Battery disconnection detection method and system for hybrid optical storage inverter system

Abstract

The invention relates to the technical field of photovoltaic energy storage systems, in particular to a battery disconnection detection method and system for a hybrid optical storage inverter system. The method comprises the steps that an ADC sampling module collects a current sampling value and a voltage sampling value of a battery in real time and sends the current sampling value and the voltage sampling value to a microcontroller module of an inverter; the microcontroller module calculates a current loop output value through a current loop PI controller based on the current set value and the current sampling value; the microcontroller module calculates and generates a voltage sampling change difference value based on the real-time voltage sampling value and the initial voltage sampling value; and a disconnection detection combined criterion group is constructed, and when all criterion conditions in the disconnection detection combined criterion group are met at the same time and lasts for a preset judgment duration, the microcontroller module judges that a battery disconnection event is established and records the battery disconnection event. According to the method, the dynamic response characteristic of the inverter control loop is combined to comprehensively carry out broken line detection, and the method has the advantages of full-working-condition coverage and quick response.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic energy storage systems, in particular to a battery disconnection detection method and system for a hybrid photovoltaic energy storage inverter system. BACKGROUND

[0002] The hybrid photovoltaic energy storage inverter system (referred to as "photovoltaic energy storage all-in-one machine") is an intelligent power device integrating photovoltaic power generation, energy storage battery management and bidirectional power conversion functions, which acts as the "control center" of the photovoltaic energy storage system.

[0003] Among them, in the hybrid photovoltaic energy storage inverter system, the inverter and the battery exchange information through CAN communication and other means, and the inverter adjusts its control measures according to the obtained BMS (battery management system) information. However, due to cable aging, BMS active disconnection switch or loose connector, etc., there may be an abnormal situation: the actual physical circuit between the inverter and the battery is disconnected, for example, the over-temperature protection actively disconnects the internal contactor, or the DC terminal is loose due to vibration.

[0004] When the actual physical circuit between the inverter and the battery is disconnected, the BMS will detect the disconnection information and send it to the inverter, and the inverter is provided with an MCU for outputting current loop control instructions to control the battery charging and discharging. It is known that the process of sending the detected disconnection information from the BMS to the inverter MCU will have a communication delay of several milliseconds, which is within the normal range for normal state communication, but when the actual physical circuit between the inverter and the battery is disconnected, the delay will cause the inverter MCU to be unable to adjust the output current loop control instructions in time, resulting in distortion of the current loop control instructions, which may cause the power device (IGBT / MOS tube) to be overcurrent breakdown due to reverse recovery current or parasitic inductance voltage spike in open circuit state, and further cause a chain failure. SUMMARY

[0005] The purpose of the present application is to provide a battery disconnection detection method and system for a hybrid photovoltaic energy storage inverter system, which detects the disconnection of the hybrid photovoltaic energy storage inverter system through inverter control loop feature analysis and multi-modal criterion fusion, combines the dynamic response characteristics of the inverter control loop to comprehensively detect the disconnection, has the advantages of full working condition coverage and fast response, and has high practical value.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] In a first aspect, the present application provides a battery disconnection detection method for a hybrid photovoltaic energy storage inverter system, which comprises:

[0008] The ADC sampling module collects current sampling values and voltage sampling values of the battery in real time and sends the current sampling values and voltage sampling values to the microcontroller module;

[0009] The microcontroller module calculates a current loop output value through a current loop PI controller based on the current setting value and the current sampling value, and the current loop output value reflects a controller saturation state caused by integral error accumulation;

[0010] The microcontroller module calculates a voltage sampling change difference value based on the real-time voltage sampling value and the initial voltage sampling value;

[0011] A broken line detection joint criterion group is constructed, and the broken line detection joint criterion group includes a first criterion condition generated based on a preset current threshold value, a second criterion condition generated based on dynamic calculation of integral accumulated error of the current loop, and a third criterion condition generated based on dynamic calculation of the bus voltage loop PI control parameter and the current loop output value;

[0012] When all criterion conditions in the broken line detection joint criterion group are met at the same time and for a preset determination duration T hold , the microcontroller module determines that a battery broken line event is established and records the battery broken line event.

[0013] As a preferred embodiment of the present application, the first criterion condition is specifically:

[0014] ≤

[0015] wherein, is the current sampling value, is the first threshold value.

[0016] As a preferred embodiment of the present application, the second criterion condition is specifically:

[0017] ≥

[0018]

[0019] wherein, is the current loop output value, is the second threshold value, is the broken line front current loop output value, is the current loop given value, is the current loop proportional coefficient, is the current loop integral coefficient, is the time difference, is the current loop period, is the margin parameter.

[0020] As a preferred embodiment of the present application, the third criterion condition is specifically:

[0021] ≥

[0022]

[0023]

[0024]

[0025] wherein, is a third threshold value, is a battery voltage sampling value, is a difference between a real-time voltage sampling value and an initial voltage sampling value, is a boost ratio, is an adjustment coefficient, is a bus voltage sampling value, is a bus voltage loop proportional coefficient, is a bus voltage loop integral coefficient, is a bus voltage given value, is a bus voltage loop period.

[0026] As a preferred embodiment of the present application, the preset determination duration T hold is at least 20 times of the time length of the bus voltage loop period or the current loop period .

[0027] As a preferred embodiment of the present application, the first threshold value is in a range of 0.01I rated to 0.03I rated , wherein I rated is a rated current of the battery.

[0028] As a preferred embodiment of the present application, the battery disconnection detection method further comprises a static working condition battery disconnection detection step, specifically:

[0029] The ADC sampling module collects a voltage sampling value of the battery in real time; the microcontroller module judges the size of the voltage sampling value and a minimum battery voltage threshold value, and when the voltage sampling value is less than the minimum battery voltage threshold value, the microcontroller module determines that a battery disconnection event is established and records the battery disconnection event.

[0030] In a second aspect, the present application further provides a battery disconnection detection system for a hybrid optical storage inverter system, which comprises:

[0031] An ADC sampling module is configured to collect current sampling values and voltage sampling values of the battery in real time and send the current sampling values and the voltage sampling values to a microcontroller module of the inverter;

[0032] The microcontroller module is configured to calculate a current loop output value by a current loop PI controller based on a current setting value and the current sampling value, and to calculate a voltage sampling change difference based on a real-time voltage sampling value and an initial voltage sampling value. hold When all criterion conditions in the criterion group module are met simultaneously and continuously for a preset determination duration T

[0033] The criterion group module includes a first criterion condition unit generated based on a preset current threshold, a second criterion condition unit generated based on dynamic calculation of an integral accumulation error of the current loop, and a third criterion condition unit generated based on dynamic calculation of the bus voltage loop PI control parameter and the current loop output value.

[0034] In a third aspect, the present application further provides a storage medium storing a computer instruction program, which, when executed by a processor, causes the processor to perform the steps of the battery disconnection detection method for the hybrid optical storage inverter system.

[0035] In a fourth aspect, the present application further provides a computer device including at least one memory and at least one processor, wherein the memory stores a computer instruction program, which, when executed by the processor, causes the processor to perform the steps of the battery disconnection detection method for the hybrid optical storage inverter system.

[0036] In summary, the present application has the following advantages:

[0037] The present application breaks through the limitation of single signal through triple criterion cooperative verification, wherein the first criterion captures the physical disconnection feature of current sudden drop to near zero through a preset current threshold; the second criterion dynamically analyzes the integral accumulation saturation state of the current loop PI controller and reflects the control instruction continuous output distortion caused by path interruption; and the third criterion combines the voltage mutation threshold dynamically calculated based on the bus voltage loop PI parameter and correlates the abnormal fluctuation of the bus voltage after disconnection. The criterion cooperative mechanism can effectively distinguish the battery disconnection from similar faults such as instantaneous disturbance (e.g., load mutation) and cell short circuit, and comprehensively performs disconnection detection in combination with the dynamic response characteristics of the inverter control loop, has the advantages of full working condition coverage and fast response, and has high practical value. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0039] Figure 1 Flow chart of the method of the present application;

[0040] Figure 2 Block diagram of the system of the present application;

[0041] Figure 3 Schematic diagram of the dynamic output state of the current loop in the charging condition in the embodiment;

[0042] Figure 4 Schematic diagram of the dynamic output state of the current loop corresponding to the second criterion condition in the charging condition in the embodiment;

[0043] Figure 5 Schematic diagram of the dynamic output state of the current loop corresponding to the third criterion condition in the charging condition in the embodiment;

[0044] Figure 6 Schematic diagram of the dynamic output state of the current loop corresponding to the second criterion condition in the discharging condition in the embodiment;

[0045] Figure 7 Schematic diagram of the dynamic output state of the current loop corresponding to the third criterion condition in the discharging condition in the embodiment;

[0046] Figure 8 Schematic diagram of the dynamic output state of the battery voltage sampling value and the lowest battery voltage threshold in the static condition in the embodiment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application clearer, the following will combine the embodiments of the present application and the corresponding drawings to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] The terms "comprise(s)," "include(s)," "have(s)," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a list of steps or elements is not necessarily limited to those listed steps or elements but can include other not-listed steps or elements. The term "if' as used herein, depending on the context, can be interpreted to mean "when" or "in response to determining," or "in response to detecting," among others.

[0049] As shown in a battery disconnection detection method for a hybrid light storage inverter system, the method comprises: Figure 1

[0050] The ADC sampling module acquires current sampling value I bat and voltage sampling value V bat in real time and sends them to the microcontroller module; wherein the microcontroller module can be realized based on an MCU controller, and the ADC conversion unit built in the MCU controller can convert the current sampling value I bat and voltage sampling value V bat into a directly processable data form in real time.

[0051] The microcontroller module calculates a current loop output value based on the current set value and the current sampling value through a current loop PI controller, and the current loop output value reflects the controller saturation state caused by the integral error accumulation;

[0052] The inverter MCU calculates the output current instruction I bat· Out through the PI controller based on the current set value I bat· Ref (i.e., the current expected to be output by the battery) and the actual sampling current I bat If the line is disconnected, the actual current drops to 0, but the set current is still present, and the integral term of the PI controller will continuously accumulate errors, causing the output instruction I to abnormally increase, i.e., "controller saturation".

[0053] The microcontroller module calculates a voltage sampling change difference value based on the real-time voltage sampling value and the initial voltage sampling value;

[0054] The inverter MCU calculates the difference value AV bat between the real-time battery voltage sampling value V bat and the initial voltage, and when the battery is disconnected, the voltage fluctuation on the bus will be fed back to the battery end through the circuit, causing AV bat to change significantly.

[0055] ​A broken line detection joint criterion group is constructed, which includes a first criterion condition generated based on a preset current threshold, a second criterion condition generated based on dynamic calculation of integral accumulated error of a current loop, and a third criterion condition generated based on dynamic calculation of a bus voltage loop PI control parameter and a current loop output value; when all criterion conditions in the broken line detection joint criterion group are simultaneously satisfied for a preset determination duration T hold , the microcontroller module determines that a battery broken line event is established, and records the battery broken line event.

[0056] The prior art uses fixed threshold judgment, which is easily disturbed by special working conditions and thus forms a misjudgment. For example, the current is zero at the moment of starting is normal. The embodiment provides three criterion conditions to form a broken line detection joint criterion group, and broken line detection is performed based on the broken line detection joint criterion group, which can solve the above problems.

[0057] Specifically, each criterion condition includes a determination threshold, and when the above three criterion conditions are simultaneously satisfied for a preset determination duration T hold , the MCU determines that the battery is broken, and records the battery broken line event, or triggers a protection mechanism (such as shutdown or switching to a backup power supply) to prevent system collapse.

[0058] The broken line detection joint criterion group can detect the broken line in both the battery charging and discharging stages.

[0059] The following embodiment provides a broken line detection joint criterion group in the battery charging stage.

[0060] During charging, the battery current instruction is positive, and the battery current loop output value is also positive. When the battery is broken, the battery current feedback decreases to close to 0 (due to sampling error, the value will be very close to 0 but not equal to 0), and cannot follow the given value. Due to the action of the integral term, the battery current loop output value rapidly increases in the positive direction, and even reaches saturation. The specific increase amplitude is related to the current instruction.(The feedback rapidly decreases to 0, the difference between the feedback and the true value rapidly increases, and the adjustment instruction increases to saturation).

[0061] The first criterion condition is to compare the current sampling value with the first threshold , when ≤ , that is, the physical broken line feature of the current sudden drop to near zero is captured by the preset current threshold as the first re-determination.

[0062] Further, since the larger the current instruction is, the larger the difference between the given value and the feedback value of the current loop is, and the faster the output value increases, therefore, the threshold of the second criterion condition should be a value that changes with the battery current instruction.

[0063] Before the battery is disconnected, the current loop feedback can follow the given value, the proportional term is small, and the integral term remains a certain value with small amplitude oscillation. After the battery is disconnected, the current loop feedback becomes zero, the proportional term immediately increases to * , and the integral term increases by * Therefore, the change of the current loop output value with time is shown in Figure 3 .

[0064] wherein, is the given value of the current loop, is the proportional coefficient of the current loop, is the integral coefficient of the current loop, is the output value of the current loop, is the upper limit of the output value of the current loop, is the output value of the current loop before the battery is disconnected, is the time when the battery is disconnected, is the time when the output reaches saturation.

[0065] During the time period from , the relationship between the output value of the current loop and time is shown in equation (1), wherein is the calculation period of the current loop.

[0066] (1)

[0067] The second threshold value in the second criterion condition should be slightly less than , and the value is shown in equation (2), wherein the upper limit is , and the problem of different sensitivities of various systems is solved by the margin parameter e. In the embodiment, e = 1 / 2 is selected.

[0068] (2)

[0069] is the time difference, which is equal to the difference between and .

[0070] Therefore, the change of the second threshold value of the second criterion condition with time is shown in Figure 4 .

[0071] Since the output value of the battery current loop is positively increased, the given value of the bus voltage loop is also increased, the bus voltage is increased, and the voltage at the battery interface of the inverter is proportional to the bus voltage and is also increased.

[0072] The given value of the bus voltage is shown in equation (3):

[0073] (3)

[0074] in This is a sampled value of the battery voltage. For the boost factor, we have equation (4):

[0075] (4)

[0076] From equations (3) and (4), we can derive equation (5):

[0077] (5)

[0078] Based on the characteristics of PI modulation, it is not difficult to derive equation (6):

[0079] (6)

[0080] The relationship between the inverter bus voltage change and its loop output change is shown in equation (7). for Time and The difference in bus voltage from before, For a specific coefficient:

[0081] (7)

[0082] From equations (4), (6), and (7), we can derive equation (8). for Time and The difference between the previous battery voltage samples:

[0083] (8)

[0084] Then take equation (1) Substituting into equation (8), we can obtain equation (9), which is the relationship between the sampled change in battery voltage and time:

[0085] (9)

[0086] As shown in equation (8), the battery voltage sample value increases with the increase of the battery current loop output value. The threshold of the third criterion should be slightly smaller than the actual battery voltage sample value. Therefore, we take... Substituting into equation (8), we obtain the threshold for the third judgment condition as shown in equation (10):

[0087] (10)

[0088] Therefore, the changes in the battery voltage sampling value and the threshold of the third criterion over time are as follows:Figure 5 as shown in (1) and (2).

[0089] wherein,

[0090] .

[0091] Therefore, under the condition of battery disconnection during charging, the three criterion conditions are:

[0092] ≤

[0093] ≥

[0094] ≥

[0095] In another possible embodiment, a joint criterion group for detecting battery disconnection under battery discharge is provided.

[0096] During discharge, the battery current command is negative, and the battery current loop output value is also negative. When the battery is disconnected, the battery current loop output value rapidly increases negatively. Therefore, the current loop output value and the second criterion condition threshold still have the relationship as shown in (1) and (2). Figure 6

[0097] Due to the negative increase of the battery current loop output value, the bus voltage loop given value will decrease, the bus voltage will decrease, and the voltage at the battery interface of the inverter will decrease in proportion to the bus voltage. The battery voltage sampling change value and the third criterion condition threshold still have the relationship as shown in (9) and (10). Wherein, Figure 7 ,

[0098] .

[0099] Therefore, under the condition of battery disconnection during discharge, the three criterion conditions are the same as those during charging.

[0100] In summary, the joint criterion group for detecting disconnection provided by the technical scheme of the present application can be applied to all working conditions of charging and discharging.

[0101] In another possible embodiment, the battery can also be in a static working condition. Specifically, as shown in Figure 8 ​​As shown, when the battery is in static state, the battery current command is 0, and the battery current loop output value is also 0, and the loop has no effect on the battery port voltage. When the battery is disconnected, the battery voltage naturally decreases, and when the battery voltage sample value is lower than the minimum battery voltage threshold of the inverter, the software triggers the battery disconnection event.

[0102] Figure 8 In some embodiments, the judgment condition for the battery disconnection detection step can be .

[0103] In the present application, under the premise that all criterion conditions in the disconnection detection joint criterion group are met at the same time, a duration judgment is also required, i.e., the microcontroller module will determine that the battery disconnection event is established and record the battery disconnection event only when the duration T hold is greater than or equal to a preset determination duration T .

[0104] In a possible implementation, the time length of the preset determination duration T hold is set to be 20 times the time length of the bus voltage loop period or the current loop period. When the duration T is greater than or equal to 20 times the bus voltage loop period or the current loop period, the software triggers the battery disconnection event and takes corresponding measures to protect the inverter. Specifically, the time length of the preset determination duration T may be set to be 20 times the maximum value of T . Since T , is generally in the range of 20us~400us, the detection time is within 8ms.

[0105] In addition, in a possible implementation, the first threshold value is in the range of 0.01I rated to 0.03I rated , where I rated is the rated current of the battery.

[0106] In a possible implementation, as shown in Figure 2 , the present embodiment provides a battery disconnection detection system for a hybrid light storage inverter system, which comprises:

[0107] an ADC sampling module, configured to collect current sample values and voltage sample values of the battery in real time and send the current sample values and voltage sample values to a microcontroller module of the inverter;

[0108] a microcontroller module, configured to calculate a current loop output value by a current loop PI controller based on a current set value and a current sample value, calculate a voltage sample change difference based on a real-time voltage sample value and an initial voltage sample value, and determine that all criterion conditions in a criterion group module are met at the same time and the duration T hold is greater than or equal to a preset determination duration T .When the microcontroller module determines that the battery disconnection event is established, the microcontroller module is further configured to record the battery disconnection event.

[0109] The criterion group module comprises a first criterion condition unit generated based on a preset current threshold, a second criterion condition unit generated based on dynamic calculation of integral accumulated error of a current loop, and a third criterion condition unit generated based on dynamic calculation of bus voltage loop PI control parameters and current loop output values.

[0110] In a possible implementation, the embodiment provides a storage medium storing a computer instruction program, which, when executed by a processor, causes the processor to perform the steps of the battery disconnection detection method for a hybrid optical storage inverter system.

[0111] In a possible implementation, the embodiment provides a computer device comprising at least one memory and at least one processor, wherein the memory stores a computer instruction program, and the computer instruction program, when executed by the processor, causes the processor to perform the steps of the battery disconnection detection method for a hybrid optical storage inverter system.

[0112] In the above embodiment, the implementation can be achieved by software, hardware, firmware or any combination thereof, entirely or partially. When implemented by software, the implementation can be achieved in the form of a computer program product, entirely or partially. The computer program product comprises one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the computer program instructions entirely or partially generate the flow or function according to the embodiment of the present specification. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions can be stored in or transmitted by a computer readable storage medium. The computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through a wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. containing one or more available media sets. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, digital versatile disc (DVD)) or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0113] Having described several embodiments of the disclosure, the above description is illustrative and not restrictive. Many variations and modifications will become apparent to those skilled in the art upon consideration of the disclosure. The terms used in this description are intended to be interpreted broadly and in a manner consistent with the principles of the present technology. The scope of the technology should be determined not with reference to the above description, but should instead be determined with reference to the appended claims, alongside the full scope of equivalents to which such claims are entitled.

Claims

1. A method for detecting battery disconnection in a hybrid photovoltaic-storage inverter system, characterized in that, The methods include: The ADC sampling module collects the current and voltage sampling values ​​of the battery in real time and sends the current and voltage sampling values ​​to the microcontroller module. The microcontroller module calculates the current loop output value based on the current setpoint and the current sample value through a current loop PI controller. The current loop output value reflects the controller saturation state caused by the accumulation of integral error. The microcontroller module calculates and generates the voltage sampling change difference based on the real-time voltage sampling value and the initial voltage sampling value; A joint criterion group for disconnection detection is constructed, which includes a first criterion condition generated based on a preset current threshold, a second criterion condition generated based on the dynamic calculation of the integral cumulative error of the current loop, and a third criterion condition generated based on the dynamic calculation of the PI control parameters of the bus voltage loop and the output value of the current loop. When all criteria conditions in the joint criterion group for disconnection detection are met simultaneously, and the preset judgment duration T is continuously maintained... hold When the battery disconnection event occurs, the microcontroller module determines that the battery disconnection event has occurred and records the battery disconnection event.

2. The battery disconnection detection method for a hybrid photovoltaic-storage inverter system according to claim 1, characterized in that, The first criterion is as follows: ≤ ， in, This is the current sample value. This is the first threshold.

3. The battery disconnection detection method for a hybrid photovoltaic-storage inverter system according to claim 2, characterized in that, The second criterion is as follows: ≥ ， ， in, This is the current loop output value. The second threshold, This is the current loop output value before the wire breakage. Set the current loop value. This is the proportionality coefficient of the current loop. The integral coefficient of the current loop is... For the time difference, For the current loop period, This is a margin parameter.

4. The battery disconnection detection method for a hybrid photovoltaic-storage inverter system according to claim 3, characterized in that, The third criterion is specifically as follows: ≥ ， ， ， ， in, This is a sampled value of the battery voltage. The third threshold It is the difference between the real-time voltage sample value and the initial voltage sample value. This is the boost factor. For adjustment coefficients, This is the bus voltage sample value. This is the proportional coefficient of the bus voltage loop. The integral coefficient of the bus voltage loop. The bus voltage setpoint, This is the bus voltage loop period.

5. A battery disconnection detection method for a hybrid photovoltaic-storage inverter system according to claim 1, characterized in that, The preset determination time T hold The time length is the bus voltage loop period or the current loop period 20 times the length of time.

6. A method for detecting battery disconnection in a hybrid photovoltaic-storage inverter system according to claim 2, characterized in that, The first threshold The value range is 0.01I. rated up to 0.03I rated , where I rated This is the battery's rated current.

7. A battery disconnection detection method for a hybrid photovoltaic-storage inverter system according to claim 1, characterized in that, This battery disconnection detection method also includes a static battery disconnection detection step, specifically: the ADC sampling module collects the battery voltage sampling value in real time; the microcontroller module determines the magnitude of the voltage sampling value and the minimum battery voltage threshold; when the voltage sampling value is less than the minimum battery voltage threshold, the microcontroller module determines that the battery disconnection event is established and records the battery disconnection event.

8. A battery disconnection detection system for a hybrid photovoltaic-storage inverter system, characterized in that, The system includes: an ADC sampling module, used to acquire the current and voltage sampling values ​​of the battery in real time, and send the current and voltage sampling values ​​to the microcontroller module; The microcontroller module is used to calculate the current loop output value based on the current setpoint and the current sample value through the current loop PI controller; it is also used to calculate and generate the voltage sampling change difference based on the real-time voltage sample value and the initial voltage sample value; when all the criteria conditions in the criterion group module are simultaneously met, and the preset judgment time T is continuously maintained... hold At the same time, the microcontroller module is also used to determine that the battery disconnection event has occurred and to record the battery disconnection event; The criterion group module includes a first criterion condition unit generated based on a preset current threshold, a second criterion condition unit generated based on the dynamic calculation of the integral cumulative error of the current loop, and a third criterion condition unit generated based on the dynamic calculation of the PI control parameters of the bus voltage loop and the output value of the current loop.

9. A storage medium, characterized in that, The system stores a computer instruction program, which, when executed by a processor, causes the processor to perform the steps of a battery disconnection detection method for a hybrid photovoltaic-storage inverter system as described in any one of claims 1-7.

10. A computer device, characterized in that, It includes at least one memory and at least one processor, the memory storing a computer instruction program, which, when executed by the processor, causes the processor to perform the steps of the battery disconnection detection method for a hybrid photovoltaic-storage inverter system as described in any one of claims 1-7.

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