CN219801910U - Energy storage power generation system - Google Patents

Abstract

The utility model provides an energy storage power generation system which comprises a plurality of photovoltaic modules, a plurality of energy storage modules and an inverter, wherein each photovoltaic module is used for converting solar energy into electric energy; the energy storage modules are connected with the photovoltaic modules in a one-to-one correspondence manner, so that each energy storage module receives electric energy output by the corresponding photovoltaic module to carry out local energy storage or external power supply, and the energy storage modules are connected in series to form a high-voltage direct current branch; the first input end and the second input end of the inverter are respectively connected with two ends of the high-voltage direct-current branch, and the output end of the inverter is used for being respectively connected with a power grid and a local load. The energy storage power generation system has good dilatability, is convenient to be arranged into a small, medium or large energy storage power generation system, and reduces the scale limit.

Description

Energy storage power generation system

Technical Field

The utility model relates to the field of photovoltaic energy, in particular to an energy storage power generation system.

Background

As shown in fig. 1A, a photovoltaic energy storage power generation system in the prior art generally includes a photovoltaic module formed by connecting a plurality of photovoltaic modules 11 in series, a photovoltaic integrated machine 12, a DC/DC converter 13 and a battery module 14, wherein the photovoltaic modules 11 are used for converting solar energy into direct current electric energy, the photovoltaic integrated machine 12 includes a photovoltaic controller 121 and an inverter 122, the photovoltaic controller 121 is connected with the inverter 122 to form a high-voltage direct current bus, the photovoltaic controller 121 is used for supplying a part of direct current electric energy output by the photovoltaic modules 11 to the battery module 14 for charging after being regulated and limited by the DC/DC converter 13, and the photovoltaic controller 121 is also used for inverting another part of direct current electric energy output by the photovoltaic modules 11 into alternating current through the inverter 122 and then supplying the alternating current electric energy to the power grid 15 or the local load 16. However, since the battery module 14 is arranged in a concentrated structure by a plurality of battery packs, when thermal runaway such as combustion, explosion, etc. occurs in a single battery pack, the thermal runaway is easily caused to occur in the remaining battery packs.

In order to solve the above technical problems, related technologies propose to disperse photovoltaic modules in a photovoltaic energy storage power generation system into a plurality of photovoltaic modules, disperse a battery module into a plurality of energy storage modules, set up a plurality of low-power inverters, and connect one photovoltaic module with one energy storage module and one inverter in sequence, so that each photovoltaic module is in grid-connected power generation through respective inverter inversion. However, since the distributed arrangement mode cannot output high-voltage direct-current electric energy to the outside, the distributed arrangement mode is only suitable for a small-sized photovoltaic energy storage power generation system, and therefore the scale of the photovoltaic energy storage power generation system is limited.

Disclosure of Invention

In view of the above, the present utility model provides an energy storage power generation system to solve the problem of scale limitation of the photovoltaic energy storage power generation system of the related art.

The utility model provides an energy storage power generation system which comprises a plurality of photovoltaic modules, a plurality of energy storage modules and an inverter, wherein each photovoltaic module is used for converting solar energy into electric energy; the energy storage modules are connected with the photovoltaic modules in a one-to-one correspondence manner, so that each energy storage module receives electric energy output by the corresponding photovoltaic module to carry out local energy storage or external power supply, and the energy storage modules are connected in series to form a high-voltage direct current branch; the first input end and the second input end of the inverter are respectively connected with two ends of the high-voltage direct-current branch, and the output end of the inverter is used for being respectively connected with a power grid and a local load.

In one embodiment, each energy storage module is disposed at the bottom or the side of the corresponding photovoltaic module.

In one embodiment, each energy storage module comprises an MPPT controller, a first DC/DC converter and a battery pack, wherein the input end of the MPPT controller is connected with the output end of the photovoltaic module, the input end of the first DC/DC converter is connected with the output end of the MPPT controller, and the battery pack is connected with the output end of the first DC/DC converter.

In one embodiment, the voltage output by the MPPT controller is greater than the charging voltage of the battery pack, the first DC/DC converter is a bi-directional DC/DC converter, the first DC/DC converter is configured to operate in a buck mode when the MPPT controller is charging the battery pack, and in a boost mode when the battery pack is powering the inverter.

In one embodiment, the voltage output by the MPPT controller is less than the charging voltage of the battery pack, the first DC/DC converter is a bi-directional DC/DC converter, the first DC/DC converter is configured to operate in a boost mode when the MPPT controller is charging the battery pack, and in a buck mode when the battery pack is powering the inverter.

In one embodiment, each battery pack includes a plurality of batteries connected in series and a battery management unit connected to each battery to detect power information of each battery;

the MPPT controller is connected with the battery management unit so that the MPPT controller controls the first DC/DC converter to work or stop working according to the electric quantity information.

In one embodiment, the MPPT controller includes a second DC/DC converter connected between the photovoltaic module and the first DC/DC converter, and a processor connected to the first DC/DC converter, the second DC/DC converter, and the battery pack, respectively.

In one embodiment, the processor is in communication with the inverter;

the processor is used for charging the battery pack through the second DC/DC converter and the first DC/DC converter under the condition that a first scheduling instruction sent by the inverter is received;

the processor is used for supplying power to the inverter through the first DC/DC converter and/or the second DC/DC converter under the condition that the second scheduling instruction sent by the inverter is received.

In one embodiment, the inverter is a bi-directional inverter, and the inverter is configured to charge the battery pack through the first DC/DC converter upon receiving a third scheduling command sent by the power grid.

In one embodiment, the second DC/DC converter is a boost DC/DC converter.

In the energy storage power generation system, on one hand, the photovoltaic modules are in one-to-one correspondence connection with the energy storage modules, so that the energy storage capacity and power of a single energy storage module can be reduced, the risk of thermal runaway of the single energy storage module is reduced, and the energy storage modules are distributed in space, so that the risk of thermal runaway of the rest energy storage modules caused by the thermal runaway of the single energy storage module is reduced. On the other hand, the high-voltage direct current branch circuit formed by connecting the energy storage modules in series is connected with the inverter, and the step-by-step integrated topological structure ensures that the energy storage power generation system has better capacity expansion, is convenient to arrange into a small-sized, medium-sized or large-sized energy storage power generation system, and reduces the scale limit of the photovoltaic energy storage power generation system.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model. Furthermore, these drawings and the written description are not intended to limit the scope of the inventive concept in any way, but to illustrate the inventive concept to those skilled in the art by referring to the specific embodiments.

Fig. 1A is a schematic circuit diagram of a photovoltaic energy storage power generation system in the prior art.

Fig. 1B shows a schematic layout of a photovoltaic energy storage power generation system in the prior art.

Fig. 2 shows a block diagram of a power storage generation system according to an embodiment of the present utility model.

Fig. 3 shows a schematic circuit configuration of an energy storage power generation system according to an embodiment of the present utility model.

Fig. 4 shows another circuit configuration diagram of the energy storage power generation system according to the embodiment of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Fig. 2 shows a block diagram of a power storage generation system according to an embodiment of the present utility model. As shown in fig. 2, the energy storage power generation system includes a plurality of photovoltaic modules 21, a plurality of energy storage modules 22, and an inverter 23. Wherein the plurality is at least two.

Each photovoltaic module 21 is used to convert solar energy into electrical energy, such as dc electrical energy. The photovoltaic module 21 may be constituted by one photovoltaic panel or at least two photovoltaic panels in series.

The plurality of photovoltaic modules 21 are connected with the plurality of energy storage modules 22 in a one-to-one correspondence manner, so that each energy storage module 22 receives electric energy output by the corresponding photovoltaic module 21 to carry out local energy storage or external power supply. And, a plurality of energy storage modules 22 are connected in series to form a high voltage direct current branch. Illustratively, the plurality of photovoltaic modules 21 are connected in parallel with the plurality of energy storage modules 22 in a one-to-one correspondence manner, and the plurality of photovoltaic modules 21 are connected in series with a plurality of parallel branches formed by the plurality of energy storage modules 22, so that the series branches form a high-voltage direct current branch. The high-voltage direct current branch circuit can be a high-voltage direct current bus.

A first input terminal (one terminal labeled "+" in fig. 2) and a second input terminal (one terminal labeled "-" in fig. 2) of the inverter 23 are respectively connected to two ends of the high-voltage dc branch, so as to receive the electric energy output by the high-voltage dc branch. The output of the inverter 23 is used to connect with the grid 24 and a local load 25, respectively, to supply power to the grid 24 or the local load 25. Illustratively, the inverter 23 is a high-power inverter 23, and may convert the electric energy output by the high-voltage direct-current branch into 380V of alternating current and supply the alternating current to the power grid 24, or convert the alternating current into 220V of alternating current and supply the alternating current to the local load 25.

In the above scheme, on the one hand, the plurality of photovoltaic modules 21 are connected with the plurality of energy storage modules 22 in a one-to-one correspondence manner, so that the energy storage capacity and power of a single energy storage module 22 can be reduced, the risk of thermal runaway of the single energy storage module 22 is reduced, the plurality of energy storage modules 22 can be distributed in space, and distributed arrangement is realized, so that the risk of thermal runaway of the rest of energy storage modules 22 caused by the thermal runaway of the single energy storage module 22 is reduced. On the other hand, the plurality of energy storage modules 22 are connected in series to form a high-voltage direct-current branch, and the high-voltage direct-current branch is connected with the inverter 23, so that the energy storage power generation system has better capacity expansion and compatibility due to the step-by-step integrated topological structure, the energy storage power generation system is conveniently arranged into a small-sized, medium-sized or large-sized energy storage power generation system, and the scale limitation on the photovoltaic energy storage power generation system is reduced.

In addition, the above scheme performs local energy storage through the energy storage module 22, which is beneficial to greatly reducing disturbance of the photovoltaic module 21 to the energy storage power generation system.

In an application scenario, the energy storage module 22 is disposed at the bottom or the side of the photovoltaic module 21 to form an integrated energy storage power generation module, and the energy storage power generation module can be prefabricated and transported to the site for installation, so that the site installation and maintenance are simple and efficient.

As shown in fig. 1B, in the prior art, when the photovoltaic energy storage power generation system is applied to a residential building, the photovoltaic module 11 is usually placed on the roof A1 of the building, and the integrated photovoltaic storage device 12 and the battery module 14 are placed in the interior of the building or in the area A2 such as the eave, so that the safety accident is easily caused once the thermal runaway occurs in the battery module 14. In addition, the photovoltaic energy storage power generation system of the prior art may further include an electricity meter 17 and a data recording device 18, wherein the electricity meter is used for recording the power supply amount of the power grid 14, and the data recording device 18 is connected with the optical storage integrated machine 12 through the Internet (Internet) to collect and record relevant data information of the photovoltaic energy storage power generation system.

Compared to the prior art, please refer to fig. 2, the above scheme of the present utility model disperses the plurality of energy storage modules 22 in space, which is more helpful for avoiding causing safety accidents and reducing potential safety hazards. And, through integrating energy storage module 22 on photovoltaic module 21, can install energy storage module 22 and photovoltaic module 21 together in the roof position of keeping away from the activity region to under the circumstances that energy storage module 22 appears thermal runaway, can reduce the injury to the user to the maximum extent, make the security of system higher.

In one embodiment, as shown in fig. 2, each energy storage module 22 includes an MPPT (Maximum Power Point Tracking, maximum power tracking point) controller 221, a first DC/DC converter 222, and a battery pack 223. Wherein, the liquid crystal display device comprises a liquid crystal display device,

an input terminal of the MPPT controller 221 is connected to an output terminal of the photovoltaic module 21, an input terminal of the first DC/DC converter 222 is connected to an output terminal of the MPPT controller 221, and the battery pack 223 is connected to an output terminal of the first DC/DC converter 222. In this connection, MPPT controller 221 may track the maximum power of photovoltaic module 21, so that photovoltaic module 21 outputs electrical energy at the maximum power. In this way, the MPPT controller 221 may efficiently charge the battery pack 223 through the first DC/DC converter 222 or the MPPT controller 221 may efficiently supply power to the inverter 23, so as to maximize the power generation efficiency of the photovoltaic module 21.

Illustratively, the photovoltaic module 21 may be a photovoltaic panel, which has an output power of 300W to 500W (inclusive) and an open circuit voltage of about 40V when converting solar energy into electric energy. The battery 223 may be a micro battery 223 with a voltage between 24V and 48V (inclusive) and a power between 200Wh and 500Wh (inclusive).

In one embodiment, as shown in fig. 2, the voltage output by MPPT controller 221 is greater than the charging voltage of battery pack 223, first DC/DC converter 222 is a bi-directional DC/DC converter, and first DC/DC converter 222 is configured to operate in a buck mode when MPPT controller 221 charges battery pack 223 and in a boost mode when battery pack 223 supplies power to inverter 23.

Illustratively, the bi-directional DC/DC converter is a Buck converter that operates in Buck mode when MPPT controller 221 charges battery pack 223; the Buck converter operates in Boost mode when the battery pack 223 is supplying power to the inverter 23.

The above-mentioned structure can make the energy storage power generation system be applicable to the scene that the output voltage of MPPT controller 221 is greater than the charge voltage of group battery 223, make MPPT controller 221 when charging group battery 223, supply group battery 223 after stepping down the electric energy that MPPT controller 221 outputted through first DC/DC converter 222 earlier to and when group battery 223 supplies power to inverter 23, supply group battery 23 after stepping up the electric energy that group battery 223 outputted through first DC/DC converter 222 earlier.

In one embodiment, as shown in fig. 2, the voltage output by MPPT controller 221 is less than the charging voltage of battery pack 223, first DC/DC converter 222 is a bi-directional DC/DC converter, and first DC/DC converter 222 is configured to operate in a boost mode when MPPT controller 221 charges battery pack 223 and in a buck mode when battery pack 223 supplies power to inverter 23.

Illustratively, the bi-directional DC/DC converter is a Boost converter that operates in Boost mode when MPPT controller 221 charges battery pack 223; the Boost converter operates in buck mode when the battery pack 223 is supplying power to the inverter 23.

The above-mentioned structure can make the energy storage power generation system be applicable to the scene that the output voltage of MPPT controller 221 is less than the charging voltage of group battery 223, make MPPT controller 221 when charging group battery 223, supply group battery 223 after stepping up the electric energy that MPPT controller 221 outputted through first DC/DC converter 222 earlier to and when group battery 223 supplies power to inverter 23, supply inverter 23 after stepping down the electric energy that group battery 223 outputted through first DC/DC converter 222 earlier.

In one embodiment, referring to fig. 2 and 3, each of the battery packs 223 includes a plurality of batteries (not labeled in the drawing) connected in series and a battery management unit 223A connected to each of the batteries to detect charge information of each of the batteries, respectively. The MPPT controller 221 is connected to the battery management unit 223A such that the MPPT controller 221 controls the first DC/DC converter 222 to operate or stop operating according to the power information.

Illustratively, in the case of local energy storage, the MPPT controller 221 controls the first DC/DC converter 222 to operate to charge the battery pack 223 through the first DC/DC converter 222 according to the power information being smaller than the maximum power value of the battery pack 223. In the case of external power supply, the MPPT controller 221 controls the first DC/DC converter 222 to operate according to the power information being greater than the first power threshold value, so as to transmit the power of the battery pack 223 to the inverter 23 through the first DC/DC converter 222; the MPPT controller 221 controls the first DC/DC converter 222 to stop operating according to the power information being less than the first power threshold, so that the battery pack 223 stops supplying power to the outside. Wherein the first power threshold is less than the maximum power value.

It should be noted that, in this example, the specific control procedure of the MPPT controller 221 for operating or stopping the first DC/DC converter 222 according to the power information is a conventional control procedure in the prior art in the case of locally storing energy or externally supplying power, and this example is not used for limiting the specific control procedure, but is used for explaining the connection relationship between the MPPT controller 221 and the battery pack 223.

In one embodiment, referring to fig. 2 and 3, mppt controller 221 includes a second DC/DC converter (not labeled in fig. 3) connected between photovoltaic module 21 and first DC/DC converter 222, and a processor 221A connected to first DC/DC converter 222, second DC/DC converter, and battery pack 223, respectively.

Illustratively, an input of the second DC/DC converter is connected to an output of the photovoltaic module 21, an output of the second DC/DC converter is connected to an input of the first DC/DC converter 222, and the processor 221A is connected to control terminals of the first and second DC/DC converters 222 and 222, respectively. The processor 221A is connected with the battery pack 223 to receive power information of the battery pack 223.

In the case of local energy storage, the processor 221A controls the first DC/DC converter 222 and the second DC/DC converter to operate when the power information of the battery pack 223 is smaller than the maximum power value, so that the second DC/DC converter stores the power output by the photovoltaic module 21 to the battery pack 223 through the first DC/DC converter 222 to realize local energy storage. In the case where the power information is equal to the maximum power value, the processor 221A stops the operation of the first DC/DC converter 222 and the second DC/DC converter, ending the charging of the battery pack 223.

In the case of external power supply, the processor 221A controls the second DC/DC converter to stop operating in the case where the power information of the battery pack 223 is greater than the first power threshold value, so that the battery pack 223 transmits power to the inverter 23 through the first DC/DC converter 222. The processor 221A controls the first DC/DC converter 222 and the second DC/DC converter to operate such that the battery pack 223 transmits electric power to the inverter 23 through the first DC/DC converter 222 and the photovoltaic module 21 transmits electric power to the inverter 23 through the second DC/DC converter in a case where the electric power information of the battery pack 223 is greater than the second electric power threshold and less than the first electric power threshold.

It should be noted that, in this example, the specific control procedure of the processor 221A on the operating states of the first DC/DC converter 222 and the second DC/DC converter according to the electric quantity information is a conventional control procedure in the prior art, and this example is not used to limit the specific control procedure, but is used to describe the connection relationship between the processor 221A and the first DC/DC converter 222, the second DC/DC converter, and the battery pack 223.

In addition, in the centralized energy storage power generation system in the prior art, as shown in fig. 1A, since the photovoltaic module is formed by connecting a plurality of photovoltaic modules 11 in series, the photovoltaic module 21 only can provide high-voltage direct current electric energy, so that a high-power DC/DC converter 13 needs to be used for adapting to the photovoltaic module, wherein the high-power DC/DC converter 13 needs to adopt a high-voltage transistor design circuit structure, which results in higher cost of the system, and in the working process of the high-power DC/DC converter 13, a high-voltage transistor needs to be turned on and off at high frequency, and electromagnetic interference (Electromagnetic Interference, for short, EMI) needs to be caused to be larger. Compared with the prior art, as shown in fig. 2, the utility model realizes the distributed arrangement of the photovoltaic module 21 and the energy storage module 22 by connecting one photovoltaic module 21 and one energy storage module 22 in a one-to-one correspondence manner, wherein the photovoltaic module 21 can provide low-voltage direct current electric energy, so that the energy storage module 22 can use a low-power DC/DC converter as the first DC/DC converter 222 and the first DC/DC converter 222, and the low-power DC/DC converter can adopt a low-voltage transistor design circuit structure, thereby effectively reducing the system cost, and the high-frequency on-off low-voltage transistor can not generate larger electromagnetic interference in the working process of the low-power DC/DC converter because the voltage processed by the DC/DC converter is smaller, so that the electromagnetic interference is reduced.

In one embodiment, referring to fig. 2 to 4, the processor 221A is communicatively connected to the inverter 23, and the processor 221A is configured to charge the battery pack 223 through the second DC/DC converter and the first DC/DC converter 222 to implement local energy storage when receiving the first scheduling command sent by the inverter 23. The first scheduling instruction is sent to the inverter 23 by the power grid 24 under the condition of sufficient self power, and forwarded to the processor 221A through the inverter 23. At this time, the power grid 24 can meet the power supply requirement without the photovoltaic module 21 delivering power thereto.

In one embodiment, referring to fig. 2 to 4, the processor 221A is configured to supply power to the inverter 23 through the first DC/DC converter 222 and/or the second DC/DC converter upon receiving the second scheduling instruction transmitted from the inverter 23. The second scheduling instruction is sent to the inverter 23 by the power grid 24 under the condition of insufficient self power, and forwarded to the processor 221A through the inverter 23. At this time, the power grid 24 needs the photovoltaic module 21 to deliver power to meet the power supply demand due to insufficient power.

In one embodiment, referring to fig. 2 to 4, the inverter 23 is a bi-directional inverter 23, and the inverter 23 is configured to charge the battery pack 223 through the first DC/DC converter 222 when receiving a third scheduling command sent from the power grid 24. The first scheduling instruction is sent to the inverter 23 by the power grid 24 with a margin of its own power, and forwarded to the processor 221A via the inverter 23. In this way, the power grid 24 rectifies the ac power output from the power grid 24 into dc power by the inverter 23, and charges each battery 223, so that the surplus power in the power grid 24 can be stored in the battery 223.

It should be noted that, the generation of the first scheduling instruction, the second scheduling instruction, and the third scheduling instruction by the power grid 24 according to the self-power is a conventional technical means in the art, and the above embodiment of the present utility model is not limited to the generation process of the first scheduling instruction, the second scheduling instruction, and the third scheduling instruction.

In one embodiment, the second DC/DC converter is a boost DC/DC converter. The second DC/DC converter is illustratively a Boost converter.

The following describes a specific circuit structure of the energy storage power generation system according to the embodiment of the present utility model with reference to fig. 3 and fig. 4.

Fig. 3 shows a circuit configuration diagram of an energy storage power generation system according to an embodiment of the present utility model.

The energy storage power generation system is suitable for an application scenario in which the voltage output by the MPPT controller 221 is greater than the charging voltage of the battery pack 223. Referring to fig. 2 and 3, the energy storage power generation system includes a plurality of photovoltaic modules 21, a plurality of energy storage modules 22, and an inverter 23. Each energy storage module 22 includes an MPPT controller 221, a first DC/DC converter 222, and a battery pack 223, and the MPPT controller 221 includes a second DC/DC converter and a processor 221A.

The second DC/DC converter is exemplified as a Boost converter, and the second DC/DC converter includes a first capacitor C1, a first inductor L1, a first transistor Q1, a second transistor Q2, and a second capacitor C2. The first capacitor C1 is connected in parallel between the first electrode and the second electrode of the photovoltaic module 21, so as to realize connection between the input end of the second DC/DC converter and the output end of the photovoltaic module 21. The first end of the first inductor L1 is connected with the first end of the first capacitor C1, the second end of the first inductor L1 is connected with the drain electrode of the first transistor Q1 and the source electrode of the second transistor Q2 respectively, the source electrode of the first transistor Q1 is connected with the second end of the first capacitor C1, the drain electrode of the second transistor Q2 is connected with the first end of the second capacitor C2, the second end of the second capacitor C2 is connected with the source electrode of the first transistor Q1, and the first end and the second end of the second capacitor C2 form the output end of the second DC/DC converter.

Taking the first DC/DC converter 222 as an example, the first DC/DC converter 222 includes a third transistor Q3, a fourth transistor Q4, a second inductor L2, and a third capacitor C3. The drain electrode of the third transistor Q3 is connected to the first end of the second capacitor C2, the source electrode of the third transistor Q3 is connected to the drain electrode of the fourth transistor Q4 and the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the third capacitor C3, and the source electrode of the fourth transistor Q4 and the second end of the third capacitor C3 are connected to the second end of the second capacitor C2. A first electrode of the battery pack 223 is connected to a first end of the third capacitor C3, and a second electrode of the battery pack 223 is connected to a second end of the third capacitor C3, so that the battery pack 23 is connected to an output end of the first DC/DC converter 222.

The processor 221A is connected to the gates of the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4, respectively, so that the MPPT controller 221 is connected to the control terminals of the first DC/DC converter 222 and the second DC/DC converter, respectively. The processor 221A transmits respective PWM signals to the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4, respectively, to implement high-frequency on-off control of the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4.

The second capacitors C2 of the energy storage modules 22 are connected in series, so that the energy storage modules 22 and the parallel branches of the photovoltaic modules 21 are connected in series to form a high-voltage direct current branch. Among the plurality of energy storage modules 22, a first end of a second capacitor C2 of the energy storage module 22 located at the head of the serial branch is connected with a first input end of the inverter 23, and a second end of the second capacitor C2 of the energy storage module 22 located at the tail of the serial branch is connected with a second input end of the inverter 23, so that two ends of the high-voltage direct-current branch are respectively connected with the first input end and the second input end of the inverter 23.

The energy storage power generation system includes a photovoltaic power mode, a local energy storage mode, a battery power mode, a simultaneous power mode, and a grid 24 energy storage mode.

In the photovoltaic power supply mode, the processor 221A respectively transmits respective PWM signals to the first transistor Q1 and the second transistor Q2 to control the first transistor Q1 and the second transistor Q2 to perform a high-frequency on-off operation, so that the second DC/DC converter receives the direct-current power transmitted by the photovoltaic module 21, boosts the direct-current power, and then supplies the boosted direct-current power to the inverter 23. The boosting process comprises the following steps: in the first stage T11, the first transistor Q1 is turned on and the second transistor Q2 is turned off, and the current output from the photovoltaic module 21 flows through the first inductor L1 and the first transistor Q1 to store energy in the first inductor L1; in the second stage T12, the first transistor Q1 is turned off, and the second transistor Q2 is turned on, and the voltage on the first inductor L1 is superimposed with the dc voltage output by the photovoltaic module 21, so that the dc voltage output from the two ends of the second capacitor C2 is greater than the dc voltage output by the photovoltaic module 21. In this mode, the processor 221A also controls the third transistor Q3 and the fourth transistor Q4 to be turned off, and stops the first DC/DC converter 222 from operating. In this way, the direct current power delivered by the photovoltaic module 21 is boosted by the second DC/DC converter and then supplied to the inverter 23, so as to realize external power supply to the photovoltaic module 21.

In the local energy storage mode, on the one hand, the processor 221A respectively transmits respective PWM signals to the first transistor Q1 and the second transistor Q2, and controls the first transistor Q1 and the second transistor Q2 to perform high-frequency on-off operation, so that the second DC/DC converter receives the direct-current electric energy output by the photovoltaic module 21 and boosts the direct-current electric energy. The boosting process is the same as the photovoltaic power supply mode, and is not repeated here. On the other hand, the processor 221A outputs PWM signals to the third transistor Q3 and the fourth transistor Q4, respectively, controls the third transistor Q3 to be turned on and the fourth transistor Q4 to perform a high-frequency on-off operation, so that the first DC/DC converter 222 receives the direct-current power output from the second DC/DC converter, steps down the direct-current power, and supplies the stepped-down direct-current power to the battery pack 223, and in this mode, the first DC/DC converter 222 operates in the Buck mode. The depressurization process comprises the following steps: in the first stage T21, the third transistor Q3 is turned on and the fourth transistor Q4 is turned off, and the current output from the second DC/DC converter flows through the third transistor Q3 and the second inductor L2 to charge the battery pack 223; in the second phase T22, the third transistor Q3 is turned off and the fourth transistor Q4 is turned on, and the second inductor L2 and the fourth transistor Q4 form a freewheeling circuit to continue charging the battery pack 223, while the second inductor L2 is reset. In this way, the direct current power output by the second DC/DC converter may be reduced and then supplied to the battery 223 for local energy storage.

In the battery-powered mode, on the one hand, the processor 221A controls the first transistor Q1 and the second transistor Q2 to be both turned off, causing the second DC/DC converter to stop operating; on the other hand, the processor 221A also transmits the PWM signals to the third transistor Q3 and the fourth transistor Q4, controls the third transistor Q3 and the fourth transistor Q4 to perform the high-frequency on-off operation, and causes the first DC/DC converter 222 to Boost the direct-current power output from the battery pack 223 and then to output the boosted direct-current power to the outside from both ends of the second capacitor C2, and in this mode, the first DC/DC converter 222 operates in the Boost mode. The boosting process comprises the following steps: in the first stage T31, the third transistor Q3 is turned off and the fourth transistor Q4 is turned on, and the current output from the battery pack 223 flows through the second inductor L2 and the fourth transistor Q4 to store the electric energy in the second inductor L2; in the second stage T32, the third transistor Q3 is turned on, the fourth transistor Q4 is turned off, and the voltage output from the battery pack 223 and the voltage in the second inductor L2 are superimposed and then output from both ends of the second capacitor C2. Since the second DC/DC converter stops operating, the direct current power output from the battery pack 223 can be boosted and supplied to the inverter 23 alone.

In the simultaneous power supply mode, the processor 221A outputs respective PWM signals to the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4, respectively, so that the second DC/DC converter receives the DC power output by the photovoltaic module 21, boosts the DC power, and outputs the boosted DC power to the outside; meanwhile, the first DC/DC converter 222 boosts the direct current power output from the battery pack 223 and outputs the boosted direct current power to the outside. In this way, it is possible to realize that the photovoltaic module 21 and the battery pack 223 supply power to the inverter 23 at the same time. In this mode, the boosting process of the second DC/DC converter may refer to the boosting process in the above-described photovoltaic power supply mode, and the boosting process of the first DC/DC converter 222 may refer to the boosting process in the above-described battery power supply mode, which is not described herein.

In the grid energy storage mode, the ac power output by the grid 24 is rectified by the inverter 23 to DC power, and then is delivered to the first DC/DC converter 222, so that the first DC/DC converter 222 steps down the DC power and then supplies the DC power to the battery pack 223 for storage. In this mode, the second DC/DC converter is in a stopped state, and the step-down process of the first DC/DC converter 222 to the DC power output from the inverter 23 may refer to the step-down process in the above-mentioned local energy storage mode, which is not described herein.

Fig. 4 shows a circuit configuration diagram of another energy storage power generation system according to an embodiment of the present utility model.

The energy storage power generation system is suitable for an application scenario in which the voltage output by the MPPT controller 221 is less than the charging voltage of the battery pack 223. As shown in fig. 4, the energy storage power generation system is similar to the energy storage power generation system in fig. 3, except that the first DC/DC converter 222 is a Boost converter, and the first DC/DC converter 222 includes a third inductor L3, a fifth transistor Q5, a sixth transistor Q6, and a fourth capacitor C4. The first end of the third inductor L3 is connected to the first end of the second capacitor C2, the second end of the third inductor L3 is connected to the source of the fifth transistor Q5 and the drain of the sixth transistor Q6, respectively, the drain of the fifth transistor Q5 is connected to the first electrode of the battery 223, and the source of the sixth transistor Q6 is connected to the second end of the second capacitor C2 and the second electrode of the battery 223, respectively. The fourth capacitor C4 is connected in parallel between the first electrode and the second electrode of the battery pack 223, so that the output terminal of the first DC/DC converter 222 is connected to the battery pack 223.

Accordingly, the energy storage power generation system includes a photovoltaic power mode, a local energy storage mode, a battery power mode, a simultaneous power mode, and a grid 24 energy storage mode.

In each mode of the present embodiment, the operation of the second DC/DC converter is the same as that of the above embodiment, and will not be described here again. The operation of the first DC/DC converter 222 in each mode in this embodiment will be described below.

In the photovoltaic power mode, the processor 221A controls the fifth transistor Q5 and the sixth transistor Q6 to be turned off to put the first DC/DC converter 222 in a stopped state.

In the local energy storage mode, the first DC/DC converter 222 boosts the direct current power output by the photovoltaic module 21 and supplies the boosted direct current power to the battery pack 223 for local energy storage. The boosting process comprises the following steps: in the first stage T41, the fifth transistor Q5 is turned off and the sixth transistor Q6 is turned on, and the current output from the photovoltaic module 21 flows through the third inductor L3 and the sixth transistor Q6 to store energy in the third inductor L3; in the second stage T42, the fifth transistor Q5 and the sixth transistor Q6 are turned off, and the voltage output by the second DC/DC converter and the voltage in the third inductor L3 are superimposed, so that the current flows through the parasitic diode of the fifth transistor Q5 and then is supplied to the battery pack 223 for local energy storage.

In the grid energy storage mode, the first DC/DC converter 222 boosts the direct current power rectified by the inverter 23 from the grid 24 and supplies the boosted direct current power to the battery pack 223 for storage. The boosting process of the first DC/DC converter 222 is the same as that in the local energy storage mode described above, and will not be described here.

In the battery power supply mode, the first DC/DC converter 222 steps down the direct-current power output from the battery pack 223 and supplies the stepped down direct-current power to the inverter 23. The depressurization process comprises the following steps: in the first stage T51, the fifth transistor Q5 is turned on, the sixth transistor Q6 is turned off, the current output from the battery pack 223 flows through the fifth transistor Q5 and the third inductor L3 to be supplied to the inverter 23 and charge the third inductor L3, and since the polarity of the voltage in the third inductor L3 is opposite to the polarity of the voltage of the battery pack 223, the voltage output from the two ends of the second capacitor C2 to the outside is smaller than the voltage of the battery pack 223; in the second stage T52, the fifth transistor Q5 is turned off and the sixth transistor Q6 is turned on, and the third inductor L3 and the sixth transistor Q6 form a freewheeling loop, so that the third inductor L3 continues to discharge to the outside, and meanwhile, the third inductor L3 is reset. In this way, the direct current power output from the battery pack 223 may be reduced in voltage by the first DC/DC converter 222 and then supplied to the inverter 23.

In the simultaneous power supply mode, the first DC/DC converter 222 steps down the direct-current power output from the battery pack 223 and supplies the stepped down direct-current power to the inverter 23. The step-down process of the first DC/DC converter 222 is the same as that in the battery power mode described above, and will not be repeated here.

In addition, in the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and the like are to be construed broadly, and may be fixedly connected, detachably connected, or integrated, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is to be construed as including any modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (10)

1. An energy storage power generation system, comprising

The photovoltaic modules are used for converting solar energy into electric energy;

the energy storage modules are connected with the photovoltaic modules in a one-to-one correspondence manner, so that each energy storage module receives electric energy output by the corresponding photovoltaic module to carry out local energy storage or external power supply, and the energy storage modules are connected in series to form a high-voltage direct-current branch;

and the output end of the inverter is used for being connected with a power grid and a local load respectively.

2. The energy storage power generation system according to claim 1, wherein each energy storage module is disposed at a bottom or a side of a corresponding photovoltaic module, respectively.

3. The energy storage power generation system of claim 1, wherein each of the energy storage modules comprises:

the input end of the MPPT controller is connected with the output end of the photovoltaic module;

the input end of the first DC/DC converter is connected with the output end of the MPPT controller;

and the battery pack is connected with the output end of the first DC/DC converter.

4. The energy storage and generation system according to claim 3, wherein the voltage output by the MPPT controller is greater than the charging voltage of the battery pack, the first DC/DC converter is a bi-directional DC/DC converter, the first DC/DC converter is configured to operate in a buck mode when the MPPT controller is charging the battery pack and in a boost mode when the battery pack is powering the inverter.

5. The energy storage and generation system of claim 3, wherein the voltage output by the MPPT controller is less than the charging voltage of the battery pack, the first DC/DC converter is a bi-directional DC/DC converter, the first DC/DC converter is configured to operate in a boost mode when the MPPT controller is charging the battery pack and in a buck mode when the battery pack is powering the inverter.

6. The energy storage and generation system according to claim 3, wherein each of the battery packs includes a plurality of batteries connected in series and a battery management unit connected to each of the batteries to detect electric quantity information of each of the batteries, respectively;

and the MPPT controller is connected with the battery management unit, so that the MPPT controller controls the first DC/DC converter to work or stop working according to the electric quantity information.

7. The energy storage and generation system of claim 3, wherein the MPPT controller comprises a second DC/DC converter connected between the photovoltaic assembly and the first DC/DC converter and a processor connected to the first DC/DC converter, the second DC/DC converter, and the battery, respectively.

8. The energy storage and generation system of claim 7, wherein the processor is communicatively coupled to the inverter;

the processor is used for charging the battery pack through the second DC/DC converter and the first DC/DC converter under the condition that a first scheduling instruction sent by the inverter is received;

the processor is used for supplying power to the inverter through the first DC/DC converter and/or the second DC/DC converter under the condition that a second scheduling instruction sent by the inverter is received.

9. The energy storage and generation system according to claim 8, wherein the inverter is a bi-directional inverter for charging the battery pack through the first DC/DC converter upon receiving a third scheduling instruction sent by the grid.

10. The energy storage power generation system of claim 7, wherein the second DC/DC converter is a boost DC/DC converter.