KR102370792B1 - Charging device with efficiency-aware cooperative multi-charger technology for high efficiency energy harvesting - Google Patents

Abstract

The present invention relates to a charging device, and more particularly, to develop an efficiency-aware cooperative multi-charging circuit for high-efficiency energy harvesting that improves power conversion efficiency and power range and minimizes inductor current ripple. A charging device according to an embodiment of the present application is a charging device for increasing power conversion efficiency according to an amount of input power, a first solar cell and a second solar cell that convert solar energy into electrical energy and output; A first charging circuit and a second charging circuit for receiving electric energy converted from at least one of the first solar cell and the second solar cell based on any one of a first mode and a second mode, a first solar cell; and a first capacitor connected between the first charging circuit and a second capacitor connected between a second solar cell and the second charging circuit. Efficiency-aware cooperative multichargers technology, when harvesting at least one or more energy solar cells into at least two or more charging circuits, can obtain an increase in power conversion efficiency and an extension of the input power range at various input wattages.

Description

CHARGING DEVICE WITH EFFICIENCY-AWARE COOPERATIVE MULTI-CHARGER TECHNOLOGY FOR HIGH EFFICIENCY ENERGY HARVESTING

The present invention relates to a charging device, and more particularly, to develop an efficiency-aware cooperative multi-charger for high-efficiency energy harvesting that improves power conversion efficiency and power range and minimizes inductor current ripple.

While issues such as depletion of fossil fuels and global warming have become global issues, the development of new energy technologies capable of replacing existing fossil fuels and capable of continuous production is emerging as an urgent problem. As a way to solve these problems, devices for harvesting various types of energy sources such as light, mechanical (wind, waves, sound waves, microvibration, etc.), thermal and magnetic energy, and static electricity that exist around us are ideally designed and related technologies are being reported.

In particular, solar energy harvesting using solar cells is widely used to improve the battery life of mobile devices. A multi-charger system composed of parallel-connected chargers is used to minimize a decrease in efficiency due to instantaneous partial shading, and is an example of a module integrated converter (MIC) method.

However, in existing technologies, when there is a difference in the amount of input power of each charger, the power conversion efficiency is limited, because each charger is independently connected to each solar cell. Therefore, the surplus capability of the charger that is harvesting relatively low power cannot be used.

In addition, in the case of the existing proposed cooperative multi-charger system, unlike the present application, as a technique for improving the maximum P _IN of the charger, η _TOT is not considered. Therefore, when P _PV1 is above a certain level, charger 2 harvests P _PV1 together with charger 1, and thus P _PV2 is not harvested at all and is wasted. Therefore, the problem that η _TOT is very low was found.

The present application intends to propose an efficiency-aware cooperative multi-charger to complement the problems of the prior art.

When harvesting single/multi-input (one or more energy solar cells) using multiple harvesting chargers (two or more chargers), it is an object of the present invention to obtain maximum power conversion efficiency at various input wattages.

Also, to provide a method for efficiently distributing the inductor current in terms of inductor current ripple and input voltage ripple.

Finally, a method for enabling multiple charging through the expansion of the number of inputs and the number of chargers of the harvesting system is provided.

A charging device according to an embodiment of the present application is a charging device for increasing power conversion efficiency according to an amount of input power, a first solar cell and a second solar cell that convert solar energy into electrical energy and output; A first charging circuit and a second charging circuit for receiving electric energy converted from at least one of the first solar cell and the second solar cell based on any one of the first mode and the second mode, the first solar cell and the first It includes a first capacitor connected between the charging circuit and a second capacitor connected between the second solar cell and the second charging circuit.

In one embodiment of the present application, the first charging circuit is a first input terminal for receiving the first electrical energy provided from the first solar cell, and the second receiving the second electrical energy provided from the second solar cell It includes an input terminal, an output terminal for outputting output energy determined based on the first electrical energy and the second electrical energy, and a master terminal for receiving the output energy.

In an embodiment of the present application, a mode determining unit for determining at least one of the first mode and the second mode may be further included.

In an embodiment of the present application, the first charging circuit and the second charging circuit are for adjusting the source switch control unit and the source switch control unit such that the converted energy is distributed based on at least one of the first mode and the second mode and a signal generator for generating a control signal.

In one embodiment of the present application, the signal generator sets a solar cell outputting power higher than the first threshold to a high priority, and sets a solar cell in which the current of the inductor is reduced to a low priority.

In an embodiment of the present application, the first mode equally distributes the converted energy to the first charging circuit and the second charging circuit when the total sum of the converted energy is greater than the second threshold, and the second mode is When the total sum of the converted energy is less than the second threshold value, the converted energy is independently distributed to the first charging circuit and the second charging circuit.

In one embodiment of the present application, in order to distribute the converted energy based on at least one of the first mode and the second mode, the first source switching signal and the second for controlling the source switch for power distribution in the source switch control unit generate at least one of the source switching signals.

In the method of operating a charging device for maximizing power conversion efficiency according to the amount of input power according to an embodiment of the present application, the steps of converting solar energy into electrical energy and outputting the solar energy are converted into electrical energy and converting the converted electrical energy into a first mode and a second mode and receiving the converted electrical energy according to the step of classifying into .

In an embodiment of the present application, the method of operating the charging device includes the steps of receiving the first electrical energy provided from the first solar cell, receiving the second electrical energy provided from the second solar cell, and the first and outputting an output energy determined based on the electrical energy and the second electrical energy and feeding back the output energy.

In an embodiment of the present application, the step of setting the energy solar cell outputting power higher than the first threshold by the signal generator to a high priority, setting the energy solar cell in which the current of the inductor is reduced to a low priority include

In one embodiment of the present application, the step of receiving the electrical energy converted according to the mode, if the first mode, equally distributing the converted energy to the first charging circuit and the second charging circuit, the second mode In one case, it comprises the step of independently distributing the converted energy to the first charging circuit and the second charging circuit.

A charging system according to an embodiment of the present application includes a charging device, a storage unit for storing the output of the charging device, and a load unit for transmitting the output, and in the charging device for increasing power conversion efficiency according to the amount of input power, solar energy Any one of a first mode and a second mode for converting electrical energy converted from at least one of a first solar cell and a second solar cell, and a first solar cell and a second solar cell that converts and outputs to electrical energy A first charging circuit and a second charging circuit to receive based on, a first capacitor connected between the first solar cell and the first charging circuit, and a second capacitor connected between the second solar cell and the second charging circuit includes

Efficiency-aware cooperative multichargers (Efficiency-aware cooperative multichargers) technology can obtain increased power conversion efficiency and extended input power range at various input wattages when harvesting at least one energy solar cell using at least two or more chargers.

In addition, the inductor current distribution technology can minimize the inductor current ripple and the input voltage ripple, and the communication technology between the chargers can theoretically increase the number of inputs and the number of chargers of the harvesting system to infinity.

1A and 1B are an overall structural diagram and an efficiency curve of an existing charging device.
2a and 2b are the overall structural diagram and efficiency curve of the proposed charging device.
3 is a diagram of a charging system according to an embodiment of the present invention.
4 is an overall structural diagram of the unit charger of the charging device.
5 is a flowchart illustrating power distribution criteria of a charging device.
6A, 6B, and 6C are diagrams illustrating a conceptual diagram and a principle of a total power monitor (TPM).
7A and 7B are waveforms showing the application effect of the charging device 10 .
8A and 8B are results of efficiency (η _TOT ) measured using the charging device 10 .

Hereinafter, the present disclosure will be described with reference to the accompanying drawings. As the present disclosure is capable of various changes and may have various embodiments, specific embodiments are illustrated in the drawings and the related detailed description is set forth. However, this is not intended to limit the present disclosure to specific embodiments, and should be understood to include all modifications and/or equivalents or substitutes included in the spirit and scope of the present disclosure. In connection with the description of the drawings, like reference numerals have been used for like elements.

Expressions such as “comprises” or “may include” that may be used in the present disclosure indicate the existence of the disclosed function, operation, or component, and do not limit one or more additional functions, operations, or components. In addition, in the present disclosure, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification is present, but one or more It is to be understood that this does not preclude the possibility of addition or presence of other features or numbers, steps, operations, components, parts, or combinations thereof.

In the present disclosure, expressions such as “or” include any and all combinations of the words listed together. For example, "A or B" may include A, may include B, or may include both A and B.

In the present disclosure, expressions such as “first,” “second,” “first,” or “second,” may modify various components of the disclosure, but do not limit the components. For example, the above expressions do not limit the order and/or importance of corresponding components. The above expressions may be used to distinguish one component from another. For example, both the first user device and the second user device are user devices, and represent different user devices. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

Terms used in the present disclosure are used only to describe specific embodiments, and are not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly dictates otherwise.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present disclosure. does not

1A and 1B are an overall structural diagram and an efficiency curve of the conventional charging device 1 .

Referring to FIG. 1A , the conventional charging device 1 includes a first solar cell (PV1) and a second solar cell (PV2), a first charging circuit (CH1) and a second charging circuit (CH2), a second It includes a first capacitor (C1) and a second capacitor (C2).

The first solar cell PV1 (solar cell) and the second solar cell PV2 convert solar energy into electrical energy and output it.

The first charging circuit CH1 receives electric energy converted from the first solar cell PV1.

The second charging circuit CH2 receives the electric energy converted from the second solar cell PV2.

The first capacitor C1 is connected between the first solar cell PV1 and the first charging circuit CH1, and the second capacitor C2 is between the second solar cell PV2 and the second charging circuit CH2. is connected to

In the case of the existing multi-charging circuit, the output power of each solar cell is independently harvested in each charging circuit. For example, the first solar cell output power P _PV1 is harvested by the first charging circuit CH1 , and the second solar cell output power P _PV2 is harvested by the second charging circuit CH2 . Therefore, the first charging circuit input (P _IN1 ) is equal to the first solar cell output power (P _PV1 ), and the second charging circuit input (P _IN2 ) is equal to the second solar cell output power (P _PV2 ).

As such, when the first charging circuit input (P _IN1 ) is equal to the first solar cell output power (P _PV1 ), and the second charging circuit input (P _IN2 ) is equal to the second solar cell output power (P _PV2 ), Since a large amount of conduction loss occurs in the charging circuit to which a high output is applied, the system power conversion efficiency (η _TOT ) is reduced.

)은 80.5%에 불과하다는 것이 확인할 수 있다.It can be seen that the system power conversion efficiency (η _TOT ) is reduced with reference to FIG. 1B . Referring to Figure 1b, when it is assumed that the first solar cell output power (P _PV1 ) is 2W and the second solar cell (PV2) is 0.2W, since the efficiency of the first charging circuit is lower than the efficiency of the second charging circuit, the system power conversion efficiency (

) is only 80.5%.

2a and 2b are the overall structural diagram and efficiency curve of the proposed charging device 10.

Referring to FIG. 2A , in the charging device 10 for increasing power conversion efficiency according to the amount of input power, the charging device 10 includes a first solar cell (PV1) and a second solar cell (PV2), the second It includes a first charging circuit (CH1) and a second charging circuit (CH2), a first capacitor (C1), and a second capacitor (C2).

The first solar cell PV1 (solar cell) and the second solar cell PV2 convert solar energy into electrical energy and output it.

The first charging circuit (CH1) and the second charging circuit (CH2) may convert electrical energy converted from at least one of the first solar cell (PV1) and the second solar cell (PV2) into any one of the first mode and the second mode receive based on

The first capacitor C1 is connected between the first solar cell PV1 and the first charging circuit CH1, and the second capacitor C2 is between the second solar cell PV2 and the second charging circuit CH2. is connected to

The charging device 10 is the first solar cell output power (P _PV1 ) and the second solar cell output power (P _PV2 ) is distributed to the first charging circuit (CH1) and the second charging circuit (CH2), system power conversion efficiency (η _TOT ).

The first charging circuit CH1 receives the first input terminal V _IN1 for receiving the first electrical energy provided from the first solar cell PV1 and the second electrical energy provided from the second solar cell PV2. A second input terminal for receiving (V _IN2 ), and an output terminal (V _OUT ) for outputting an output energy determined based on the first electrical energy and the second electrical energy, and a master terminal for receiving the output energy (master) do.

Similarly, the second charging circuit CH2 also receives the first electrical energy provided from the first solar cell PV1, the first input terminal V _IN1 , and the second electricity provided from the second solar cell PV2. A second input terminal (V _IN2 ) for receiving energy, an output terminal (V _OUT ) for outputting output energy determined based on the first electrical energy and the second electrical energy, and a master terminal for receiving the output energy (master) includes

The first charging circuit (CH1) and the second charging circuit (CH2) are the source switch control unit 20 and the source switch control unit 20 so that the converted electrical energy is distributed based on at least one of the first mode and the second mode and a signal generator 30 that generates a control signal for adjusting the .

In the first mode, when the total sum of the converted energy is greater than the second threshold, the converted energy is equally distributed to the first charging circuit CH1 and the second charging circuit CH2, and the second mode is the When the total sum is less than the second threshold value, the converted energy is independently distributed to the first charging circuit CH1 and the second charging circuit CH2 . For example, in the first mode, the input power of the first charging circuit (P _IN1 = (P _PV1 + P _PV2 )/2) and the input power of the second charging circuit (P _IN2 = (P _PV1 + P _PV2 )/ 2) is the same. On the other hand, in the second mode, the first charging circuit input power (P _IN1 ) is the same as the first solar cell output power (P _PV1 ), and the second charging circuit input power (P _IN2 ) is the second solar cell output power (P _PV2 ).

)은 89%로 향상될 수 있다. 이와 관련된 자세한 내용은 도4에서 후술될 것이다.Referring to Figure 2b, the first solar cell output power (P _PV1 ) is 2W, the second solar cell (PV2) is 0.2W, assuming that the first mode, the first charging circuit input power (P _IN1 ) and The second charging circuit input power (P _IN2 ) is 1.1W, which is half the sum of the first solar cell output power (P _PV1 ) and the second solar cell output power (P _PV2 ). Therefore, the system power conversion efficiency (η _TOT ) moves to a higher power section, and the system power conversion efficiency (η TOT )

) can be improved to 89%. Details related thereto will be described later with reference to FIG. 4 .

3 is a diagram of a charging system according to an embodiment of the present invention.

Referring to FIG. 3 , the charging system may include a charging device 10 , a storage unit 120 for storing the output of the charging device 10 , and a load unit 110 for transmitting the output.

In this case, the charging device 10 includes a first solar cell (PV1) (solar cell) and a second solar cell (PV2) in the charging device 10 that increases the power conversion efficiency according to the amount of input power, It includes a first charging circuit (CH1) and a second charging circuit (CH2), a first capacitor (C1) and a second capacitor (C2). A detailed description related thereto will be omitted since it is disclosed in FIGS. 2A to 2B .

The charging system includes a plurality of charging circuits, and in this case, N of CHN may be a natural number of 4 or more. Likewise, although two solar cells are also expressed, the present invention is not limited thereto and may exist in plurality.

In addition, the charging system may further include a mode determining unit 130 that determines at least one of the first mode and the second mode. The mode determiner 130 feeds back the output power of the first charging circuit to select one of the first mode and the second mode. The mode determining unit 130 may exist the same as the number of charging circuits.

4 is an overall structural diagram of a unit charging circuit of the charging device 10 .

Referring to FIG. 4 , the unit charging circuit structure of the charging device is a double input single inductor booster. A first input terminal (V _IN1 ) and a second input terminal (V _IN2 ) exist, and an output terminal (V _OUT ) and a master terminal (master) exist. The number of inputs can be determined by considering three things. The three considerations are as follows. The first is the granularity of the module division of energy solar cells, the second is the partial shading trend, and finally, the tradeoff between the power density and the system power conversion efficiency (η _TOT ) increase due to the proposed efficiency-aware cooperative control method.

The present application provides a first solar cell (PV1) and a second solar cell (PV2) and a first charging circuit (CH1) and a charging device (10) having two inputs to the second charging circuit (CH2) for clear explanation. Although presented as an example, the number of solar cells and charging circuits may vary depending on the application.

The first charging circuit CH1 and the second charging circuit CH2 control the source switch control unit 20 and the source switch control unit 20 so that the converted energy is distributed based on at least one of the first mode and the second mode and a signal generator for generating a control signal for

A 35V Li-ion battery, 10 μF input/output capacitors (C _IN /C _OUT ), and a 10 μH inductor (L) were used.

The first comparator and the second comparator compare the inputs (V _IN1 , V _IN2 ) of the charging circuit and the fraction(F _VOC ) of the open circuit voltage (V _OC ) of the energy solar cell to obtain LS ₁ and LS, respectively. create ₂ . Through this, the maximum power point (MPP) is tracked.

The first signal generator 31 appropriately processes LS ₁ and LS ₂ to generate a first switching signal LS for controlling a low-side switch (S _LS ). The second switching signal HS for controlling the high-side switch S _HS is supplied from the second signal generator 32 . The second signal generating unit 32 is configured to detect a zero inductor current (I _L ), or LS ₂ or LS ₁ to be “high” rather than a previous signal immediately following immediately after at least one of LS ₁ or LS ₂ turn off S _HS .

The inductor current I _L ripple may be reduced through the first signal generator 31 . Energy solar cells that output relatively high power will have a higher priority. Accordingly, an energy solar cell having a high priority is harvested when the inductor current (I _L ) increases, and an energy solar cell having a low priority is harvested when the inductor current (I _L ) is decreased.

When the zero-current switching (ZCS) block included in the second signal generator 32 is zero I _L , a V _ZCS signal is generated and S _HS is turned off according to the V _ZCS signal. When P _TOT is greater than the reference value (V _{P_TOT} > V _{P_TH} ), COOP becomes “high” and the system operates in the first mode.

If the falling I _L is not sufficient to harvest P _PV2 , rising I _L is used to additionally harvest P _PV2 . When P _TOT is less than the reference value (V _{P_TOT} < V _{P_TH} ), COOP becomes “low” and the system operates in the second mode.

The source switch control unit 20 is a first source switching signal (EN _S1 ) and a second source switching signal (EN) for controlling the on-off of the first switch (S ₁ ) and the second switch (S ₂ ) for power distribution _S2 ) is created. The proposed system is divided into a first mode and a second mode. In order to determine which mode to operate in, a total power monitor (TPM) estimates P _TOT and outputs the estimated value in the voltage domain (V _{P_TOT} ). A third comparator compares the voltage domain V _{P_TOT} and the threshold voltage V _{P_TH} to generate a COOP signal, and the operation mode of the system is determined according to the signal.

5 is a flowchart illustrating power distribution criteria of the charging device 10 .

Referring to FIG. 5 , in the first mode, when the total sum of the converted energy is greater than the second threshold, the converted energy is equally distributed to the first charging circuit CH1 and the second charging circuit CH2, and the second In the second mode, when the sum of the total conversion energy is less than the second threshold value, the converted energy is independently distributed to the first charging circuit CH1 and the second charging circuit.

Step S11 compares the sum of the output powers of the plurality of solar cells (P _TOT =P _V1 +P _V2 ) and a second threshold value.

In step S12, when the sum of the output powers of the plurality of solar cells (P _TOT =P _V1 +P _V2 ) is greater than the second threshold, COOP becomes “high”.

In step S13, the charging device 10 operates in the first mode.

In step S14, the first solar cell input power (P _IN1 ) is P _TOT /2, and the second solar cell input power (P _IN2 ) is P _TOT /2.

For example, if the first solar cell output power (P _PV1 ) is 2W and the second solar cell output power (P _PV2 ) is 2.4W, the sum of the output powers of a plurality of solar cells (P _TOT =P _V1 +P _V2 ) is 4.4 W, but with 4.4 W/2 = 2.2 W, the charging device 10 enters the first mode because the overall system power conversion efficiency η(P _TOT ) is lower than the individual system power conversion efficiency η(P _TOT /2). In operation, the output power is 2.2W with the first charging circuit input power (P _IN1 = (P _PV1 + P _PV2 )/2) and the second charging circuit input power (P _IN2 = (P _PV1 + P _PV2 )/2) are distributed each

As such, when COOP becomes “high”, the system operates in the first mode, and as the system operates in the first mode, the master and slave charging circuits operate with the same switching signals. At this time, the switching signals (LS _MST , HS _MST , EN _{S1_MST} , EN _{S2_MST} ) of the master charging circuit are used as the switching signals of the slave charging circuit, because mismatch between charging circuits can cause input power unevenness. .

Step S15 is when the overall system power conversion efficiency η(P _TOT ) is higher than the individual system power conversion efficiency η(P _TOT /2).

In step S16, COOP becomes “low”.

In step S17, the charging device 10 operates in the second mode.

In step S18, the first solar cell input power (P _IN1 ) is P _PV1 , and the second solar cell input power (P _IN2 ) is P _PV2 .

For example, if the first solar cell output power (P _PV1 ) is 2W and the second solar cell output power (P _PV2 ) is 0.6W, the sum of the output powers of the plurality of solar cells (P _TOT ) is 2.6W, but 2.6W Because η(P _TOT ) is higher than η(P _TOT /2) with W/2 = 1.3W, the charging device 10 operates in the second mode, so that power is supplied to each charging circuit, and the first charging circuit input is 2W , the second charging circuit input is independently distributed to 0.6W.

6A, 6B, and 6C are diagrams illustrating a conceptual diagram and a principle of a total power monitor (TPM).

)을 추정하여 그 추정치를 전압 도메인(V_{P_TOT})으로 출력한다. 한편 P_PV vs V_OC 커브는 기울기α의 직선으로 근사될 수 있다. 따라서 복수의 솔라셀의 출력 전력의 합(P_TOT)은 α1V_OC1 + α2V_OC2 로 표현 될 수 있다.Referring to Figure 6a, TPM is a Total Power Monitor, the sum of the output power of a plurality of solar cells (

) and output the estimate in the voltage domain (V _{P_TOT} ). Meanwhile, the P _PV vs V _OC curve may be approximated by a straight line with a slope α. Therefore, the sum of the output powers of the plurality of solar cells (P _TOT ) can be expressed as α1V _OC1 + α2V _OC2 .

Referring to FIG. 6B , V _OC1 and V _OC2 are stored in the first capacitor C1 and the second capacitor C2 , respectively. The stored V _OCs are divided by a capacitive divider. Therefore, α1 and α2 are expressed as C1 / (C1 + C1') and C2 / (C2 + C2'), respectively.

Referring to FIG. 6C , the TPM includes a switched capacitor and a non-overlapping clock generator to reduce charge loss. α1V _OC1 and α2V _OC2 output from the TPM are compared with each other to determine which solar cell has the highest power. If P _PV1 is greater than P _PV2 , CMP _P becomes “high”, and LS ₁ is given a higher priority than LS ₂ . If LS2 changes to “ _high ” when LS1 is “ _high ”, P _PV2 is harvested after P _PV1 harvesting is completed.

7A and 7B are waveforms showing the application effect of the charging device 10 .

Referring to FIGS. 7A and 7B , a situation in which the first charging circuit CH1 and the second charging circuit CH2 harvest the first solar cell PV1 and the second solar cell PV2 was measured.

Referring to FIG. 7A , it shows the operation of the first mode when P _PV1 = 502 mV and P _PV2 = 240 mV. When V _IN1 is greater than F _VOC1 , LS ₁ and LS become “high”. When LS1 and _LS become “high”, IL increases, and _IL is supplied from the first solar cell PV1. V _IN2 becomes greater than F _VOC2 , and LS ₂ becomes “high”. After V _IN1 becomes smaller than F _VOC1 , I _L decreases and the second solar cell PV2 is harvested.

Referring to FIG. 7B , an operation of the first mode is shown when P _PV1 = 502 mV and P _PV2 = 446 mV. The measured waveform when P _PV2 is increased is as follows. As the duty cycle of LS ₂ increases and the second solar cell PV2 increases (rising) I _L is additionally harvested.

8A and 8B are results of efficiency (η _TOT ) measured using the charging device 10 .

8a and 8b are efficiency (η _TOT ) results measured by applying the charging device 10 of the present application.

Referring to FIG. 8A , the first solar cell PV1, the first charging circuit CH1, and the second charging circuit CH2 were harvested. It is a view comparing the case of applying the existing charging device (1) and the case of applying the charging device (10). The graph indicated by the dotted line shows that the charging device 10 is applied to the prior art, and when compared to the case where only the existing charging station 1 is applied, η _TOT increased by up to 16%, and the input power range (η of 80% or more η _TOT ) was improved by 0.84 W.

Referring to FIG. 8B , harvesting was performed with the first solar cell PV1 and the second solar cell PV2 , and the first charging circuit CH1 and the second charging circuit CH2 . P _PV2 was fixed at 43 mW. It is a view comparing the case of applying the existing charging device (1) and the case of applying the charging device (10). The graph indicated by the dotted line shows that the charging device 10 is applied to the prior art, and when compared to the case where only the existing charging station 1 is applied, η _TOT increased by up to 14%, and the input power range (η of 80% or more _TOT ) was improved by 0.61 W.

The operation method of the charging device 10 for maximizing the power conversion efficiency according to the amount of input power as in the present application is as follows.

First, it is a step of converting solar energy into electrical energy and outputting it. For example, the first electric energy provided from the first solar cell PV1 is received and the second electric energy provided from the second solar cell PV2 is received. Thereafter, output energy determined based on the first electrical energy and the second electrical energy is output, and the previously outputted output energy is fed back.

Next, it is a step of dividing the converted electrical energy into a first mode and a second mode. For example, the signal generator sets a solar cell outputting power higher than the first threshold to a high priority, and sets a solar cell in which the inductor current is reduced to a low priority. Also, when the sum of the output powers of the plurality of solar cells (P _TOT ) is greater than the second threshold value, the COOP becomes “high” and the charging device 10 operates in the first mode, and the output power of the plurality of solar cells When the sum P _TOT is less than the second threshold, COOP becomes “low” and the charging device 10 operates in the second mode.

Finally, it is a step of receiving the converted electrical energy. For example, in the first mode, the converted energy is equally distributed to the first charging circuit (CH1) and the second charging circuit (CH2), and in the second mode, the converted energy is distributed to the first charging circuit (CH1) and Independently distributed to the second charging circuit (CH2).

The present application provides a charging device (10) including an efficiency-aware cooperative multi-chargers (Efficiency-aware cooperative multi-chargers) technology that maximizes power conversion efficiency according to various input power amounts of a single/multi-input multiple harvesting charger system. As an embodiment, an inductor current distribution technology for minimizing inductor current ripple and input voltage ripple is provided, and a communication technology between chargers that guarantees scalability of the number of inputs and the number of chargers of a harvesting system is provided.

Embodiments disclosed in the present specification and drawings are merely provided for specific examples to easily explain the contents of the present disclosure and help understanding, and are not intended to limit the scope of the present disclosure. Therefore, the scope of the present disclosure should be construed as including all changes or modifications derived from the technical spirit of the present disclosure in addition to the embodiments disclosed herein as being included in the scope of the present disclosure.

Existing charging device: 1
Charging device: 10
Charging system: 100
Rod part: 110
Storage: 120
Mode determiner: 130
Source switch control: 20
Signal generator: 30
First signal generator: 31
Second signal generator: 32
C1: first capacitor
C2: second capacitor
PV1: 1st solar cell
PV2: 2nd solar cell
CH1: first charging circuit
CH2: second charging circuit
V _OUT : output terminal
V _IN1 : 1st input terminal
V _IN2 : 2nd input terminal
master: master terminal

Claims (12)

In the charging device for increasing the power conversion efficiency according to the amount of input power,
A first solar cell (solar cell) and a second solar cell that converts solar energy into electrical energy and outputs;
A first charging circuit comprising an inductor receiving electric energy converted from at least one of the first solar cell and the second solar cell, and receiving the electric energy based on any one of a first mode and a second mode and a second charging circuit;
a first capacitor connected between the first solar cell and the first charging circuit; and
a second capacitor connected between the second solar cell and the second charging circuit;
The first charging circuit and the second charging circuit,
a source switch control unit configured to distribute the electrical energy based on at least one of the first mode and the second mode; and
and a signal generator for generating a control signal for adjusting the source switch controller,
The signal generator generates the control signal to harvest by setting a solar cell outputting power higher than a first threshold to a high priority, and sets a solar cell in which the current of the inductor is reduced to a low priority to harvest A charging device that generates the control signal to be turned on. According to claim 1,
The first charging circuit,
a first input terminal for receiving the first electrical energy provided from the first solar cell;
a second input terminal for receiving second electrical energy provided from the second solar cell;
an output terminal for outputting an output energy determined based on the first electrical energy and the second electrical energy; and
Charging device further comprising a master terminal for receiving the output energy. According to claim 1,
The charging device may further include a mode determining unit for determining at least one of the first mode and the second mode. delete delete According to claim 1,
In the first mode, when the total sum of the electrical energy is greater than a second threshold, the electrical energy is equally distributed to the first charging circuit and the second charging circuit,
The second mode is a charging device for independently distributing the electrical energy to the first charging circuit and the second charging circuit when the total sum of the electrical energy is less than a second threshold value. 7. The method of claim 6,
to distribute the electrical energy based on at least one of the first mode and the second mode;
A charging device for generating at least one of a first source switching signal and a second source switching signal for controlling a source switch for power distribution in the source switch controller. In the operating method of a charging device for maximizing power conversion efficiency according to the amount of input power,
The first and second solar cells converting solar energy into electrical energy and outputting it;
dividing the converted electrical energy into a first mode and a second mode by the first and second charging circuits; and
and receiving, by the first and second charging circuits, the electrical energy converted according to the mode,
The first and second charging circuits divide the converted electrical energy into a first mode and a second mode,
generating a control signal to cause the electrical energy to be distributed based on at least one of the first mode and the second mode;
The step of generating the control signal comprises:
generating the control signal to be harvested by setting an energy solar cell outputting power higher than a first threshold to a high priority; and
generating the control signal to be harvested by setting an energy solar cell in which a current of an inductor receiving electric energy converted from at least one of the first solar cell and the second solar cell is reduced to a low priority How to operate the charging device. 9. The method of claim 8,
The method of operation of the charging device,
Receiving the first electrical energy provided by the first input terminal from the first solar cell;
receiving, by a second input terminal, a second electrical energy provided from a second solar cell;
determining at least one of the first mode and the second mode by a mode determination unit;
causing the electrical energy to be distributed based on at least one of the first mode and the second mode, by a source switch control unit; and an output terminal determined based on the first electrical energy and the second electrical energy. and outputting
The method of operating a charging device further comprising the step of the master terminal feeding back the output energy to the mode determination unit. delete 9. The method of claim 8,
Receiving the electrical energy converted according to the mode comprises:
In the first mode, equally distributing the electrical energy to the first charging circuit and the second charging circuit;
In the case of the second mode, the method of operating a charging device comprising the step of independently distributing the converted electrical energy to the first charging circuit and the second charging circuit. charging device;
a storage unit for storing the output of the charging device; and
In the charging system comprising a rod for transmitting the output,
The charging device is
In the charging device for increasing the power conversion efficiency according to the amount of input power,
A first solar cell (solar cell) and a second solar cell that converts solar energy into electrical energy and outputs;
A first charging circuit comprising an inductor receiving electric energy converted from at least one of the first solar cell and the second solar cell, and receiving the electric energy based on any one of a first mode and a second mode and a second charging circuit;
a first capacitor connected between the first solar cell and the first charging circuit; and
a second capacitor connected between the second solar cell and the second charging circuit;
including,
The first charging circuit and the second charging circuit,
a source switch control unit configured to distribute the electrical energy based on at least one of the first mode and the second mode; and
and a signal generator for generating a control signal for adjusting the source switch controller,
The signal generator generates the control signal to harvest by setting a solar cell outputting power higher than a first threshold to a high priority, and sets a solar cell in which the current of the inductor is reduced to a low priority to harvest A charging system that generates the control signal to be turned on.

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