Fault protection method, energy storage inverter circuit and inverter equipment

Abstract

The invention belongs to the technical field of inversion, and provides a fault protection method, an energy storage inversion circuit and inversion equipment. The fault protection method comprises the following steps: acquiring first working state information of the AC conversion circuit and second working state information of the auxiliary power supply circuit, and generating a fault alarm signal when the first working state information and the second working state information meet a preset fault condition; determining fault position information of the energy storage inverter circuit according to the fault alarm signal; when the fault position information indicates that the alternating current conversion circuit has a fault, a turn-off control signal is generated to control the alternating current conversion circuit to stop working, the method can accurately judge the fault position according to the fault alarm information, and corresponding protection actions are implemented according to different fault positions. The response speed and the processing efficiency of the system are improved, the unnecessary downtime is reduced, and the stability and the flexibility of the system are effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of inverter technology, and in particular relates to a fault protection method, an energy storage inverter circuit and an inverter device. Background Art

[0002] With the rapid development of the energy storage industry, energy storage inverter equipment plays an increasingly important role in grid and off-grid applications. Traditional energy storage inverter circuits usually include DC conversion circuits and AC conversion circuits, which convert DC power in energy storage devices such as battery packs into AC power that can be used in homes and industries, thereby achieving efficient transmission and use of electricity.

[0003] However, the existing technology faces a major problem: in terms of fault detection and protection, traditional methods usually rely only on simple circuit disconnection protection and lack the ability to classify and detect complex faults and respond to and adjust them, which may result in the power system being unable to recover quickly or continue to operate stably when a fault occurs. This not only affects the reliability and flexibility of the energy storage inverter system, but may also reduce its economic efficiency and user satisfaction in practical applications. These challenges need to be addressed urgently. Summary of the invention

[0004] The purpose of this application is to provide a fault protection method, an energy storage inverter circuit and an inverter device, aiming to solve the problem of lack of reliability and flexibility in fault protection of existing energy storage inverter systems.

[0005] A first aspect of an embodiment of the present application provides a fault protection method for an energy storage inverter circuit, wherein the energy storage inverter circuit comprises: a DC conversion circuit, an AC conversion circuit and an auxiliary power supply circuit, wherein a first end of the DC conversion circuit is used to be connected to a battery pack, and a second end of the DC conversion circuit is connected to a first end of the AC conversion circuit; a second end of the AC conversion circuit is used to be connected to a power grid, and the auxiliary power supply circuit is connected to the AC conversion circuit, and the auxiliary power supply circuit is used to control the working state of the AC conversion circuit; the fault protection method comprises:

[0006] Acquire first working state information of the AC conversion circuit and second working state information of the auxiliary power supply circuit, and generate a fault alarm signal when the first working state information and the second working state information meet a preset fault condition;

[0007] Determining fault location information of the energy storage inverter circuit according to the fault alarm signal;

[0008] When the fault location information is an AC conversion circuit fault, a shutdown control signal is generated to control the AC conversion circuit to stop working.

[0009] By adopting the above technical solution, through the preset fault conditions, the method can quickly detect potential faults and generate fault alarm signals immediately to ensure that the system can respond in time. In addition, through the precise positioning of the fault location information, the circuit part where the fault is located can be quickly identified and isolated, especially when there is a problem with the AC conversion circuit, a shutdown control signal can be quickly sent to stop its operation, thereby reducing the scope of the fault impact and preventing greater damage to the entire energy storage inverter circuit.

[0010] The fault protection method of this application can accurately determine the fault location based on the fault alarm information, and implement corresponding protection actions according to different fault locations. It not only improves the response speed and processing efficiency of the system, but also reduces unnecessary downtime. Through this detailed protection strategy, the system can more effectively isolate and solve problems and protect the remaining parts to continue to operate stably.

[0011] A second aspect of an embodiment of the present application provides an energy storage inverter circuit, the energy storage inverter circuit comprising:

[0012] A DC conversion circuit, wherein a first end of the DC conversion circuit is used to be connected to a battery pack;

[0013] an AC conversion circuit, wherein a first end of the AC conversion circuit is connected to a second end of the DC conversion circuit, and the second end of the AC conversion circuit is used to be connected to a power grid;

[0014] an auxiliary power supply circuit, the auxiliary power supply circuit being connected to the AC conversion circuit;

[0015] The auxiliary power supply circuit is used to execute the fault protection method as described in any one of the above.

[0016] By adopting the above technical solutions, the fault protection solution is integrated into the energy storage inverter circuit. The multi-level fault response strategy allows the system to quickly respond to temperature, overvoltage, overcurrent and other problems, reducing the risk of equipment damage. At the same time, through intelligent derating and shutdown measures, the system maintains high energy efficiency, reduces unnecessary energy consumption, and extends the service life of the equipment. This integrated control solution provides a more economical and reliable power solution, bringing users a flexible and intelligent power management experience.

[0017] A third aspect of an embodiment of the present application provides an inverter device, comprising the energy storage inverter circuit as described above.

[0018] By adopting the above technical solution, the inverter device integrates the above energy storage inverter circuit, including DC conversion circuit, AC conversion circuit and auxiliary power supply circuit. The DC conversion circuit is connected to the battery pack to ensure efficient conversion and transmission of electric energy; the AC conversion circuit is connected to the power grid, allowing electricity to be flexibly exchanged between the energy storage system and the power grid. The auxiliary power supply circuit monitors the temperature and overvoltage conditions of the system in real time through the fault detection and response mechanism, and generates a derating or shutdown control signal to provide accurate and effective protection measures. This design significantly improves the safety, reliability and operational efficiency of the inverter equipment. The equipment can flexibly respond to faults, respond quickly and adjust to the optimal working state, which not only reduces the risk of equipment damage, but also achieves efficient energy consumption management. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of an energy storage inverter circuit provided in one embodiment of the present application;

[0020] Figure 2 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 1 ;

[0021] Figure 3 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 2 ;

[0022] Figure 4 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 3 ;

[0023] Figure 5 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 4 ;

[0024] Figure 6 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 5 ;

[0025] Figure 7 A schematic diagram of a fault protection method for an energy storage inverter circuit provided in an embodiment of the present application Figure 6 . DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] It should be noted that the terms "first" and "second" in the specification, claims and drawings of the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0030] Some embodiments will be described below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0031] With the rapid development of the energy storage industry, energy storage inverter equipment plays an increasingly important role in grid and off-grid applications. Traditional energy storage inverter circuits usually include DC conversion circuits and AC conversion circuits, which convert DC power in energy storage devices such as battery packs into AC power that can be used in homes and industries, thereby achieving efficient transmission and use of electricity.

[0032] However, the existing technology faces a major problem: in terms of fault detection and protection, traditional methods usually rely only on simple circuit disconnection protection and lack the ability to classify and detect complex faults and respond to and adjust them, which may result in the power system being unable to recover quickly or continue to operate stably when a fault occurs. This not only affects the reliability and flexibility of the energy storage inverter system, but may also reduce its economic efficiency and user satisfaction in practical applications. These challenges need to be addressed urgently.

[0033] In order to solve the above technical problems, refer to Figure 1 , Figure 2 As shown, an embodiment of the present application provides a fault protection method for an energy storage inverter circuit. The energy storage inverter circuit includes: a DC conversion circuit 10, an AC conversion circuit 20 and an auxiliary power supply circuit 30. The first end of the DC conversion circuit 10 is used to connect to the battery pack 100, and the second end of the DC conversion circuit 10 is connected to the first end of the AC conversion circuit 20; the second end of the AC conversion circuit 20 is used to connect to the power grid 200, and the auxiliary power supply circuit 30 is connected to the AC conversion circuit 20. The auxiliary power supply circuit 30 is used to control the working state of the AC conversion circuit 20.

[0034] Furthermore, the fault protection method includes steps S10 to S30:

[0035] Step S10: acquiring first working state information of the AC conversion circuit 20 and second working state information of the auxiliary power supply circuit 30, and generating a fault alarm signal when the first working state information and the second working state information meet a preset fault condition.

[0036] Step S20: determining the fault location information of the energy storage inverter circuit according to the fault alarm signal.

[0037] Step S30: When the fault location information indicates that the AC conversion circuit 20 is faulty, a shutdown control signal is generated to control the AC conversion circuit 20 to stop working.

[0038] In this embodiment, the energy storage inverter circuit includes the following three circuits: a DC conversion circuit 10, an AC conversion circuit 20, and an auxiliary power supply circuit 30. The first end of the DC conversion circuit 10 is connected to the battery pack 100, and the second end of the DC conversion circuit 10 is connected to the first end of the AC conversion circuit 20. The second end of the AC conversion circuit 20 is connected to the power grid 200. At the same time, the auxiliary power supply circuit 30 is connected to the AC conversion circuit 20, and the auxiliary power supply circuit 30 is used to adjust the working state of the AC conversion circuit 20.

[0039] The DC conversion circuit 10 can adopt a bidirectional isolated DC-DC design, can charge the battery pack 100, and can take power from the battery pack 100 to transmit power to the AC conversion circuit 20. The AC conversion circuit 20 adopts a bidirectional DC-AC design, which obtains power from the power grid 200 and converts it into DC power to charge the battery pack 100, or obtains power from the DC conversion circuit 10 to power the load connected thereto.

[0040] The auxiliary power supply circuit 30 is responsible for monitoring and adjusting the working state of the DC conversion circuit 10 and the AC conversion circuit 20. For example, when the energy storage inverter circuit system fails, the auxiliary power supply circuit 30 can control the DC conversion circuit 10 and / or the AC conversion circuit 20 to stop operating.

[0041] In this embodiment, in step S10, the auxiliary power supply circuit 30 can obtain the first working state information of the AC conversion circuit 20 and the second working state information of the auxiliary power supply circuit 30. Specifically, the auxiliary power supply circuit 30 can obtain the first working state information of the AC conversion circuit 20 and the second working state information of the auxiliary power supply circuit 30 according to the first frequency timing, so as to understand the working state of the DC conversion circuit 10 and the AC conversion circuit 20 in real time. Among them, the first working state signal may include: the output voltage and output current of the AC conversion circuit 20, and the temperature of the inverter in the AC conversion circuit 20, which can reflect the working state of the AC conversion circuit 20; the second working state signal may include: the output voltage and output current of the auxiliary power supply circuit 30, and the temperature of the transformer in the auxiliary power supply circuit 30, which can reflect the working state of the auxiliary power supply circuit 30. In this embodiment, by obtaining the first working state information and the second working state information in real time, the working state of the AC conversion circuit 20 and the auxiliary power supply circuit 30 can be understood in real time, laying a foundation for the fault diagnosis of the energy storage inverter circuit.

[0042] In this embodiment, in step S10, the auxiliary power supply circuit 30 also generates a fault alarm signal when the first working state information and the second working state information meet the preset fault condition. The preset fault condition may be that the output voltage, output current, and temperature of either the AC conversion circuit 20 or the auxiliary power supply circuit 30 exceed the corresponding preset value. When the condition is met, a fault alarm signal is generated to indicate that the AC conversion circuit 20 and / or the auxiliary power supply circuit 30 may have a fault.

[0043] In this embodiment, in step S20, the auxiliary power supply circuit 30 also determines the fault location information of the energy storage inverter circuit according to the fault alarm signal. It should be noted that when a fault alarm signal occurs, it may be that the AC conversion circuit 20 fails, the auxiliary power supply circuit 30 fails, or both the AC conversion circuit 20 and the auxiliary power supply circuit 30 fail. At this time, the auxiliary power supply circuit 30 can locate the specific location of the fault according to the fault alarm information, so as to perform different protection actions according to different fault locations.

[0044] In this embodiment, in step S30, when the auxiliary power supply circuit 30 determines that the fault location information is a fault of the AC conversion circuit 20, that is, a fault occurs in the AC conversion circuit 20, then the MCU of the auxiliary power supply circuit 30 directly generates a shutdown control signal, and then sends the shutdown control signal to the AC conversion circuit 20 to control the switch tube in the AC conversion circuit 20 to close, so as to control the AC conversion circuit 20 to stop working.

[0045] It should be noted that the AC conversion circuit 20, as a key circuit in the energy storage inverter circuit, plays an important role. Therefore, when it is determined that the AC conversion circuit 20 has failed, it is necessary to immediately control the AC conversion circuit 20 to stop working. It is understandable that the cause of the AC conversion circuit 20 failure at this time may be: the output current of the AC conversion circuit 20 exceeds the corresponding preset value, or the output voltage of the AC conversion circuit 20 exceeds the corresponding preset value, or the temperature of the AC conversion circuit 20 exceeds the corresponding preset value. Therefore, as long as any one of the conditions is met, the AC conversion circuit 20 is controlled to stop working.

[0046] In this embodiment, the fault protection method of the energy storage inverter circuit significantly improves the reliability and safety of the system by monitoring the status information of the AC conversion circuit 20 and the auxiliary power supply circuit 30. Through the preset fault conditions, the method can quickly detect potential faults and generate fault alarm signals in real time to ensure that the system can respond in time. In addition, through the precise positioning of the fault location information, the circuit part where the fault is located can be quickly identified and isolated. In particular, when a problem occurs in the AC conversion circuit 20, a shutdown control signal can be quickly sent to stop its operation, thereby reducing the scope of the fault impact and preventing greater damage to the entire energy storage inverter circuit.

[0047] The fault protection method of this application can accurately determine the fault location based on the fault alarm information, and implement corresponding protection actions according to different fault locations. It not only improves the response speed and processing efficiency of the system, but also reduces unnecessary downtime. Through this detailed protection strategy, the system can more effectively isolate and solve problems and protect the remaining parts to continue to operate stably.

[0048] In one embodiment, reference Figure 3 As shown, the fault protection method further includes: step S40 to step S50.

[0049] Step S40: when the fault location information is a communication fault, a communication detection signal is generated; wherein the communication detection signal is used to detect the communication status between the AC conversion circuit 20 and the auxiliary power supply circuit 30 .

[0050] Step S50: after the first delay, determine the communication state between the AC conversion circuit 20 and the auxiliary power supply circuit 30 according to the communication feedback signal, and generate a shutdown control signal when the communication state maintains a communication failure to control the AC conversion circuit 20 to stop working.

[0051] In this embodiment, in step S40, when the auxiliary power supply circuit 30 determines that the fault location information points to a communication fault according to the fault alarm signal, the auxiliary power supply circuit 30 generates a communication detection signal to evaluate the communication status between the AC conversion circuit 20 and the auxiliary power supply circuit 30. It can be understood that when a communication fault is determined, the communication detection signal generated at this time is used to detect the communication status between the AC conversion circuit 20 and the auxiliary power supply circuit 30 in real time; it should be noted that the communication status between the AC conversion circuit 20 and the auxiliary power supply circuit 30 is detected by the system all the time, but after the communication detection signal is generated after the communication fault is determined, the detection frequency will increase, and the communication status can be detected multiple times in a short period of time, so that the communication status can be detected more accurately.

[0052] The system uses high-frequency communication detection signals to capture any anomalies on the communication link to ensure that each communication node responds as expected.

[0053] In this embodiment, in step S50, considering that the impact of communication failure is relatively minor compared to the failure directly occurring in the AC conversion circuit 20, the system will start a first delay, which is usually set to 2 seconds, after the communication failure is first discovered. During this delay period, the system will continue to monitor the communication status. After the delay period, if the communication status still shows that the fault has not been resolved, the system will generate a shutdown control signal to disable the AC conversion circuit 20. This delay strategy allows the system to confirm multiple times before making a shutdown decision to avoid unnecessary shutdowns caused by temporary communication interruptions.

[0054] In this embodiment, by setting the first delay window of 2 seconds, the system effectively reduces the misoperation caused by short-term or occasional communication problems, and improves the flexibility and intelligence of the system in dealing with communication failures. Shutdown measures are only taken when it is confirmed that the fault persists, ensuring the stability and reliability of the system. In addition, this method avoids unnecessary downtime.

[0055] In one embodiment, reference Figure 4 As shown, the fault protection method further includes: step S60.

[0056] Specifically, step S60: when the fault location information indicates that the auxiliary power supply circuit 30 is faulty, determine the fault category of the auxiliary power supply circuit 30 according to the second working state information; wherein the fault categories include: a first fault category, a second fault category and a third fault category.

[0057] In this embodiment, in step S60, when the auxiliary power supply circuit 30 identifies that the fault source is the auxiliary power supply circuit 30 itself, the auxiliary power supply circuit 30 classifies the fault in detail with the help of the second working state information. The core of this step is that the fault is divided into three categories according to the specific cause of the fault: the first category is relatively minor or transient; the second category involves partial functional abnormalities but has not yet posed a threat to the overall system; the third category is a serious fault, and it may be necessary to immediately suspend the operation of the relevant system to prevent greater risks.

[0058] In this embodiment, by carefully classifying the fault causes in step S60, the system can adopt targeted operations to deal with different fault scenarios. For example, a minor fault may only require a simple restart or delayed detection before making a decision, while a serious fault may require an immediate system shutdown to avoid further damage. This strategy not only improves the operating efficiency of the system, reduces unnecessary intervention and resource consumption, but also ensures the system's ability to respond to complex faults, and comprehensively maintains the safety and stability of the energy storage inverter system.

[0059] In one embodiment, reference Figure 5 As shown, the fault protection method further includes: step S70.

[0060] Step S70: When the fault type of the auxiliary power supply circuit 30 is the first fault type, a temperature detection signal is generated. After the second delay, the temperature state of the auxiliary power supply circuit 30 is determined according to the temperature feedback signal, and the working state of the AC conversion circuit 20 is controlled according to the temperature state of the auxiliary power supply circuit 30.

[0061] In this embodiment, in step S70, when the fault category of the auxiliary power supply circuit 30 is the first fault category, the auxiliary power supply circuit 30 generates a temperature detection signal. The system sets a fixed second delay (for example, 1 second) to ensure accurate temperature feedback monitoring within a sufficient time span. After the delay, the auxiliary power supply circuit 30 determines the temperature state of the auxiliary power supply circuit 30 based on the obtained temperature feedback signal, and adjusts the working state of the AC conversion circuit 20 accordingly to ensure that the system continues to operate within a safe temperature range.

[0062] It can be understood that when it is judged as the first fault category, the temperature detection signal generated at this time is used to detect the temperature status of the auxiliary power supply circuit 30 in real time; it should be noted that the system will continue to detect the temperature status of the auxiliary power supply circuit 30, but when it is judged as the first fault category, after the temperature detection signal is generated, the detection frequency will be increased, and the temperature status can be detected multiple times in a short time, so that the temperature status of the auxiliary power supply circuit 30 can be detected more accurately.

[0063] In this embodiment, by setting the temperature detection signal and the delay monitoring mechanism, the system realizes active management of possible thermal hazards. In this way, the energy storage inverter circuit can not only quickly take protective measures when the temperature rises to reduce the damage caused by overheating, but also optimize the system operating conditions and improve the overall energy efficiency.

[0064] In one embodiment, reference Figure 6 As shown, the fault protection method further includes: step S80.

[0065] In step S80, when the fault category of the auxiliary power supply circuit 30 is the second fault category, an overcurrent detection signal is generated; after the third delay, the overcurrent state of the auxiliary power supply circuit 30 is determined according to the overcurrent feedback signal, and when the overcurrent state of the auxiliary power supply circuit 30 maintains the second fault category, a shutdown control signal is generated to control the AC conversion circuit 20 to stop working.

[0066] In this embodiment, in step S80, when the auxiliary power supply circuit 30 is identified as the second fault category (indicating that the output current of the auxiliary power supply circuit 30 is too large and an overcurrent fault occurs), the system generates an overcurrent detection signal and sets a third delay (for example, 500 milliseconds). During the delay period, the auxiliary power supply circuit 30 continues to monitor the overcurrent condition. After the delay is over, the overcurrent state of the auxiliary power supply circuit 30 is determined by the overcurrent feedback signal. If the overcurrent condition still exists, the auxiliary power supply circuit 30 will generate a shutdown control signal to safely terminate the operation of the AC conversion circuit 20 (because the auxiliary power supply circuit 30 controls the working state of the AC control circuit, when the auxiliary power supply circuit 30 fails, the AC conversion circuit 20 also needs to stop working) to prevent the equipment from being overloaded and damaged, and ensure the safety and stability of the overall system.

[0067] In this embodiment, by setting a special overcurrent detection and delay processing strategy for the second fault category, the system can respond in time and prevent potential risks caused by overcurrent. This method improves the effectiveness of fault processing, reduces the accidental damage caused by it, and enables the energy storage inverter circuit to maintain a high degree of stability and safety in a complex operating environment.

[0068] In one embodiment, reference Figure 7 As shown, the fault protection method further includes: step S90.

[0069] Step S90: When the fault category of the auxiliary power supply circuit 30 is the third fault category, an overvoltage detection signal is generated; after a third delay, the overvoltage state of the auxiliary power supply circuit 30 is determined according to the overvoltage feedback signal, and when the overvoltage state of the auxiliary power supply circuit 30 maintains the third fault category, a shutdown control signal is generated to control the AC conversion circuit 20 to stop working.

[0070] In this embodiment, in step S90, when the auxiliary power supply circuit 30 is identified as the third fault category (indicating that the output voltage of the auxiliary power supply circuit 30 is too large and an overvoltage fault occurs), the auxiliary power supply circuit 30 generates an overvoltage detection signal and starts a third delay (e.g., 100 milliseconds) to ensure sufficient evaluation time. During the delay period, the auxiliary power supply circuit 30 continuously monitors the overvoltage condition, and after the delay ends, determines the overvoltage state of the auxiliary power supply circuit 30 through the overvoltage feedback signal. If the overvoltage state still persists, the system will generate a shutdown control signal to immediately stop the operation of the AC conversion circuit 20.

[0071] In this embodiment, by defining a special overvoltage detection and delay strategy for the third fault category, the system can quickly sense and effectively respond to overvoltage problems. This mechanism ensures that timely action is taken after a potential overvoltage risk is detected to prevent possible equipment damage or safety accidents. In addition, this protective measure greatly improves the safety and reliability of the overall operation by reducing the scope of the fault's impact on the system.

[0072] In one embodiment, after the second delay, the temperature state of the auxiliary power supply circuit 30 is determined according to the temperature feedback signal, and the working state of the AC conversion circuit 20 is controlled according to the temperature state of the auxiliary power supply circuit 30, including: when it is determined that the temperature state of the auxiliary power supply circuit 30 is the first temperature, after a fourth delay, a shutdown control signal is generated to control the AC conversion circuit 20 to stop working.

[0073] In this embodiment, the fault protection method of the energy storage inverter circuit ensures the stability and safety of the system by monitoring the temperature. For example, when the system detects that the auxiliary power supply circuit 30 has a first type of fault, it first generates a temperature detection signal and sets a second delay. After the delay ends, the system evaluates the temperature state of the auxiliary power supply circuit 30 based on the temperature feedback signal. If the monitored temperature reaches the first temperature, the system will start the fourth delay. The purpose of the fourth delay is to confirm whether the temperature state still exceeds the safety threshold after giving the system a short time window for self-adjustment. If the high temperature state continues, the system will generate a shutdown control signal to safely shut down the AC conversion circuit 20 to prevent system failure or damage caused by overheating.

[0074] In this embodiment, by introducing the second and fourth delays, the system can accurately monitor temperature changes and take corresponding shutdown measures when necessary. This strategy not only provides preventive safety protection to prevent the risk of overheating of the circuit under high load, but also improves the operational flexibility and response capability of the system.

[0075] In one embodiment, after the second delay, the temperature state of the auxiliary power supply circuit 30 is determined according to the temperature feedback signal, and the working state of the AC conversion circuit 20 is controlled according to the temperature state of the auxiliary power supply circuit 30, including: when it is determined that the temperature state of the auxiliary power supply circuit 30 is the second temperature, a derating control signal is generated to control the AC conversion circuit 20 to operate at a derating. The first temperature is greater than the second temperature.

[0076] In this embodiment, after the auxiliary power supply circuit 30 is detected to have a fault, a temperature detection signal is first generated and after a second delay, the system determines the temperature state of the auxiliary power supply circuit 30 based on information obtained from the temperature feedback signal.

[0077] If the temperature is the second temperature (lower than the first temperature), the system generates a derating control signal. This signal is used to adjust the operating state of the AC conversion circuit 20 so that it works in a derating mode. This adjustment can reduce the power output of the system and reduce heat generation, thereby effectively controlling the temperature of the circuit components.

[0078] When the temperature reaches the first temperature (higher temperature), after a fourth delay, a shutdown control signal is generated to ensure that the AC conversion circuit 20 stops working to prevent overheating damage.

[0079] In this embodiment, by dynamically adjusting the working state of the AC conversion circuit 20 (such as derating operation), the system can alleviate temperature pressure at an early stage and avoid component aging or failure caused by long-term high-temperature operation. At the same time, by setting two temperature thresholds, the system's autonomous decision-making ability is greatly improved, and appropriate measures are taken in the first time to reduce potential risks. This hierarchical management strategy can extend the service life of the equipment while ensuring operating efficiency, ensuring the reliability and sustainability of the energy storage inverter circuit.

[0080] The embodiment of the present application further provides an energy storage inverter circuit, wherein the energy storage inverter circuit includes: a DC conversion circuit 10 , an AC conversion circuit 20 and an auxiliary power supply circuit 30 .

[0081] Specifically, the first end of the DC conversion circuit 10 is used to connect to the battery pack 100. The first end of the AC conversion circuit 20 is connected to the second end of the DC conversion circuit 10, and the second end of the AC conversion circuit 20 is used to connect to the power grid 200. The auxiliary power supply circuit 30 is connected to the AC conversion circuit 20, and the auxiliary power supply circuit 30 is used to execute any of the above-mentioned fault protection methods.

[0082] In this embodiment, the energy storage inverter circuit is composed of a DC conversion circuit 10, an AC conversion circuit 20 and an auxiliary power supply circuit 30, providing efficient power management and fault protection. The DC conversion circuit 10 is connected to the battery pack 100 to convert electrical energy into a form suitable for use by the AC conversion circuit 20. The AC conversion circuit 20 is connected to the power grid 200 to achieve flexible energy exchange. The auxiliary power supply circuit 30 monitors the temperature and overvoltage status in real time through a precise fault detection and response mechanism, generates a derating or shutdown control signal, and ensures effective protection in different fault scenarios.

[0083] Through this design, the system significantly enhances safety and efficiency. The multi-level fault response strategy allows the system to quickly respond to temperature and overvoltage problems, reducing the risk of equipment damage. At the same time, through intelligent derating and shutdown measures, the system maintains high energy efficiency, reduces unnecessary energy consumption, and extends the service life of equipment. This integrated control solution provides a more economical and reliable power solution, bringing users a flexible and intelligent power management experience.

[0084] An embodiment of the present application also provides an inverter device, including the energy storage inverter circuit as described above.

[0085] In this embodiment, the inverter device integrates the above-mentioned energy storage inverter circuit, including a DC conversion circuit 10, an AC conversion circuit 20, and an auxiliary power supply circuit 30. The DC conversion circuit 10 is connected to the battery pack 100 to ensure efficient conversion and transmission of electric energy; the AC conversion circuit 20 is connected to the power grid 200, allowing electricity to be flexibly exchanged between the energy storage system and the power grid 200. The auxiliary power supply circuit 30 monitors the temperature and overvoltage conditions of the system in real time through a fault detection and response mechanism, and generates a derating or shutdown control signal to provide accurate and effective protection measures.

[0086] This design significantly improves the safety, reliability and operational efficiency of the inverter equipment. The equipment can flexibly respond to faults, quickly respond and adjust to the best working state, which not only reduces the risk of equipment damage, but also achieves efficient energy consumption management. Intelligent fault emergency measures extend the service life of the equipment.

[0087] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0088] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0089] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0090] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0091] Each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0092] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0093] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Claims

1. A fault protection method for an energy storage inverter circuit, characterized in that: The energy storage inverter circuit includes: a DC conversion circuit, an AC conversion circuit and an auxiliary power supply circuit, wherein the first end of the DC conversion circuit is used to connect to the battery pack, and the second end of the DC conversion circuit is connected to the first end of the AC conversion circuit; the second end of the AC conversion circuit is used to connect to the power grid, and the auxiliary power supply circuit is connected to the AC conversion circuit, and the auxiliary power supply circuit is used to control the working state of the AC conversion circuit; the fault protection method includes: Acquire first working state information of the AC conversion circuit and second working state information of the auxiliary power supply circuit, and generate a fault alarm signal when the first working state information and the second working state information meet a preset fault condition; Determining fault location information of the energy storage inverter circuit according to the fault alarm signal; When the fault location information is an AC conversion circuit fault, a shutdown control signal is generated to control the AC conversion circuit to stop working.

2. The fault protection method for the energy storage inverter circuit according to claim 1, characterized in that: The fault protection method further comprises: When the fault location information is a communication fault, a communication detection signal is generated; wherein the communication detection signal is used to detect the communication state between the AC conversion circuit and the auxiliary power supply circuit; After the first delay, the communication state between the AC conversion circuit and the auxiliary power supply circuit is determined according to the communication feedback signal, and the shutdown control signal is generated when the communication state maintains a communication fault to control the AC conversion circuit to stop working.

3. The fault protection method for the energy storage inverter circuit according to claim 1, characterized in that: The fault protection method further comprises: When the fault location information is an auxiliary power supply circuit fault, the fault category of the auxiliary power supply circuit is determined according to the second working state information; wherein the fault category includes: a first fault category, a second fault category and a third fault category.

4. The fault protection method for the energy storage inverter circuit according to claim 3, characterized in that: The fault protection method further comprises: When the fault category of the auxiliary power supply circuit is a first fault category, generating a temperature detection signal; After the second delay, the temperature state of the auxiliary power supply circuit is determined according to the temperature feedback signal, and the working state of the AC conversion circuit is controlled according to the temperature state of the auxiliary power supply circuit.

5. The fault protection method for the energy storage inverter circuit according to claim 3, characterized in that: The fault protection method further comprises: When the fault category of the auxiliary power supply circuit is a second fault category, generating an overcurrent detection signal; After the third delay, the overcurrent state of the auxiliary power supply circuit is determined according to the overcurrent feedback signal, and the shutdown control signal is generated when the overcurrent state of the auxiliary power supply circuit maintains the second fault category to control the AC conversion circuit to stop working.

6. The fault protection method for energy storage inverter circuit according to claim 3, characterized in that: The fault protection method further comprises: When the fault category of the auxiliary power supply circuit is a third fault category, generating an overvoltage detection signal; After the third delay, the overvoltage state of the auxiliary power supply circuit is determined according to the overvoltage feedback signal, and the shutdown control signal is generated when the overvoltage state of the auxiliary power supply circuit maintains the third fault category to control the AC conversion circuit to stop working.

7. The fault protection method for energy storage inverter circuit according to claim 4, characterized in that: After the second delay, determining the temperature state of the auxiliary power supply circuit according to the temperature feedback signal, and controlling the working state of the AC conversion circuit according to the temperature state of the auxiliary power supply circuit, comprises: When it is determined that the temperature state of the auxiliary power supply circuit is the first temperature, after a fourth delay, the shutdown control signal is generated to control the AC conversion circuit to stop working.

8. The fault protection method for energy storage inverter circuit according to claim 4, characterized in that: After the second delay, determining the temperature state of the auxiliary power supply circuit according to the temperature feedback signal, and controlling the working state of the AC conversion circuit according to the temperature state of the auxiliary power supply circuit, comprises: When it is determined that the temperature state of the auxiliary power supply circuit is a second temperature, a derating control signal is generated to control the AC conversion circuit to operate at a derating level.

9. An energy storage inverter circuit, characterized in that: The energy storage inverter circuit includes: A DC conversion circuit, wherein a first end of the DC conversion circuit is used to be connected to a battery pack; an AC conversion circuit, wherein a first end of the AC conversion circuit is connected to a second end of the DC conversion circuit, and the second end of the AC conversion circuit is used to be connected to a power grid; an auxiliary power supply circuit, the auxiliary power supply circuit being connected to the AC conversion circuit; The auxiliary power supply circuit is used to execute the fault protection method according to any one of claims 1 to 8.

10. An inverter device, characterized in that: It comprises the energy storage inverter circuit as claimed in claim 9.

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