Energy storage charging system and control method

Abstract

The present application provides an energy storage charging system and a control method. The energy storage charging system includes an inverter, a charging pile and an energy storage battery. The battery connection end of the inverter is used to connect the energy storage battery, and the off-grid output port of the inverter is used to connect the charging pile and the load; the inverter and the charging pile communicate with each other. The inverter determines the remaining available power of the charging pile according to the maximum load power and the real-time output power in the off-grid state, and sends the remaining available power to the charging pile, so that the charging pile can output the corresponding charging power to the target device according to the remaining available power and the remaining available target power, and then adjust the power obtained by the charging pile from the inverter, so that the remaining available power gradually approaches the remaining available target power (zero), which can make the real-time output power of the inverter gradually approach the maximum load power, and finally make the inverter stably work at the maximum load power. In this way, the inverter can be prevented from being overloaded and the stability of the inverter can be improved.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic energy storage technology, and in particular, relates to an energy storage charging system and a control method. Background Art

[0002] With the development of the photovoltaic field and the popularization of new energy vehicles, a photovoltaic charging system has been formed that combines charging piles, energy storage batteries, inverters and photovoltaic modules. The photovoltaic charging system can also be connected to the mains to power the charging piles, and the photovoltaic charging system can also be used to power other loads. The electrical energy generated by the photovoltaic modules in the photovoltaic charging system will change with the lighting conditions, and the power demand of other loads may also change. When the photovoltaic charging system is off-grid, if the charging power of the charging pile and the power demand of other loads are too large, it is easy to cause the inverter to overload and shut down. Summary of the invention

[0003] The embodiments of the present application provide an energy storage charging system and a control method, which can prevent the inverter from being overloaded and improve the stability of the inverter.

[0004] In a first aspect, the present application provides an energy storage charging system, comprising an inverter, a charging pile and an energy storage battery; the DC input end of the inverter is used to connect a photovoltaic module; the battery connection end of the inverter is used to connect an energy storage battery, and the off-grid output port of the inverter is used to connect the charging pile and the load; the inverter and the charging pile communicate with each other; wherein, when the inverter is in an off-grid state, the inverter determines the remaining available power based on its maximum load power and real-time output power, and sends the remaining available power to the charging pile; wherein the remaining available power is the power that the photovoltaic module and the energy storage battery can also provide to the charging pile; the charging pile outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power, wherein the remaining available target power is zero.

[0005] In an embodiment of the present application, the remaining available power of the charging pile is determined by the inverter in an off-grid state according to the maximum load power and the real-time output power, and the remaining available power is sent to the charging pile, so that the charging pile can output the corresponding charging power to the target device according to the remaining available power and the remaining available target power, and then adjust the power obtained by the charging pile from the inverter so that the remaining available power gradually approaches the remaining available target power (zero). In this way, the real-time output power of the inverter can gradually approach the maximum load power, and finally the inverter can stably operate at the maximum load power. If the load power suddenly increases, the real-time output power of the inverter will increase, and the inverter will be in an overloaded state. At this time, the remaining available power determined by the inverter based on the maximum load power and the real-time output power is less than zero. The charging pile adjusts the power obtained from the inverter again according to the remaining available power and the remaining available target power, so that the remaining available power is gradually adjusted from a value less than zero to the remaining available target power (zero), so that the power obtained by the charging pile from the inverter is reduced. When the load power remains unchanged, the real-time output power of the inverter decreases, and the remaining available power becomes larger (still less than zero). In this way, the remaining available power is gradually adjusted to the remaining available target power, so that the real-time output power of the inverter is restored to work at the maximum load power, and then the inverter exits the overload state. In this way, the inverter can be prevented from being overloaded and the stability of the inverter can be improved.

[0006] In one possible implementation, the inverter is also used to: when the inverter is in an off-grid state, set the remaining available target power to zero, and send the remaining available target power to the charging pile; or, the inverter is also used to: when the inverter is in an off-grid state, send off-grid status information to the charging pile; the charging pile receives the off-grid status information and sets the remaining available target power to zero according to the off-grid status information.

[0007] In one possible implementation, the inverter is also used to: obtain the maximum allowable discharge power of the energy storage battery and the photovoltaic output power of the photovoltaic module; obtain the first load power of the inverter according to the maximum allowable discharge power, the photovoltaic output power and the conversion efficiency of the inverter; obtain the rated output power of the inverter; obtain the maximum load power according to the first load power and the rated output power; wherein the maximum load power is the smaller value of the first load power and the rated output power.

[0008] In one possible implementation, the inverter is also used to: obtain the maximum allowable discharge current and battery output voltage of the energy storage battery; obtain the maximum allowable discharge power based on the maximum allowable discharge current and battery output voltage; obtain the photovoltaic output voltage and photovoltaic output current of the photovoltaic module; and obtain the photovoltaic output power based on the photovoltaic output voltage and photovoltaic output current.

[0009] In one possible implementation, the charging pile is used to: receive the remaining available power sent by the inverter; generate a charging instruction according to the remaining available power and the remaining available target power; and enable the charging pile to output the corresponding charging power to the target device according to the charging instruction.

[0010] In a possible implementation, the charging pile is an AC charging pile, and correspondingly, the charging pile is also used to: send a charging instruction to a target device, so that the target device obtains a corresponding charging power from the charging pile according to the charging instruction.

[0011] In one possible implementation, the charging pile is also used to: obtain a first deviation value based on the remaining available power and the remaining available target power received in the current cycle; obtain a second deviation value based on the remaining available power and the remaining available target power received in the previous cycle; and generate a charging instruction corresponding to the current cycle based on the first deviation value, the second deviation value and the charging instruction corresponding to the previous cycle.

[0012] In one possible implementation, the charging pile is also used to: obtain a first compensation value based on the product of a first deviation value and a first preset parameter; obtain a second compensation value based on the product of a second deviation value and a second preset parameter; wherein the first preset parameter and the second preset parameter are pre-set control parameters; and obtain a charging instruction corresponding to a current cycle based on the sum of the first compensation value, the second compensation value and the charging instruction corresponding to a previous cycle.

[0013] In a second aspect, the present application provides a control method, which is applied to an inverter, and the control method includes: when the inverter is in an off-grid state, obtaining the maximum load power and real-time output power of the inverter; determining the remaining available power based on the maximum load power and the real-time output power; wherein the remaining available power is the power that the photovoltaic components and the energy storage battery can also provide to the charging pile; the remaining available power is transmitted to the charging pile, so that the charging pile can output the corresponding charging power to the target device according to the remaining available power and the remaining available target power; wherein the remaining available target power is zero.

[0014] In one possible implementation, the control method also includes: when the inverter is in an off-grid state, setting the remaining available target power to zero, and sending the remaining available target power to the charging pile; or, when the inverter is in an off-grid state, sending off-grid state information to the charging pile; the off-grid state information is used to trigger the charging pile to set the remaining available target power to zero.

[0015] In one possible implementation, the maximum load power of the inverter is obtained, including: obtaining the maximum allowable discharge power of the energy storage battery and the photovoltaic output power of the photovoltaic module; determining the first load power of the inverter according to the maximum allowable discharge power, the photovoltaic output power and the conversion efficiency of the inverter; obtaining the rated output power of the inverter; and obtaining the maximum load power according to the first load power and the rated output power; wherein the maximum load power is the smaller value of the first load power and the rated output power.

[0016] In a possible implementation, obtaining the maximum allowable discharge power of the energy storage battery includes: obtaining the maximum allowable discharge current and the battery output voltage of the energy storage battery; and obtaining the maximum allowable discharge power according to the maximum allowable discharge current and the battery output voltage.

[0017] In a possible implementation, the control method further includes: acquiring a photovoltaic output voltage and a photovoltaic output current of the photovoltaic component; and obtaining a photovoltaic output power according to the photovoltaic output voltage and the photovoltaic output current.

[0018] In one possible implementation, the control method also includes: obtaining the real-time output voltage and real-time output current of the inverter; obtaining the real-time output power according to the real-time output voltage and the real-time output current; wherein the real-time output power includes the power provided by the inverter to the charging pile and the load.

[0019] In a third aspect, the present application provides a control method applied to a charging pile, the control method comprising: receiving the remaining available power sent by the inverter, the remaining available power being obtained by the inverter based on its maximum load power and real-time output power; wherein the remaining available power is the power that the photovoltaic components and the energy storage battery can still provide to the charging pile; generating a charging instruction based on the remaining available power and the remaining available target power; wherein the remaining available target power is zero; and according to the charging instruction, causing the charging pile to output the corresponding charging power to the target device to charge the target device.

[0020] In one possible implementation, the control method also includes: receiving the remaining available target power sent by the inverter, and the remaining available target power is set to zero by the inverter in an off-grid state; or, receiving off-grid state information sent by the inverter, and setting the remaining available target power to zero according to the off-grid state information.

[0021] In one possible implementation, the charging pile is an AC charging pile, and correspondingly, the charging pile outputs corresponding charging power to the target device according to the charging instruction, including: sending a charging instruction to the target device so that the target device obtains the corresponding charging power from the charging pile according to the charging instruction.

[0022] In one possible implementation, a charging instruction is generated based on the remaining available power and the remaining available target power, including: obtaining a first deviation value based on the remaining available power and the remaining available target power received in the current cycle; obtaining a second deviation value based on the remaining available power and the remaining available target power received in the previous cycle; and generating a charging instruction corresponding to the current cycle based on the first deviation value, the second deviation value, and the charging instruction corresponding to the previous cycle.

[0023] In one possible implementation, a charging instruction corresponding to the current cycle is generated based on a first deviation value, a second deviation value, and a charging instruction generated in a previous cycle, including: obtaining a first compensation value based on the product of the first deviation value and a first preset parameter; obtaining a second compensation value based on the product of the second deviation value and a second preset parameter; wherein the first preset parameter and the second preset parameter are pre-set control parameters; and obtaining a charging instruction corresponding to the current cycle based on the sum of the first compensation value, the second compensation value, and the charging instruction corresponding to the previous cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a module schematic diagram of the energy storage charging system provided in an embodiment of the present application.

[0025] Figure 2 It is a flowchart of a control method provided in one embodiment of the present application.

[0026] Figure 3 yes Figure 2 Schematic diagram of a partial detailed process of step S100.

[0027] Figure 4 yes Figure 2 Another detailed flowchart of step S100 is shown in FIG.

[0028] Figure 5 It is a flow chart of a control method provided in another embodiment of the present application.

[0029] Figure 6 yes Figure 5 Detailed flowchart of step S600 in FIG.

[0030] Figure 7 yes Figure 6 Detailed flowchart of step S630 in FIG. DETAILED DESCRIPTION

[0031] It should be noted that the terms "first" and "second" in the specification, claims and drawings of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. In the specification, claims and drawings of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "multiple" in the specification, claims and drawings of the present application refers to two or more than two.

[0032] It is understandable that the connection relationship described in the present application refers to direct or indirect connection. For example, A is connected to B or A is electrically connected to B, which can be either A and B are directly connected or A and B are indirectly connected through one or more other electrical components, for example, A and C are directly connected, and C and B are directly connected, so that A and B are connected through C.

[0033] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0034] Some embodiments will be described below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0035] The power generated by the photovoltaic modules in the photovoltaic charging system will change with the lighting conditions, and the power demand of other loads may also change. When the photovoltaic charging system is off-grid, if the charging power of the charging pile and the power demand of other loads are too large, it is easy to cause the inverter to overload and shut down.

[0036] In view of this, the embodiments of the present application provide an energy storage charging system and a control method, which can prevent the inverter from being overloaded and improve the stability of the inverter.

[0037] Please refer to Figure 1 , Figure 1 A module schematic diagram of an energy storage charging system 10 provided in an embodiment of the present application.

[0038] The energy storage charging system 10 includes an inverter 100 , a charging pile 200 and an energy storage battery 300 .

[0039] The DC input terminal of the inverter 100 is connected to the photovoltaic module 20. The battery connection terminal of the inverter 100 is used to connect the energy storage battery 300. The off-grid output port of the inverter 100 is used to connect the charging pile 200 and the load 30. The inverter 100 and the charging pile 200 communicate with each other.

[0040] The photovoltaic assembly 20 and the energy storage battery 300 can supply power to the charging pile 200 and the load 30 via the off-grid output port through the inverter 100 .

[0041] It can be understood that the inverter 100 can also be provided with a grid-connected output port, and the grid-connected output port of the inverter 100 is used to connect the power grid 40. The grid-connected output port of the inverter 100 can also be used to connect the charging pile 200 and the load 30. When the power grid 40 is connected to the grid-connected output port, that is, when the inverter 100 is in the grid-connected state, the power grid 40 can also supply power to the charging pile 200 and the load 30 through the grid-connected output port.

[0042] Among them, the energy storage charging system 10 and the control method of the embodiment of the present application are applicable to the case where the inverter 100 is in an off-grid state, that is, the power grid 40 is not connected to the grid-connected output port of the inverter 100.

[0043] In the embodiment of the present application, the inverter 100 and the charging pile 200 can be connected by wired communication, such as RS485 bus or CAN bus. Of course, the inverter 100 and the charging pile 200 can also be connected by wireless communication, such as Bluetooth communication, Zigbee communication, UWB communication, etc., and the present application does not limit this.

[0044] In the embodiment of the present application, when the inverter 100 is in an off-grid state, the inverter 100 determines the remaining available power according to its maximum load power and real-time output power, and sends the remaining available power to the charging pile 200.

[0045] The remaining available power is the power that the photovoltaic module 20 and the energy storage battery 300 can provide to the charging pile 200 through the inverter 100 in addition to the power that has been provided to the charging pile 200 and the load 30 through the inverter 100. The real-time output power is the power that the inverter 100 has currently provided to the charging pile 200 and the load 30. Therefore, the remaining available power can be determined according to the difference between the maximum load power and the real-time output power.

[0046] The charging pile 200 outputs corresponding charging power to the target device according to the remaining available power and the remaining available target power.

[0047] The remaining available target power is zero. The charging pile 200 outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power to charge the target device.

[0048] It can be understood that the remaining available power can be greater than zero or less than zero. When the remaining available power is greater than zero, it means that the maximum load power is greater than the real-time output power, that is, the inverter 100 can also provide additional power for the charging pile 200. When the remaining available power is less than zero, it means that the maximum load power is less than the real-time output power, that is, the inverter 100 is in an overloaded state.

[0049] The remaining available power is sent to the charging pile 200 through the inverter 100, and the charging pile 200 outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power, and then adjusts the power obtained by the charging pile 200 from the inverter 100, so that the remaining available power gradually approaches the remaining available target power, until the remaining available power is zero, so that the inverter 100 can stably work at the maximum load power. Among them, when the remaining available power is greater than zero, the charging pile 200 adjusts the charging power to increase according to the remaining available power and the remaining available target power, so that the power obtained by the charging pile 200 from the inverter 100 increases. When the load power remains unchanged, the real-time output power of the inverter 100 increases, and the remaining available power will become smaller, so that the remaining available power is gradually adjusted to the remaining available target power. When the remaining available power is adjusted to the remaining available target power (zero), the real-time output power of the inverter 100 reaches the maximum load power, and the inverter 100 stably works at the maximum load power.

[0050] If the load power increases suddenly, the real-time output power of the inverter 100 will increase, and the inverter 100 will be in an overload state. At this time, the remaining available power determined by the inverter 100 according to the difference between the maximum load power and the real-time output power is less than zero. The charging pile 200 adjusts its charging power for the target device according to the remaining available power and the remaining available target power at this time. It is necessary to gradually adjust the remaining available power from a value less than zero to the remaining available target power (zero). Then the charging power needs to be reduced, so that the power obtained by the charging pile 200 from the inverter 100 is reduced. When the load power remains unchanged, the real-time output power of the inverter 100 decreases, and the remaining available power will increase (still less than zero). In this way, the remaining available power is gradually adjusted to the remaining available target power (zero), so that the real-time output power of the inverter 100 is restored to work at the maximum load power, and then the inverter 100 exits the overload state. In this way, the inverter 100 can be prevented from being overloaded and the stability of the inverter 100 can be improved.

[0051] The energy storage charging system 10 and the control method provided by the embodiment of the present invention will be described in detail below through specific embodiments.

[0052] See also Figure 2, which shows a flow chart of a control method provided by an embodiment of the present invention, the control method is applied to the inverter 100, and the control method includes:

[0053] S100: When the inverter is in an off-grid state, obtain the maximum load power and real-time output power of the inverter.

[0054] The inverter 100 can determine whether it is in an off-grid state by performing an off-grid detection on its grid-connected output port. When it is detected that the grid 40 is not connected to the grid-connected output port, it is determined that the inverter 100 is in an off-grid state.

[0055] The maximum load power of the inverter 100 refers to the maximum power that the inverter 100 can provide to the charging pile 200 and the load 30 connected to its off-grid output port. When the inverter 100 is in the off-grid pile, its maximum load power and real-time output power are obtained. It can be understood that the real-time output power is the power that the inverter 100 has currently provided to the charging pile 200 and the load 30 through the off-grid output port.

[0056] S200: Determine remaining available power according to the maximum load power and the real-time output power.

[0057] The remaining available power is the power that the photovoltaic module 20 and the energy storage battery 300 can provide to the charging pile 200 through the inverter 100 in addition to the power that has been provided to the charging pile 200 and the load 30 through the inverter 100. Therefore, the remaining available power can be determined according to the difference between the maximum load power and the real-time output power. That is, the inverter 100 can obtain the remaining available power according to the maximum load power and the real-time output power.

[0058] It can be understood that the power of the load 30 cannot be controlled by the inverter 100 , and the load 30 directly obtains the required power from the inverter 100 according to its own operating requirements.

[0059] S300: Send the remaining available power to the charging pile, so that the charging pile outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power.

[0060] The remaining available target power is zero. The inverter 100 sends the remaining available power to the charging pile 200, so that the charging pile 200 outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power.

[0061] In the embodiment of the present application, the control method applied to the inverter 100 may be executed by a control device in the inverter 100, such as a microcontroller unit (MCU), a digital signal processor (DSP) or an energy management system (EMS) in the inverter 100. The control device may include multiple controllers or control chips, such as a DSP chip and a RAM (Random Access Memory) chip.

[0062] It is understandable that, in the embodiment of the present application, the inverter 100 may repeatedly perform steps S100 to S300 to gradually adjust the remaining available power to the remaining available target power (zero), so that the inverter 100 stably operates at the maximum load power. For example, the inverter 100 repeatedly performs steps S100 to S300 at a preset cycle, and re-acquires the maximum load power and real-time output power of the inverter 100 in each cycle, thereby updating the remaining available power.

[0063] In some embodiments, the control method may further include: when the inverter 100 is in an off-grid state, the inverter 100 sets the remaining available target power to zero, and sends the remaining available target power to the charging pile 200 .

[0064] When the inverter 100 is in an off-grid state, the remaining available target power is sent to the charging pile 200. It can be understood that the inverter 100 can send the remaining available target power and the remaining available power to the charging pile 200 at the same time.

[0065] In some other embodiments, the control method may further include: when the inverter 100 is in an off-grid state, sending off-grid state information to the charging pile 200 .

[0066] The off-grid status information is used to trigger the charging pile 200 to set the remaining available target power to zero. At this time, the remaining available target power is a parameter built into the charging pile 200, and the charging pile 200 sets the remaining available target power to zero when receiving the off-grid status information.

[0067] See also Figure 3 , Figure 3 Shows Figure 2 Detailed flowchart of step S100 in FIG.

[0068] like Figure 3 As shown, in some embodiments, "obtaining the maximum load power of the inverter" in step S100 may include:

[0069] S110: Obtain the maximum allowable discharge power of the energy storage battery and the photovoltaic output power of the photovoltaic module.

[0070] The maximum allowable discharge power of the energy storage battery 300 is the maximum power that can be output when the energy storage battery 300 is discharged. The inverter 100 can obtain the maximum allowable discharge power of the energy storage battery 300 by communicating with a battery management system (BMS) inside the energy storage battery 300.

[0071] Furthermore, the inverter 100 may obtain the maximum allowable discharge current and the battery output voltage of the energy storage battery 300, and then obtain the maximum allowable discharge power according to the maximum allowable discharge current and the battery output voltage.

[0072] Specifically, the inverter 100 can obtain the maximum allowable discharge current by communicating with the battery management system in the energy storage battery 300, obtain the battery output voltage by performing voltage detection on the energy storage battery 300, and then obtain the maximum allowable discharge power according to the product of the obtained maximum allowable discharge current and the battery output voltage.

[0073] Among them, the maximum allowable discharge current is Ibatmax, the battery output voltage is Ubat, the maximum allowable discharge power is Pbatmax, then Pbatmax=Ibatmax*Ubat.

[0074] It can be understood that the inverter 100 may be provided with a voltage detection circuit connected to the output end of the energy storage battery 300, and the voltage detection circuit is used to detect the voltage of the output end of the energy storage battery 300 to obtain the battery output voltage. Alternatively, the voltage detection circuit connected to the output end of the energy storage battery 300 may be provided independently of the control device in the inverter 100, and the control device may be connected to the voltage detection circuit, and the control device obtains the battery output voltage through the voltage detection circuit. Of course, the voltage detection circuit may also be integrated into the control device, and the present application does not limit this.

[0075] The inverter 100 can obtain the photovoltaic output voltage and the photovoltaic output current of the photovoltaic assembly 20, and then obtain the photovoltaic output power according to the photovoltaic output voltage and the photovoltaic output current.

[0076] Specifically, the inverter 100 can obtain the photovoltaic output voltage and photovoltaic output current by performing voltage detection and current detection on the output end of the photovoltaic assembly 20, and obtain the photovoltaic output power according to the product of the obtained photovoltaic output voltage and photovoltaic output current. The photovoltaic output voltage is Upv, the photovoltaic output current is Ipv, and the photovoltaic output power is Ppv, then Ppv=Upv*Ipv.

[0077] It can be understood that the inverter 100 may be provided with a voltage detection circuit and a current detection circuit connected to the output end of the photovoltaic module 20, and the photovoltaic output voltage and photovoltaic output current are obtained by performing voltage detection and current detection on the output end of the photovoltaic module 20 through the voltage detection circuit and the current detection circuit. Alternatively, the voltage detection circuit and the current detection circuit connected to the output end of the photovoltaic module 20 may be set independently of the control device in the inverter 100, and the control device may be connected to the voltage detection circuit and the current detection circuit, and the control device obtains the photovoltaic output voltage and photovoltaic output current through the voltage detection circuit and the current detection circuit. Alternatively, the voltage detection circuit and the current detection circuit may also be integrated into the control device, and the present application does not limit this.

[0078] S120: Determine a first load power of the inverter according to the maximum allowable discharge power, the photovoltaic output power, and the conversion efficiency of the inverter.

[0079] Wherein, the first load power is P1, and the conversion efficiency is K, then P1=K*(Pbatmax+Ppv). It can be understood that the conversion efficiency K of the inverter 100 is less than 1, which can be obtained by performing an efficiency test on the inverter 100 in an off-grid state.

[0080] S130: Obtain the rated output power of the inverter.

[0081] The rated output power of the inverter 100 is a certain value, which can be obtained from the manual of the inverter 100. Of course, the rated output power of the inverter 100 can be pre-stored in the storage space of the control device of the inverter 100, and retrieved from the storage space when needed.

[0082] S140. Obtain a maximum load power according to the first load power and the rated output power; wherein the maximum load power is a smaller value between the first load power and the rated output power.

[0083] The inverter 100 obtains its maximum load power according to the acquired first load power and the rated output power. Specifically, the rated output power is Pn, the maximum load power is Pmax, and the maximum load power Pmax=MIN(Pn, P1).

[0084] It is understandable that the output power of the inverter 100 cannot exceed its rated output power, otherwise it will cause the inverter 100 to be overloaded. The output power of the inverter 100 in the off-grid state is all provided by the photovoltaic module 20 and the energy storage battery 300, and cannot exceed the sum of the maximum allowable discharge power and the photovoltaic output power (the first load power). Therefore, the smaller value of the first load power and the rated output power is used as the maximum load power to ensure that the output power of the inverter 100 does not exceed the first load power or the rated output power.

[0085] In some embodiments, the energy storage battery 300 may be built with an AEF chip, and battery information such as power information and temperature information of the energy storage battery 300 may be obtained through the AEF chip, and then the maximum allowable discharge current is obtained according to the obtained battery information.

[0086] It can be understood that the maximum allowable discharge current can be a positive value or a negative value. When the power of the energy storage battery 300 is too low, the maximum allowable discharge current can be a negative value. At this time, the energy storage battery 300 needs to be charged and cannot be discharged. Then a part of the photovoltaic output power output by the photovoltaic assembly 20 needs to be provided to the energy storage battery 300 for charging, and the remaining part is provided to the inverter 100 for output. Correspondingly, the maximum allowable discharge power calculated by the inverter 100 based on the maximum allowable discharge current and the battery output voltage is also a negative value. When the power of the energy storage battery 300 can meet the discharge demand, the maximum allowable discharge current is a positive value. Even if the energy storage battery 300 is in a charging state at this time, the maximum allowable discharge power calculated by the inverter 100 based on the maximum allowable discharge current and the battery output voltage is also a positive value. The inverter 100 will give priority to providing the photovoltaic output power output by the photovoltaic assembly 20 and the maximum allowable discharge power that the energy storage battery 300 can output to the inverter 100 for output to the load 30 and the charging pile 200.

[0087] See also Figure 4 , Figure 4 Shows Figure 2 Partially detailed flowchart of step S110 in FIG.

[0088] like Figure 4 As shown, in some embodiments, the “obtaining the real-time output power of the inverter 100 ” in step S110 may include:

[0089] S150: Obtain the real-time output voltage and real-time output current of the inverter.

[0090] It can be understood that the real-time output voltage and real-time output current of the inverter 100 refer to the real-time output voltage and output current of the off-grid output port of the inverter 100 .

[0091] The inverter 100 can obtain the real-time output voltage and the real-time output current by performing voltage detection and current detection on its off-grid output port. It can be understood that the inverter 100 can be provided with a voltage detection circuit and a current detection circuit connected to the off-grid output port, and the voltage detection and current detection of the off-grid output port are performed by the voltage detection circuit and the current detection circuit to obtain the real-time output voltage and the real-time output current. Alternatively, the voltage detection circuit and the current detection circuit connected to the off-grid output port can be set independently of the control device in the inverter 100, and the control device can be connected to the voltage detection circuit and the current detection circuit, and the control device in the inverter 100 obtains the real-time output voltage and the real-time output current through the voltage detection circuit and the current detection circuit. Alternatively, the voltage detection circuit and the current detection circuit can also be integrated in the control device, and this application does not limit this.

[0092] S160: Obtain real-time output power according to the real-time output voltage and the real-time output current.

[0093] It can be understood that the inverter 100 obtains the real-time output power according to the product of the real-time output voltage and the real-time output current, wherein the real-time output power includes the power provided by the inverter 100 to the charging pile 200 and the load 30 .

[0094] See also Figure 5 , which shows a flow chart of a control method provided by another embodiment of the present application, the control method is applied to a charging pile 200, and the control method includes:

[0095] S500: Receive the remaining available power sent by the inverter.

[0096] The charging pile 200 receives the remaining available power sent by the inverter 100. It can be understood that the remaining available power is obtained by the inverter 100 according to the difference between its maximum load power and the real-time output power, and then sent to the charging pile 200.

[0097] S600: Generate a charging instruction according to the remaining available power and the remaining available target power.

[0098] Among them, the remaining available target power is zero. In the embodiment of the present application, the charging pile 200 can generate a charging instruction according to the received remaining available power and the remaining available target power. In some specific examples, the charging pile 200 can perform PI adjustment on the remaining available power and the remaining available target power to obtain a charging instruction.

[0099] S700: Enable the charging pile to output corresponding charging power to the target device according to the charging instruction.

[0100] The charging pile 200 can output the corresponding charging power to the target device according to the charging instruction.

[0101] In the embodiment of the present application, the control method applied to the charging pile 200 can be executed by a control device in the charging pile 200, such as a microcontroller unit (MCU) or a digital signal processor (DSP) in the charging pile 200.

[0102] It can be understood that in the embodiment of the present application, the charging pile 200 can repeatedly perform steps S210 to S230 to gradually adjust the remaining available power to the remaining available target power (zero), so that the charging pile 200 gradually uses the remaining available power that the inverter 100 can increase for the charging pile 200, thereby making the inverter 100 stably operate at the maximum load power.

[0103] In some embodiments, the control method may further include: receiving the remaining available target power sent by the inverter 100 .

[0104] The remaining available target power is set to zero by the inverter 100 in the off-grid state. It can be understood that the charging pile 200 can receive the remaining available target power and the remaining available power sent by the inverter 100 at the same time.

[0105] In some other embodiments, the control method may further include: receiving off-grid status information sent by the inverter 100, and setting the remaining available target power to zero according to the off-grid status information.

[0106] At this time, the remaining available target power is a parameter built into the charging pile 200, and the charging pile 200 sets the remaining available target power to zero when receiving the off-grid state information.

[0107] In some embodiments, the charging pile 200 may be an AC charging pile. Figure 5 Step S230 in the method may include: sending a charging instruction to a target device, so that the target device obtains a corresponding charging power from the charging pile 200 according to the charging instruction.

[0108] The charging pile 200 sends the charging instruction to the target device, so that the target device can adjust the charging power obtained from the charging pile 200 according to the received charging instruction, and then adjust the power obtained by the charging pile 200 from the inverter 100.

[0109] Of course, the charging pile 200 of the present application may also be a DC charging pile 200. In this case, the charging pile 200 may directly adjust the charging power provided by the charging pile 200 to the target device according to the charging instruction, thereby adjusting the power obtained by the charging pile 200 from the inverter 100.

[0110] like Figure 6As shown, in some embodiments, Figure 5 Step S600 in may include:

[0111] S610: Obtain a first deviation value according to the remaining available power received in the current cycle and the remaining available target power.

[0112] It is understandable that the charging pile 200 can receive the remaining available power sent by the inverter 100 at a preset period. The charging pile 200 obtains the first deviation value based on the remaining available power received in the current period and the remaining available target power. Among them, the remaining available power in the current period is Pev (n), the remaining available target power in the current period is Pref (n), and the first deviation value is Pev (n) - Pref (n).

[0113] S620: Obtain a second deviation value according to the remaining available power received in the previous cycle and the remaining available target power.

[0114] It can be understood that in the current cycle, the remaining available power and the remaining available target power of the previous cycle can be stored in the charging pile 200, so that the charging pile 200 can obtain the second deviation value. It can be understood that since the first deviation value of the current cycle is calculated in each cycle, the second deviation value is the first deviation value of the previous cycle. Specifically, the remaining available power of the previous cycle is Pev (n-1), the remaining available target power of the previous cycle is Pref (n-1), and the second deviation value is Pev (n-1) - Pref (n-1).

[0115] S630: Generate a charging instruction corresponding to the current cycle according to the first deviation value, the second deviation value, and the charging instruction generated in the previous cycle.

[0116] The charging pile 200 generates a charging instruction corresponding to the current cycle according to the first deviation value, the second deviation value and the charging instruction generated in the previous cycle.

[0117] Specifically, if Figure 7 As shown, step S630 may include:

[0118] S631. Obtain a first compensation value according to a product of a first deviation value and a first preset parameter.

[0119] The first preset parameter is a preset control parameter. If the first preset parameter is kp, the first compensation value is: kp*[Pev(n)-Pref(n)].

[0120] S632: Obtain a second compensation value according to the product of the second deviation value and the second preset parameter.

[0121] The second preset parameter is a preset control parameter. If the second preset parameter is ki, the second compensation value is: ki*[Pev(n-1)-Pref(n-1)].

[0122] S633: Obtain a charging instruction corresponding to the current cycle according to the sum of the first compensation value, the second compensation value, and the charging instruction corresponding to the previous cycle.

[0123] The charging instruction of the previous cycle is Pwm (n-1), and the charging instruction of the current cycle is Pwm (n). Then, the charging instruction of the current cycle can be obtained as follows:

[0124] Pwm(n)=kp*[Pev(n)-Pref(n)]+ki*[Pev(n-1)-Pref(n-1)]+ Pwm(n-1);

[0125] It is understood that the charging instruction can be a control signal for controlling the operation of the charging circuit in the target device, such as a PWM control signal. The target device controls the operation of the charging circuit through the charging instruction, thereby controlling the charging circuit in the target device to obtain the corresponding charging power from the charging pile 200.

[0126] In the embodiment of the present application, the target device may be a new energy vehicle, that is, the charging pile 200 may charge the new energy vehicle. The charging pile 200 may send a charging instruction to the charging system of the new energy vehicle, and the charging system controls the new energy vehicle to charge according to the charging instruction, so that the new energy vehicle obtains the corresponding charging power from the charging pile 200 according to the charging instruction.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. In the actual application process, the entire content of the technical solutions described in any embodiment of the present application can be implemented, or some content can be added, or some content can be deleted, or some content can be changed / replaced. Although the present application is described in detail with reference to the preferred embodiments, it should be understood by those of ordinary skill in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An energy storage charging system, characterized in that: Including inverter, charging pile and energy storage battery; The DC input terminal of the inverter is used to connect to a photovoltaic module; The battery connection end of the inverter is used to connect the energy storage battery, and the off-grid output port of the inverter is used to connect the charging pile and the load; the inverter and the charging pile communicate with each other; Wherein, when the inverter is in an off-grid state, the inverter determines the remaining available power according to its maximum load power and real-time output power, and sends the remaining available power to the charging pile; wherein, the remaining available power is the power that the photovoltaic module and the energy storage battery can still provide to the charging pile, and the real-time output power includes the power provided by the inverter to the charging pile and the load; The charging pile outputs corresponding charging power to the target device according to the remaining available power and the remaining available target power, wherein the remaining available target power is zero; The inverter is also used for: Obtaining the maximum allowable discharge power of the energy storage battery and the photovoltaic output power of the photovoltaic module; Obtaining a first load power of the inverter according to the maximum allowable discharge power, the photovoltaic output power and the conversion efficiency of the inverter; Obtaining the rated output power of the inverter; Obtaining the maximum load power according to the first load power and the rated output power; The maximum load power is the smaller value between the first load power and the rated output power; Obtaining the maximum allowable discharge current and battery output voltage of the energy storage battery; Obtaining the maximum allowable discharge power according to the maximum allowable discharge current and the battery output voltage; Obtaining a photovoltaic output voltage and a photovoltaic output current of the photovoltaic module; The photovoltaic output power is obtained according to the photovoltaic output voltage and the photovoltaic output current.

2. The energy storage charging system according to claim 1, characterized in that: The inverter is also used for: When the inverter is in an off-grid state, setting the remaining available target power to zero, and sending the remaining available target power to the charging pile; Alternatively, the inverter is further used to: when the inverter is in an off-grid state, send off-grid state information to the charging pile; the charging pile receives the off-grid state information and sets the remaining available target power to zero according to the off-grid state information.

3. The energy storage charging system according to claim 1 or 2, characterized in that: The charging pile is used for: receiving the remaining available power sent by the inverter; generating a charging instruction according to the remaining available power and the remaining available target power; According to the charging instruction, the charging pile outputs the corresponding charging power to the target device.

4. The energy storage charging system according to claim 3, characterized in that: The charging pile is an AC charging pile, and the charging pile is also used for: The charging instruction is sent to the target device, so that the target device obtains the corresponding charging power from the charging pile according to the charging instruction.

5. The energy storage charging system according to claim 3, characterized in that: The charging pile is also used for: Obtaining a first deviation value according to the remaining available power received in the current cycle and the remaining available target power; Obtaining a second deviation value according to the remaining available power received in a previous cycle and the remaining available target power; The charging instruction corresponding to the current cycle is generated according to the first deviation value, the second deviation value and the charging instruction corresponding to the previous cycle.

6. The energy storage charging system according to claim 5, characterized in that: The charging pile is also used for: Obtaining a first compensation value according to the product of the first deviation value and a first preset parameter; Obtaining a second compensation value according to the product of the second deviation value and a second preset parameter; wherein the first preset parameter and the second preset parameter are preset control parameters; The charging instruction corresponding to the current cycle is obtained according to the sum of the first compensation value, the second compensation value and the charging instruction corresponding to the previous cycle.

7. A control method, characterized in that: Applied to an inverter, the DC input end of the inverter is used to connect to a photovoltaic module, the battery connection end of the inverter is used to connect to an energy storage battery, and the off-grid output port of the inverter is used to connect to a charging pile and a load; the control method includes: When the inverter is in an off-grid state, obtaining the maximum load power and real-time output power of the inverter, wherein the real-time output power includes the power provided by the inverter to the charging pile and the load; Determine the remaining available power according to the maximum load power and the real-time output power; wherein the remaining available power is the power that the photovoltaic module and the energy storage battery can still provide to the charging pile; The remaining available power is sent to the charging pile, so that the charging pile outputs the corresponding charging power to the target device according to the remaining available power and the remaining available target power; wherein the remaining available target power is zero; The obtaining of the maximum load power of the inverter includes: Obtaining the maximum allowable discharge power of the energy storage battery and the photovoltaic output power of the photovoltaic module; Determining a first load power of the inverter according to the maximum allowable discharge power, the photovoltaic output power and the conversion efficiency of the inverter; Obtaining the rated output power of the inverter; Obtaining the maximum load power according to the first load power and the rated output power; The maximum load power is the smaller value between the first load power and the rated output power; The control method further comprises: Obtaining a photovoltaic output voltage and a photovoltaic output current of the photovoltaic module; The photovoltaic output power is obtained according to the photovoltaic output voltage and the photovoltaic output current.

8. The control method according to claim 7, characterized in that: The control method further comprises: When the inverter is in an off-grid state, setting the remaining available target power to zero, and sending the remaining available target power to the charging pile; Alternatively, when the inverter is in an off-grid state, off-grid state information is sent to the charging pile; the off-grid state information is used to trigger the charging pile to set the remaining available target power to zero.

9. The control method according to claim 7, characterized in that: The obtaining of the maximum allowable discharge power of the energy storage battery includes: Obtaining the maximum allowable discharge current and battery output voltage of the energy storage battery; The maximum allowable discharge power is obtained according to the maximum allowable discharge current and the battery output voltage.

10. The control method according to claim 7, characterized in that: The control method further comprises: Obtaining the real-time output voltage and real-time output current of the inverter; The real-time output power is obtained according to the real-time output voltage and the real-time output current.

11. A control method, characterized in that: Applied to a charging pile, the charging pile is applied to the energy storage charging system according to any one of claims 1 to 6, and the control method includes: Receive the remaining available power sent by the inverter, where the remaining available power is obtained by the inverter according to its maximum load power and real-time output power; wherein the remaining available power is the power that the photovoltaic module and the energy storage battery can still provide to the charging pile; generating a charging instruction according to the remaining available power and the remaining available target power; wherein the remaining available target power is zero; According to the charging instruction, the charging pile outputs the corresponding charging power to the target device to charge the target device.

12. The control method according to claim 11, characterized in that: The control method further comprises: receiving the remaining available target power sent by the inverter, where the remaining available target power is set to zero by the inverter in an off-grid state; Alternatively, off-grid status information sent by the inverter is received, and the remaining available target power is set to zero according to the off-grid status information.

13. The control method according to claim 11, characterized in that: The charging pile is an AC charging pile, and the step of causing the charging pile to output corresponding charging power to a target device according to the charging instruction includes: The charging instruction is sent to the target device, so that the target device obtains the corresponding charging power from the charging pile according to the charging instruction.

14. The control method according to any one of claims 11 to 13, characterized in that: The generating a charging instruction according to the remaining available power and the remaining available target power includes: Obtaining a first deviation value according to the remaining available power received in the current cycle and the remaining available target power; Obtaining a second deviation value according to the remaining available power received in a previous cycle and the remaining available target power; The charging instruction corresponding to the current cycle is generated according to the first deviation value, the second deviation value and the charging instruction corresponding to the previous cycle.

15. The control method according to claim 14, characterized in that: The step of generating the charging instruction corresponding to the current cycle according to the first deviation value, the second deviation value, and the charging instruction generated in the previous cycle includes: Obtaining a first compensation value according to the product of the first deviation value and a first preset parameter; Obtaining a second compensation value according to the product of the second deviation value and a second preset parameter; wherein the first preset parameter and the second preset parameter are preset control parameters; The charging instruction corresponding to the current cycle is obtained according to the sum of the first compensation value, the second compensation value and the charging instruction corresponding to the previous cycle.

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