Energy storage inverter, energy storage system and control method thereof, and energy storage device

Abstract

The present disclosure relates to a kind of energy storage inverter, energy storage system and its control method, energy storage equipment.Wherein, energy storage inverter includes: first auxiliary power supply, control unit, relay, DC / DC module;First auxiliary power supply can be respectively with external photovoltaic module and external battery module electrically connected use;Control unit, relay are electrically connected with photovoltaic module respectively;Control unit is electrically connected with first auxiliary power supply and DC / DC module respectively, and relay is electrically connected with DC / DC module.Through the present disclosure, the problem that photovoltaic energy storage system frequently starts and stops, leading to the noise of relay can be solved.

Description

Technical Field

[0001] This disclosure relates to the field of photovoltaic energy storage technology, and in particular to energy storage inverters, energy storage systems and their control methods, and energy storage equipment. Background Technology

[0002] With the increasingly widespread application of solar radiation technology, more and more devices are integrating photovoltaic (PV) modules to generate electricity through solar photovoltaic power, thereby meeting the needs for extended battery life or providing clean energy. A PV module is a power generation device made up of a certain number of photovoltaic cells connected in series and parallel and then packaged.

[0003] However, due to the instability of solar radiation, the power generation of photovoltaic modules is also unstable, especially under weak sunlight conditions. This can lead to frequent start-up and shutdown of the product, and frequent switching of internal relays can cause relay noise, which can reduce the user experience.

[0004] Therefore, the relevant technologies suffer from the problem of frequent start-ups and shutdowns of photovoltaic energy storage systems, resulting in high relay noise. Summary of the Invention

[0005] This disclosure provides an energy storage inverter, an energy storage system and its control method, and an energy storage device to solve the problem of frequent start-stop of photovoltaic energy storage systems, which leads to high relay noise in related technologies.

[0006] According to a first aspect of the present disclosure, an energy storage inverter is provided, comprising: a first auxiliary power supply, a control unit, a relay, and a DC / DC module; the first auxiliary power supply can be electrically connected to an external photovoltaic module and an external battery module respectively; the control unit and the relay are respectively electrically connected to the photovoltaic module; the control unit is respectively electrically connected to the first auxiliary power supply and the DC / DC module, and the relay is electrically connected to the DC / DC module;

[0007] The control unit is configured to: acquire the output voltage of the photovoltaic module, and when it is determined that the output voltage is greater than a preset first voltage value, turn on the first auxiliary power supply, and control the first auxiliary power supply to output a power signal according to a preset second voltage value, wherein the first voltage value is less than a target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches a preset requirement;

[0008] The first auxiliary power supply is used to: convert the power signal output by the photovoltaic module into a power signal with the second voltage value as the output voltage, and to charge the battery module, wherein the second voltage value satisfies the charging voltage range of the battery module;

[0009] The control unit is further configured to: continue to control the first auxiliary power supply to output a power signal according to the second voltage value when the voltage output by the photovoltaic module is within a preset voltage range, wherein the upper limit of the preset voltage range is the target voltage value;

[0010] The control unit is further configured to: when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, close the relay, and convert the voltage output by the photovoltaic module into a power signal with the second voltage value as the output voltage through the DC / DC module, so as to charge the battery module.

[0011] Optionally, as described above, the energy storage inverter further includes: a second auxiliary power supply for electrical connection with the battery assembly.

[0012] The input terminal of the second auxiliary power supply is connected to the photovoltaic module via an electrical connection to the DC / DC module, and the output terminal of the second auxiliary power supply is connected to the control unit.

[0013] The control unit is further configured to shut down the first auxiliary power supply and provide redundant power to the control unit via the second auxiliary power supply when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range.

[0014] Optionally, the energy storage inverter as described above further includes: a first capacitor;

[0015] The first capacitor is located on the bus between the relay and the DC / DC module, and is located between the positive bus and the negative bus in the bus.

[0016] The control unit is also configured to: control the DC / DC module to start before closing the relay, and shut down the DC / DC module after charging the first capacitor to the same output voltage as the photovoltaic module.

[0017] Optionally, the energy storage inverter as described above is characterized by further comprising: a second capacitor;

[0018] The second capacitor is located on the busbar between the first connection point and the second connection point, and is located between the positive busbar and the negative busbar in the busbar. The first connection point is the connection point between the output terminal of the first auxiliary power supply and the busbar, and the second connection point is the connection point between the input terminal of the second auxiliary power supply and the busbar.

[0019] Optionally, the energy storage inverter as described above may also include: voltage divider resistors;

[0020] The voltage divider resistor is located between the output terminal of the first auxiliary power supply and the connection point of the bus.

[0021] The voltage divider resistor is used to reduce the charging power of the first auxiliary power supply to the battery assembly.

[0022] According to a second aspect of the present disclosure, an energy storage system is also provided, including an energy storage inverter, a photovoltaic module, and a battery module as described in any of the foregoing claims, wherein the energy storage inverter is electrically connected to the photovoltaic module and the battery module, respectively.

[0023] According to a third aspect of the present disclosure, an energy storage system control method is also provided, applied to the energy storage system as described in the foregoing embodiments, comprising:

[0024] The output voltage of the photovoltaic module is obtained, and if the output voltage is determined to be greater than a preset first voltage value, a first auxiliary power supply is turned on, wherein the first voltage value is less than a target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches a preset requirement;

[0025] The first auxiliary power source converts the power signal output by the photovoltaic module into a power signal with a preset second voltage value as the output voltage, and charges the battery module, wherein the second voltage value satisfies the charging voltage range of the battery module.

[0026] When the voltage output by the photovoltaic module is within a preset voltage range, the first auxiliary power supply continues to be controlled to output a power signal according to the second voltage value, wherein the upper limit of the preset voltage range is the target voltage value;

[0027] When the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the relay is closed, and the voltage output by the photovoltaic module is converted into a power signal with the second voltage value as the output voltage through the DC / DC module, so as to charge the battery module.

[0028] Optionally, as described in the aforementioned energy storage system control method, the method further includes:

[0029] If the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the first auxiliary power supply is turned off, and the control unit is redundantly powered by the second auxiliary power supply.

[0030] Optionally, in the aforementioned energy storage system control method, the step of closing the relay comprises:

[0031] The DC / DC module is started up and then turned off after the first capacitor is charged to the same voltage as the output voltage of the photovoltaic module.

[0032] Close the relay to precharge the first capacitor.

[0033] According to a fourth aspect of the present disclosure, an energy storage device is also provided, comprising:

[0034] processor;

[0035] Memory used to store processor-executable program instructions;

[0036] The processor is configured to implement the method described in any of the foregoing embodiments during execution.

[0037] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0038] As can be seen from the above embodiments, the energy storage inverter of this disclosure includes a first auxiliary power supply, a control unit, a relay, and a DC / DC module. The first auxiliary power supply can be electrically connected to an external photovoltaic module and an external battery module. The control unit and the relay are electrically connected to the photovoltaic module. The control unit is electrically connected to the first auxiliary power supply and the DC / DC module, and the relay is electrically connected to the DC / DC module. The control unit is used to: acquire the output voltage of the photovoltaic module, and when the output voltage is determined to be greater than a preset first voltage value, turn on the first auxiliary power supply and control the first auxiliary power supply to output a power signal according to a preset second voltage value, wherein the first voltage value is less than a target voltage value, and the target voltage value is the value of the photovoltaic module when the light intensity reaches a preset requirement. The control unit is further configured to: convert the power signal output by the photovoltaic module into a power signal with the second voltage value as the output voltage, and charge the battery module, wherein the second voltage value satisfies the charging voltage range of the battery module; the control unit is further configured to: continue to control the first auxiliary power supply to output a power signal according to the second voltage value when the voltage output by the photovoltaic module is within a preset voltage range, wherein the upper limit of the preset voltage range is the target voltage value; the control unit is further configured to: close the relay when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, and convert the voltage output by the photovoltaic module into a power signal with the second voltage value as the output voltage through the DC / DC module to charge the battery module. Therefore, even when the light intensity does not meet the preset requirements, the power output of the photovoltaic module can charge the battery module through the first auxiliary power source without turning on the relay. Furthermore, the relay will only close when the voltage of the power signal output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range. The DC / DC module then converts the power output by the photovoltaic module into a power signal with the second voltage value as the output voltage to charge the battery module. Thus, even with weak light intensity, the relay does not need to repeatedly activate to charge or stop charging the battery module; it only closes when the light intensity is strong. This solves the problem of frequent start-stop cycles in photovoltaic energy storage systems, which leads to high relay noise in related technologies.

[0039] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the electrical connections of an energy storage inverter according to an embodiment of the present disclosure.

[0042] Figure 2 This is a schematic diagram of the electrical connections of an energy storage system according to an embodiment of the present disclosure.

[0043] Figure 3 This is a flowchart illustrating a control method applied to an energy storage system according to an application example of this disclosure.

[0044] Figure 4 This is a schematic flowchart illustrating an energy storage system control method according to an embodiment of the present disclosure.

[0045] Figure 5 This is a schematic diagram of the structure of an energy storage device according to an embodiment of the present disclosure. Detailed Implementation

[0046] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0047] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms “a” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0048] It should be understood that although the terms first, second, third, etc., may be used to describe various information in embodiments of this disclosure, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of embodiments of this disclosure, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination." The "connection" in this disclosure relating to the transmission of current or signals between electronic devices generally refers to an "electrical connection."

[0049] For the sake of brevity and ease of understanding, this document uses the terms "greater than" or "less than", "higher than" or "lower than" to describe size relationships. However, it will be understood by those skilled in the art that the term "greater than" also includes the meaning of "greater than or equal to", and "less than" also includes the meaning of "less than or equal to"; the term "higher than" also includes the meaning of "higher than or equal to", and "lower than" also includes the meaning of "lower than or equal to".

[0050] Figure 1 This is a schematic diagram illustrating the structure of an energy storage inverter according to an embodiment of this disclosure. Figure 1 As shown, an energy storage inverter includes: a first auxiliary power supply 2, a control unit 1, a relay RY1, and a DC / DC module 4; the first auxiliary power supply 2 can be electrically connected to an external photovoltaic module and an external battery module respectively; the control unit 1 and the relay RY1 are electrically connected to the photovoltaic module respectively; the control unit 1 is electrically connected to the first auxiliary power supply 2 and the DC / DC module 4 respectively, and the relay RY1 is electrically connected to the DC / DC module 4.

[0051] The control unit 1 is used to: acquire the output voltage of the photovoltaic module, and when it is determined that the output voltage is greater than a preset first voltage value, turn on the first auxiliary power supply 2, and control the first auxiliary power supply 2 to output a power signal according to a preset second voltage value, wherein the first voltage value is less than the target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches the preset requirement;

[0052] The first auxiliary power supply 2 is used to: convert the power signal output by the photovoltaic module into a power signal with a second voltage value as the output voltage, and to charge the battery module, wherein the second voltage value meets the charging voltage range of the battery module.

[0053] Specifically, the energy storage inverter includes the aforementioned first auxiliary power supply 2 and control unit 1. The control unit 1 can be a unit for controlling the auxiliary power supply, and it can have a voltage sampling point set on the bus electrically connected to the power output terminal of the photovoltaic module. Thus, the control unit 1 can obtain the output voltage (i.e., the input voltage sampling value used to charge the battery) by sampling the output voltage of the photovoltaic module. After obtaining the output voltage, it can compare it with a first voltage value, which is a preset voltage value less than a target voltage value. Since the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches the preset requirement, the first voltage value can be understood as the output voltage of the photovoltaic module in a low-light environment. A low-light environment can be a situation where the light intensity is insufficient for the photovoltaic module to reach its optimal operating state. The performance of the photovoltaic module will vary under different light conditions, especially in a low-light environment, where power generation efficiency and output power will decrease significantly. For example, the light intensity in a low-light environment is less than 500W / m². 2 Therefore, the preset requirement is a light intensity greater than or equal to 500W / m². 2 .

[0054] When the output voltage exceeds the first voltage value, in this embodiment, the first auxiliary power supply 2 is activated by the control unit 1, and the first auxiliary power supply 2 converts the power signal output by the photovoltaic module into a power signal with a second voltage value as the output voltage, so as to charge the battery module with a power signal that meets the charging voltage of the battery module. In this case, the first auxiliary power supply 2 enters the heavy load stage. Optionally, the auxiliary power supply can be an independent power supply that provides power to components in the energy storage inverter that perform auxiliary functions such as control, monitoring, and communication (e.g., control unit 1), ensuring that these functional components can operate normally even when the photovoltaic module does not generate power or generates insufficient power.

[0055] Furthermore, the first auxiliary power supply 2 is positioned on the side of the voltage acquisition point away from the connection end with the photovoltaic module.

[0056] Control unit 1 is also used to: continue to control the first auxiliary power supply 2 to output a power signal according to the second voltage value when the voltage output by the photovoltaic module is within the preset voltage range, wherein the upper limit of the preset voltage range is the target voltage value;

[0057] The control unit 1 is also used to: shut down the first auxiliary power supply 2, close the relay RY1, and convert the voltage output by the photovoltaic module into a power signal with a second voltage value as the output voltage when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, so as to charge the battery module.

[0058] Specifically, this energy storage inverter incorporates a relay RY1 and a DC / DC module 4, which are electrically connected to each other. Furthermore, in this embodiment, the line in the energy storage inverter used to connect to the photovoltaic modules and charge the battery modules via the relay RY1 and the DC / DC module 4 is referred to as the bus. One end of the relay RY1 is electrically connected to the photovoltaic module connection terminal in this energy storage inverter, which is used for electrical connection to the photovoltaic modules. Moreover, the relay RY1 is positioned on the bus further away from the photovoltaic module connection terminal relative to the connection point between the first auxiliary power supply 2 and the bus. Therefore, even if the relay RY1 is disconnected, the first auxiliary power supply 2 can still receive power.

[0059] Since the output voltage of the photovoltaic module decreases after the battery module is charged by the first auxiliary power supply 2, in this embodiment, as long as the output voltage of the photovoltaic module meets the requirement of being within the preset voltage range, the first auxiliary power supply 2 continues to output power according to the second voltage value, and the relay RY1 is not controlled to close. That is to say, within the preset voltage range, the photovoltaic module is considered to still be in a low light environment.

[0060] Conversely, if the control unit 1 determines that the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range (i.e., the photovoltaic module is in a strong light environment), it shuts off the first auxiliary power supply 2, closes the relay RY1, and converts the power output by the photovoltaic module into a second voltage value through the DC / DC module 4. In other words, under this condition, the photovoltaic module is considered to have reached its optimal working state, thus preventing the relay RY1 from repeatedly operating, and directly closing the relay RY1 to charge the battery module.

[0061] Furthermore, if the control unit determines that the output voltage of the photovoltaic module is less than or equal to the lower limit of the preset voltage range, it indicates that the light intensity is extremely weak and the charging efficiency is extremely low, and then controls the first auxiliary power supply 2 to shut down, and the entire system is shut down.

[0062] In this embodiment, by setting up relay RY1 and DC / DC module 4, the battery pack can be stably charged in strong light environments without the requirement of frequently opening and closing relay RY1.

[0063] As can be seen from the above embodiments, the energy storage inverter of this disclosure can charge the battery module 6 through the first auxiliary power supply without turning on the relay when the light intensity does not meet the preset requirements. Moreover, the relay will only close when the voltage of the power signal output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range. The DC / DC module converts the power output by the photovoltaic module into a power signal with the second voltage value as the output voltage to charge the battery module 6. Thus, even if the light intensity is weak, the relay does not need to be repeatedly activated to charge or stop charging the battery module 6. The relay will only close when the light intensity is strong. Therefore, it can solve the problem of frequent start-stop of photovoltaic energy storage systems in related technologies, which leads to high relay noise.

[0064] like Figure 1 As shown, in some optional embodiments, such as the aforementioned energy storage inverter, a second auxiliary power supply 3 for electrical connection with the battery assembly is also included.

[0065] The input terminal of the second auxiliary power supply 3 is connected to the photovoltaic module through an electrical connection with the DC / DC module 4, and the output terminal of the second auxiliary power supply 3 is connected to the control unit 1.

[0066] The control unit 1 is also used to shut down the first auxiliary power supply 2 and provide redundant power to the control unit 1 through the second auxiliary power supply 3 when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range.

[0067] In other words, in this embodiment, a second auxiliary power supply 3 is also provided. One end of the second auxiliary power supply 3 is electrically connected to the battery module 6 and the photovoltaic module respectively, and the other end is electrically connected to the control unit 1. This provides redundant power supply to the control unit 1 when the first auxiliary power supply 2 stops operating (for example, when the output voltage is less than or equal to the first voltage value). This allows the control unit 1 to continue operating even when the first auxiliary power supply 2 cannot obtain input power from the photovoltaic module, thus facilitating subsequent control of the first auxiliary power supply 2 and other components.

[0068] like Figure 1 As shown, in some optional embodiments, such as the aforementioned energy storage inverter, it further includes: a first capacitor C1;

[0069] The first capacitor C1 is located on the bus between the relay RY1 and the DC / DC module 4, and is located between the positive bus and the negative bus in the bus.

[0070] Control unit 1 is also used to control the DC / DC module 4 to start before closing relay RY1, and to turn off DC / DC module 4 after charging the first capacitor C1 to the same output voltage as the photovoltaic module.

[0071] In other words, in this embodiment, a first capacitor C1 is also provided. The first capacitor C1 is located on the bus between the relay RY1 and the DC / DC module 4, and the two ends of the first capacitor C1 are electrically connected to the positive bus and the negative bus, respectively.

[0072] Furthermore, in this embodiment, before closing relay RY1, control unit 1 first instructs DC / DC module 4 to charge the first capacitor C1 using electricity output from the auxiliary power supply. After confirming that the voltage of the first capacitor C1 is the same as the output voltage of the photovoltaic module, control unit 1 shuts down DC / DC module 4. Then, relay RY1 is closed, thus completing the pre-charging of the first capacitor C1. Finally, control unit 1 controls DC / DC module 4 to start operating, at which point the battery module enters a state where it is directly charged via the bus.

[0073] In this embodiment, by setting a first capacitor C1, the instantaneous current can be prevented from being too high at the beginning stage of charging the battery pack directly through the bus, thus effectively ensuring the safety of the circuit.

[0074] like Figure 1 As shown, in some optional embodiments, such as the aforementioned energy storage inverter, a second capacitor C2 is also included;

[0075] The second capacitor C2 is located on the bus between the first connection point and the second connection point, and is located between the positive bus and the negative bus in the bus. The first connection point is the connection point between the output terminal of the first auxiliary power supply 2 and the bus, and the second connection point is the connection point between the input terminal of the second auxiliary power supply 3 and the bus.

[0076] In other words, in this embodiment, a second capacitor C2 is also provided. The position of the second capacitor C2 on the bus is between the output terminal of the first auxiliary power supply 2 and the first connection point of the bus and the input terminal of the second auxiliary power supply 3 and the second connection point of the bus. The two ends of the second capacitor C2 are electrically connected to the positive bus and the negative bus, respectively.

[0077] Based on the placement of the second capacitor C2, whether the battery module 6 is charged directly through the closed relay RY1 or through the first auxiliary power supply 2, the second capacitor C2 will be energized. In both cases, the second capacitor C2 can smooth the DC voltage, making the output power supply more stable and smooth. This allows the battery module 6 to accept a stable voltage for charging, thereby optimizing the charging process of the battery module 6, improving its charging performance and lifespan, and reducing the system failure rate.

[0078] like Figure 1 As shown, in some optional embodiments, such as the aforementioned energy storage inverter, it further includes: a voltage divider resistor R;

[0079] The voltage divider resistor R is located between the output terminal of the first auxiliary power supply 2 and the connection point of the bus; the voltage divider resistor R is used to reduce the charging power of the first auxiliary power supply 2 to the battery assembly 6.

[0080] Generally, the output power of the first auxiliary power supply 2 is relatively small. If the load power is too large, i.e., when the load is charging the battery pack 6 through the first auxiliary power supply 2, it will drain the first auxiliary power supply 2. In this case, by setting a voltage divider resistor R, the current can be reduced, thereby reducing the charging power for the battery pack 6. Furthermore, the resistance value of the voltage divider resistor R can be selected based on the maximum power of the first auxiliary power supply 2, as long as the load power when charging the battery pack 6 through the first auxiliary power supply 2 does not exceed the maximum limit of the first auxiliary power supply 2. No specific limitation is placed on the value of the voltage divider resistor R here.

[0081] Furthermore, a switching module and a BAT control unit can be provided. The switching module can be electrically connected to the battery pack, the BAT control unit, and the bus, and the switching module is electrically connected to the control unit 1 through the BAT control unit. The control unit 1 can send a signal to the BAT control unit to control the switching of the switching module, thereby enabling the BAT control unit to control the switching of the switching module to charge or disconnect the battery pack 6.

[0082] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this disclosure according to actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0083] According to a second aspect of the present disclosure, an energy storage system is also provided, including an energy storage inverter, a photovoltaic module 5, and a battery module 6 of any of the foregoing embodiments, wherein the energy storage inverter is electrically connected to the photovoltaic module 5 and the battery module 6 respectively.

[0084] like Figure 2 As shown, the photovoltaic module 5 is electrically connected to the voltage acquisition point of the energy storage inverter, and the battery module 6 is electrically connected to the switching module (e.g., the Switch module) in the energy storage inverter.

[0085] like Figure 3 The application example shown provides a control method for controlling the above-mentioned energy storage system:

[0086] Step 1: Connect photovoltaic module 5.

[0087] Step 2: When the auxiliary power supply 1 (e.g., the first auxiliary power supply 2) is powered on, and the voltage level of the photovoltaic module 5 is greater than the threshold Vth2 (e.g., the first voltage value), the auxiliary power supply 1 starts to work, and the bus capacitor C2 (e.g., the second capacitor C2) is powered on.

[0088] Step 3: At the same time, the DC-DC control unit (e.g., control unit 1) is powered on and starts working, and controls the auxiliary power supply 1 to output the set voltage threshold Vbus (e.g., the second voltage value);

[0089] Auxiliary power supply 2 (e.g., second auxiliary power supply 3) also starts working, providing redundant power to the DC-DC control unit together with auxiliary power supply 1.

[0090] Step 4: DC-DC control unit and battery pack control unit (e.g., Figure 1 The system communicates with the BAT control unit (shown) to control the Switch to close (e.g., switch modules), and the battery assembly 6 starts charging. At this time, the auxiliary power supply 1 enters the heavy load stage.

[0091] Step 5: The DC-DC control unit detects the output voltage of the photovoltaic module. When the output voltage of the photovoltaic module 5 is between Vth1 and Vth3 (e.g., a preset voltage range), the status quo is maintained, and the auxiliary power supply 1 continues to charge the battery module 6. When the output voltage of the photovoltaic module 5 is ≥ Vth3, the auxiliary power supply 1 is turned off, and the process proceeds to step 6, where the voltage level Vth1 < Vth2 < Vth3.

[0092] Step 6: The DC / DC control unit controls the DC / DC module 4 to start working, charging the bus capacitor C1 (e.g., the first capacitor C1) to the same voltage as the output voltage of the photovoltaic module 5, and then shutting down the DC / DC module 4; simultaneously closing the relay RY1 to complete the pre-charging of the bus capacitor C1.

[0093] Step 7: The DC / DC control unit controls the DC / DC module 4 to start working, and the battery assembly 6 enters the charging state.

[0094] like Figure 4 As shown, according to another aspect of the embodiments of this disclosure, an energy storage system control method is also provided, applied to the energy storage system described in any of the foregoing embodiments, comprising the following steps:

[0095] Step S401: Obtain the output voltage of the photovoltaic module, and turn on the first auxiliary power supply when the output voltage is determined to be greater than the preset first voltage value. The first voltage value is less than the target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches the preset requirement.

[0096] Step S402: The power signal output by the photovoltaic module is converted into a power signal with a preset second voltage value as the output voltage through the first auxiliary power supply, and the battery module is charged. The second voltage value meets the charging voltage range of the battery module.

[0097] Step S403: When the voltage output by the photovoltaic module is within the preset voltage range, continue to control the first auxiliary power supply to output a power signal according to the second voltage value, wherein the upper limit of the preset voltage range is the target voltage value;

[0098] In step S404, when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the relay is closed, and the voltage output by the photovoltaic module is converted into a power signal with a second voltage value as the output voltage through the DC / DC module to charge the battery module.

[0099] In some alternative embodiments, such as the aforementioned energy storage inverter control method, the method further includes:

[0100] When the output voltage of the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the first auxiliary power supply is turned off, and the control unit is redundantly powered by the second auxiliary power supply.

[0101] In some alternative embodiments, such as the aforementioned energy storage inverter control method, closing the relay includes:

[0102] The DC / DC module is started and then turned off after the first capacitor is charged to the same output voltage as the photovoltaic module.

[0103] Close the relay to complete the pre-charging of the first capacitor.

[0104] According to a fourth aspect of the present disclosure, an energy storage device is also provided, including a processor;

[0105] Memory used to store processor-executable program instructions;

[0106] The processor is configured to implement the steps in any of the methods described above when executing the program instructions.

[0107] According to a fifth aspect of the present disclosure, a computer-readable storage medium is also provided, having a computer program stored thereon that, when executed by a processor, implements the steps in the methods of any of the above embodiments.

[0108] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0109] The specific execution methods of each step in the above embodiments have been described in detail in the embodiments of the relevant devices, and will not be elaborated here.

[0110] For the method embodiments, since they are basically corresponding to the device embodiments, the relevant parts can be referred to in the description of the device embodiments.

[0111] Figure 5 This is a schematic structural diagram of an energy storage device provided in an exemplary embodiment. Please refer to... Figure 5 At the hardware level, the device includes a processor 502, an internal bus 504, a network interface 506, memory 508, and non-volatile memory 510, and may also include other hardware required for business operations. One or more embodiments of this specification can be implemented in software, such as the processor 502 reading the corresponding computer program from the non-volatile memory 510 into memory 508 and then running it. Of course, in addition to software implementation, one or more embodiments of this specification do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0112] Among them, the implementation is as described above. Figure 4 The apparatus of the method can be applied to, for example... Figure 5 The device shown is used to implement the technical solution described above.

[0113] The apparatus, module, or unit described in the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function.

[0114] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0115] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0116] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. An energy storage inverter, characterized in that, include: First auxiliary power supply, control unit, relay, DC / DC module; The first auxiliary power supply can be electrically connected to an external photovoltaic module and an external battery module respectively; the control unit and the relay are respectively electrically connected to the photovoltaic module; the control unit is respectively electrically connected to the first auxiliary power supply and the DC / DC module, and the relay is electrically connected to the DC / DC module. The control unit is configured to: acquire the output voltage of the photovoltaic module, and when it is determined that the output voltage is greater than a preset first voltage value, turn on the first auxiliary power supply, and control the first auxiliary power supply to output a power signal according to a preset second voltage value, wherein the first voltage value is less than a target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches a preset requirement; The first auxiliary power supply is used to: convert the power signal output by the photovoltaic module into a power signal with the second voltage value as the output voltage, and to charge the battery module, wherein the second voltage value satisfies the charging voltage range of the battery module; The control unit is further configured to: continue to control the first auxiliary power supply to output a power signal according to the second voltage value when the voltage output by the photovoltaic module is within a preset voltage range, wherein the upper limit of the preset voltage range is the target voltage value; The control unit is further configured to: when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, close the relay, and convert the voltage output by the photovoltaic module into a power signal with the second voltage value as the output voltage through the DC / DC module, so as to charge the battery module.

2. The energy storage inverter according to claim 1, characterized in that, Also includes: A second auxiliary power source for electrical connection with the battery assembly; The input terminal of the second auxiliary power supply is connected to the photovoltaic module via an electrical connection to the DC / DC module, and the output terminal of the second auxiliary power supply is connected to the control unit. The control unit is further configured to shut down the first auxiliary power supply and provide redundant power to the control unit via the second auxiliary power supply when the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range.

3. The energy storage inverter according to claim 1, characterized in that, Also includes: First capacitor; The first capacitor is located on the bus between the relay and the DC / DC module, and is located between the positive bus and the negative bus in the bus. The control unit is also configured to: control the DC / DC module to start before closing the relay, and shut down the DC / DC module after charging the first capacitor to the same output voltage as the photovoltaic module.

4. The energy storage inverter according to claim 2, characterized in that, Also includes: Second capacitor; The second capacitor is located on the busbar between the first connection point and the second connection point, and is located between the positive busbar and the negative busbar in the busbar. The first connection point is the connection point between the output terminal of the first auxiliary power supply and the busbar, and the second connection point is the connection point between the input terminal of the second auxiliary power supply and the busbar.

5. The energy storage inverter according to claim 1, characterized in that, Also includes: Voltage divider resistors; The voltage divider resistor is located between the output terminal of the first auxiliary power supply and the connection point of the bus. The voltage divider resistor is used to reduce the charging power of the first auxiliary power supply to the battery assembly.

6. An energy storage system, characterized in that, It includes an energy storage inverter, a photovoltaic module, and a battery module as described in any one of claims 1 to 5, wherein the energy storage inverter is electrically connected to the photovoltaic module and the battery module, respectively.

7. A control method for an energy storage system, characterized in that, Applied to the energy storage system of claim 6, comprising: The output voltage of the photovoltaic module is obtained, and if the output voltage is determined to be greater than a preset first voltage value, a first auxiliary power supply is turned on, wherein the first voltage value is less than a target voltage value, and the target voltage value is the output voltage of the photovoltaic module when the light intensity reaches a preset requirement; The first auxiliary power source converts the power signal output by the photovoltaic module into a power signal with a preset second voltage value as the output voltage, and charges the battery module, wherein the second voltage value satisfies the charging voltage range of the battery module. When the voltage output by the photovoltaic module is within a preset voltage range, the first auxiliary power supply continues to be controlled to output a power signal according to the second voltage value, wherein the upper limit of the preset voltage range is the target voltage value; When the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the relay is closed, and the voltage output by the photovoltaic module is converted into a power signal with the second voltage value as the output voltage through the DC / DC module, so as to charge the battery module.

8. The energy storage system control method according to claim 7, characterized in that, The method further includes: If the voltage output by the photovoltaic module is greater than or equal to the upper limit of the preset voltage range, the first auxiliary power supply is turned off, and the control unit is redundantly powered by the second auxiliary power supply.

9. The energy storage system control method according to claim 7, characterized in that, Closing the relay includes: The DC / DC module is started up and then turned off after the first capacitor is charged to the same voltage as the output voltage of the photovoltaic module. Close the relay to precharge the first capacitor.

10. An energy storage device, characterized in that, include: processor; Memory used to store processor-executable program instructions; The processor is configured to implement the method of any one of claims 7 to 9 when executed.

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