value determined as the capability (accuracy) of the circuit during circuit design. It is approximately a few percent to ten percent, but can also be greater depending on the accuracy (capability) of the circuit's voltage identification or the MPPT control capability of the power conditioner.

[0022] The voltage converter is connected to the power conditioner via a parallel connection line, which is used to parallel the generated output power of the module; and outputs the generated output power to a system line by converting the generated output power into a power form required by a system that uses the power conditioner.

[0023] It should be noted that the present invention is not limited to the configuration described above or a configuration described in an embodiment described later, and it is a matter of course that various changes are possible within the scope of the technical idea of ​​the present invention. Advantageous effects of the invention

[0024] The plateau shape control according to the invention allows optimizers to be connected independently of the functions of commercially available power conditioners and enables the maximum power output to be extracted on a single plate basis. Short description of the drawings Fig. 1 is an explanatory diagram of a voltage-power characteristic (PV curve) showing an embodiment of an electric power control method and a voltage converter therefor in a maximum power point tracking controller according to the present invention. Fig. 2 is a functional block diagram of the hardware used in Fig. 1 shown OP-MPPT control is used. Fig. 3 is a flowchart illustrating a control flow performed by a controller 45. Fig. 4(a) to 4(c) are explanatory diagrams for explaining MPPT, where Fig. 4(a) shows a voltage-power curve (PV curve) of a plate, Fig. 4(b) a PCS (constant voltage PCS) of a constant voltage maintenance type and Fig. 4(c) a PCS with only one MPPT function (MPPT PCS). Fig. 5(a) and Fig. 5(b) are explanatory diagrams of a voltage-power curve classified by optimization function, where Fig. 5(a) is an explanatory diagram of a voltage-power curve of a full-voltage OP-MPPT type optimizer which Fig. 4(a), and Fig. 5(b) is an explanatory diagram of a voltage-power (PV) curve of an optimizer having a control function mentioned below with a plateau shape relevant to the present invention. Fig. 6(a) and Fig. 6(b) are explanatory diagrams of a PV curve of the optimizer output, where Fig. 6(a) a triangle control (so-called climbing control) and Fig. 6(b) shows a plateau shape control (without edge step). Fig. 7 is an explanatory diagram of a parallel plate circuit scheme in a solar module according to the present invention. Description of the embodiment

[0025] The present invention provides a method and means for connecting an optimizer (OP) to the Fig. 4(c) and Fig. 5(b). First, with respect to MPPT control of the optimizer, an existing control method and a control method according to the present invention will be described.

[0026] The Fig. 6(a) and Fig. 6(b) are explanatory diagrams of a PV curve of the optimizer output, where Fig. 6(a) a triangle control (so-called climbing control) and Fig. 6(b) shows a plateau shape control (without edge step). In Fig. 6(a), the optimizer inductively controls an operating voltage of the power conditioner to adjust an MPPT target voltage of the power conditioner based on a voltage-power characteristic curve of the optimizer.

[0027] That is, when the power conditioner voltage is lower than a target value, the optimizer increases the output power when the power conditioner increases its voltage, and when the power conditioner decreases its voltage, the optimizer decreases the output power.

[0028] When the power conditioner voltage is higher than the target value, the optimizer decreases the output power, when the power conditioner increases its voltage, and when the power conditioner decreases its voltage, the optimizer increases the output power.

[0029] As in Fig. As shown in Figure 4(a), the MPPT-PCS performs MPPT control, targeting the peak of the PV curve of a panel by changing the voltage in the direction of increasing the voltage. In the case of Fig. In Figure 6(a), the voltage is varied with a target of 800 V (800 V is only an example and may vary depending on the type and number of panels). After reaching 800 V, the voltage continues to be raised and lowered around 800 V to maintain the peak using the MPPT. Therefore, the MPPT-PCS can be connected to the optimizer if an output curve of the optimizer is controlled such that "on the opposite sides of 800 V, which serves as the peak, the power decreases with a decrease in voltage on a left slope and the power decreases with an increase in voltage on the right slope."

[0030] Using Fig. 6(a) the details of the triangle control are described in more detail below. Fig. Figure 6(a) shows an example where the input power is set to 300 W and the target voltage is set to 800 V. Increases and decreases in voltage and power are indicated by arrows "→". When the power conditioner voltage is lower than the target voltage of 800 V, the optimizer increases the electrical output power when the power conditioner increases its voltage, and the optimizer decreases the output power when the power conditioner decreases its voltage.

[0031] When the power conditioner voltage is above the target voltage of 800 V, the optimizer lowers the output power, when the power conditioner increases its voltage, and when the power conditioner lowers its voltage, the optimizer increases the output power.

[0032] In this way, the optimizer induces the operating voltage of the power conditioner.

[0033] Delta control can make the MPPT-PCS connectable by performing a control so that the voltage-power curve (PV curve) of the optimizer output becomes a triangle curve, as shown in Fig. 6(a). For example, the optimizer's "power control pulse width" can be kept unchanged as a "fixed value." Using a "fixed value" frees the optimizer from power control, and consequently, the PV curve of the optimizer output remains in the shape of the PV curve ( Fig. 4(a)) of the plate (only an increase is made). To obtain a PV curve as in Fig. 6(a), a pulse width (fixed value) can therefore be chosen that results in a peak (MPP voltage) of 800 V.

[0034] The optimizer “continues to change the power control pulse width” to deliver the maximum power at a voltage set by the power conditioner (e.g., 800 V), and the process of “continued changing of the power control pulse width” is OP-MPPT, as in Fig. 5(a). However, if the pulse width is set to a fixed value, the optimizer simply becomes a "voltage converter that only increases power by bypassing the power characteristics of the panel." Therefore, to achieve maximum power, the MPPT-PCS must constantly change the voltage.

[0035] With the above-mentioned delta control, OP-MPPT can only be performed at one point, namely the peak (800 V), and therefore OP-MPPT cannot be performed sufficiently in practice. This is because a power conditioner voltage at which one optimizer reaches 800 V will not cause another optimizer to reach 800 V due to variations in the sensing voltage between optimizers, cable voltage losses, and so on. This means that delta control cannot make the optimizers exert their strength of "outputting the maximum power of each panel." Therefore, it is necessary to provide a "constant voltage range" for OP-MPPT to be performed.

[0036] It is also conceivable to perform OP-MPPT in the flat region (voltage range in which the output power assumes a constant value) of the plateau shape by controlling the PV curve of the optimizer output so that the PV curve has the Fig. 6(b). As a concrete example, a range from 750 V to 820 V is used as the tracking range for OP-MPPT. Sloping sections of the PV curve that are equal to or lower than 750 V and equal to or higher than 820 V are adjusted by selecting fixed values ​​of the “power control pulse widths” suitable for the respective sections. That is, a fixed value resulting in an MPPT voltage of 750 V is selected for the range below 750 V, and a fixed value resulting in an MPPT voltage of 820 V is selected for the range above 820 V. Consequently, the PV curve of the optimizer output becomes a PV curve “whose peak is at 750 V or 820 V” and that corresponds to the Fig. similar to the PV curve shown in Figure 4(a).

[0037] At the Fig. 6(b) described plateau-shaped control (without edge step), the power differences at the edges (around 750 V and 820 V in Fig. 6(b)) between "fixed power control pulse width control" and "MPPT control with variable power control pulse width" is unclear because the power changes are continuous. As a result, the voltage remains slightly lower than 750 V or slightly higher than 820 V, depending on the control by the power conditioner, so OP-MPPT cannot be implemented.

[0038] For example, if the optimizer power values ​​on the PV curve are "295 W at 752 V and 290 W at 742 V," the difference is only 5 W at 10 V (1.7%). When the voltage is 742 V, the power conditioner is expected to increase the voltage by 10 V, so that 750 V is exceeded. In reality, a small power difference of about 5 W may be absorbed (ignored) due to fluctuations in the detection voltage (±8 V when the fluctuation is ±1%), changes in the amount of light, and the like. This may cause the power conditioner to not increase the voltage (but decrease it), and the voltage never reaches 750 V. Therefore, control should be performed to ensure "clear power differences" at the boundaries.

[0039] For example, if the optimizer power values ​​on the PV curve are "295 W at 752 V and 275 W at 742 V," the difference is 20 W at 10 V (7%). With this significant power difference, if the power conditioner increases the voltage from 742 V by 10 V, it can reliably detect the power increase and increase the voltage to over 750 V, thus reliably transitioning to OP-MPPT. Embodiment

[0040] Based on the above description, an embodiment of the present invention will be described below with reference to Fig. 1, Fig. 2 and Fig. 3 described.

[0041] Fig. 1 is a voltage-power characteristic (PV curve) illustrating an embodiment of an electric power control method and a voltage converter therefor in a maximum power point tracking controller according to the present invention, Fig. 2 is a functional block diagram of the hardware used to perform the Fig. 1 shown OP-MPPT control is used, and Fig. 3 is a flowchart illustrating a control flow.

[0042] According to the present embodiment, a PV curve of the optimizer output is controlled to have a plateau shape with a marginal step (a significant power difference in a marginal region) as shown in Fig. 1. For example, a stage is provided at 750 V and 820 V. In the falling sections, equal to or lower than 750 V and equal to or higher than 820 V, fixed values ​​for "power control pulse widths" are chosen, which reduce the power values ​​at 750 V and 820 V by approximately 10% (voltage values ​​that practically make the power differences clear). At 750 V or lower, a fixed value is chosen that brings the MPPT voltage to 800 V or higher (e.g., 830 V), and at 820 V or higher, a fixed value is chosen that brings the MPPT voltage to 800 V or lower (e.g., 770 V).

[0043] The 10 percent described above were chosen as voltage values ​​that actually show the voltage differences.

[0044] That is, with reference to a voltage value of a maximum power point provided as a peak of a voltage-power curve (PV curve), the operating voltage of the power conditioner is induced by maintaining an optimal operating point at which the power of a solar cell panel 3 is maximized at a constant power value forming a plateau shape (flat shape) having a lower step whose lower end descends to the slopes of the voltage-power curve 1 on a low-voltage side and a high-voltage side of the voltage-power curve.

[0045] The operating voltage of the power conditioner can then be output by maintaining it in a constant, fixed range in the flat part of the plateau shape.

[0046] For example, if a voltage at the point of maximum power in the voltage-power curve D T(V) is a voltage corresponding to the voltage-power curve on the low-voltage side of the plateau shape, D L (V), and a voltage on the high voltage side of the plateau form is D H (V); D L < D H and the performance at points D L (V) and D H is ΔV lower than the power at point D T (V) (e.g., about 10%, as described above: significant difference in performance).

[0047] If the voltage at the point of maximum power on the voltage-power curve is 800 V, which is a currently common setpoint, the voltage drop until the voltage-power curve is touched on the low-voltage side of the plateau shape is taken as 750 V and the voltage drop until the voltage-power curve is touched on the high-voltage side of the plateau shape is taken as 820 V.

[0048] In this way, with respect to the voltage value of the maximum power point provided as the apex of the voltage-power curve, stable MPPT control can be achieved by making the operating voltage of the power conditioner fall into a constant fixed range in the flat portion of the plateau shape in which a constant power value is maintained, the plateau shape having a lower step whose lower end drops on a low-voltage and a high-voltage side of the voltage-power curve.

[0049] Fig. 2 shows a functional block of the hardware (optimizer) used to perform the Fig. 1 MPPT control is used. In Fig. 2, the output power of the solar cell panel 3 is input to an input device 41 of the optimizer 4. The input voltage is adjusted to a predetermined voltage by a step-up / step-down device 42. In this case, the input voltage is increased to 800 V and output to the power conditioner via an output device 43.

[0050] The input device 41 is connected to a voltage / current / power detector 44 for the plate output and supplies control signals such as power control pulses to the step-up / step-down device 42 via a controller 45. Note that the plate power input to the input device 41 is also supplied to an optimizer power supply 48.

[0051] The controller 45 has the function of maintaining the power of the solar cell panel 3 at a constant power value with respect to the voltage value of the maximum power point, which is provided as the apex of the voltage-power curve at which the voltage of the solar cell panel 3 is maximum, so that the voltage-power curve forms a plateau shape with a step formed by vertically sloping straight lines on the low-voltage side and the high-voltage side, a step formed by vertically sloping straight lines on the low-voltage side and the high-voltage side, respectively, which in Fig. 1 and abut the slopes of the voltage-power curve 1, induces the operating voltage of the power conditioner to fall into a constant fixed range in the flat portion of the plateau shape, then maintains the operating voltage of the power conditioner in the constant fixed range, and outputs the operating voltage as generated power.

[0052] As described above, the step formed by vertically descending straight lines on the low-voltage and high-voltage sides, respectively, which meet the slopes of the voltage-power curve 1, has a value that allows the power difference to be clearly seen during power point tracking, and the D L and the D Hhave performance values ​​that are slightly lower than the performance value of the plateau shape. In fact, the performance difference is a design value determined as the capability (accuracy) of the circuit during circuit design. It is approximately a few percent to ten percent, but can also be larger depending on the accuracy (capability) of the circuit's voltage identification.

[0053] The output device 43 is also connected to a voltage / current / power detector 46, and a feedback control signal for adjusting the boost conversion power is generated by the output device 43 and input to the boost / down converter 42 via the controller 45. When power line communication (PLC) is performed between an external server or the like and the controller 45, a power line communication unit 47 is interposed.

[0054] Fig. Figure 3 is a flowchart illustrating a control sequence performed by controller 45. Each process step is represented in the S-xx format.

[0055] When the control is started (Start), the Fig. 2, the voltage / current / power detector 46 determines whether the voltage of the output device 43 is “not higher than 750 V” or not lower than 820 V and whether the power is suitable for plateau shape control (S-1) or not.

[0056] If the result of the determination is “No” (N: No), the controller 45 performs OP-MPPT to increase power by increasing or decreasing the power control pulses (S-4) and returns to (S-1).

[0057] If it is determined in (S-1) that plateau control is possible (Y: Yes), it is determined whether the voltage value is "750 V or less" (S-2) or not. If the determination result is "Yes," the controller 45 sets the power control pulse width to value B (S-5) and returns to (S-1). Value B is a pulse width estimated by the optimizer to deliver maximum power at 800 V, and is set for use at a voltage "not higher than 750 V."

[0058] If the determination result in (S-2) is N, it is determined whether the voltage is 850 V or more (S-3). If the determination result in (S-3) is N, the controller 45 returns directly to (S-1), but if the result is Y, the controller 45 sets the power control pulse width to the value C (S-6) and returns to (S-1). The value C is a pulse width estimated by the optimizer to deliver maximum power at 800 V, and is set for use at a voltage of "not less than 820 V."

[0059] Through this process, the operating voltage of the power conditioner is induced in a range of “750 to 820 V” and then maintained in the range of “750 to 820 V” so that OP-MPPT control can be performed.

[0060] The present embodiment allows optimizers to be connected independently of the functions of commercially available power conditioners and allows the maximum power output to be extracted on a single-plate basis. List of reference symbols 1 PV curve of the optimizer output power 2 OP-MPPT control range (plateau shape) 21 module-internal parallel connection line 3 solar cell panels 4 Optimizers (OP) 41 Entrance device 42 Up / down device 43 Exit device 44 Voltage / Current / Power Detector (Input Side) 45 Control 46 Voltage / Current / Power Detector (Output Side) 47 Power line communication unit 48 Power supply for optimizers 60 Module 7 Power Conditioners (PCS) 8 System management QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2009-540419

[0008] JP 2018-195225

[0008]

Claims

[1] A method for controlling electric power for maximum power point tracking control intended to efficiently utilize the generated power of a solar module formed from a large number of solar cell panels, wherein: the solar module comprises an optimizer configured to increase the output power of the solar module to a predetermined voltage and a power conditioner provided with a MPPT function; and the optimizer induces an operating voltage of the power conditioner to set an MPPT target voltage of the power conditioner based on a voltage-power characteristic curve of the optimizer and thereby obtain a maximum output power of the solar module. [2] The electric power control method for maximum power point tracking control according to claim 1, wherein the operating voltage of the power conditioner is induced in the manner described in notes 1 and 2 below: Notes 1. When the power conditioner voltage is lower than a target value, the optimizer increases the output power when the power conditioner increases its voltage, and the optimizer decreases the output power when the power conditioner decreases its voltage.

2. When the power conditioner voltage is higher than the target value, the optimizer decreases the output power when the power conditioner increases its voltage, and the optimizer increases the output power when the power conditioner decreases its voltage. [3] Voltage converter to maximum power point tracking controller, designed to efficiently use the power generated by a solar module formed from a large number of solar cell panels, where: each of the solar cell panels has an optimizer and a power conditioner provided with a maximum power point tracking control circuit; the maximum power point tracking circuit comprises a controller configured to maintain the power of the solar module at a constant power value with respect to a voltage value of a maximum power point provided as the apex of a voltage-power curve at which the voltage of the solar module is at its maximum, such that the voltage-power curve forms a plateau shape with a step formed by straight lines that drop vertically on a low-voltage side and a high-voltage side, respectively, and abut corresponding slopes of the voltage-power curve; and using the electric power control method according to claim 1 or 2, the controller induces an operating voltage of the power conditioner to fall within a constant fixed range in a flat sub-range of the plateau shape, then maintains the operating voltage of the power conditioner in the constant fixed range, and outputs the operating voltage as generated output power. [4] A voltage converter according to claim 3, wherein when a voltage at the maximum power point in the voltage-power curve D T (V) is a voltage that matches the voltage-power curve on the low-voltage side of the plateau shape, D L (V) and a voltage on the high voltage side of the plateau form D H (V) is; D L < D H , and the values ​​of the power at a point D L (V) and the power at a point D Hare such that the circuits forming the optimizer and the power conditioner can detect the power difference more clearly than a value of the power at a point D T (V) in the performance tracking control, and that the D L and the D H have slightly lower performance than the plateau shape.

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