A method and device for protecting an energy storage inverter, an electronic device, and a storage medium

Abstract

This application relates to the field of inverter technology, and discloses a protection method, device, electronic device, and storage medium for an energy storage inverter. The method includes: when the voltage value of the current sampling period is higher than a preset voltage value, recording the duration for which the voltage value of the current sampling period is higher than the preset voltage value, and obtaining the difference between the voltage value of the current sampling period and the voltage value of the previous period; generating the voltage change rate of a common DC bus by dividing the absolute value of the difference by the sampling period; when the voltage change rate of the common DC bus is less than or equal to a preset change rate threshold, and the duration is greater than a preset duration, identifying parallel circulating currents generated between multiple energy storage inverters, obtaining the shutdown ratio corresponding to the amplitude value of the parallel circulating current, and controlling multiple energy storage inverters to stop operating according to the shutdown ratio to suppress the parallel circulating currents generated between multiple energy storage inverters. This application is beneficial for improving the protection efficiency of multiple energy storage inverters.

Description

Technical Field

[0001] This application relates to the field of inverter technology, and in particular to a method, device, electronic equipment and storage medium for protecting an energy storage inverter. Background Technology

[0002] A single energy storage inverter is limited by the capacity of its power devices, making it difficult to meet the demands of large-scale grid connection. Therefore, operating multiple energy storage inverters in parallel has become a key technological approach for capacity expansion.

[0003] When multiple energy storage inverters are connected in parallel, parallel circulating currents are very likely to be generated. These circulating currents can cause the internal components of multiple energy storage inverters to overheat, and in severe cases, they can directly damage the power switching transistors, filter inductors, and other core components of multiple energy storage inverters.

[0004] However, existing technologies for detecting and handling parallel circulating currents largely rely on manual on-site inspection and debugging, which consumes a lot of human resources and increases the protection time of multiple energy storage inverters, thus hindering the improvement of protection efficiency. Therefore, how to protect multiple energy storage inverters when they are operating in parallel is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a method, device, electronic device, and storage medium for protecting energy storage inverters, in order to solve the technical problem of how to protect multiple energy storage inverters when they are operating in parallel.

[0006] In a first aspect, embodiments of this application provide a protection method for an energy storage inverter, applied to an electronic device connected to an energy storage inverter system. The energy storage inverter system includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system. The energy storage inverter protection method includes: The output voltage at the output port is sampled to generate a voltage sampling signal. The inverter inductor current is sampled to generate a current sampling signal. The voltage sampling signal and the current sampling signal are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator which refers to the current flowing through the inverter inductor in a specified energy storage inverter. The specified energy storage inverter is any one of multiple energy storage inverters. The voltage sampling signal after full-wave rectification is input to the voltage protection circuit, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit, and the protection signal output by the current protection circuit is read through the current detection pin. When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is collected, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated. When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period. When the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, the shutdown ratio corresponding to the amplitude value of the parallel circulating current is obtained, and the multiple energy storage inverters are controlled to stop operating according to the shutdown ratio to suppress the parallel circulating current generated between multiple energy storage inverters.

[0007] In one possible implementation of the first aspect, sampling the output voltage of the output port to generate a voltage sampling signal, sampling the inverter inductor current to generate a current sampling signal, and performing full-wave rectification on the voltage sampling signal and the current sampling signal to generate a full-wave rectified voltage sampling signal and a full-wave rectified current sampling signal include: Read the preset sampling time and determine whether the current time is the sampling time; If the current time is the sampling time, the output voltage at the output port is sampled to generate a voltage sampling signal, the inverter inductor current is sampled to generate a current sampling signal, and the voltage and current sampling signals are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and a full-wave rectified current sampling signal.

[0008] In one possible implementation of the first aspect, the step of inputting the full-wave rectified voltage sampling signal to the voltage protection circuit and reading the protection signal output by the voltage protection circuit through the voltage detection pin, and inputting the full-wave rectified current sampling signal to the current protection circuit and reading the protection signal output by the current protection circuit through the current detection pin, includes: The voltage sampling signal after full-wave rectification is input to the voltage protection circuit through the first output pin, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit through the second output pin, and the protection signal output by the current protection circuit is read through the current detection pin.

[0009] In one possible implementation of the first aspect, when the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is acquired, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated, including: When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, a data acquisition enable signal is sent to the voltage sensor corresponding to the common DC bus. The receiving voltage sensor samples the voltage signal of the common DC bus returned by the acquisition enable signal within the current sampling period, and generates the voltage value of the common DC bus in the current sampling period.

[0010] In one possible implementation of the first aspect, when the voltage value of the current sampling period is higher than a preset voltage value, recording the duration for which the voltage value of the current sampling period is higher than the preset voltage value, and obtaining the difference between the voltage value of the current sampling period and the voltage value of the previous period, and generating the voltage change rate of the common DC bus by dividing the absolute value of the difference by the sampling period, includes: When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and configure a timing thread; A timing thread is used to record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period.

[0011] In one possible implementation of the first aspect, when the voltage value in the current sampling period is higher than a preset voltage value, the duration for which the voltage value in the current sampling period is higher than the preset voltage value is recorded, and the difference between the voltage value in the current sampling period and the voltage value sampled in the previous period is obtained, and the voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period, the energy storage inverter protection method further includes: When the voltage change rate of the common DC bus exceeds the preset change rate threshold, the reverse current from the load to the common DC bus is detected, and the discharge circuit is activated to eliminate the reverse current from the load to the common DC bus.

[0012] In one possible implementation of the first aspect, the energy storage inverter includes a photovoltaic energy storage inverter and a wind power energy storage inverter.

[0013] Secondly, embodiments of this application provide an energy storage inverter protection device applied to electronic devices. The electronic devices are connected to an energy storage inverter system, which includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system, including: The first sampling module is used to sample the output voltage of the output port to generate a voltage sampling signal, sample the inverter inductor current to generate a current sampling signal, perform full-wave rectification on the voltage sampling signal and the current sampling signal to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator which refers to the current flowing through the inverter inductor in a specified energy storage inverter. The specified energy storage inverter is any one of multiple energy storage inverters. The input module is used to input the voltage sampling signal after full-wave rectification to the voltage protection circuit and read the protection signal output by the voltage protection circuit through the voltage detection pin. It also inputs the current sampling signal after full-wave rectification to the current protection circuit and reads the protection signal output by the current protection circuit through the current detection pin. The second sampling module is used to sample the voltage signal of the common DC bus when the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, and to generate the voltage value of the common DC bus in the current sampling period. The generation module is used to record the duration for which the voltage value in the current sampling period is higher than the preset voltage value when the voltage value in the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The absolute value of the difference is divided by the sampling period to generate the voltage change rate of the common DC bus. The protection module is used to identify parallel circulating currents generated between multiple energy storage inverters when the voltage change rate of the common DC bus is less than or equal to a preset change rate threshold and the duration is longer than a preset duration. It then obtains the shutdown ratio corresponding to the amplitude value of the parallel circulating current and controls multiple energy storage inverters to stop operating according to the shutdown ratio, so as to suppress the parallel circulating currents generated between multiple energy storage inverters.

[0014] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the energy storage inverter protection method described in the first aspect above.

[0015] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the energy storage inverter protection method described in the first aspect above.

[0016] Fifthly, embodiments of this application provide a computer program product that, when run on an electronic device, causes the electronic device to execute the energy storage inverter protection method described in the first aspect.

[0017] The beneficial effects of the embodiments of this application are as follows: Firstly, when the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, and a shutdown command is generated. Through the shutdown command, some inverters among the multiple inverters are controlled to stop operating, so as to suppress the parallel circulating current generated between the multiple energy storage inverters. Since no manual operation is required, the protection time of multiple energy storage inverters is reduced, which is conducive to improving the protection efficiency of multiple energy storage inverters. Secondly, by using shutdown commands to control some of the inverters in a multi-inverter system to stop operating, the parallel circulating current generated between the multiple energy storage inverters can be eliminated at the source. This can effectively prevent the multiple energy storage inverters from overheating, aging, or even being damaged due to the continuous impact of the parallel circulating current, and significantly improve the safety and service life of the multiple energy storage inverters. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an application scenario diagram of the energy storage inverter protection method provided in the embodiments of this application; Figure 2 This is a flowchart illustrating the energy storage inverter protection method provided in the embodiments of this application; Figure 3 A flowchart illustrating the implementation of S203 provided in this application embodiment; Figure 4 A schematic block diagram of an energy storage inverter protection device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0022] It should be understood that in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "comprising," "including," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0023] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0024] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0025] The energy storage inverter protection method provided in this application embodiment can be applied to electronic devices. The electronic devices are connected to an energy storage inverter system. The energy storage inverter system includes a common DC bus and multiple energy storage inverters connected to the common DC bus in parallel. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system. The electronic devices include, but are not limited to, servers, mobile phones, tablets, wearable devices, vehicle-mounted devices, and laptops. This application embodiment does not impose any restrictions on the specific type of electronic devices.

[0026] Please see Figure 1 , Figure 1 The application scenario diagram of the energy storage inverter protection method provided in the embodiments of this application is described in detail below: Electronic devices are connected to an energy storage inverter system, which includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system.

[0027] The common DC bus is a shared DC power supply backbone that provides DC power to multiple inverters.

[0028] Among them, multiple energy storage inverters connected in parallel to the common DC bus no longer rectify and supply power independently, but are provided with a stable DC voltage by the common DC bus.

[0029] In this system, the control terminals of multiple energy storage inverters are connected in parallel and then connected to an electronic device, which centrally controls each inverter.

[0030] In this embodiment, multiple energy storage inverters are connected in parallel and uniformly connected to electronic devices. This enables centralized management and coordinated operation of multiple energy storage inverters, simplifies the system wiring structure, reduces wiring costs and construction complexity, and ensures synchronous operation and power balance of multiple energy storage inverters through a unified communication link. This avoids timing disorders and operational conflicts caused by independent control, while facilitating centralized monitoring, fault location, and system expansion, thereby improving the stability, reliability, and intelligent management level of the entire energy storage inverter system.

[0031] Please see Figure 2 , Figure 2 This is a flowchart illustrating the energy storage inverter protection method provided in this application embodiment. The method can be applied to electronic devices connected to an energy storage inverter system. The energy storage inverter system includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system.

[0032] like Figure 2 As shown in the figure, the energy storage inverter protection method provided in this application includes the following steps, which are detailed below: S201 samples the output voltage of the output port to generate a voltage sampling signal, samples the inverter inductor current to generate a current sampling signal, performs full-wave rectification on the voltage sampling signal and the current sampling signal to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator (current flowing through the inverter inductor in a specified energy storage inverter). The specified energy storage inverter is any one of multiple energy storage inverters. The steps include sampling the output voltage at the output port to generate a voltage sampling signal, sampling the inverter inductor current to generate a current sampling signal, and performing full-wave rectification on the voltage and current sampling signals to generate rectified voltage and current sampling signals, including: Read the preset sampling time and determine whether the current time is the sampling time; If the current time is the sampling time, the output voltage at the output port is sampled to generate a voltage sampling signal, the inverter inductor current is sampled to generate a current sampling signal, and the voltage and current sampling signals are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and a full-wave rectified current sampling signal.

[0033] Full-wave rectification is a processing method that converts all positive and negative half-cycle waveforms of an AC signal into a single-direction DC signal.

[0034] In this process, after full-wave rectification, the AC waveform of the voltage sampling signal is converted into a continuous DC waveform of single polarity, which can fully reflect the amplitude change of the AC voltage.

[0035] Among them, after full-wave rectification, the current sampling signal is transformed into a continuous DC signal with the same direction, which can reflect the amplitude change of the current.

[0036] In this configuration, multiple energy storage inverters are connected in parallel to a common DC bus. All inverters share the same AC / DC bus, operate under the same system voltage, and follow a unified grid-connected control strategy and power dispatch commands. Each inverter maintains consistency in topology, control logic, and electrical characteristics, possessing equivalent functional status and operating conditions; no single inverter is unique or irreplaceable. Therefore, any one of these multiple energy storage inverters is designated as the energy storage inverter.

[0037] S202 inputs the voltage sampling signal after full-wave rectification to the voltage protection circuit and reads the protection signal output by the voltage protection circuit through the voltage detection pin. It also inputs the current sampling signal after full-wave rectification to the current protection circuit and reads the protection signal output by the current protection circuit through the current detection pin. The steps include inputting the full-wave rectified voltage sampling signal to the voltage protection circuit, reading the protection signal output by the voltage protection circuit through the voltage detection pin, and inputting the full-wave rectified current sampling signal to the current protection circuit, reading the protection signal output by the current protection circuit through the current detection pin. The voltage sampling signal after full-wave rectification is input to the voltage protection circuit through the first output pin, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit through the second output pin, and the protection signal output by the current protection circuit is read through the current detection pin.

[0038] The voltage sampling signal after full-wave rectification is a DC voltage sampling signal, which no longer has polarity reversal. This enables the voltage protection circuit to accurately identify fault states such as overvoltage, undervoltage, and overcurrent. Based on the voltage sampling signal after full-wave rectification, the voltage protection circuit outputs a more accurate protection signal.

[0039] The current sampling signal after full-wave rectification is a DC current sampling signal, which no longer has polarity reversal. This enables the current protection circuit to accurately identify fault states such as overvoltage, undervoltage, and overcurrent. Based on the current sampling signal after full-wave rectification, the current protection circuit outputs a more accurate protection signal.

[0040] S203: When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is collected, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated. S204, when the voltage value of the current sampling period is higher than the preset voltage value, record the duration for which the voltage value of the current sampling period is higher than the preset voltage value, and obtain the difference between the voltage value of the current sampling period and the voltage value of the previous period. By dividing the absolute value of the difference by the sampling period, the voltage change rate of the common DC bus is generated. The step of recording the duration for which the voltage value in the current sampling period is higher than the preset voltage value when the voltage value in the current sampling period is higher than the preset voltage value, and obtaining the difference between the voltage value in the current sampling period and the voltage value in the previous period, and generating the voltage change rate of the common DC bus by dividing the absolute value of the difference by the sampling period, includes: When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and configure a timing thread; A timing thread is used to record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period.

[0041] S205: When the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, the shutdown ratio corresponding to the amplitude value of the parallel circulating current is obtained, and the multiple energy storage inverters are controlled to stop operating according to the shutdown ratio to suppress the parallel circulating current generated between multiple energy storage inverters.

[0042] The energy storage inverter protection method further includes, when the voltage value in the current sampling period is higher than the preset voltage value, recording the duration for which the voltage value in the current sampling period is higher than the preset voltage value, obtaining the difference between the voltage value in the current sampling period and the voltage value sampled in the previous period, and generating the voltage change rate of the common DC bus by dividing the absolute value of the difference by the sampling period. Step A: When the voltage change rate of the common DC bus is greater than the preset change rate threshold, the reverse current from the load to the common DC bus is identified, and the discharge circuit is started to eliminate the reverse current from the load to the common DC bus.

[0043] S205 and step A are parallel steps. When the voltage value of the current sampling period is higher than the preset voltage value, the duration for which the voltage value of the current sampling period is higher than the preset voltage value is recorded, and the difference between the voltage value of the current sampling period and the voltage value of the previous period is obtained. After the absolute value of the difference is divided by the sampling period to generate the voltage change rate of the common DC bus, the energy storage inverter protection method executes S205 and step A.

[0044] Among them, energy storage inverters include photovoltaic energy storage inverters and wind power energy storage inverters.

[0045] Among them, photovoltaic energy storage inverters are mainly used to connect photovoltaic modules and energy storage batteries. They are responsible for inverting and stabilizing the DC power generated by solar energy, and realizing the charging and discharging management of batteries, so as to stably deliver clean energy to the load or grid. Among them, the wind power energy storage inverter is adapted to wind turbine generator sets. After wind energy is converted into electrical energy, it smooths out the intermittent and unstable characteristics of wind power fluctuations and works with energy storage units to achieve power buffering and efficient grid connection.

[0046] The shutdown ratio corresponding to the amplitude value of the parallel circulating current is defined as follows: When the amplitude of the cascading current is between 10% and 30% of the rated current, the shutdown rate is 20%. When the amplitude of the parallel circulating current is greater than 30% but not greater than 50% of the rated current, the shutdown ratio is 50%. When the amplitude of the parallel circulating current is greater than 50% of the rated current, the shutdown ratio is 100%.

[0047] Among them, controlling multiple energy storage inverters to stop operating according to the shutdown ratio can flexibly adjust the shutdown scale according to the actual parallel circulating current size, achieving precise and adaptable parallel circulating current suppression.

[0048] In renewable energy grid-connected and energy storage power supply scenarios, such as photovoltaic parallel inverters and energy storage parallel discharge, controlling the shutdown of multiple energy storage inverters according to the shutdown ratio can suppress the parallel circulating current generated between multiple energy storage inverters. This effectively ensures the safe and stable operation of the renewable energy power generation system and better leverages the positive role of clean energy in social energy supply. By precisely suppressing parallel circulating currents, the safe and reliable operation of multiple energy storage inverters can be effectively protected.

[0049] For ease of explanation, the following example is provided: For example, multiple households in the area share a single photovoltaic parallel inverter and energy storage parallel system with village-level public service facilities. By controlling the shutdown of multiple energy storage inverters according to the magnitude of circulating current, the circulating current can be quickly eliminated, protecting the photovoltaic panels, energy storage batteries, and inverter equipment from burnout, while maintaining enough inverters to continue supplying power, ensuring uninterrupted basic electricity for villagers and village-level public services. This solution reduces the cost and resource waste of repairing and replacing faulty power equipment, while also improving the reliability of clean energy power supply.

[0050] The beneficial effects of the embodiments of this application are as follows: Firstly, when the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, and a shutdown command is generated. Through the shutdown command, some inverters among the multiple inverters are controlled to stop operating, so as to suppress the parallel circulating current generated between the multiple energy storage inverters. Since no manual operation is required, the protection time of multiple energy storage inverters is reduced, which is conducive to improving the protection efficiency of multiple energy storage inverters. Secondly, by using shutdown commands to control some of the inverters in a multi-inverter system to stop operating, the parallel circulating current generated between the multiple energy storage inverters can be eliminated at the source. This can effectively prevent the multiple energy storage inverters from overheating, aging, or even being damaged due to the continuous impact of the parallel circulating current, and significantly improve the safety and service life of the multiple energy storage inverters.

[0051] Please see Figure 3 , Figure 3 The implementation flowchart of S203 provided in the embodiments of this application is described in detail below: S301: When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, a data acquisition enable signal is sent to the voltage sensor corresponding to the common DC bus. S302 receives the voltage signal of the common DC bus returned by the voltage sensor based on the acquisition enable signal, samples the voltage signal of the common DC bus within the current sampling period, and generates the voltage value of the common DC bus in the current sampling period.

[0052] In this embodiment, the voltage signal of the common DC bus is sampled to generate the voltage value of the common DC bus in the current sampling period, which can reflect the current electrical operating status of the bus in real time.

[0053] For the energy storage inverter protection method described in the above embodiments, please refer to [link / reference]. Figure 4 , Figure 4 This is a schematic block diagram of an energy storage inverter protection device provided in an embodiment of this application. Figure 4 The energy storage inverter protection device 400 shown can be applied to, for example... Figure 1 The application scenario diagram shows electronic devices. The following section uses electronic devices as an example to illustrate this. Figure 4 The energy storage inverter protection device 400 shown will be described in detail. The energy storage inverter protection device 400 may include a first sampling module 401, an input module 402, a second sampling module 403, a generation module 404, and a protection module 405.

[0054] The first sampling module 401 is used to sample the output voltage of the output port to generate a voltage sampling signal, sample the inverter inductor current to generate a current sampling signal, perform full-wave rectification on the voltage sampling signal and the current sampling signal to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator which refers to the current flowing through the inverter inductor in a specified energy storage inverter. The specified energy storage inverter is any one of multiple energy storage inverters. The input module 402 is used to input the voltage sampling signal after full-wave rectification to the voltage protection circuit, and read the protection signal output by the voltage protection circuit through the voltage detection pin; and to input the current sampling signal after full-wave rectification to the current protection circuit, and read the protection signal output by the current protection circuit through the current detection pin. The second sampling module 403 is used to sample the voltage signal of the common DC bus when the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, and to generate the voltage value of the common DC bus in the current sampling period. The generation module 404 is used to record the duration for which the voltage value of the current sampling period is higher than the preset voltage value when the voltage value of the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value of the current sampling period and the voltage value of the previous period. The absolute value of the difference is divided by the sampling period to generate the voltage change rate of the common DC bus. The protection module 405 is used to identify parallel circulating currents generated between multiple energy storage inverters when the voltage change rate of the common DC bus is less than or equal to a preset change rate threshold and the duration is longer than a preset duration. It then obtains the shutdown ratio corresponding to the amplitude value of the parallel circulating current and controls multiple energy storage inverters to stop operating according to the shutdown ratio, so as to suppress the parallel circulating currents generated between multiple energy storage inverters.

[0055] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0056] The beneficial effects of the embodiments of this application are as follows: Firstly, when the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, and a shutdown command is generated. Through the shutdown command, some inverters among the multiple inverters are controlled to stop operating, so as to suppress the parallel circulating current generated between the multiple energy storage inverters. Since no manual operation is required, the protection time of multiple energy storage inverters is reduced, which is conducive to improving the protection efficiency of multiple energy storage inverters. Secondly, by using shutdown commands to control some of the inverters in a multi-inverter system to stop operating, the parallel circulating current generated between the multiple energy storage inverters can be eliminated at the source. This can effectively prevent the multiple energy storage inverters from overheating, aging, or even being damaged due to the continuous impact of the parallel circulating current, and significantly improve the safety and service life of the multiple energy storage inverters.

[0057] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0058] like Figure 5 As shown, Figure 5 The electronic device includes: at least one processor 20, a memory 21, and a computer program 22 stored in the memory 21 and executable on the at least one processor 20, wherein the processor 20 executes the computer program 22 to implement the steps in any of the above method embodiments.

[0059] The electronic device may include, but is not limited to, processor 20 and memory 21. Those skilled in the art will understand that... Figure 5 This is merely an example of an electronic device and does not constitute a limitation on electronic devices. It may include more or fewer components than shown in the illustration, or combinations of certain components, or different components. For example, it may also include input / output devices, network access devices, etc.

[0060] The processor 20 is used to run a computer program 22 stored in the memory 21, and performs the following steps when executing the computer program 22: The output voltage at the output port is sampled to generate a voltage sampling signal. The inverter inductor current is sampled to generate a current sampling signal. The voltage sampling signal and the current sampling signal are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator which refers to the current flowing through the inverter inductor in a specified energy storage inverter. The specified energy storage inverter is any one of multiple energy storage inverters. The voltage sampling signal after full-wave rectification is input to the voltage protection circuit, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit, and the protection signal output by the current protection circuit is read through the current detection pin. When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is collected, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated. When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period. When the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, the shutdown ratio corresponding to the amplitude value of the parallel circulating current is obtained, and the multiple energy storage inverters are controlled to stop operating according to the shutdown ratio to suppress the parallel circulating current generated between multiple energy storage inverters.

[0061] The processor 20 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors, field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0062] In some embodiments, the memory 21 may be an internal storage unit of the electronic device, such as a hard disk or memory of the electronic device. In other embodiments, the memory 21 may also be an external storage device of the electronic device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the electronic device.

[0063] Furthermore, the memory 21 may include both internal storage units and external storage devices of the electronic device. The memory 21 is used to store the operating system, applications, boot loader, data, and other programs, such as the program code of the computer program. The memory 21 can also be used to temporarily store data that has been output or will be output.

[0064] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0065] This application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0066] The computer-readable storage medium may also be an external storage device of the energy storage inverter protection device or electronic device, such as a plug-in hard drive, smart media card (SMC), secure digital (SD) card, flash card, or non-transitory computer-readable storage medium equipped on the energy storage inverter protection device or electronic device.

[0067] Since the computer program stored in the computer-readable storage medium can execute any of the energy storage inverter protection methods provided in the embodiments of this application, the computer-readable storage medium can achieve the beneficial effects that any of the energy storage inverter protection methods provided in the embodiments of this application can achieve, as detailed in the preceding embodiments, and will not be repeated here.

[0068] This application provides a computer program product that, when run on an electronic device, causes the electronic device to execute the aforementioned energy storage inverter protection method.

[0069] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0070] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A protection method for an energy storage inverter, characterized in that, This method is applied to electronic devices connected to an energy storage inverter system. The energy storage inverter system includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC output terminals of the multiple energy storage inverters are connected in parallel to form the output port of the energy storage inverter system. The energy storage inverter protection method includes: The output voltage at the output port is sampled to generate a voltage sampling signal. The inverter inductor current is sampled to generate a current sampling signal. The voltage sampling signal and the current sampling signal are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator (current flowing through the inverter inductor in a specified energy storage inverter). The specified energy storage inverter is any one of multiple energy storage inverters. The voltage sampling signal after full-wave rectification is input to the voltage protection circuit, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit, and the protection signal output by the current protection circuit is read through the current detection pin. When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is collected, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated. When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period. When the voltage change rate of the common DC bus is less than or equal to the preset change rate threshold and the duration is longer than the preset duration, the parallel circulating current generated between multiple energy storage inverters is identified, the shutdown ratio corresponding to the amplitude value of the parallel circulating current is obtained, and the multiple energy storage inverters are controlled to stop operating according to the shutdown ratio to suppress the parallel circulating current generated between multiple energy storage inverters.

2. The energy storage inverter protection method according to claim 1, characterized in that, The process of sampling the output voltage at the output port to generate a voltage sampling signal, sampling the inverter inductor current to generate a current sampling signal, and performing full-wave rectification on the voltage and current sampling signals to generate full-wave rectified voltage and current sampling signals includes: Read the preset sampling time and determine whether the current time is the sampling time; If the current time is the sampling time, the output voltage of the output port is sampled to generate a voltage sampling signal, the inverter inductor current is sampled to generate a current sampling signal, and the voltage sampling signal and the current sampling signal are rectified by full-wave rectification to generate a full-wave rectified voltage sampling signal and a full-wave rectified current sampling signal.

3. The energy storage inverter protection method according to claim 1, characterized in that, The process of inputting the full-wave rectified voltage sampling signal to the voltage protection circuit and reading the protection signal output by the voltage protection circuit through the voltage detection pin, and inputting the full-wave rectified current sampling signal to the current protection circuit and reading the protection signal output by the current protection circuit through the current detection pin, includes: The voltage sampling signal after full-wave rectification is input to the voltage protection circuit through the first output pin, and the protection signal output by the voltage protection circuit is read through the voltage detection pin. The current sampling signal after full-wave rectification is input to the current protection circuit through the second output pin, and the protection signal output by the current protection circuit is read through the current detection pin.

4. The energy storage inverter protection method according to claim 1, characterized in that, When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, the voltage signal of the common DC bus is acquired, the voltage signal of the common DC bus is sampled, and the voltage value of the common DC bus in the current sampling period is generated, including: When the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, a data acquisition enable signal is sent to the voltage sensor corresponding to the common DC bus. The receiving voltage sensor samples the voltage signal of the common DC bus returned by the acquisition enable signal within the current sampling period, and generates the voltage value of the common DC bus in the current sampling period.

5. The energy storage inverter protection method according to claim 1, characterized in that, When the voltage value in the current sampling period is higher than a preset voltage value, the duration for which the voltage value in the current sampling period is higher than the preset voltage value is recorded, and the difference between the voltage value in the current sampling period and the voltage value sampled in the previous period is obtained. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period, including: When the voltage value in the current sampling period is higher than the preset voltage value, record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and configure a timing thread; A timing thread is used to record the duration for which the voltage value in the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The voltage change rate of the common DC bus is generated by dividing the absolute value of the difference by the sampling period.

6. The energy storage inverter protection method according to claim 1, characterized in that, When the voltage value in the current sampling period is higher than a preset voltage value, the duration for which the voltage value in the current sampling period is higher than the preset voltage value is recorded, and the difference between the voltage value in the current sampling period and the voltage value sampled in the previous period is obtained. After generating the voltage change rate of the common DC bus by dividing the absolute value of the difference by the sampling period, the energy storage inverter protection method further includes: When the voltage change rate of the common DC bus exceeds the preset change rate threshold, the reverse current from the load to the common DC bus is detected, and the discharge circuit is activated to eliminate the reverse current from the load to the common DC bus.

7. The energy storage inverter protection method according to claim 1, characterized in that, Energy storage inverters include photovoltaic energy storage inverters and wind power energy storage inverters.

8. A protection device for an energy storage inverter, characterized in that, This system is applied to electronic devices connected to an energy storage inverter system. The system includes a common DC bus and multiple energy storage inverters connected in parallel to the common DC bus. The AC outputs of these inverters are connected in parallel to form the output ports of the energy storage inverter system, including: The first sampling module is used to sample the output voltage of the output port to generate a voltage sampling signal, sample the inverter inductor current to generate a current sampling signal, perform full-wave rectification on the voltage sampling signal and the current sampling signal to generate a full-wave rectified voltage sampling signal and an inverter inductor current indicator which refers to the current flowing through the inverter inductor in a specified energy storage inverter. The specified energy storage inverter is any one of multiple energy storage inverters. The input module is used to input the voltage sampling signal after full-wave rectification to the voltage protection circuit and read the protection signal output by the voltage protection circuit through the voltage detection pin. It also inputs the current sampling signal after full-wave rectification to the current protection circuit and reads the protection signal output by the current protection circuit through the current detection pin. The second sampling module is used to sample the voltage signal of the common DC bus when the protection signal output by the voltage protection circuit or the protection signal output by the current protection circuit is a high-level signal, and to generate the voltage value of the common DC bus in the current sampling period. The generation module is used to record the duration for which the voltage value in the current sampling period is higher than the preset voltage value when the voltage value in the current sampling period is higher than the preset voltage value, and to obtain the difference between the voltage value in the current sampling period and the voltage value in the previous period. The absolute value of the difference is divided by the sampling period to generate the voltage change rate of the common DC bus. The protection module is used to identify parallel circulating currents generated between multiple energy storage inverters when the voltage change rate of the common DC bus is less than or equal to a preset change rate threshold and the duration is longer than a preset duration. It then obtains the shutdown ratio corresponding to the amplitude value of the parallel circulating current and controls multiple energy storage inverters to stop operating according to the shutdown ratio, so as to suppress the parallel circulating currents generated between multiple energy storage inverters.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the energy storage inverter protection method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the energy storage inverter protection method as described in any one of claims 1 to 7.

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