A kind of idle low-power consumption control method, device and energy storage system of inverter

Abstract

The application discloses a kind of no-load low-power consumption control method, device and energy storage system of inverter, the method includes: the output power of the AC output end of inverter is detected, if output power is less than the first power threshold of preset, then control inverter enters no-load low-power consumption mode;After inverter enters no-load low-power consumption mode, power collection operation is executed;Current no-load input power is compared with the target no-load power of preset, if current no-load input power is greater than or equal to target no-load power, then adjust the power consumption control parameter of inverter, and after each adjustment, power collection operation is re-executed to update current no-load input power, until the current no-load input power after updating is less than target no-load power;Power consumption control parameter includes: at least one of the voltage fluctuation range of DC bus, switching frequency, duty cycle and phase shift angle of switch tube.The application can realize low-power consumption of inverter under off-grid no-load working condition, energy saving and efficiency increasing.

Description

Technical Field

[0001] This invention relates to the field of inverter technology, and in particular to an inverter's no-load low-power control method, apparatus, and energy storage system. Background Technology

[0002] With the rapid development of power electronics technologies such as new energy, inverters have also experienced rapid development and growth. As part of energy storage systems, inverters can be applied to power systems such as backup power systems, photovoltaic energy storage systems, outdoor power systems, and microgrid systems.

[0003] Currently, after an inverter detects no-load in off-grid mode, it determines the control strategy based on the power consumption under operating conditions. However, under some typical operating conditions, the no-load output power consumption is too high, which will directly aggravate the self-discharge of the battery connected to the inverter, significantly shorten the standby and driving time of the energy storage system, and significantly reduce the effective available power of the battery. This will have a long-term and significant impact on the economy of the energy storage system, battery life and power supply reliability. Summary of the Invention

[0004] This invention provides a method, device, and energy storage system for controlling low power consumption of inverters under no-load conditions, in order to solve the problem of high no-load output power consumption of inverters in off-grid mode.

[0005] According to one aspect of the present invention, a method for controlling low power consumption under no-load conditions in an inverter is provided, wherein the inverter is connected to a battery module via a DC bus, and the method includes: The output power of the inverter's AC output terminal is detected. If the output power is less than a preset first power threshold, the inverter is controlled to enter an idle low power consumption mode. After the inverter enters the no-load low-power mode, a power acquisition operation is performed. The specific execution process of the power acquisition operation is as follows: the current input from the DC bus to the inverter is acquired, and the current input power is calculated by combining it with the voltage of the DC bus. The current no-load input power is compared with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, the power consumption control parameters of the inverter are adjusted, and the power acquisition operation is re-executed after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistor in the inverter, the duty cycle of the switching transistor, and the phase shift angle of the switching transistor.

[0006] According to another aspect of the present invention, an idle-load low-power control device for an inverter is provided, the inverter being connected to a battery module via a DC bus, the idle-load low-power control device comprising: The mode entry module is used to detect the output power of the AC output terminal of the inverter. If the output power is less than a preset first power threshold, the inverter is controlled to enter the no-load low power consumption mode. The power acquisition module is used to perform a power acquisition operation after the inverter enters the no-load low-power mode. The specific execution process of the power acquisition operation is as follows: acquire the current input from the DC bus to the inverter, and calculate the current no-load input power by combining it with the voltage of the DC bus. The power consumption adjustment module is used to compare the current no-load input power with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, the power consumption control parameters of the inverter are adjusted, and the power acquisition operation is re-executed after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistor in the inverter, the duty cycle of the switching transistor, and the phase shift angle of the switching transistor.

[0007] According to another aspect of the present invention, an energy storage system is provided, comprising: an inverter and a no-load low-power control device as described above.

[0008] In this invention, the no-load low-power control device executes the no-load low-power control method. First, it detects the output power of the inverter's AC output terminal. If the output power is less than a preset first power threshold, it controls the inverter to enter the no-load low-power mode. Then, after the inverter enters the no-load low-power mode, it performs a power acquisition operation to obtain the current no-load input power. If the current no-load input power is greater than or equal to the target no-load power, it adjusts the inverter's power consumption control parameters and re-executes the power acquisition operation after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. In this invention, the no-load low-power control device can automatically identify the off-grid no-load output situation and enter the no-load low-power mode, which can save energy and improve efficiency. In the no-load low-power mode, the target no-load power is used as the loop control object for closed-loop control. Combining the comparison results of the current no-load input power and the target no-load power, the power consumption control parameters are flexibly adjusted to optimize the current no-load input power until the current no-load input power of the inverter is less than the target no-load power. This ensures that the actual no-load power consumption of the inverter within the off-grid no-load operating voltage range meets the preset target requirements, achieving low power consumption and energy saving and efficiency improvement of the inverter under off-grid no-load conditions. In this invention, the energy storage system using the no-load low-power control method reduces the standby power consumption of the inverter when the AC output is no-load in off-grid mode, which can effectively reduce the self-discharge of the battery module in the energy storage system, significantly improve the standby and endurance time of the battery module in the energy storage system, significantly increase the effective available power of the energy storage system, and improve the economy of the energy storage system, user experience, intelligence level of the energy storage system, battery life and power supply reliability.

[0009] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of an energy storage system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of an inverter's no-load low-power control method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another inverter no-load low power consumption control method provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of step 230 provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of another step 230 provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of an inverter's no-load low-power control device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of another energy storage system provided in an embodiment of the present invention; Figure 8 yes Figure 7 A schematic diagram of a medium current sampling circuit. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0013] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0014] Figure 1 This is a schematic diagram of an energy storage system provided in an embodiment of the present invention. Figure 2This is a schematic diagram of an inverter's no-load low-power control method provided in an embodiment of the present invention. The energy storage system 100 provided in this embodiment includes a no-load low-power control device 101 and an inverter 102. The no-load low-power control device 101 can be used to execute the no-load low-power control method for the inverter provided in this embodiment. The no-load low-power control device 101 can be implemented in hardware and / or software, and can be configured in the energy storage system 100 where the inverter 102 is located. The energy storage system 100 can be a home energy storage system, a balcony energy storage system, a core backup power energy storage system, etc.

[0015] It is understood that the energy storage system 100 provided in the embodiments of the present invention includes Figure 1 The inverter 102 shown is not limited to this. The no-load low-power control method provided in this embodiment of the invention is applicable not only to... Figure 1 The inverter 102 and its associated energy storage system 100 shown are also applicable to any other inverter and its associated energy storage system, specifically applicable to energy storage scenarios such as photovoltaic energy storage, residential backup power, outdoor power supply, and off-grid microgrid systems. The no-load low-power control method provided in this embodiment enables the inverter to maintain stable low power consumption under no-load conditions; this is only discussed in conjunction with… Figure 1 The circuit structure of the inverter 102 shown illustrates the no-load low-power control method provided in this embodiment of the invention. However, it is not limited to this method. For example, the inverter 102 is a split-phase inverter.

[0016] refer to Figure 1 The energy storage system 100 includes an idle low-power control device 101 and an inverter 102. The inverter 102 includes an input unit 103, a transformer unit 104, an output unit 105, and a filter unit 106.

[0017] In inverter 102, input unit 103 includes a DC bus (DC), a DC bus capacitor (C1), and switching transistors Q1, Q2, Q3, and Q4. A low-power no-load control device 101 is electrically connected to input unit 103. Specifically, the low-power no-load control device 101 is electrically connected to the DC bus (DC) in input unit 103 to control the voltage fluctuation range of the DC bus (DC) in input unit 103. The low-power no-load control device 101 is also electrically connected to the control terminals of each switching transistor in input unit 103 to control the on / off state of each switching transistor. The low-power no-load control device 101 is also electrically connected to the input terminal of inverter 102, where interface B1 and interface B2 constitute the input terminal of inverter 102. Inverter 102 is electrically connected to a battery module (not shown in the figure) via the DC bus (DC), and the DC bus capacitor (C1) is installed between the positive and negative terminals of the DC bus (DC). In some embodiments, the input terminal of the inverter needs to be connected to mains power or the power grid.

[0018] In inverter 102, transformer unit 104 is electrically connected between input unit 103 and output unit 105. Transformer unit 104 includes inductor L1 and isolation transformer T1.

[0019] In inverter 102, output unit 105 includes switching transistors Q5, Q6, Q7, and Q8, and capacitor C2. A no-load low-power control device 101 is electrically connected to output unit 105. Specifically, the no-load low-power control device 101 is electrically connected to the control terminals of each switching transistor in output unit 105, and is used to control the on / off state of each switching transistor in output unit 105.

[0020] In inverter 102, filter unit 106 is electrically connected to output unit 105. Filter unit 106 is also electrically connected to the AC output terminal of inverter 102. Interfaces A1 and A2 constitute the AC output terminal of inverter 102. When no load (AC load as shown in the figure) is connected to the AC output terminal of inverter 102, inverter 102 operates in an no-load state. Filter unit 106 includes switching transistors Q9, Q10, Q11, and Q12, inductors L2 and L3, and capacitor C3. No-load low-power control device 101 is electrically connected to filter unit 106. Specifically, no-load low-power control device 101 is electrically connected to the control terminals of each switching transistor in filter unit 106 to control the on / off state of each switching transistor in filter unit 106. No-load low-power control device 101 is also electrically connected to the AC output terminal of inverter 102.

[0021] In inverter 102, the switching transistor can be a MOSFET, which has the advantages of fast switching speed and low conduction loss, but is not limited to this. In some embodiments, the switching transistor in the inverter can be an IGBT or other types of switching devices.

[0022] In this embodiment, the no-load low-power control device 101 includes an MCU controller, which includes a PWM generator, but is not limited to this. When the inverter 102 is off-grid and outputting under no-load conditions, the MCU controller controls the inverter 102 to enter the no-load low-power mode. Then, the MCU controller samples parameters such as the DC bus voltage, the DC bus current input to the inverter 102, and the output voltage of the AC output terminal of the inverter 102. The MCU controller uses the DC bus voltage signal to calculate the real-time peak-to-peak value of the DC bus voltage ripple, the peak-to-peak value of the output voltage ripple, and the peak value of the input current, and simultaneously calculates the real-time power consumption under no-load conditions. Based on the comparison between the real-time power consumption and the target power consumption, and combined with the loop regulator processing of the DC bus voltage ripple peak-to-peak value, the output voltage ripple peak-to-peak value, and the input current peak value, parameters such as the duty cycle, frequency, and phase shift angle of the switching transistor are obtained. After receiving these parameters, the PWM generator in the MCU controller generates the drive signal for the switching transistor.

[0023] refer to Figure 1 and Figure 2 The no-load low-power control method for inverters provided in this embodiment of the invention includes: Step 210: Detect the output power of the inverter's AC output terminal. If the output power is less than the preset first power threshold, control the inverter to enter the no-load low power consumption mode. Step 220: After the inverter enters the no-load low-power mode, perform a power acquisition operation. The specific execution process of the power acquisition operation is as follows: acquire the current input from the DC bus to the inverter, and calculate the current no-load input power by combining it with the voltage of the DC bus. Step 230: Compare the current no-load input power with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, adjust the power consumption control parameters of the inverter and re-execute the power acquisition operation after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistors in the inverter, the duty cycle of the switching transistors, and the phase shift angle of the switching transistors.

[0024] In this embodiment, the no-load low-power control method of the inverter is a low-power control strategy for the inverter in the off-grid state and the AC output terminal is in the no-load state. The off-grid state of the inverter refers to the situation where the input side of the inverter is connected to the battery module instead of the mains / grid. The inverter in the off-grid state is powered by the energy storage battery. The no-load AC output terminal of the inverter means that the load electrically connected to the AC output terminal of the inverter is very light or there is no load connected to the AC output terminal.

[0025] The no-load low-power control device can detect the output power of the inverter's AC output terminal. Specifically, the no-load low-power control device is electrically connected to the inverter's AC output terminal, where the inverter's AC output terminal is... Figure 1 Interfaces A1 and A2 are used by the no-load low-power control device to collect signals from the inverter's AC output terminal and then accurately calculate the power based on these signals. This calculated power is the output power of the inverter's AC output terminal. The no-load low-power control device has a pre-stored first power threshold. The device acquires the output power of the inverter's AC output terminal and compares it with the first power threshold.

[0026] If the no-load low-power control device detects that the output power of the inverter's AC output terminal is less than the first power threshold, it controls the inverter to enter the no-load low-power mode and sequentially executes step 220. Conversely, if the no-load low-power control device detects that the output power of the inverter's AC output terminal is greater than or equal to the first power threshold, it controls the inverter to maintain the current operating mode and repeats step 210. It can be understood that the no-load low-power control device can detect the output power of the inverter's AC output terminal in real time, or it can detect the output power of the inverter's AC output terminal at regular intervals according to a certain period. This is not specifically limited in this invention.

[0027] It should be noted that in some embodiments, at least one of the host computer and the mobile terminal is communicatively connected to the energy storage system. In this case, the host computer / mobile terminal can directly issue a command to enter the no-load low-power mode based on the no-load status of the energy storage system. Therefore, the no-load low-power control device can also control the inverter to enter the no-load low-power mode. Furthermore, users can modify various preset thresholds, such as the first power threshold, in the no-load low-power control device through the host computer / mobile terminal according to product application requirements; these are not limited to this.

[0028] After the inverter enters the no-load low-power mode, the no-load low-power control device performs a power acquisition operation. Specifically, the no-load low-power control device is electrically connected to the input terminal of the inverter, where the input terminal is... Figure 1 Interfaces B1 and B2 are used by the no-load low-power control device to collect the current signal at the inverter's input terminal. This current signal is the current signal input from the DC bus to the inverter. Combined with the current voltage signal of the DC bus, the power is accurately calculated. This calculated power is the current no-load input power of the inverter's input terminal. The current no-load input power is determined by the product of the current voltage signal of the DC bus and the current current signal at the inverter's input terminal. The no-load low-power control device can detect the current no-load input power of the inverter's input terminal in real time, or it can detect the current no-load input power of the inverter's input terminal at regular intervals; this is not specifically limited in this invention. The current no-load input power of the inverter's input terminal can be used to characterize the inverter's current actual no-load power consumption.

[0029] The no-load low-power control device has a pre-stored target no-load power. The no-load low-power control device acquires the current no-load input power and compares it with the target no-load power. If the no-load low-power control device detects that the inverter's current no-load input power is greater than or equal to the target no-load power, it adjusts the inverter's power control parameters. These parameters include any one or any combination of the following: DC bus voltage fluctuation range, switching frequency of the switching transistors in the inverter, duty cycle of the switching transistors, and phase shift angle of the switching transistors. The adjustment is performed sequentially. After completion, the process returns to step 220, and the power acquisition operation is re-executed to obtain a new current no-load input power. Step 230 is then executed to compare the current no-load input power with the preset target no-load power until the no-load low-power control device detects that the inverter's current no-load input power is less than the target no-load power.

[0030] In this embodiment, if the no-load low-power control device detects that the current no-load input power of the inverter is less than the target no-load power, it controls the inverter to exit the no-load low-power mode and then controls the inverter to enter the normal power consumption mode.

[0031] Changes in the DC bus voltage fluctuation range in an inverter affect its actual power consumption. Therefore, when the current no-load input power of the inverter is greater than or equal to the target no-load power, adjusting the DC bus voltage fluctuation range can regulate the current no-load input power, thereby adjusting the actual power consumption. Similarly, changes in the operating parameters of the switching transistors in the inverter affect its actual power consumption. Therefore, when the current no-load input power of the inverter is greater than or equal to the target no-load power, adjusting the operating parameters of at least one switching transistor in the inverter can regulate the current no-load input power, thereby adjusting the actual power consumption. The operating parameters of the switching transistor include at least one of the following: switching frequency, duty cycle, and phase shift angle.

[0032] It is understood that, regarding the operation of adjusting the power consumption control parameters of the inverter in step 230, this embodiment includes four power consumption control parameters: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistors in the inverter, the duty cycle of the switching transistors, and the phase shift angle of the switching transistors. In step 230, any one of the power consumption control parameters can be adjusted in a single adjustment process; specifically, in a single adjustment process, any one of the following can be adjusted: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistors in the inverter, the duty cycle of the switching transistors, and the phase shift angle of the switching transistors. Alternatively, in step 230, multiple power consumption control parameters can be adjusted in a single adjustment process; specifically, in a single adjustment process, any combination of the following can be adjusted: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistors in the inverter, the duty cycle of the switching transistors, and the phase shift angle of the switching transistors.

[0033] It should be noted that the target no-load power represents the no-load power consumption limit of the inverter under off-grid no-load conditions. The fact that the current no-load input power of the inverter is less than the target no-load power can represent the optimal no-load power consumption of the inverter under off-grid no-load conditions. Users can modify various preset thresholds such as the target no-load power in the no-load low-power control device through the host computer / mobile terminal according to the product application requirements, and are not limited to this.

[0034] Figure 3 This is a schematic diagram of another inverter no-load low-power control method provided by an embodiment of the present invention. In some embodiments, refer to Figures 1 to 3 The no-load low-power control method for inverters provided in this embodiment of the invention further includes: Step 230: Compare the current no-load input power with the preset target no-load power; based on the comparison result, proceed to step 230A or step 230B. Step 230A: If the current no-load input power is greater than or equal to the target no-load power, adjust the inverter's power consumption control parameters, and return to step 220 after each adjustment to re-execute the power acquisition operation in step 220 to update the current no-load input power. Step 230B: If the current no-load input power is less than the target no-load power and the output power is greater than or equal to the preset second power threshold, then control the inverter to enter the normal power consumption mode; the second power threshold is greater than or equal to the first power threshold.

[0035] The no-load low-power control device has a pre-stored second power threshold, which can be designed to be greater than or equal to the first power threshold. During power acquisition, the no-load low-power control device obtains the current no-load input power and compares it with the target no-load power. It should be noted that users can modify various preset thresholds, such as the second power threshold, in the no-load low-power control device via a host computer / mobile terminal according to product application requirements; these are not limited to this.

[0036] If the low-power no-load control device detects that the inverter's current no-load input power is greater than or equal to the target no-load power, it adjusts the inverter's power consumption control parameters and then returns to step 220 to re-execute the power acquisition operation to update the current no-load input power. Alternatively, if the low-power no-load control device detects that the inverter's current no-load input power is less than the target no-load power and the output power is less than the second power threshold, it indicates that the inverter's output power is low, and the inverter may still be in a light-load or no-load state. Based on this, the inverter's power consumption control parameters can be further adjusted, and then the power acquisition operation can be re-executed in step 220 to update the current no-load input power. Alternatively, if the low-power no-load control device detects that the inverter's current no-load input power is less than the target no-load power and the output power is greater than or equal to the preset second power threshold, it indicates that the inverter's output power is high, and the inverter may no longer be in a light-load or no-load state. Based on this, the inverter can be controlled to enter normal power consumption mode.

[0037] In this invention, the no-load low-power control device executes the no-load low-power control method. First, it detects the output power of the inverter's AC output terminal. If the output power is less than a preset first power threshold, it controls the inverter to enter the no-load low-power mode. Then, after the inverter enters the no-load low-power mode, it performs a power acquisition operation to obtain the current no-load input power. If the current no-load input power is greater than or equal to the target no-load power, it adjusts the inverter's power consumption control parameters and re-executes the power acquisition operation after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. In this invention, the no-load low-power control device can automatically identify the off-grid no-load output situation and enter the no-load low-power mode, which can save energy and improve efficiency. In the no-load low-power mode, the target no-load power is used as the loop control object for closed-loop control. Combining the comparison results of the current no-load input power and the target no-load power, the power consumption control parameters are flexibly adjusted to optimize the current no-load input power until the current no-load input power of the inverter is less than the target no-load power. This ensures that the actual no-load power consumption of the inverter within the off-grid no-load operating voltage range meets the preset target requirements, achieving low power consumption and energy saving and efficiency improvement of the inverter under off-grid no-load conditions. In this invention, the energy storage system using the no-load low-power control method reduces the standby power consumption of the inverter when the AC output is no-load in off-grid mode, which can effectively reduce the self-discharge of the battery module in the energy storage system, significantly improve the standby and endurance time of the battery module in the energy storage system, significantly increase the effective available power of the energy storage system, and improve the economy of the energy storage system, user experience, intelligence level of the energy storage system, battery life and power supply reliability.

[0038] In some embodiments, the operation of calculating the current no-load input power in step 220 includes: during a switching cycle, acquiring the real-time current input from the DC bus to the inverter, and combining it with the real-time voltage of the DC bus to calculate the no-load input power of the inverter during the switching cycle; sequentially determining the average no-load input power of the inverter over a first set duration as the current no-load input power, the first set duration including at least one switching cycle. The inverter's operation includes multiple switching cycles.

[0039] When the first set duration includes one switching cycle, after the no-load low-power control device controls the inverter to enter the no-load low-power mode, it performs a power acquisition operation during one switching cycle of the inverter to obtain the no-load input power of the inverter in that switching cycle. Specifically, in one switching cycle, the no-load low-power control device acquires the current current signal (real-time current) at the inverter's input terminal and the current voltage signal (real-time voltage) of the DC bus. The product of the current voltage signal and the current current signal is determined as the no-load input power of the inverter in the current switching cycle, and the no-load input power of the current switching cycle is also determined as the current no-load input power.

[0040] When the first set duration includes multiple switching cycles, after the no-load low-power control device controls the inverter to enter the no-load low-power mode, it performs power acquisition operations in each of the inverter's multiple switching cycles to obtain the no-load input power of the inverter in each switching cycle. The no-load low-power control device can obtain the no-load input power of multiple switching cycles within the first set duration, calculate the average value of these multiple no-load input powers, and determine the calculated average no-load input power as the current no-load input power. Here, one switching cycle is approximately 20ms, and the first set duration can be 1 second, but is not limited to this.

[0041] Figure 4 This is a schematic diagram of step 230 provided in an embodiment of the present invention. In some embodiments, refer to Figure 4 The operation of adjusting the power consumption control parameters of the inverter in step 230 includes: Step 231A: Adjust the voltage fluctuation range of the DC bus; Step 231B: If the voltage fluctuation range of the DC bus is within the preset first voltage difference range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust the voltage fluctuation range of the DC bus. Step 231C: If the voltage fluctuation range of the DC bus reaches the first differential voltage range, and the updated current no-load input power is greater than or equal to the target no-load power, adjust the switching frequency of the switching transistors sequentially.

[0042] In this embodiment, if the current no-load input power is greater than or equal to the target no-load power, the voltage fluctuation range of the DC bus can be adjusted first. The no-load low-power control device pre-stores a first voltage difference range, which is the maximum adjustable range of the DC bus voltage fluctuation. This maximum adjustable range of the DC bus voltage fluctuation is preset based on extensive laboratory testing, reliability testing, and dynamic testing results. Conversely, if the current no-load input power is less than the target no-load power, the inverter is controlled to enter normal power consumption mode.

[0043] Specifically, if the current no-load input power is greater than or equal to the target no-load power, the voltage fluctuation range of the DC bus is increased. After each adjustment, return to step 220 to re-execute the power acquisition operation and update the current no-load input power. If the updated current no-load input power is greater than or equal to the target no-load power, and the current voltage fluctuation range of the DC bus is still within the first voltage difference range, then continue to adjust (increase) the voltage fluctuation range of the DC bus; conversely, if the current voltage fluctuation range of the DC bus coincides with the first voltage difference range, it indicates that the current voltage fluctuation range of the DC bus meets the system requirements, and the adjustment of the DC bus voltage fluctuation range is stopped, and the switching frequency of the switching transistors is adjusted accordingly.

[0044] In some embodiments, reference Figure 4 The operation of adjusting the power consumption control parameters of the inverter in step 230 includes: Step 232A: Adjust the switching frequency of the switching transistor; Step 232B: If the switching frequency of the switching transistor is within the preset first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust the switching frequency of the switching transistor. Step 232C: If the switching frequency of the switching transistor reaches the first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, adjust the duty cycle of the switching transistor sequentially.

[0045] In this embodiment, if the current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistors can be adjusted sequentially. For example, if the DC bus voltage fluctuation range reaches a first differential voltage range, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistors is adjusted sequentially. The no-load low-power control device pre-stores a first frequency range, which is the maximum adjustable range of the switching frequency of the switching transistors. This maximum adjustable range is pre-set based on the power consumption and dynamic characteristics of the switching transistors in the inverter. Conversely, if the current no-load input power is less than the target no-load power, the inverter is controlled to enter normal power consumption mode.

[0046] Specifically, if the current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor is adjusted according to a preset frequency step value. For example, the adjustment process involves gradually decreasing the switching frequency of the switching transistor from the maximum value to the minimum value of the first frequency range according to the preset step value. After each adjustment, the process returns to step 220 to re-execute the power acquisition operation and update the current no-load input power. If the current switching frequency of the switching transistor is still within the first frequency range after the update, and the current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor is adjusted (e.g., decreased) as needed. Conversely, if the current switching frequency of the switching transistor reaches the minimum value of the first frequency range, it indicates that the switching frequency adjustment range of the switching transistor meets the system requirements, and the adjustment of the switching frequency of the switching transistor is stopped. The duty cycle of the switching transistor is then adjusted accordingly.

[0047] In some embodiments, reference Figure 4 The operation of adjusting the power consumption control parameters of the inverter in step 230 includes: Step 233A: Adjust the duty cycle of the switching transistor; Step 233B: If the duty cycle of the switching transistor is within the preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust the duty cycle of the switching transistor. Step 233C: If the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, adjust the phase shift angle of the switching transistor sequentially.

[0048] In this embodiment, if the current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor can be adjusted sequentially. For example, if the DC bus voltage fluctuation range reaches a first differential voltage range and the switching frequency adjustment range of the switching transistor reaches a first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor is adjusted sequentially. The no-load low-power control device pre-stores a first duty cycle range, which is the maximum adjustment range of the switching transistor's duty cycle. This maximum adjustment range is pre-set based on the power consumption and dynamic characteristics of the switching transistor in the inverter. Conversely, if the current no-load input power is less than the target no-load power, the inverter is controlled to enter normal power consumption mode. For example, the first duty cycle range is between 0.05 and 0.45.

[0049] Specifically, if the current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor is adjusted according to a preset duty cycle step value. For example, the adjustment process gradually decreases the duty cycle of the switching transistor from the maximum value to the minimum value of the first duty cycle range according to the preset step value. After each adjustment, the process returns to step 220 to re-execute the power acquisition operation and update the current no-load input power. If the current duty cycle of the switching transistor is still within the first duty cycle range after the update, it continues to be adjusted (e.g., decreased). Conversely, if the current duty cycle of the switching transistor reaches the minimum value of the first duty cycle range, it indicates that the duty cycle adjustment range of the switching transistor meets the system requirements, and the adjustment of the duty cycle of the switching transistor is stopped. The phase shift angle of the switching transistor is then adjusted accordingly.

[0050] In some embodiments, reference Figure 4 The operation of adjusting the power consumption control parameters of the inverter in step 230 includes: Step 234A: Adjust the phase shift angle of the switching transistor; Step 234B: If the phase shift angle of the switching transistor is within the preset first phase shift angle range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust the phase shift angle of the switching transistor; Step 234C: If the phase shift angle of the switching transistor reaches the first phase shift angle range, and the updated current no-load input power is greater than or equal to the target no-load power, exit the no-load low-power mode.

[0051] In this embodiment, if the current no-load input power is greater than or equal to the target no-load power, the phase shift angle of the switching transistor can be adjusted sequentially. The no-load low-power control device pre-stores a first phase shift angle range, which is the maximum adjustment range of the switching transistor's phase shift angle. This maximum adjustment range is preset based on the power consumption and dynamic characteristics of the switching transistor in the inverter. Conversely, if the current no-load input power is less than the target no-load power, the inverter is controlled to enter normal power consumption mode. For example, the first phase shift angle range is between 0° and 45°.

[0052] Specifically, if the current no-load input power is greater than or equal to the target no-load power, the phase shift angle of the switching transistor is adjusted according to a preset angle value. For example, the adjustment process is to gradually decrease the phase shift angle of the switching transistor from the maximum value to the minimum value of the first phase shift angle range according to the preset angle value. After each adjustment, return to step 220 to re-execute the power acquisition operation and update the current no-load input power. If the current phase shift angle of the switching transistor is still within the first phase shift angle range after the update, and the current phase shift angle of the switching transistor is greater than or equal to the target no-load power, the phase shift angle of the switching transistor is adjusted (e.g., decreased) as long as it is still within the first phase shift angle range. Conversely, if the current phase shift angle of the switching transistor reaches the minimum value of the first phase shift angle range, it means that the phase shift angle adjustment range of the switching transistor meets the system requirements, and the adjustment of the phase shift angle of the switching transistor is stopped. At this time, if the voltage fluctuation range of the DC bus reaches the first voltage difference range, the switching frequency adjustment range of the switching transistor reaches the first frequency range, and the duty cycle adjustment range of the switching transistor reaches the first duty cycle range, then the no-load low-power mode can be exited.

[0053] As shown above, when adjusting the inverter's power consumption control parameters, the four power consumption control parameters are adjusted separately. Specifically, they can be adjusted in the following order: DC bus voltage fluctuation range, switching frequency of the switching transistors, duty cycle of the switching transistors, and phase shift angle of the switching transistors. Specifically, if the inverter's current no-load input power is still greater than or equal to the target no-load power after the previous adjusted power consumption control parameter reaches its corresponding adjustment range, it indicates that the inverter's no-load power consumption does not meet the low no-load power consumption requirement. In this case, the next power consumption control parameter can be adjusted sequentially.

[0054] It is understandable that when adjusting the power consumption control parameters of the inverter, the adjustment order of the four power consumption control parameters is not limited to... Figure 4 As shown.

[0055] In this embodiment, the target no-load power is used as the controlled object for closed-loop control. By adjusting various power consumption control parameters that affect the inverter's power consumption, the current no-load input power of the inverter is adjusted and optimized. This continues until the current no-load input power of the inverter is less than the target no-load power. In other words, the no-load power consumption of the energy storage system meets the set target no-load power, thus achieving the requirement of low no-load power consumption.

[0056] Figure 5 This is a schematic diagram of another step 230 provided in an embodiment of the present invention. In some embodiments, refer to Figure 5 The operation of adjusting the power consumption control parameters of the inverter in step 230 includes: Step 2301: Adjust the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor; Step 2302: If the voltage fluctuation range of the DC bus is within the preset first voltage difference range and / or the duty cycle of the switching transistor is within the preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust at least one of the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor. Step 2303: If the voltage fluctuation range of the DC bus reaches the first voltage difference range and the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, adjust at least one of the switching frequency and phase shift angle of the switching transistor in sequence.

[0057] As shown above, when adjusting the inverter's power consumption control parameters, two power consumption control parameters can be adjusted in groups. For example, the DC bus voltage fluctuation range and the switching transistor's duty cycle can be adjusted simultaneously as a group, and sequentially, the switching frequency and phase shift angle of the switching transistor can be adjusted simultaneously as a group. Specifically, if the inverter's current no-load input power is still greater than or equal to the target no-load power after the current group of adjusted power consumption control parameters (such as the DC bus voltage fluctuation range and the switching transistor's duty cycle) have all reached their corresponding adjustment ranges, then the inverter's no-load power consumption does not meet the low no-load power consumption requirement. In this case, the next group of power consumption control parameters (such as the switching frequency and phase shift angle of the switching transistor) can be adjusted sequentially.

[0058] Specifically, if the current no-load input power is greater than or equal to the target no-load power, the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor are adjusted. After each adjustment, the process returns to step 220 to re-execute the power acquisition operation and update the current no-load input power. If the updated current no-load input power is greater than or equal to the target no-load power, and either the voltage fluctuation range of the DC bus or the duty cycle of the switching transistor reaches its corresponding adjustment range, the other is adjusted. After each adjustment, the process returns to step 220 to re-execute the power acquisition operation and update the current no-load input power. If both the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor reach their corresponding adjustment ranges, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency and phase shift angle of the switching transistor are adjusted sequentially. The no-load low-power mode can be exited when the updated current no-load input power is less than the target no-load power; or when the voltage fluctuation range of the DC bus reaches the first differential voltage range, the switching frequency adjustment range of the switching transistor reaches the first frequency range, the duty cycle adjustment range of the switching transistor reaches the first duty cycle range, and the phase shift angle adjustment range of the switching transistor reaches the first phase shift angle range.

[0059] In some embodiments, when adjusting the power consumption control parameters of the inverter, the three power consumption control parameters can be adjusted in groups, or the four power consumption control parameters can be adjusted simultaneously.

[0060] In this embodiment, the target no-load power is used as the controlled object for closed-loop control. By adjusting various power consumption control parameters that affect the inverter's power consumption, the current no-load input power of the inverter is adjusted and optimized. This continues until the current no-load input power of the inverter is less than the target no-load power. In other words, the no-load power consumption of the energy storage system meets the set target no-load power, thus achieving the requirement of low no-load power consumption.

[0061] Based on the same inventive concept, embodiments of the present invention provide an inverter no-load low-power control device. The no-load low-power control device provided by the embodiments of the present invention can be used to execute the no-load low-power control method of the inverter provided by the embodiments of the present invention. The no-load low-power control device can be implemented in hardware and / or software and can be configured in the energy storage system where the inverter is located.

[0062] Figure 6 This is a schematic diagram of an inverter's no-load low-power control device provided in an embodiment of the present invention. (Reference) Figure 6 The no-load low-power control device provided in this embodiment of the invention includes: a mode entry module 310, a power acquisition module 320, and a power consumption adjustment module 330. The mode entry module 310 is used to detect the output power of the AC output terminal of the inverter. If the output power is less than a preset first power threshold, the inverter is controlled to enter the no-load low-power mode. The power acquisition module 320 is used to perform a power acquisition operation after the inverter enters the no-load low-power mode. The specific execution process of the power acquisition operation is as follows: the current input from the DC bus to the inverter is acquired, and the current is calculated by combining it with the voltage of the DC bus. The no-load input power; the power consumption adjustment module 330 is used to compare the current no-load input power with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, the power consumption control parameters of the inverter are adjusted, and the power acquisition operation is re-executed after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistors in the inverter, the duty cycle of the switching transistors, and the phase shift angle of the switching transistors.

[0063] In some embodiments, the mode entry module 310 is further configured to control the inverter to enter a normal power consumption mode if the current no-load input power is less than the target no-load power and the output power is greater than or equal to a preset second power threshold; the second power threshold is greater than or equal to the first power threshold.

[0064] In some embodiments, the power acquisition module 320 is further configured to acquire the real-time current input from the DC bus to the inverter during a switching cycle, and calculate the no-load input power of the inverter during the switching cycle by combining the real-time voltage of the DC bus; and determine the average no-load input power of the inverter for a first set time period as the current no-load input power, wherein the first set time period includes at least one switching cycle.

[0065] In some embodiments, the power consumption adjustment module 330 is further used to adjust the voltage fluctuation range of the DC bus; if the voltage fluctuation range of the DC bus is within a preset first voltage difference range, and the updated current no-load input power is greater than or equal to the target no-load power, the voltage fluctuation range of the DC bus continues to be adjusted; if the voltage fluctuation range of the DC bus reaches the first voltage difference range, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor is sequentially adjusted.

[0066] In some embodiments, the power consumption adjustment module 330 is further configured to adjust the switching frequency of the switching transistor; if the switching frequency of the switching transistor is within a preset first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor is further adjusted; if the switching frequency of the switching transistor reaches the first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor is sequentially adjusted.

[0067] In some embodiments, the power consumption adjustment module 330 is further configured to adjust the duty cycle of the switching transistor; if the duty cycle of the switching transistor is within a preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor is further adjusted; if the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, the phase shift angle of the switching transistor is sequentially adjusted.

[0068] In some embodiments, the power consumption adjustment module 330 is further configured to adjust the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor; if the voltage fluctuation range of the DC bus is within a preset first voltage difference range and / or the duty cycle of the switching transistor is within a preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, at least one of the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor is further adjusted; if the voltage fluctuation range of the DC bus reaches the first voltage difference range and the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, at least one of the switching frequency and phase shift angle of the switching transistor is sequentially adjusted.

[0069] The no-load low-power control device provided in the embodiments of the present invention can execute the no-load low-power control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method execution, which will not be repeated here.

[0070] Based on the same inventive concept, embodiments of the present invention provide an energy storage system. The energy storage system provided by the embodiments of the present invention includes an idle low power consumption control device provided by the embodiments of the present invention, which can be used to execute the idle low power consumption control method of the inverter provided by the embodiments of the present invention. Figure 7 This is a schematic diagram of another energy storage system provided in an embodiment of the present invention, for reference. Figure 1 and Figure 7 The energy storage system 100 provided in this embodiment of the invention includes: an inverter 102 and an idle low power consumption control device 101.

[0071] It is understood that the energy storage system 100 can be a consumer-grade energy storage system or an industrial / commercial energy storage system. Consumer-grade energy storage systems include balcony photovoltaic energy storage systems, home energy storage systems, or portable energy storage systems. Balcony photovoltaic energy storage systems are suitable for apartment balconies, offering plug-and-play functionality. They generate and store energy during the day and supply power at night or on cloudy days. Combined with mobile app monitoring, they automatically optimize charging and discharging, significantly reducing household electricity costs. Home energy storage systems are suitable for detached houses, working with rooftop photovoltaics to store energy during the day and use it at night, utilizing peak-valley electricity price differences to save costs. They also serve as backup power, ensuring the normal operation of critical equipment during power outages. Portable energy storage systems are suitable for outdoor camping and road trips, charging devices such as mobile phones, cameras, and drones. They can also be used for fieldwork, emergency lighting, and core backup power. They are lightweight, portable, and support multiple output interfaces to meet diverse needs.

[0072] Specifically, the energy storage system 100 includes a battery module, a battery management system (BMS), and an energy management system (EMS). The inverter 102 is electrically connected to the battery module and converts the direct current (DC) generated by the battery module into alternating current (AC) for use by electrical devices. The battery management system monitors the status information of each cell in the battery module, such as current, temperature, or voltage, to prevent overcharging, over-discharging, or short circuits, thus protecting the cells from damage. The energy management system includes an EMS control board, which connects to the battery module and the inverter 102. Through a user input port, it receives user commands and controls the charging and discharging processes of the battery module and the inverter 102.

[0073] In some embodiments, reference Figure 7The energy storage system 100 also includes a current sampling circuit 107, which is electrically connected between the no-load low-power control device 101 and the inverter 102. The current sampling circuit 107 is used to collect the DC current input to the inverter 102 from the DC bus. Specifically, after the inverter 102 enters the no-load low-power mode, the current sampling circuit 107 collects the DC current input to the inverter 102 from the DC bus. The no-load low-power control device 101 is electrically connected to the current sampling circuit 107 to obtain the DC current input to the inverter 102 from the DC bus. The current sampling circuit 107 can be a precision current sampling circuit.

[0074] Figure 8 yes Figure 7 A schematic diagram of a medium current sampling circuit. In some embodiments, refer to... Figure 7 and Figure 8 The current sampling circuit 107 includes: a differential amplifier U1 and a first resistor R1 to a fifth resistor R5; the first resistor R1 is electrically connected between the first end of the third resistor R3 and the first input terminal (-) of the differential amplifier U1, the second resistor R2 is electrically connected between the second end of the third resistor R3 and the second input terminal (+) of the differential amplifier U1, the fourth resistor R4 is electrically connected between the ground terminal GND and the second input terminal (+) of the differential amplifier U1, and the fifth resistor R5 is electrically connected between the output terminal Vout of the differential amplifier U1 and the first input terminal (-).

[0075] In this embodiment, the two ends of the third resistor R3 are connected to the positive and negative terminals of the DC bus. The current sampling circuit 107 obtains the current input from the DC bus to the inverter 102 through the third resistor R3. Even if the input current is a small-range (below 1A) current signal, the current sampling circuit 107 can convert the input current into a voltage signal through the third resistor R3. Then, the voltage signal enters the differential amplifier U1, which amplifies the input voltage signal and sends it to the no-load low-power control device 101.

[0076] Specifically, the ratio of the fifth resistor R5 to the third resistor R3 is very large. When the current signal obtained by the current sampling circuit 107 through the third resistor R3 is very small, the voltage signal across the third resistor R3 is also very small. Through the large-scale amplification by the differential amplifier U1, high current detection accuracy can be achieved. The resistance value of the third resistor R3 can be chosen to be relatively large; correspondingly, the voltage signal obtained by the current sampling circuit 107 through the third resistor R3 is relatively large, resulting in strong anti-interference capability.

[0077] As described above, the no-load low-power control device 101 incorporates a current sampling circuit 107. Even when the current to be detected is very small, the output load of the inverter 102 is light, or it is unloaded, the current sampling circuit 107 maintains high accuracy in acquiring the input current and calculates the accurate current no-load input power, i.e., the off-grid no-load power consumption, thus achieving low-power control. In this invention, the controlled variables include the inverter's output voltage, the DC bus voltage ripple, the inverter's off-grid no-load power consumption, and the DC bus input peak current, ensuring comprehensive control and optimizing the system to achieve low power consumption.

[0078] In this embodiment, by adding a current sampling circuit, even with a very small input current (below 1A), the sampling accuracy of the current sampling circuit can be very high. Therefore, the no-load low-power control device can accurately calculate the real-time power, especially when the output is under light load or no load. By adjusting the control strategy and drive output in a timely manner, and by controlling parameters such as DC bus voltage, drive frequency of the switching transistor, duty cycle, and phase shift angle, the inverter can achieve the lowest power consumption. In this embodiment, using the current no-load input power (no-load power consumption) as the control object, it can be ensured that the inverter can achieve the lowest no-load power consumption throughout the entire operating voltage range.

[0079] Note that the above embodiments of this application are merely illustrative examples for the purpose of clearly illustrating the present application, and are not intended to limit the implementation of the present application, nor do they constitute a limitation on the scope of protection of the present application. For those skilled in the art, various obvious changes, readjustments, and substitutions can be made according to design requirements and other factors without departing from the scope of protection of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present application. It is neither necessary nor possible to exhaustively describe all implementation methods here. The scope of the present application is determined by the scope of the appended claims. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application should be included within the scope of protection of the claims of the present application.

Claims

1. A method for controlling low power consumption under no-load conditions in an inverter, characterized in that, The inverter is connected to the battery module via a DC bus, and the no-load low-power control method includes: The output power of the inverter's AC output terminal is detected. If the output power is less than a preset first power threshold, the inverter is controlled to enter an idle low power consumption mode. After the inverter enters the no-load low-power mode, a power acquisition operation is performed. The specific execution process of the power acquisition operation is as follows: the current input from the DC bus to the inverter is acquired, and the current input power is calculated by combining it with the voltage of the DC bus. The current no-load input power is compared with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, the power consumption control parameters of the inverter are adjusted, and the power acquisition operation is re-executed after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistor in the inverter, the duty cycle of the switching transistor, and the phase shift angle of the switching transistor.

2. The no-load low-power control method according to claim 1, characterized in that, Also includes: If the current no-load input power is less than the target no-load power, and the output power is greater than or equal to a preset second power threshold, then the inverter is controlled to enter the normal power consumption mode. The second power threshold is greater than or equal to the first power threshold.

3. The no-load low-power control method according to claim 1, characterized in that, Calculate the current no-load input power, including: During one switching cycle, the real-time current input from the DC bus to the inverter is collected, and combined with the real-time voltage of the DC bus, the no-load input power of the inverter during that switching cycle is calculated. The average no-load input power of the inverter for a first set period of time is determined as the current no-load input power, wherein the first set period of time includes at least one of the switching cycles.

4. The no-load low-power control method according to claim 1, characterized in that, Adjusting the power consumption control parameters of the inverter includes: Adjust the voltage fluctuation range of the DC bus; If the voltage fluctuation range of the DC bus is within the preset first voltage difference range, and the updated current no-load input power is greater than or equal to the target no-load power, the voltage fluctuation range of the DC bus continues to be adjusted. If the voltage fluctuation range of the DC bus reaches the first voltage difference range, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor is adjusted sequentially.

5. The no-load low-power control method according to claim 1, characterized in that, Adjusting the power consumption control parameters of the inverter includes: Adjust the switching frequency of the switching transistor; If the switching frequency of the switching transistor is within a preset first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, the switching frequency of the switching transistor continues to be adjusted. If the switching frequency of the switching transistor reaches the first frequency range, and the updated current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor is adjusted sequentially.

6. The no-load low-power control method according to claim 1, characterized in that, Adjusting the power consumption control parameters of the inverter includes: Adjust the duty cycle of the switching transistor; If the duty cycle of the switching transistor is within the preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, the duty cycle of the switching transistor continues to be adjusted. If the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, the phase shift angle of the switching transistor is adjusted sequentially.

7. The no-load low-power control method according to claim 1, characterized in that, Adjusting the power consumption control parameters of the inverter includes: Adjust the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor; If the voltage fluctuation range of the DC bus is within a preset first voltage difference range and / or the duty cycle of the switching transistor is within a preset first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, continue to adjust at least one of the voltage fluctuation range of the DC bus and the duty cycle of the switching transistor. If the voltage fluctuation range of the DC bus reaches the first differential voltage range and the duty cycle of the switching transistor reaches the first duty cycle range, and the updated current no-load input power is greater than or equal to the target no-load power, at least one of the switching frequency and phase shift angle of the switching transistor is adjusted sequentially.

8. A low-power no-load control device for an inverter, characterized in that, The inverter is connected to the battery module via a DC bus, and the no-load low-power control device includes: The mode entry module is used to detect the output power of the AC output terminal of the inverter. If the output power is less than a preset first power threshold, the inverter is controlled to enter the no-load low power consumption mode. The power acquisition module is used to perform a power acquisition operation after the inverter enters the no-load low-power mode. The specific execution process of the power acquisition operation is as follows: acquire the current input from the DC bus to the inverter, and calculate the current no-load input power by combining it with the voltage of the DC bus. The power consumption adjustment module is used to compare the current no-load input power with the preset target no-load power. If the current no-load input power is greater than or equal to the target no-load power, the power consumption control parameters of the inverter are adjusted, and the power acquisition operation is re-executed after each adjustment to update the current no-load input power until the updated current no-load input power is less than the target no-load power. The power consumption control parameters include any one or any combination of the following: the voltage fluctuation range of the DC bus, the switching frequency of the switching transistor in the inverter, the duty cycle of the switching transistor, and the phase shift angle of the switching transistor.

9. An energy storage system, characterized in that, include: The inverter and the no-load low-power control device as described in claim 8.

10. The energy storage system according to claim 9, characterized in that, Also includes: A current sampling circuit is electrically connected between the no-load low-power control device and the inverter. The current sampling circuit is used to collect the current input from the DC bus to the inverter.

11. The energy storage system according to claim 10, characterized in that, The current sampling circuit includes: a differential amplifier and a first resistor to a fifth resistor; The first resistor is electrically connected between the first end of the third resistor and the first input terminal of the differential amplifier; the second resistor is electrically connected between the second end of the third resistor and the second input terminal of the differential amplifier; the fourth resistor is electrically connected between the ground terminal and the second input terminal of the differential amplifier; and the fifth resistor is electrically connected between the output terminal of the differential amplifier and the first input terminal of the differential amplifier.

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