Sensor fault detection method, energy storage system and photovoltaic power generation system

Abstract

The invention discloses a sensor fault detection method, an energy storage system and a photovoltaic power generation system.The sensor fault detection method is applied to the energy storage system, the energy storage system comprises a battery module, an inverter module and a sensor, the sensor is used for detecting electric signals of the battery module, and the battery module is in communication connection with the inverter module; the method comprises the following steps: judging the current state of a battery module according to a first electric signal detected by an inverter module; under the condition that the current state is the first state, the difference between the first electric signal and a second electric signal is determined, the second electric signal is obtained through detection of the sensor and sent to the inverter module through the battery module, and the first electric signal and the second electric signal are the same in type; and when the difference is greater than a preset difference, determining that the sensor has a fault. An additional detection circuit is not needed, and hardware cost is not increased.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a sensor fault detection method, an energy storage system, and a photovoltaic power generation system. Background Art

[0002] Battery energy storage systems typically employ a variety of sensors to detect single faults in the energy storage devices within the system. To improve the safety of battery energy storage systems, fault detection of sensors within the system is necessary to prevent failures in energy storage devices from being detected due to sensor failures.

[0003] In related technologies, sensor fault detection methods usually use two detection circuits to detect signals on one detection circuit, and then compare the synchronously detected data to determine whether the sensor is working normally. However, this method requires the use of two detection circuits, which increases hardware costs. Summary of the Invention

[0004] The present invention aims to at least partially address one of the technical problems in the related art. To this end, a first object of the present invention is to provide a sensor fault detection method that, when a battery module is determined to be in a first state based on a first electrical signal, performs sensor fault detection based on the first electrical signal and a second electrical signal. This method does not require additional detection circuitry and does not increase hardware costs.

[0005] A second object of the present invention is to provide a computer-readable storage medium.

[0006] The third object of the present invention is to provide an energy storage system.

[0007] A fourth objective of the present invention is to provide a photovoltaic power generation system.

[0008] To achieve the above-mentioned purpose, according to an embodiment of the first aspect of the present invention, a sensor fault detection method is proposed, which is applied to an energy storage system. The energy storage system includes a battery module, an inverter module and a sensor. The sensor is used to detect the electrical signal of the battery module. The battery module and the inverter module are communicatively connected. The method includes: judging the current state of the battery module based on the first electrical signal detected by the inverter module; when the current state is the first state, determining the difference between the first electrical signal and the second electrical signal, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type; when the difference is greater than the preset difference, determining that the sensor has failed.

[0009] According to a sensor fault detection method according to an embodiment of the present invention, the current state of the battery module is determined based on a first electrical signal detected by the inverter module, and when the current state is the first state, the sensor fault detection is performed based on the difference between the first electrical signal and the second electrical signal, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type. The sensor fault detection method is applied to an energy storage system, which includes a battery module, an inverter module, and a sensor, wherein the sensor is used to detect the electrical signal of the battery module, and the battery module and the inverter module are communicatively connected. Therefore, because the battery module and the inverter module are communicatively connected, the battery module can send the second electrical signal detected by the sensor to the inverter module. When the inverter module determines that the battery module is in the first state based on the first electrical signal detected by itself, the sensor fault detection is performed based on the difference between the first electrical signal and the received second electrical signal. No additional signal detection circuit is required, and therefore, the hardware cost of the energy storage system will not be increased.

[0010] According to one embodiment of the present invention, the current state of the battery module is judged based on the first electrical signal detected by the inverter module, including: determining the difference between the first electrical signal and a reference electrical signal, wherein the reference electrical signal is determined based on the first electrical signal obtained for the first time; when the difference satisfies a preset range and lasts for a preset time, determining that the battery module is in the first state; when the difference is outside the preset range, determining that the battery module is in the second state.

[0011] According to one embodiment of the present invention, after determining that the battery module is in the second state, the method further includes: updating the reference electrical signal based on the first electrical signal, so as to determine the working state of the battery module according to the updated reference electrical signal.

[0012] According to an embodiment of the present invention, when the difference is an absolute value of a difference between the first electrical signal and the second electrical signal, the preset difference is a preset threshold.

[0013] According to an embodiment of the present invention, the first electrical signal and the second electrical signal are respectively at least one of a voltage signal and a current signal.

[0014] According to one embodiment of the present invention, before determining the difference between the first electrical signal and the second electrical signal, the method also includes: performing low-pass filtering on the first electrical signal and the second electrical signal so as to calculate the difference between the first electrical signal after low-pass filtering and the second electrical signal after low-pass filtering.

[0015] According to an embodiment of the present invention, when the difference is less than or equal to a preset difference, the method further includes: determining that the sensor operates normally.

[0016] According to one embodiment of the present invention, the battery module and the inverter module are communicatively connected via one of the following methods: CAN, 485, SPI, and 232.

[0017] To achieve the above-mentioned object, according to a second aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is processed by a processor, the sensor fault detection method of any of the above-mentioned embodiments is executed.

[0018] According to the computer-readable storage medium of an embodiment of the present invention, by executing a computer program of the above-mentioned sensor fault detection method, when it is determined that the battery module is in the first state according to the first electrical signal, the sensor fault detection is performed according to the first electrical signal and the second electrical signal, without adding additional detection circuits and without increasing hardware costs.

[0019] To achieve the above-mentioned purpose, according to an embodiment of the third aspect of the present invention, an energy storage system is proposed, comprising: a battery module; a sensor, the sensor being suitable for detecting an electrical signal of the battery module; an inverter module, the inverter module being communicatively connected to the battery module, and transmitting power between the inverter module and the battery module, the inverter module being configured to judge the current state of the battery module based on a first electrical signal detected by the inverter module, and determining the difference between the first electrical signal and the second electrical signal when the current state is the first state, and determining that the sensor has failed when the difference is greater than a preset difference, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type.

[0020] According to the energy storage system of an embodiment of the present invention, the inverter module is communicatively connected to the battery module. The inverter module determines the current state of the battery module based on the first electrical signal detected by the inverter module, and when the current state is the first state, the sensor is detected based on the difference between the first electrical signal and the second electrical signal. The second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type. Therefore, because the battery module is communicatively connected to the inverter module, the battery module can send the second electrical signal detected by the sensor to the inverter module. When the inverter module determines that the battery module is in the first state based on the first electrical signal detected by itself, the sensor is detected based on the difference between the first electrical signal and the received second electrical signal. There is no need to add an additional signal detection circuit, and therefore, the hardware cost of the energy storage system will not be increased.

[0021] To achieve the above-mentioned purpose, according to a fourth aspect of the present invention, a photovoltaic power generation system is proposed, comprising the aforementioned energy storage system.

[0022] According to the photovoltaic power generation system of an embodiment of the present invention, by adopting the above-mentioned energy storage system, when it is determined that the battery module is in the first state according to the first electrical signal, fault detection of the sensor is performed according to the first electrical signal and the second electrical signal, without adding additional detection circuits and without increasing hardware costs.

[0023] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural diagram of an energy storage system according to one embodiment of the present invention;

[0025] Figure 2 is a schematic structural diagram of an energy storage system according to another embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of an energy storage system according to another embodiment of the present invention;

[0027] Figure 4 is a flow chart of a sensor fault detection method according to an embodiment of the present invention;

[0028] Figure 5 is a flow chart of a sensor fault detection method according to a specific embodiment of the present invention;

[0029] Figure 6 FIG. 4 is a schematic diagram of a photovoltaic power generation system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0031] The following describes a sensor fault detection method, a storage medium, an energy storage system, and a photovoltaic power generation system according to embodiments of the present invention with reference to the accompanying drawings.

[0032] Figure 1 FIG is a schematic diagram of the structure of an energy storage system according to an embodiment of the present invention. Figure 1 As shown, the energy storage system includes: a battery module 10 , a sensor 20 and an inverter module 30 .

[0033] The sensor 20 is suitable for detecting the electrical signal of the battery module 10 ; the energy storage converter 30 and the battery module 10 are communicatively connected, and power is transmitted between the converter module 30 and the battery module 10 .

[0034] Specifically, the inverter module 30 is connected to the battery module 10. The inverter module 30 controls the charging and discharging of the battery module 10 and converts direct current (DC) into alternating current (AC). The sensor 20 is located within the battery module 10 to detect electrical signals from the battery module 10. Specifically, it detects electrical signals on the power line between the battery module 10 and the inverter module 20 and then transmits these signals to the inverter module 30 via the battery module 10. The inverter module 30 itself has a signal detection function and can detect electrical signals on the power line.

[0035] The sensor fault detection method of this embodiment is applied to inverter module 30. Based on the communication transmission function between battery module 10 and inverter module 30, battery module 10 transmits the second electrical signal detected by sensor 20 to inverter module 30. Because inverter module 30 and sensor 20 detect the same object, if sensor 20 is not faulty, the difference between the first and second electrical signals is relatively small. Therefore, inverter module 30 can detect a fault in sensor 20 based on the first electrical signal it detects and the second electrical signal it receives. Therefore, the method of this embodiment utilizes the signal detection function of the inverter module 30 itself to synchronously detect the electrical signal of the battery module 10 to obtain a first electrical signal without adding an additional detection circuit. Based on the communication between the battery module 10 and the inverter module 30, the second electrical signal detected by the sensor 20 is sent to the inverter module 30, so that the inverter module 30 can perform fault detection on the sensor based on the first electrical signal and the second electrical signal. Therefore, in this embodiment, only the sensor 20 is used, and no additional sensors or detection circuits are added, so that whether the sensor 20 has a fault is detected only based on the electrical signal detected by the sensor 20, which not only reduces the cost of the energy storage system, but also reduces the volume of the energy storage system. Moreover, since the additional detection circuit needs to consume electrical energy when performing signal detection, the method of this embodiment can also reduce the power loss of the energy storage system, thereby improving the energy utilization rate of the energy storage system.

[0036] Furthermore, the sensor fault detection method of this embodiment can be used not only to detect the sensor on the battery module 10 side, but also to detect the sensor on the inverter module 30 side. Figure 2As shown, the sensor 20 includes a first sensor 21 and a second sensor 22. The first sensor 21 is disposed within the battery module 10 to detect the electrical signal of the battery module 10 and obtain a second electrical signal. The second sensor 22 is disposed within the inverter module 30 to detect the electrical signal of the battery module 10 and obtain a first electrical signal. When the inverter module 30 determines that the battery module 10 is in the first state based on the first electrical signal, it can perform fault detection on the first sensor 21 and the second sensor 22 based on the first electrical signal and the second electrical signal. When the inverter module 30 determines that the battery module 10 is in the first state based on the first electrical signal, it determines the difference between the first electrical signal and the second electrical signal. If the difference between the first electrical signal and the second electrical signal is greater than a preset difference, it determines that at least one of the first sensor 21 and the second sensor 22 has failed.

[0037] It should be noted that Figure 1 The structure of the energy storage system shown is exemplary. In actual applications, the structure of the energy storage system can also be as follows Figure 3 As shown, the energy storage system includes a battery module 10, a sensor 20 and an energy storage converter 40. The energy storage converter 40 is communicatively connected to the battery module 10. The energy storage converter 40 itself also has a signal detection function. Therefore, the sensor fault detection method of this embodiment can also be applied to the energy storage converter 40, and no specific limitation is made here.

[0038] In some embodiments, the battery module 10 and the inverter module 30 are communicatively connected via one of the following methods: CAN (Controller Area Network), 485, SPI (Serial Peripheral Interface), 232.

[0039] It is understandable that the communication method between the battery module 10 and the inverter module 30 needs to be selected from the above communication methods according to requirements such as communication distance and output transmission rate.

[0040] In the embodiment of the present invention, the battery module 10 and the inverter module 30 use CAN communication.

[0041] Figure 4 FIG. 1 is a flow chart of a sensor fault detection method according to an embodiment of the present invention. Figure 4 As shown, the sensor fault detection method includes:

[0042] S101 , determining a current state of a battery module according to a first electrical signal detected by an inverter module.

[0043] Specifically, because the inverter module detects the electrical signal on the power line between the inverter module and the battery module, the inverter module also detects the electrical signal from the battery module. Furthermore, because there is a communication delay between the battery module and the inverter module, there is a transmission delay for the second electrical signal. If the current state of the battery module is determined based on the second electrical signal, there will also be a delay. For example, if the battery module is in the first state when the sensor performs detection, there will be a delay in the transmission of the second electrical signal. At this time, the operating state of the battery module may change to the second state. However, the inverter module makes judgments based on the second electrical signal in the first state, so the inverter module will obtain an incorrect operating state. Therefore, the current state of the battery module is determined based on the first electrical signal.

[0044] In some embodiments, the current state of the battery module is judged based on the first electrical signal detected by the inverter module, including: determining the difference between the first electrical signal and a reference electrical signal, wherein the reference electrical signal is determined based on the first electrical signal obtained for the first time; when the difference satisfies a preset range and lasts for a preset period of time, determining that the battery module is in the first state; when the difference is outside the preset range, determining that the battery module is in the second state.

[0045] Specifically, the first state of the battery module includes a steady-state operating condition in a static operating condition and a dynamic operating condition, and the second state of the battery module is a fluctuating operating condition in a dynamic operating condition. When the battery module is in the first state, the fluctuation of the electrical signal of the battery module is small, and when the battery module is in the second state, the fluctuation of the electrical signal of the battery module is large. The first electrical signal obtained for the first time is used as the reference electrical signal, and the difference between the first electrical signal obtained subsequently and the basic electrical signal is calculated. If the difference between the first electrical signal and the basic electrical signal obtained within the preset time length is within the preset range, the fluctuation of the first electrical signal is small, and it is determined that the battery module is in the first state. If the difference between the first electrical signal and the basic electrical signal obtained within the preset time length exceeds the preset range, the fluctuation of the first electrical signal is large, and it is determined that the battery module is in the second state.

[0046] For example, assuming the preset range is -0.5A to 0.5A, if the difference between the first electrical signal and the base electrical signal obtained within the preset time period is between -0.5A and 0.5A, the battery module is determined to be in the first state. If the difference between the first electrical signal and the base electrical signal obtained within the preset time period exceeds -0.5A to 0.5A, the battery module is determined to be in the second state.

[0047] In an optional implementation, the preset duration may be the sum of the basic transmission duration and the maximum communication delay duration.

[0048] In some embodiments, after determining that the battery module is in the second state, the method further includes: updating the reference electrical signal based on the first electrical signal, so as to determine the working state of the battery module according to the updated reference electrical signal.

[0049] That is to say, if the difference between the first electrical signal and the basic electrical signal obtained within the preset time exceeds the preset range, the battery module is in the second state at this time, and the basic electrical signal needs to be updated according to the first electrical signal to determine the subsequent working state of the battery module.

[0050] S102, when the current state is the first state, determining the difference between the first electrical signal and the second electrical signal, wherein the second electrical signal is detected by a sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type.

[0051] Specifically, there will be a communication delay between the battery module and the inverter module. When the battery module is in the second state, there will be a delay in the transmission of the second electrical signal. Therefore, the first electrical signal and the second electrical signal detect the electrical signals of the battery module at different times, resulting in an increase in the difference between the first electrical signal and the second electrical signal, thereby affecting the fault detection result. When the battery module is in the second state, the fluctuation of the second electrical signal is relatively small. Even if there is a communication delay between the battery module and the inverter module, the fluctuation of the second electrical signal is relatively small, and the impact on the difference between the first electrical signal and the second electrical signal is relatively small. Therefore, when the battery module is in the second state, the sensor is detected for faults. When the first electrical signal and the second electrical signal are of the same type, the first electrical signal and the second electrical signal can be compared. For example, if the first electrical signal is a current signal, the second electrical signal is also a current signal. If the first electrical signal is a voltage signal, the second electrical signal is also a voltage signal.

[0052] In some embodiments, the first electrical signal and the second electrical signal are respectively at least one of a voltage signal and a current signal.

[0053] Specifically, the types of the first electrical signal and the second electrical signal need to be determined according to the type of the sensor. For example, if the sensor is a voltage sensor, the first electrical signal and the second electrical signal are voltage signals respectively. If the sensor is a current sensor, the first electrical signal and the second electrical signal are current signals respectively. If the sensor set is an integration of a voltage sensor and a current sensor, the first electrical signal and the second electrical signal are current signals and voltage signals respectively.

[0054] S103: If the difference is greater than a preset difference, it is determined that the sensor is faulty.

[0055] Specifically, because the sensor's detection target and the signal sampling circuit's detection target within the battery module are the same, if the sensor is not faulty, the difference between the first and second electrical signals is relatively small. If the difference is greater than a preset difference, it indicates that the first and second electrical signals differ significantly, and the second electrical signal detected by the sensor is inaccurate, indicating a sensor fault.

[0056] In some embodiments, when the difference is an absolute value of a difference between the first electrical signal and the second electrical signal, the preset difference is a preset threshold.

[0057] It will be appreciated that the preset difference may be determined based on the method for determining the difference between the first and second electrical signals. When the difference can be the absolute value of the difference between the first and second electrical signals, the preset difference may be a preset threshold. If the absolute value is greater than the preset threshold, then the difference between the first and second electrical signals is significant, and the sensor is determined to be faulty.

[0058] It should be noted that in actual applications, the difference between the first electrical signal and the second electrical signal is not limited to the absolute value of the difference, but can also be based on the difference, ratio or other relationship between the first electrical signal and the second electrical signal. When the difference between the first electrical signal and the second electrical signal is a difference, the preset difference can be a preset difference range. When the difference between the first electrical signal and the second electrical signal is a ratio, the preset difference can be a preset ratio. There is no specific limitation here.

[0059] In the above embodiment, the communication function of the battery module is used to transmit the second electrical signal to the inverter module, and the signal detection function of the inverter module itself is used to detect the electrical signal of the battery. In this way, there is no need to add an additional detection circuit. When the battery module is in the first state, even if there is a communication delay between the battery module and the inverter module, the impact on the difference between the first electrical signal and the second electrical signal is relatively small. At this time, the inverter module can perform sensor fault detection based on the first electrical signal and the second electrical signal, thereby realizing sensor fault detection without adding additional detection circuits, thereby reducing the hardware cost of the energy storage system.

[0060] In some embodiments, before determining the difference between the first electrical signal and the second electrical signal, the method further includes: performing low-pass filtering on the first electrical signal and the second electrical signal so as to calculate the difference between the first electrical signal after low-pass filtering and the second electrical signal after low-pass filtering.

[0061] Specifically, there may be high-frequency noise in the first electrical signal and the second electrical signal during the acquisition process. The high-frequency noise may cause the difference between the first electrical signal and the second electrical signal to increase, thereby affecting the sensor fault detection result. Therefore, it is necessary to perform low-pass filtering on the first electrical signal and the second electrical signal before calculating the difference between the first electrical signal and the second electrical signal to reduce the high-frequency noise in the first electrical signal and the second electrical signal, and then determine whether the sensor has a fault based on the difference between the first electrical signal after low-pass filtering and the second electrical signal after low-pass filtering.

[0062] In the above embodiment, by performing low-pass filtering on the first electrical signal and the second electrical signal, high-frequency noise in the first electrical signal and the second electrical signal is reduced, thereby obtaining a more accurate sensor fault detection result.

[0063] In some embodiments, when the difference is less than or equal to a preset difference, the method further includes: determining that the sensor operates normally.

[0064] It can be understood that when the difference is less than or equal to the preset difference, it indicates that the difference between the first electrical signal and the second electrical signal is small, and it can be considered that the first electrical signal detected by the sensor is accurate, so the sensor is working normally.

[0065] The technical solution of this application is further described in detail below in conjunction with specific implementation methods:

[0066] like Figure 5 As shown, the sensor fault detection method includes the following steps:

[0067] S201: Acquire a first electrical signal detected by an inverter module, and receive a second electrical signal sent by a battery module.

[0068] S202 , calculating a difference between the first electrical signal and a reference electrical signal, wherein the reference electrical signal is determined based on the first electrical signal obtained for the first time, and starting timing when the first electrical signal is obtained for the first time.

[0069] S203, determining whether the difference meets a preset range. If the difference meets the preset range, executing step S204; if the difference exceeds the preset range, executing step S211.

[0070] S204, determining whether the timing duration reaches the preset duration. If the timing duration reaches the preset duration, executing step S205; if the timing duration does not reach the preset duration, returning to step S201.

[0071] S205: Determine whether the battery module is in the first state.

[0072] S206: Perform low-pass filtering on the first electrical signal and the second electrical signal.

[0073] S207 , calculating the absolute value of the difference between the first electrical signal processed by low-pass filtering and the second electrical signal processed by low-pass filtering.

[0074] S208, determining whether the absolute value is greater than a preset difference threshold, if the absolute value is greater than the preset difference threshold, executing step S209, if the absolute value is less than or equal to the preset difference threshold, executing step S210.

[0075] S209: Determine if the sensor fails.

[0076] S210, determining that the sensor is working properly.

[0077] S211, determining that the battery module is in the second state.

[0078] S212, updating the reference electrical signal according to the first electrical signal, clearing the timing duration, and restarting the timing, and then executing step S201.

[0079] In the above embodiment, the state of the battery module is determined by obtaining a first electrical signal based on the signal detection function of the inverter module itself. When the battery module is in the first state, even if there is a communication delay between the battery module and the inverter module, the difference between the first electrical signal and the second electrical signal is relatively small. At this time, the inverter module can perform sensor fault detection. By utilizing the detection function of the inverter module itself and the communication function of the battery module, additional detection circuits are eliminated, thereby reducing the hardware cost of the energy storage system. In addition, the first and second electrical signals are low-pass filtered to reduce high-frequency noise in the first and second electrical signals, thereby obtaining more accurate sensor fault detection results.

[0080] In summary, the current state of the battery module is determined based on the first electrical signal detected by the inverter module, and when the current state is the first state, the sensor fault detection is performed based on the difference between the first electrical signal and the second electrical signal, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type. The sensor fault detection method is applied to the energy storage system, which includes a battery module, an inverter module and a sensor, and the sensor is used to detect the electrical signal of the battery module, and the battery module and the inverter module are communicatively connected. Therefore, because the battery module is communicatively connected to the inverter module, the battery module can send the second electrical signal detected by the sensor to the inverter module. When the inverter module determines that the battery module is in the first state based on the first electrical signal detected by itself, the sensor fault detection is performed based on the difference between the first electrical signal and the received second electrical signal. There is no need to add an additional signal detection circuit, and therefore, the hardware cost of the energy storage system will not be increased.

[0081] Corresponding to the above embodiments, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is processed by a processor, the sensor fault detection method of any of the above embodiments is executed.

[0082] According to the computer-readable storage medium of an embodiment of the present invention, by executing a computer program of the above-mentioned sensor fault detection method, when it is determined that the battery module is in the first state according to the first electrical signal, the sensor fault detection is performed according to the first electrical signal and the second electrical signal, without adding additional detection circuits and without increasing hardware costs.

[0083] Corresponding to the above embodiment, the embodiment of the present invention further provides an energy storage system. Figure 1 As shown, the energy storage system includes: a battery module 10 , a sensor 20 and an inverter module 30 .

[0084] Among them, the sensor 20 is suitable for detecting the electrical signal of the battery module 10; the inverter module 30 is communicatively connected to the battery module 10, and power is transmitted between the inverter module 30 and the battery module 10. The inverter module 30 is configured to judge the current state of the battery module 10 based on the first electrical signal detected by the inverter module 30, and when the current state is the first state, determine the difference between the first electrical signal and the second electrical signal, and when the difference is greater than the preset difference, determine that the sensor 20 has a fault, wherein the second electrical signal is detected by the sensor 20 and sent to the inverter module 30 through the battery module 10, and the first electrical signal and the second electrical signal are of the same type.

[0085] In some embodiments, the inverter module 30 is further configured to: determine the difference between the first electrical signal and a reference electrical signal, wherein the reference electrical signal is determined based on the first electrical signal obtained for the first time; when the difference satisfies a preset range and lasts for a preset period of time, determine that the battery module 10 is in the first state; when the difference is outside the preset range, determine that the battery module 10 is in the second state.

[0086] In some embodiments, the inverter module 30 is further configured to: after determining that the battery module 10 is in the second state, update the reference electrical signal based on the first electrical signal, so as to judge the working state of the battery module 10 according to the updated reference electrical signal.

[0087] In some embodiments, when the difference is an absolute value of a difference between the first electrical signal and the second electrical signal, the preset difference is a preset threshold.

[0088] In some embodiments, the first electrical signal and the second electrical signal are respectively at least one of a voltage signal and a current signal.

[0089] In some embodiments, the inverter module 30 is further configured to: before determining the difference between the first electrical signal and the second electrical signal, perform low-pass filtering on the first electrical signal and the second electrical signal so as to calculate the difference between the first electrical signal after low-pass filtering and the second electrical signal after low-pass filtering.

[0090] In some embodiments, the inverter module 30 is further configured to: determine that the sensor 20 is operating normally when the difference is less than or equal to a preset difference.

[0091] In some embodiments, the battery module 10 and the inverter module 30 are communicatively connected via one of the following methods: CAN, 485, SPI, and 232.

[0092] It should be noted that the specific implementation of the energy storage system in the embodiment of the present invention corresponds one-to-one to the specific implementation of the sensor fault detection method in the aforementioned embodiment of the present invention, and will not be repeated here.

[0093] According to the energy storage system of an embodiment of the present invention, the inverter module is communicatively connected to the battery module. The inverter module determines the current state of the battery module based on the first electrical signal detected by the inverter module, and when the current state is the first state, the sensor is detected based on the difference between the first electrical signal and the second electrical signal. The second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type. Therefore, because the battery module is communicatively connected to the inverter module, the battery module can send the second electrical signal detected by the sensor to the inverter module. When the inverter module determines that the battery module is in the first state based on the first electrical signal detected by itself, the sensor is detected based on the difference between the first electrical signal and the received second electrical signal. There is no need to add an additional signal detection circuit, and therefore, the hardware cost of the energy storage system will not be increased.

[0094] Corresponding to the above embodiment, the embodiment of the present invention further provides a photovoltaic power generation system. Figure 6 As shown, the photovoltaic power generation system 200 includes the aforementioned energy storage system 100 .

[0095] According to the photovoltaic power generation system of an embodiment of the present invention, by adopting the above-mentioned energy storage system, when it is determined that the battery module is in the first state according to the first electrical signal, fault detection of the sensor is performed according to the first electrical signal and the second electrical signal, without adding additional detection circuits and without increasing hardware costs.

[0096] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0097] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0098] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0099] In addition, the terms "first" and "second" used in the embodiments of the present invention are only used for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in this embodiment. Therefore, the features defined by the terms "first" and "second" in the embodiments of the present invention can explicitly or implicitly indicate that the embodiment includes at least one of such features. In the description of the present invention, the word "plurality" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0100] In the present invention, unless otherwise clearly specified or limited in the embodiments, the terms "installed," "connected," "connect," and "fixed" appearing in the embodiments should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection. It can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements, or an interaction between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood based on the specific implementation.

[0101] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A sensor fault detection method, characterized in that: Applied to an energy storage system, the energy storage system includes a battery module, an inverter module and a sensor, the sensor is used to detect the electrical signal of the battery module, the battery module and the inverter module are communicatively connected, and the method includes: determining a current state of the battery module according to a first electrical signal detected by the inverter module; When the current state is the first state, determining a difference between the first electrical signal and a second electrical signal, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type; When the difference is greater than a preset difference, it is determined that the sensor fails.

2. The method according to claim 1, characterized in that Determining a current state of the battery module according to the first electrical signal detected by the inverter module includes: determining a difference between the first electrical signal and a reference electrical signal, wherein the reference electrical signal is determined based on the first electrical signal obtained for the first time; When the difference satisfies a preset range and lasts for a preset time, determining that the battery module is in the first state; When the difference is outside a preset range, it is determined that the battery module is in the second state.

3. The method according to claim 2, characterized in that After determining that the battery module is in the second state, the method further includes: The reference electrical signal is updated based on the first electrical signal, so as to determine the working state of the battery module according to the updated reference electrical signal.

4. The method according to any one of claims 1 to 3, characterized in that In a case where the difference is an absolute value of a difference between the first electrical signal and the second electrical signal, the preset difference is a preset threshold.

5. The method according to claim 1, characterized in that The first electrical signal and the second electrical signal are respectively at least one of a voltage signal and a current signal.

6. The method according to claim 1, characterized in that Before determining the difference between the first electrical signal and the second electrical signal, the method further includes: Low-pass filtering is performed on the first electrical signal and the second electrical signal to calculate a difference between the first electrical signal after low-pass filtering and the second electrical signal after low-pass filtering.

7. The method according to claim 1, characterized in that When the difference is less than or equal to the preset difference, the method further includes: Make sure the sensor is functioning properly.

8. The method according to claim 1, characterized in that The battery module and the inverter module are communicatively connected via one of the following methods: CAN, 485, SPI and 232.

9. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is processed by a processor, the sensor fault detection method according to any one of claims 1 to 8 is executed.

10. An energy storage system, characterized in that: include: Battery modules; a sensor, wherein the sensor is adapted to detect an electrical signal from the battery module; An inverter module, the inverter module is communicatively connected to a battery module, and power is transmitted between the inverter module and the battery module. The inverter module is configured to determine a current state of the battery module based on a first electrical signal detected by the inverter module, and when the current state is the first state, determine a difference between the first electrical signal and a second electrical signal, and when the difference is greater than a preset difference, determine that the sensor has failed, wherein the second electrical signal is detected by the sensor and sent to the inverter module through the battery module, and the first electrical signal and the second electrical signal are of the same type.

11. A photovoltaic power generation system, characterized in that: Comprising the energy storage system according to claim 10.

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