CN215185883U

CN215185883U - Light storage system

Info

Publication number: CN215185883U
Application number: CN202120692228.7U
Authority: CN
Inventors: 陈长春; 丁杰
Original assignee: Sungrow Power Supply Co Ltd
Current assignee: Sungrow Power Supply Co Ltd
Priority date: 2021-04-06
Filing date: 2021-04-06
Publication date: 2021-12-14
Anticipated expiration: 2031-04-06

Abstract

The utility model provides a light stores up system, if the rated power of whole first DCDC converters and the rated power that equals corresponding the DC-to-ac converter, can all be used for when being incorporated into the power networks at each first photovoltaic array's total energy, provide the energy by each second photovoltaic array and charge for energy storage battery, and then the equivalence has improved the output of whole preceding stage DC/DC converter in the light stores up system, in order to satisfy the demand of full power operation simultaneously that back inverter and energy storage battery charge, the loss of system's generated energy has been avoided.

Description

Light storage system

Technical Field

The utility model relates to a photovoltaic power generation technical field, in particular to light stores up system.

Background

In the prior art, a schematic structural diagram of a light storage system is shown in fig. 1, wherein a photovoltaic array is connected to a power grid through a light storage converter, the light storage converter includes a front-stage conversion unit and a rear-stage conversion unit, the front stage is a DC/DC unit, the rear stage is a DC/AC unit, and the DC/AC unit is generally located on a direct current bus (for example, V in fig. 1)_BUSShown) is provided with an energy storage interface, and an external charging and discharging DC/DC unit and a battery can be additionally connected.

The working principle of the light storage system is as follows: when the illumination is sufficient in the daytime, on one hand, the photovoltaic array performs grid-connected power generation operation through a DC/DC unit and a DC/AC unit inside the light storage converter, and on the other hand, the photovoltaic array can charge a battery through an energy storage interface on a direct current bus through an external charging and discharging DC/DC unit; and if the illumination is insufficient or at night, the battery discharges through the charging and discharging DC/DC unit and the rear-stage DC/AC unit of the light storage converter.

However, since the demand of the energy storage market is small, the optical storage converter is generally designed according to the power ratio of the front-stage DC/DC unit to the rear-stage DC/AC unit being 1:1 in consideration of the system cost. Therefore, due to the power limitation of the front-stage DC/DC unit, the inverter operation of the rear-stage DC/AC unit and the full-capacity operation of the external battery charging cannot be performed simultaneously, resulting in a loss of power generation.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the utility model provides a light stores up system, has the problem of generated energy loss among the solution prior art.

In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:

the utility model discloses the first aspect provides a light stores up system, include: at least one inverter, and the direct current side of each said inverter all is provided with: the photovoltaic system comprises at least one first photovoltaic array and a first DCDC converter thereof, at least one second photovoltaic array and a second DCDC converter thereof, and at least one energy storage battery and an energy storage converter thereof;

the output end of each first photovoltaic array is connected with the first side of the corresponding first DCDC converter, and the second side of the first DCDC converter is connected to the direct current side of the corresponding inverter through a direct current bus;

the output end of each second photovoltaic array is connected with the first side of the corresponding second DCDC converter, and the second side of the second DCDC converter is connected to the second side of the corresponding energy storage converter;

the electrical interface of the energy storage battery is connected with the first side of the energy storage converter, and the second side of the energy storage converter is also connected with the direct current bus;

and the alternating current side of each inverter is connected to a power grid.

Preferably, the first DCDC converter and the second DCDC converter are unidirectional converters, and the energy storage converter is a bidirectional converter.

Preferably, the number of the second DCDC converters is equal to the number of the energy storage converters;

or the number of the second DCDC converters is larger than that of the energy storage converters;

or, when the number of the energy storage converters 170 is greater than 1, the number of the second DCDC converters is smaller than the number of the energy storage converters.

Preferably, for each of the inverters, a sum of power ratings of all of the first DCDC converters is equal to a power rating of the corresponding inverter.

Preferably, the sum of the rated powers of all the second DCDC converters is equal to the sum of the rated powers of all the energy storage converters.

Preferably, the sum of the power ratings of all the energy storage converters is equal to or less than the power rating of the corresponding inverter.

Preferably, the light storage system further comprises: at least one first controllable switch; wherein:

and the first controllable switch is arranged between the second side of the energy storage converter and the direct current bus.

Preferably, when the energy storage battery operates in a charging mode, the first controllable switch is turned off; when the energy storage battery operates in a discharging mode, the first controllable switch is closed.

Preferably, when the number of the energy storage converters is greater than 1, the second sides of each energy storage converter and each second DCDC converter are connected in parallel, and the two ends after being connected in parallel are connected to the direct current bus through corresponding first cables.

Preferably, the second side of each energy storage converter shares the same first controllable switch on the first cable to connect with the dc bus.

Preferably, when the number of the energy storage converters is greater than 1, the second side of each energy storage converter is connected to the dc bus through a corresponding one of the first controllable switches.

Preferably, the method further comprises the following steps: at least one second controllable switch;

the second side of each first DCDC converter is connected with the direct current bus through a corresponding second controllable switch.

Preferably, when the first DCDC converter is in a grid-connected state, the corresponding second controllable switch is closed; when the first DCDC converter is in an off-grid state, the corresponding second controllable switch is turned off.

Preferably, the method further comprises the following steps: at least one third controllable switch;

the second side of each second DCDC converter is connected with the direct current bus through a corresponding third controllable switch.

Preferably, when the energy storage battery operates in a charging mode, the corresponding third controllable switch is closed; when the energy storage battery operates in a discharging mode, the corresponding third controllable switch is turned off.

Preferably, the sum of the rated powers of all the first DCDC converters is equal to the rated power of the corresponding inverter;

the sum of the rated powers of all the second DCDC converters is equal to the sum of the rated powers of all the energy storage converters.

Based on the above, the utility model provides a light stores up system, if the sum of the rated power of whole first DCDC converter equals the rated power of corresponding DC-to-ac converter, can be when all energy of each first photovoltaic array all are used for being incorporated into the power networks, provide the energy by each second photovoltaic array and charge for the energy storage battery, and then the equivalence has improved the output of whole preceding stage DC/DC converter in the light stores up system, in order to satisfy the demand of full power operation simultaneously of back level inverter and energy storage battery charging, the loss of system generated energy has been avoided; and, the utility model provides an in the light storage system quantity and the unit capacity of first photovoltaic array and energy storage battery can carry out nimble configuration according to actual need, conveniently hold the ratio adjustment.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic diagram of a light storage system in the prior art;

fig. 2 is a schematic structural diagram of an optical storage system according to an embodiment of the present invention;

fig. 3 to 9 are schematic structural diagrams of seven other light storage systems according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The embodiment of the utility model provides a pair of light stores up system can equivalently improve the output of whole preceding stage DC converter in the light stores up system to satisfy the demand of full power operation simultaneously of back level DC-to-ac converter and energy storage battery charging, and then avoided the loss of system's generated energy.

The schematic structural diagram of the light storage system is shown in fig. 2, and includes:

at least one inverter 110, and the direct current side of each inverter 110 is provided with: at least one first photovoltaic array 120 and its first DCDC converter 130, at least one second photovoltaic array 140 and its second DCDC converter 150, and at least one energy storage cell 160 and its energy storage converter 170. This embodiment is shown and described for example that the quantity of using inverter 110 and setting at its direct current side's equipment is 1, during practical application, can set up other quantity by the technical staff according to the application scene, and its relation of connection can be so analogized, all is in the protection scope of the embodiment of the utility model.

As shown in fig. 2, the output terminal of each first photovoltaic array 120 is connected to the first side of the corresponding first DCDC converter 130, and the second side of the first DCDC converter 130 is connected to the dc side of the corresponding inverter through the dc bus (shown as Vbus in fig. 2); the output of each second photovoltaic array 140 is connected to a first side of a respective second DCDC converter 150, and a second side of the second DCDC converter 150 is connected to a second side of the corresponding energy storage converter 170. Preferably, the first DCDC converter 130 and the second DCDC converter 150 are unidirectional converters, and the first side of the unidirectional converters is an input side, and the second side of the unidirectional converters is an output side, so that the first photovoltaic array 120 and the first DCDC converter 130 thereof can form a unidirectional flow conversion unit, and the second photovoltaic array 140 and the second DCDC converter 150 thereof can form a unidirectional flow conversion unit; therefore, the energy output by the first DCDC converter 130 can be directly incorporated into the grid via the inverter 110, and the energy output by the second DCDC converter 150 can be used to charge the energy storage battery 160 through the energy storage converter 170.

The electrical interface of the energy storage battery 160 is connected with the first side of the energy storage converter 170, and the second side of the energy storage converter 170 is also connected with a direct current bus; the ac side of each inverter 110 is connected to the grid.

The energy storage converter 170 may be a bidirectional converter, and the second side of the energy storage converter 170 is connected to the second side of the second DCDC converter 150 and the dc bus, so that the bidirectional flowing energy storage conversion unit composed of the energy storage battery 160 and the energy storage converter 170 specifically includes: when the lighting condition is good and the photovoltaic array is electrified, for example, in daytime, the energy storage battery 160 is charged through the second photovoltaic array 140, and the energy storage battery 160 operates in a charging mode; and when the lighting condition is poor, the photovoltaic array is very low in power or is dead, for example, at night, the energy storage battery 160 operates in a discharge mode, and the output energy is merged into the power grid.

Therefore, the light storage system provided in this embodiment can charge the energy storage battery 160 by adding the second DCDC converter 150 and the second photovoltaic array 140 thereof connected to the second side of the energy storage converter 170, even under the premise of not changing the power ratio of the front-stage topology and the back-stage topology of the existing light storage converter, that is, when the power ratio of all the first DCDC converters 130 to the inverter 110 is designed according to 1: 1; that is, on the premise that the sum of the rated powers of all the first DCDC converters 130 is equal to the rated power of the corresponding inverter 110, the energy provided by the second photovoltaic array 140 can be used for grid connection while all the energy of the first photovoltaic array 120 is used for grid connection, so as to charge the energy storage battery 160, thereby equivalently improving the output power of the whole front-stage DC/DC converter in the optical storage system, so as to meet the requirement that the rear-stage inverter and the energy storage battery 160 are charged and run at full power, optimize the charging time of the energy storage battery 160, avoid the loss of the system power generation amount, and shorten the charging time of the energy storage battery 160. Meanwhile, in order to avoid waste, the sum of the rated powers of all the second DCDC converters 150 may be set to be equal to the sum of the rated powers of all the energy storage converters 170, so that all the energy of the second photovoltaic array 140 is used for charging the energy storage battery 160 while all the energy of the first photovoltaic array 120 is used for grid connection; furthermore, the sum of the rated powers of all the storage converters 170 may be set to be equal to or less than the rated power of the corresponding inverter 110, and further, no excess energy may be generated when the storage battery 160 is in discharge operation.

It should be noted that, in order to avoid power waste and save equipment cost, when the sum of the rated powers of all the first DCDC converters 130 is equal to the rated power of the corresponding inverter 110, the sum of the rated powers of all the second DCDC converters 150 may be set to be equal to the sum of the rated powers of all the energy storage converters 170; in practical applications, however, the application scenario is not limited to this, for example, when the sum of the rated powers of all the first DCDC converters 130 is greater than the rated power of the corresponding inverter 110, the sum of the rated powers of all the second DCDC converters 150 may be set to be less than the sum of the rated powers of all the energy storage converters 170, then all the energy of the second DCDC converters 150 is used to charge the energy storage battery 160, and the energy output by the first DCDC converter 130 may also be used to charge the energy storage battery 160 besides being incorporated into the power grid; or, when the sum of the rated powers of all the first DCDC converters 130 is smaller than the rated power of the corresponding inverter 110, and the first DCDC converter 130 cannot meet the grid connection requirement, the sum of the rated powers of all the second DCDC converters 150 may be set to be larger than the sum of the rated powers of all the energy storage converters 170, so that the second DCDC converter 150 can charge the energy storage battery 160 and connect the grid; to the different situations of various light storage converters, this light storage system homoenergetic can use, and various settlement schemes are all in the utility model discloses within the protection scope of the embodiment.

The above embodiments have explained that the number of the inverter 110 and the various devices disposed on the dc side thereof may be determined according to specific situations, and it should be noted that the number of the second DCDC converters 150 may be equal to the number of the energy storage converters 170, or the number of the second DCDC converters 150 may be greater than the number of the energy storage converters, or when the number of the energy storage converters 170 is greater than 1, the number of the second DCDC converters 150 may also be less than the number of the energy storage converters 170. That is, in practical application, can charge for a plurality of energy storage battery 160 through a second photovoltaic array 140, also can charge for a corresponding energy storage battery 160 through a second photovoltaic array 140, can also charge for an energy storage battery 160 through a plurality of second photovoltaic arrays 160 simultaneously, all are within the scope of the embodiment of the present invention.

In this embodiment, the number of the second DCDC converters 150 is equal to the number of the energy storage converters 170, and the schematic structure diagram is shown in fig. 3, which can be referred to for other situations and is not described again.

As shown in fig. 3, at this time, the second sides of the energy storage converters 170 and the second DCDC converters 150 are connected in parallel, and both ends of the parallel connection are connected to the direct current bus Vbus through corresponding first cables (shown by thick solid lines in fig. 3).

It can be seen that the number and the unit capacity of the second DCDC converter 150 and the energy storage converter 170 connected to the first cable can be flexibly configured according to actual needs, and the cable is suitable for various application scenarios and is convenient for adjusting the capacity ratio.

The rest of the principle is the same as the above embodiments, and is not described in detail here.

The embodiment of the utility model provides a still provide a light stores up system, on the basis of above-mentioned embodiment, in order to avoid energy storage battery 160 to frequently switch between the charge-discharge state, this light stores up system and can also include: at least one first controllable switch (shown as K1 in fig. 4).

As shown in fig. 4, if the number of the energy storage converters 170 in the optical storage system is 1, a first controllable switch K1 is disposed between the second side of the energy storage converter 170 and the dc bus Vbus.

In practical application, the on-off of the first controllable switch K1 may be controlled according to the operating state of the energy storage battery 160, and specifically may be: when the energy storage battery 160 operates in the charging mode, the first controllable switch K1 is turned off; when the energy storage battery 160 operates in the discharge mode, the first controllable switch K1 is closed. That is, the on-off of the first controllable switch K1 is controlled according to the power generation condition of the photovoltaic array, for example, when the illumination condition is good in the daytime and the output of the photovoltaic array is normal, the first controllable switch K1 is controlled to be turned off, and when all the energy of the first photovoltaic array 120 is connected to the grid, all the energy of the second photovoltaic array 140 is charged to the energy storage battery 160; when the illumination condition is insufficient or the energy storage battery 160 is discharged to operate at night, the first controllable switch K1 is controlled to be closed, and the energy storage converter 170 outputs energy to the power grid, so that the inverter 110 can be in grid-connected operation without illumination, and the utilization rate of the inverter 110 is improved.

The light storage system provided by this embodiment adds the first controllable switch K1, so that the energy storage battery 160 and the inverter 110 are relatively independent, and further frequent switching of the energy storage battery 160 in the charging and discharging state can be avoided, and the service life of the energy storage battery 160 is prolonged.

It should be noted that if the optical storage system is as shown in fig. 3, and the number of the energy storage converters 170 is greater than 1, the first controllable switch K1 can be set in the following two ways:

first, as shown in fig. 5, the second sides of the energy storage converters 170 share the first controllable switch K1 on the first cable, and are connected to the dc bus Vbus, so that the on/off of all the energy storage converters 170 and the dc bus Vbus is controlled by the first controllable switch K1. It should be noted that, the positive and negative electrodes of the energy storage converters 170 and the second sides of the second DCDC converters 150 connected in parallel need a first cable to connect the direct current bus Vbus, which is only shown by taking one cable as an example in fig. 3, and similarly, is also shown by taking one first controllable switch K1 as an example in fig. 5; in practical applications, only one first controllable switch K1 may be provided on the first cable connected to the positive electrode, or one first controllable switch K1 may be provided on each of the two first cables connected to the positive electrode and the negative electrode.

It should be noted that, if the sum of the rated powers of all the first DCDC converters 130 is equal to the rated power of the inverter 110, and the sum of the rated powers of all the second DCDC converters 150 is equal to the sum of the rated powers of the energy storage converters 170, all the energy of the first DCDC converters 130 is grid-connected, all the energy of each second DCDC converter 150 charges each energy storage battery 160, and at this time, the first controllable switch K1 is closed only when the energy storage batteries 160 are in discharging operation.

If the sum of the rated powers of all the first DCDC converters 130 is greater than the rated power of the inverter 110 and the sum of the rated powers of all the second DCDC converters 150 is less than the sum of the rated powers of the energy storage converter 170, the first DCDC converters 130 can be operated on the grid and can charge the energy storage battery 160, however, in this case, the capacity of the energy storage battery 160 is required to be large, for example, the sum of the rated powers of the energy storage converter 170 is greater than the sum of the rated powers of all the second DCDC converters 150, and the first controllable switch K1 is controlled to be turned off when the energy storage battery 160 is fully charged and is not discharged.

If the sum of the rated powers of all the first DCDC converters 130 is less than the rated power of the inverter 110, and the sum of the rated powers of all the second DCDC converters 150 is greater than the sum of the rated powers of the energy storage converter 170, the second DCDC converter 130 can be operated in a grid-connected mode while charging the energy storage battery 160, and it is necessary that the first controllable switch K1 is always in a closed state.

Secondly, as shown in fig. 6, the second side of each energy storage converter 170 is connected to the dc bus Vbus through a corresponding first controllable switch K1, that is, one first controllable switch K1 correspondingly controls the on/off of one energy storage converter 170 and the dc bus Vbus.

At this time, if the sum of the rated powers of all the first DCDC converters 130 is equal to the rated power of the inverter 110 and the sum of the rated powers of all the second DCDC converters 150 is equal to the sum of the rated powers of the energy storage converters 170, the first controllable switch K1 is turned off only when the energy storage battery 160 is in a fully charged and non-discharged operation and when the corresponding energy storage battery 160 has a fault.

If the sum of the rated powers of all the first DCDC converters 130 is greater than the rated power of the inverter 110 and the sum of the rated powers of all the second DCDC converters 150 is less than the sum of the rated powers of the energy storage converter 170, the first controllable switch K1 is turned off only when the energy storage battery 160 is fully charged and not discharging, and when the corresponding energy storage battery 160 fails.

If the sum of the rated powers of all the first DCDC converters 130 is less than the rated power of the inverter 110 and the sum of the rated powers of all the second DCDC converters 150 is greater than the sum of the rated powers of the energy storage converter 170, the second DCDC converter 150 needs to charge the energy storage battery 160 and operate in a grid-connected mode, that is, the first controllable switch K1 is controlled to be turned off only when the energy storage battery 160 is fully charged and does not discharge and when the corresponding energy storage battery 160 fails.

The two modes have respective advantages, the first mode can realize the control of all the energy storage converters 170 by only arranging one controllable switch K1, and the hardware cost is lower; secondly, one energy storage converter 170 is provided with a corresponding first controllable switch K1, so that individual control can be realized according to the actual conditions of each energy storage battery; for example, when a certain energy storage battery 160 fails, it can be removed alone without affecting the normal operation of the system, and specifically, a technician can select the energy storage battery according to the specific application.

The embodiment of the utility model provides a light stores up system still provides, on the basis of above-mentioned embodiment, in order to avoid each first DCDC converter 130 internal switch pipe to experience voltage stress when energy storage battery 160 discharges and is incorporated into the power networks, and this light stores up system and can also include: at least one second switch K2; the present embodiment is illustrated by taking an example, and a schematic structure thereof is shown in fig. 7, and when a plurality of first DCDC converters 130 are disposed in the optical storage system, the schematic structure thereof is similar to that, and is not repeated.

The second side of each first DCDC converter 130 is connected to the dc bus Vbus via a corresponding second controllable switch K2. In practical application, the illumination condition is good, the first photovoltaic array 120 outputs normally, and when the first DCDC converter 130 is in a grid-connected state, the corresponding second controllable switch K2 is closed; when the illumination condition is insufficient, the second photovoltaic array 120 is not powered, and the first DCDC converter 130 is in the off-grid state, the energy storage battery 160 is discharged and operates, and the corresponding second controllable switch K2 is turned off, so that voltage stress generated on the internal switch tube of the first DCDC converter 130 when the energy storage battery 160 is discharged and connected to the grid is avoided.

The embodiment of the utility model provides a light stores up system still provides, and is same, in order to avoid when energy storage battery 160 discharges and is incorporated into the power networks, voltage stress is experienced to each second DCDC converter 150 internal switch pipe, and this light stores up system and can also include: at least one second switch K3; the number of the second switches K3 may be related to the number of the second DCDC converters 150, for example, a third controllable switch K3 is provided for each second DCDC converter 150, and the second side of each second DCDC converter 150 is connected to the dc bus Vbus through a corresponding third controllable switch K3.

As shown in fig. 8, it is exemplified that one second DCDC converter 150 has one third controllable switch K3 corresponding thereto, and other cases can be analogized and are not described again. The on-off principle of the third controllable switch K3 is as follows: when the energy storage battery 160 operates in the charging mode, the corresponding third controllable switch K3 is closed; when the energy storage battery 160 operates in the discharging mode, the corresponding third controllable switch K3 is turned off, so that voltage stress on the switch tube inside the second DCDC converter 150 when the energy storage battery 160 is discharged and connected to the grid is avoided.

It should be noted that, in practical applications, technicians may select the setting modes of the first controllable switch K1, the second controllable switch K2 and the third controllable switch K3 to be combined arbitrarily as required, as shown in fig. 9, three kinds of controllable switches may be provided, but the present invention is not limited thereto. The first controllable switch K1, the second controllable switch K2, and the third controllable switch K3 may be any switches known in the art.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the above description of the disclosed embodiments, the features described in the embodiments may be interchanged or combined with each other to enable those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A light storage system, comprising: at least one first controllable switch and at least one inverter, and the direct current side of each said inverter all is provided with: the photovoltaic system comprises at least one first photovoltaic array and a first DCDC converter thereof, at least one second photovoltaic array and a second DCDC converter thereof, and at least one energy storage battery and an energy storage converter thereof;

a first controllable switch is arranged between the second side of the energy storage converter and the direct current bus;

and the alternating current side of each inverter is connected to a power grid.

2. The optical storage system of claim 1, wherein the first DCDC converter and the second DCDC converter are unidirectional converters and the energy storage converter is a bidirectional converter.

3. The optical storage system according to claim 1, wherein the number of the second DCDC converters is equal to the number of the energy storage converters;

or when the number of the energy storage converters is greater than 1, the number of the second DCDC converters is smaller than that of the energy storage converters.

4. A light storage system according to any one of claims 1-3, characterized in that for each of said inverters the sum of the power ratings of all of said first DCDC converters is equal to the power rating of the corresponding said inverter.

5. A light storage system according to any of claims 1-3, characterized in that the sum of the power ratings of all said second DCDC converters is equal to the sum of the power ratings of all said energy storage converters.

6. A light storage system according to any of claims 1-3, characterized in that the sum of the power ratings of all the energy storage converters is equal to or less than the power rating of the corresponding inverter.

7. The light storage system of claim 1, wherein the first controllable switch is turned off when the energy storage battery is operating in a charging mode; when the energy storage battery operates in a discharging mode, the first controllable switch is closed.

8. The optical storage system according to claim 7, wherein when the number of the energy storage converters is greater than 1, the second sides of each energy storage converter and each second DCDC converter are connected in parallel, and the two ends of the parallel connection are connected to the dc bus through corresponding first cables.

9. The optical storage system of claim 8, wherein the second side of each of the energy storage converters shares the first controllable switch on the first cable to connect to the dc bus.

10. The light storage system of claim 7, wherein when the number of the energy storage converters is greater than 1, the second side of each energy storage converter is connected to the dc bus through the corresponding first controllable switch.

11. The light storage system of claim 1, further comprising: at least one second controllable switch;

12. The light storage system according to claim 11, wherein when the first DCDC converter is in a grid-connected state, the corresponding second controllable switch is closed; when the first DCDC converter is in an off-grid state, the corresponding second controllable switch is turned off.

13. The light storage system of claim 1, further comprising: at least one third controllable switch;

14. The light storage system of claim 13, wherein when the energy storage battery is operating in a charging mode, the corresponding third controllable switch is closed; when the energy storage battery operates in a discharging mode, the corresponding third controllable switch is turned off.