Hall sensor correction method and energy storage system

Abstract

The application is suitable for the technical field of Hall sensor correction, and provides a Hall sensor correction method and an energy storage system.The Hall sensor correction method comprises the following steps: when a to-be-measured loop is switched from a pass-through state to an open-circuit state, in a process of environmental temperature drop, the measurement values of a target Hall sensor at multiple time points and a first environmental temperature are collected; the target Hall sensor is used for measuring a physical quantity of the to-be-measured loop; based on the measurement values at the multiple time points and the first environmental temperature, a zero drift correction table of the target Hall sensor is updated; the zero drift correction table comprises multiple preset second environmental temperatures and first zero drift correction values corresponding to each second environmental temperature respectively; when the to-be-measured loop is in the pass-through state, the target Hall sensor is corrected based on the zero drift correction table.The application can make the Hall sensor always correct through the latest zero point drift corresponding to the current temperature, thereby improving the accuracy of the measurement result of the Hall sensor under very low temperature.

Description

Technical Field

[0001] This invention belongs to the field of Hall sensor calibration technology, and particularly relates to a Hall sensor calibration method and energy storage system. Background Technology

[0002] Hall effect sensors detect the magnitude of current by measuring the magnetic field generated by the current, thus achieving non-contact current measurement. In practical applications, the measurement results of Hall effect sensors are often subject to errors due to environmental magnetic fields, stray magnetic fields, and other factors. Therefore, Hall effect sensors need to be calibrated before use.

[0003] Current Hall sensor calibration schemes typically employ linear calibration, which involves determining a linear function relationship between the actual current value acquired at room temperature and the Hall sensor's measured value. The slope of this linear function represents the Hall sensor's linear error coefficient, and its intercept represents the Hall sensor's zero-point drift. However, the inventors discovered that when the Hall sensor operates at very low temperatures, existing linear calibration methods still produce significant errors, indicating a temperature drift effect. Furthermore, the inventors found that the Hall sensor exhibits varying degrees of zero-point drift at different temperatures; however, the relationship between the Hall sensor's zero-point drift and temperature is not significant, making it difficult to calibrate the measurement results at very low temperatures. Summary of the Invention

[0004] To overcome the problems existing in related technologies, embodiments of the present invention provide a Hall sensor calibration method and energy storage system to solve the problem that the measurement results of Hall sensors are difficult to calibrate at very high temperatures.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, embodiments of the present invention provide a Hall sensor calibration method, comprising: when a circuit under test changes from a closed state to an open state, during a process of decreasing ambient temperature, acquiring measurement values ​​of a target Hall sensor at multiple times and a first ambient temperature; the target Hall sensor is used to measure physical quantities of the circuit under test; when the circuit under test is in a closed state, the ambient temperature increases; after the circuit under test changes from a closed state to an open state, the ambient temperature decreases; based on the measurement values ​​at the multiple times and the first ambient temperature, updating a zero-drift calibration table of the target Hall sensor; the zero-drift calibration table includes multiple preset second ambient temperatures and first zero-drift calibration values ​​corresponding to each second ambient temperature; when the circuit under test is in a closed state, calibrating the target Hall sensor based on the zero-drift calibration table.

[0007] In conjunction with the first aspect, in some embodiments, updating the zero-drift calibration table of the target Hall sensor based on the measurements at the plurality of times and the first ambient temperature includes:

[0008] Based on the measured values ​​at the multiple times and the first ambient temperature, the average value of the measured values ​​corresponding to each third ambient temperature is determined; the third ambient temperature is the ambient temperature in the intersection of the multiple preset second ambient temperatures and the multiple first ambient temperatures at the multiple times.

[0009] Based on the average value of the measured values ​​corresponding to each third ambient temperature, a second zero drift correction value corresponding to each third ambient temperature is determined, and the first zero drift correction value corresponding to each third ambient temperature in the zero drift correction table is updated.

[0010] In conjunction with the first aspect, in some embodiments, calibrating the target Hall sensor based on the zero-drift calibration table includes:

[0011] Based on the zero-drift correction table and the ambient temperature monitored at the current moment, determine the third zero-drift correction value of the target Hall sensor at the current moment;

[0012] Based on the third zero-drift correction value, the zero-point drift of the target Hall sensor at the current moment is corrected.

[0013] In conjunction with the first aspect, in some embodiments, the circuit under test is a circuit in an energy storage system, and the physical quantity includes current; wherein, the energy storage system includes multiple parallel battery clusters and multiple high-voltage boxes respectively connected to each battery cluster; the high-voltage box is equipped with the target Hall sensor and a temperature probe; the target Hall sensor is used to measure the current in the circuit of the battery cluster connected to the corresponding high-voltage box, and the temperature probe is used to collect the ambient temperature.

[0014] In conjunction with the first aspect, in some embodiments, when the circuit under test changes from a closed state to an open state, during the process of the ambient temperature decreasing, the measurement values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected, including: when the energy storage system changes from a charging / discharging state to a stationary state, if no circulating current is detected between the battery clusters, during the process of the ambient temperature decreasing, the measurement values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected.

[0015] The step of calibrating the target Hall sensor based on the zero-drift calibration table when the circuit under test is in a closed state includes: calibrating the target Hall sensor based on the zero-drift calibration table when the energy storage system is in a charging / discharging state.

[0016] In conjunction with the first aspect, in some embodiments, the battery cluster comprises multiple individual cells; the method further includes, before detecting no circulating current between the individual battery clusters:

[0017] Obtain the total cumulative voltage at the cluster end of each battery cluster, and determine the maximum and minimum values ​​among all the total cumulative voltages at the cluster ends; the total cumulative voltage at the cluster end of each battery cluster is the sum of the voltages of all the individual cells connected in series in that battery cluster;

[0018] If the difference between the maximum value and the minimum value is less than the preset pressure difference, it is determined that there is no circulating current between the battery clusters.

[0019] If the difference is greater than or equal to the preset pressure difference, then it is determined that there is circulating current between the battery clusters.

[0020] In conjunction with the first aspect, in some embodiments, the method further includes:

[0021] Based on multiple preset measured currents and the test values ​​obtained by the sample Hall sensor at multiple fourth ambient temperatures for each measured current, the linear error coefficient corresponding to each fourth ambient temperature is determined; wherein, the sample Hall sensor and the target Hall sensor have the same brand and model, and the linear error coefficient is the slope of a linear function of the measured current value changing with the test value.

[0022] Based on the linear error coefficients corresponding to each fourth ambient temperature, the relationship between the linear error coefficients and the ambient temperature is determined.

[0023] Based on the ambient temperature of the target Hall sensor monitored at the current moment and the relationship formula, the temperature drift of the target Hall sensor is corrected.

[0024] In conjunction with the first aspect, in some embodiments, calibrating the target Hall sensor based on the zero-drift calibration table includes:

[0025] Based on the ambient temperature monitored at the current moment, the relational expression, and the zero-drift correction table, the Hall correction function corresponding to the target Hall sensor is determined; wherein, the Hall correction function is a linear function that takes the measurement value of the target Hall sensor when it is not calibrated as input and the calibration value of the target Hall sensor after calibration as output, the slope of the Hall correction function is the relational expression, and the intercept of the Hall correction function is the first zero-drift correction value;

[0026] Based on the Hall correction function, the correction value corresponding to the measurement value of the target Hall sensor at the current moment is determined.

[0027] In conjunction with the first aspect, in some embodiments, the energy storage system further includes a power conversion system (PCS) connected in series with the plurality of parallel battery clusters, the power conversion system including a current detection device for collecting bus current; before detecting no circulating current between the battery clusters, the method further includes:

[0028] Obtain the bus current collected by the current detection device;

[0029] When the bus current is detected to change from non-zero to zero, it is determined that the energy storage system has changed from a charging / discharging state to a static state.

[0030] In a second aspect, embodiments of the present invention provide an energy storage system, including multiple parallel battery clusters, multiple high-voltage boxes respectively connected to each battery cluster, an energy storage converter connected in series with the multiple parallel battery clusters, and a data processing device.

[0031] The high-pressure box is equipped with a target Hall sensor and a temperature probe;

[0032] The target Hall sensor is used to measure the current in the circuit where the battery cluster is connected to the corresponding high-voltage box;

[0033] The temperature probe is used to collect the ambient temperature of the environment where the target Hall sensor is located;

[0034] The energy storage converter includes a current detection device, which is used to collect bus current.

[0035] The data processing device is connected to the target Hall sensor and is used to correct the measured value of the target Hall sensor according to the Hall sensor correction method as described in any of the first aspects above.

[0036] The beneficial effects of the embodiments of the present invention compared with related technologies are as follows:

[0037] The Hall sensor calibration method provided in this invention allows the target Hall sensor to measure a physical quantity that becomes zero when the circuit under test changes from a closed state to an open state. At this time, the ambient temperature of the target Hall sensor also gradually drops as the circuit under test is disconnected. During this cooling process, the measured value of the target Hall sensor and the ambient temperature are collected, which is equivalent to obtaining the latest zero-point drift corresponding to each temperature during the cooling process. The zero-point drift calibration table is updated based on these latest zero-point drift values, so that when the target Hall sensor is zero-drift calibrated according to the zero-drift calibration table at different temperatures, it can be calibrated with the latest zero-point drift value corresponding to the current temperature, thereby improving the accuracy of the Hall sensor's measurement results at very low temperatures.

[0038] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic flowchart of a Hall sensor calibration method provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram illustrating an application scenario of the Hall sensor calibration method provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of the present invention;

[0043] Figure 4 This is a graph showing the temperature change over time of a target Hall sensor during state switching, according to an embodiment of the present invention.

[0044] Figure 5 This is a schematic diagram of the structure of an energy storage system provided in another embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the structure of a battery management system provided in an embodiment of the present invention. Detailed Implementation

[0046] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention may be implemented in other embodiments without these specific details.

[0047] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0048] Furthermore, in the description of this invention and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0049] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and specific implementation details.

[0050] Figure 1 This is a schematic flowchart of a Hall sensor calibration method provided in an embodiment of the present invention. This method can be applied to, for example... Figure 2 In the exemplary scenario shown. See also Figure 2 The scenario includes a circuit under test 210 and a target Hall sensor 220, which can be used to measure physical quantities of the circuit under test 210. In this embodiment of the invention, there is typically no temperature control device around the circuit under test 210.

[0051] join Figure 1 The above-mentioned Hall sensor calibration method may include:

[0052] S101, when the circuit under test 210 changes from a closed state to an open state, during the process of the ambient temperature dropping, the measured values ​​of the target Hall sensor 220 at multiple moments and the first ambient temperature are collected.

[0053] In this embodiment of the invention, the closed state of the circuit under test 210 refers to the state in which the current in the circuit is not zero, and the open state refers to the state in which the current in the circuit is zero.

[0054] It should be noted that when the circuit under test 210 is in a closed state, the ambient temperature rises; after the circuit under test 210 changes from a closed state to an open state, the ambient temperature drops. It should be understood that when the circuit under test 210 is conducting, the wires and components within it dissipate heat, causing the temperature around the circuit under test 210 to rise. In other words, the ambient temperature around the target Hall sensor 220 will rise. However, when the circuit under test 210 changes from a closed state to an open state, there is no longer current in the wires and components, electrical energy is no longer converted into heat energy, and the temperature around the circuit under test 210 will gradually decrease.

[0055] In this embodiment, the physical quantity measured by the target Hall sensor 220 can be current, magnetic field strength, etc. When the circuit under test 210 changes from a closed state to an open state, the current in the circuit under test 210 is actually 0, and the magnetic field generated by the current in the circuit under test 210 also disappears. That is to say, the physical quantity that the target Hall sensor 220 needs to measure should actually be zero at this time. However, in practical applications, the measured value of the target sensor 220 is not zero at this time. This phenomenon may be caused by factors such as nonlinearity of the internal components of the sensor and temperature drift. Temperature drift is the main cause of zero-point drift. However, the inventors of this invention have found that the relationship between the zero-point drift of the Hall sensor and temperature is difficult to accurately represent in a certain way. Based on this, the inventors of this invention considered collecting the measured values ​​of the target Hall sensor 220 at different temperatures during the aforementioned process of ambient temperature decrease, and using these temperature data and measurement data to determine the zero-drift correction value at each temperature.

[0056] In this embodiment, a temperature sensor may be provided near the target Hall sensor 220. After the circuit under test 210 is changed from a closed state to an open state, the measurement time and measurement value of the target Hall sensor 220 and the temperature sensor are recorded to obtain the zero-point drift of the target Hall sensor 220 at each temperature during the ambient temperature drop.

[0057] S102, based on measurements at multiple times and the first ambient temperature, update the zero-drift calibration table of the target Hall sensor 220.

[0058] The zero-drift correction table includes multiple preset second ambient temperatures and first zero-drift correction values ​​corresponding to each second ambient temperature.

[0059] In this embodiment, the zero-drift correction table is a table showing the correspondence between ambient temperature and zero-drift correction values. The multiple preset second ambient temperatures can be multiple equally spaced temperatures within the operating temperature range of the target Hall sensor 220. For example, if the operating temperature range of a Hall sensor is 20℃ to 80℃, then the multiple preset second ambient temperatures could be 20℃, 25℃, 30℃, 35℃, 40℃, ..., 65℃, 70℃, 75℃, 80℃; or, the multiple preset second ambient temperatures could be 20℃, 21℃, 22℃, 23℃, 24℃, ..., 77℃, 78℃, 79℃, 80℃. In practical applications, the values ​​of the second ambient temperatures can be determined according to actual application requirements such as computational needs and accuracy requirements; this application does not impose any limitations on this.

[0060] In this embodiment, the first zero-drift correction value in the initial zero-drift correction table can be obtained by: controlling the circuit under test 210 to be turned on and monitoring the ambient temperature of the target Hall sensor 220; when the ambient temperature no longer rises, controlling the circuit under test 210 to be turned off and starting to collect the measurement values ​​of the target Hall sensor 220 at multiple preset second ambient temperatures, which are the zero-point drift values; when the ambient temperature drops to room temperature (or normal temperature), the collection stops; based on the collected measurement values ​​at multiple second ambient temperatures, the first zero-drift correction value in the initial zero-drift correction table is determined.

[0061] Once the target Hall sensor 220 is put into use, whenever the circuit under test 210 changes from a closed state to an open state, the zero-point drift of the target Hall sensor 220 can be collected during the subsequent cooling process, thereby updating the first zero-point drift correction value in the zero-point drift correction table. It should be noted that, in practical applications, after the circuit under test 210 changes from a closed state to an open state, it may remain in an open state for a relatively long time. In this case, the ambient temperature usually drops from the highest temperature to room temperature (or normal temperature) and is then maintained at room temperature (or normal temperature) until the circuit under test 210 is turned on again. In this case, the zero-point drift at all second ambient temperatures can be collected, thereby updating the entire zero-point drift correction table. On the other hand, in practical applications, after the circuit under test 210 changes from a closed state to an open state, it may quickly turn on again. That is to say, if the ambient temperature does not drop to room temperature (or normal temperature), the circuit under test 210 turns on again. In this case, only a portion of the zero drift corresponding to the second ambient temperature can be collected. Therefore, only a portion of the first zero drift correction value in the zero drift correction table can be updated.

[0062] Based on the above two situations, in some embodiments, the implementation process of step S102 may include:

[0063] S1021, based on the measured values ​​at multiple times and the first ambient temperature, determine the average value of the measured values ​​corresponding to each third ambient temperature.

[0064] In this embodiment, the third ambient temperature refers to the ambient temperature at the intersection of multiple preset second ambient temperatures and multiple moment-based first ambient temperatures. When collecting measurements and the first ambient temperature at multiple moments, the first ambient temperature may be continuous. For example, the first ambient temperature may be 78.5℃, 78℃, 77.5℃, 77℃...56.5℃. If the second ambient temperature in this embodiment is 20℃, 25℃, 30℃...75℃, 80℃, then it is necessary to filter the values ​​of the second ambient temperature from the first ambient temperature, i.e., the third ambient temperature. This third ambient temperature includes 75℃, 70℃, 65℃, and 60℃. It should be understood that the third ambient temperature is only distinguished from the second ambient temperature in the zero-drift correction table in terms of description; its actual temperature value is the same as the temperature value in the second ambient temperature table.

[0065] In this embodiment, among the measured values ​​and the first ambient temperature collected at multiple times, there may be multiple consecutive times with the same first ambient temperature but different measured values. That is to say, the zero-point drift at the same temperature may fluctuate. In this case, the measured values ​​at that temperature can be averaged to determine the average zero-point drift corresponding to that temperature.

[0066] S1022, Based on the average value of the measured values ​​corresponding to each third ambient temperature, determine the second zero drift correction value corresponding to each third ambient temperature, and update the first zero drift correction value corresponding to each third ambient temperature in the zero drift correction table.

[0067] For example, in step S1021, the average value of the current measurement corresponding to the third ambient temperature of 55°C is determined to be 0.01A. Then, in step S1022, the second zero drift correction value corresponding to the third ambient temperature of 55°C can be determined to be -0.01A, and then the first zero drift correction value corresponding to 55°C in the zero drift correction table is updated.

[0068] S103, when the circuit under test is in a closed state, the target Hall sensor is calibrated based on the zero drift calibration table.

[0069] In some embodiments, step S103 may include: determining a third zero-drift correction value for the target Hall sensor at the current time based on a zero-drift correction table and the ambient temperature monitored at the current time; and correcting the zero-point drift of the target Hall sensor at the current time based on the third zero-drift correction value.

[0070] In the above embodiment, the third zero-drift correction value refers to the first zero-drift correction value corresponding to the current ambient temperature selected from the zero-drift correction table when zero-drift correction is performed on the target Hall sensor 220. The term "third" here is only used for distinguishing descriptions.

[0071] The Hall sensor calibration method provided in the above embodiments acquires the measurement value of the target Hall sensor during the process of the measured physical quantity being actually zero and the ambient temperature decreasing, thereby obtaining the latest zero-point drift corresponding to each temperature during the cooling process. The zero-point drift calibration table is updated based on these latest zero-point drift values, so that when the target Hall sensor is zero-drift calibrated according to the zero-drift calibration table at different temperatures, it can be calibrated with the latest zero-point drift value corresponding to the current temperature, effectively improving the accuracy of the Hall sensor's measurement results at very low temperatures.

[0072] Next, a specific embodiment will be used to describe the Hall sensor calibration method provided by the present invention.

[0073] In this specific embodiment, the circuit under test is a circuit in an energy storage system, and the physical quantity includes current. Please refer to [link / reference]. Figure 3 In this embodiment, the energy storage system 300 includes multiple parallel battery clusters 310 and multiple high-voltage boxes 320 connected to each battery cluster. Each high-voltage box 320 contains a target Hall sensor 220 and a temperature probe 321. The target Hall sensor 220 measures the current in the circuit of the battery cluster 310 connected to the corresponding high-voltage box 320, and the temperature probe 321 collects ambient temperature data. Figure 3 As shown, the battery cluster 310 includes multiple individual battery cells 311. The energy storage system 300 also includes an energy storage converter 330 connected in series with the multiple parallel battery clusters 310. The energy storage converter 330 includes a current detection device 331 for collecting bus current. The energy storage converter 330 is used to connect the energy storage system 300 to the power grid to achieve bidirectional conversion of electrical energy.

[0074] In this embodiment, the high-voltage box 320 generally does not have a temperature control device. Therefore, during the charging and discharging process of the energy storage system 300, the heat dissipated by the energy storage system 300 will be conducted to the high-voltage box 320, causing the ambient temperature of the target Hall sensor 220 to rise. Correspondingly, when the energy storage system 300 stops dissipating heat, the ambient temperature of the target Hall sensor 220 will no longer rise. If the circuit where each battery cluster 310 is located changes from a state with current flow to a state without current flow, then the ambient temperature of the target Hall sensor 220 will gradually decrease. Figure 4 The graph shows the temperature change over time of a target Hall sensor 220 during state switching.

[0075] In this embodiment, the implementation process of step S101 can be as follows: when the energy storage system 300 changes from the charging and discharging state to the stationary state, if it is detected that there is no circulating current between each battery cluster 310, then during the process of the ambient temperature decreasing, the measurement values ​​of the target Hall sensor 220 at multiple times and the first ambient temperature are collected.

[0076] In this embodiment, the energy storage system 300, during charging and discharging, can achieve bidirectional flow of electrical energy through the energy storage converter (PCS), enabling it to charge or discharge according to the needs of the power grid. Therefore, current flows in the circuits of each battery cluster 310 during charging or discharging. The stationary state of the energy storage system 300 refers to a state where, during periods without charging or discharging activity, the energy storage system 300 remains stationary and does not perform energy conversion. In this state, the energy storage system does not exchange energy with the power grid or load, and the battery clusters 310 maintain their current state of charge.

[0077] In the above embodiment, after collecting measurement values ​​at multiple times and the first ambient temperature, a second zero-drift correction value corresponding to the third ambient temperature can be determined, thereby updating the zero-drift correction table. It should be noted that the zero drift of the Hall sensor is mainly affected by temperature. However, the inventors of this invention have also discovered that after the Hall sensor is put into use, its zero drift may change due to the aging of the device itself, and the aging of the device is also affected by the operating conditions of the equipment in the usage scenario. Therefore, this embodiment of the invention employs an online acquisition of the initial zero-drift correction value and an online update of the zero-drift correction table to fully consider the impact of the usage environment on the zero drift of the Hall sensor. This ensures that each time the Hall sensor is zero-drift corrected, a zero-drift correction value that accurately corrects the zero-point drift of the Hall sensor in its latest state is used.

[0078] Since the zero-point drift of the target Hall sensor 220 needs to be obtained when the measured physical quantity is actually zero, it is necessary to ensure that the measured current is actually zero when determining the first and second zero-point drift correction values ​​of the zero-point drift correction table for the target Hall sensor 220. For the energy storage system 300, after switching to a static state, there may still be circulating current between the multiple battery clusters 310. At this time, the measured current is not actually zero, and a reliable zero-point drift cannot be collected. Therefore, when starting to collect the measurement values ​​at multiple times and the first ambient temperature, it is also necessary to ensure that there is no circulating current between the multiple battery clusters 310. Therefore, before detecting that there is no circulating current between the battery clusters, the above Hall sensor calibration method also includes:

[0079] Obtain the total cumulative voltage at the cluster end of each battery cluster 310, and determine the maximum and minimum values ​​among all the total cumulative voltages at the cluster ends; the total cumulative voltage at the cluster end of each battery cluster 310 is the sum of the voltages of all the individual cells 311 connected in series in that battery cluster 310; if the difference between the maximum and minimum values ​​is less than a preset voltage difference, it is determined that there is no circulating current between the battery clusters 310; if the difference is greater than or equal to the preset voltage difference, it is determined that there is circulating current between the battery clusters 310.

[0080] Optionally, the preset voltage difference is 5V. That is, when the difference in the total cumulative voltage at the terminals of any two battery clusters 310 is less than 5V, it can be considered that there is no circulating current between the battery clusters 310.

[0081] In the above embodiments, when confirming whether there is circulating current between battery clusters 310, it is necessary to ensure that no "cell voltage acquisition failure" has occurred in the energy storage system 300, so as to avoid misjudgment due to inaccurate reading of the cumulative total voltage value at the cluster end.

[0082] Optionally, the quiescent state of the energy storage system 300 can be determined by the bus current. Before detecting that there is no circulating current between the battery clusters, the above-mentioned Hall sensor calibration method may further include: acquiring the bus current collected by the current detection device 331; when the bus current is detected to change from non-zero to zero, determining that the energy storage system 300 has changed from the charging / discharging state to the quiescent state.

[0083] The implementation process of step S103 can be as follows: when the energy storage system 300 is in a charging and discharging state, the target Hall sensor 220 is calibrated based on the zero drift calibration table.

[0084] In this embodiment, the target Hall sensor 220 corresponding to each battery cluster 310 is connected to the data processing device of the energy storage system 300. The data processing device includes a Hall calibration module for storing the zero drift correction table of each target Hall sensor 200 and determining the correction value of each target Hall sensor 220 based on the zero drift correction table and the measurement value of the target Hall sensor 220.

[0085] In the above embodiment, whenever the energy storage system 300 transitions from a charging / discharging state to a static state, and there is no circulating current between the individual battery clusters 310, the target Hall sensor 220 collects measurement values ​​during the ambient temperature decrease process. This determines the zero-point drift at different temperatures and updates the zero-drift calibration table. When the energy storage system 300 is in a charging / discharging state, the calibration values ​​of the target Hall sensor 200 are determined based on the latest zero-drift calibration table, thus accurately acquiring the current values ​​of each battery cluster 310 during charging and discharging.

[0086] It should be noted that the above-mentioned zero-drift correction is an online (after power-on) real-time correction for the target Hall sensor 220. The high-voltage box 320 in the above embodiment may also include a high-voltage box relay, which controls the on / off state of the corresponding battery cluster 310. The current measured by the target Hall sensor 220 can be the current passing through the high-voltage box relay. Before the high-voltage box relay closes (before power-on), the current within it is definitely 0, at which point the target Hall sensor 220 can be directly zeroed.

[0087] In some embodiments, to improve the accuracy of the Hall sensor, in addition to zero-drift correction, temperature drift correction can also be performed simultaneously. The above-described Hall sensor correction method may further include:

[0088] S104, based on multiple preset measured currents and the test values ​​obtained by the sample Hall sensor testing each measured current at multiple fourth ambient temperatures, determines the linear error coefficient corresponding to each fourth ambient temperature.

[0089] The sample Hall sensor and the target Hall sensor 220 share the same brand and model. The fourth ambient temperature refers to the temperature value set when considering temperature drift correction. The fourth ambient temperature can be the same as the second ambient temperature, i.e., multiple equally spaced temperature values ​​preset based on the operating temperature range of the target Hall sensor 220. In other embodiments, a fourth ambient temperature that is not exactly the same as the second ambient temperature can also be preset as needed. For example, the second ambient temperature includes 20℃, 30℃, 40℃…80℃, and the fourth ambient temperature includes 20℃, 25℃, 30℃…80℃. It should be understood that the values ​​of the second and fourth ambient temperatures are determined based on the operating environment and device performance of the target Hall sensor 220. These values ​​can be above zero or below zero; the present invention does not specifically limit their range.

[0090] In this embodiment, when performing both temperature drift correction and zero drift correction on the target Hall sensor 220, a Hall correction function can be used:

[0091] y = kx + b

[0092] Where x is the measured value of the Hall sensor; y is the calibration value of the Hall sensor; k is the linearity error coefficient, which mainly considers temperature drift; and b represents the zero drift correction value.

[0093] Research has shown that temperature drift exhibits a linear relationship, meaning that temperature and the linear error coefficient k are linearly related. The linear error coefficient k used for temperature drift correction can be determined offline. Therefore, the temperature drift pattern of the target Hall sensor 220 can be determined using test data from the manufacturer or test data from self-tested sample devices. In other words, the multiple measured currents in step S104, and the test values ​​obtained by testing each measured current at multiple fourth ambient temperatures using the sample Hall sensor, can be test data from the Hall sensor manufacturer or self-tested data. In practical applications, the specific data used can be chosen reasonably based on the actual situation.

[0094] S105, based on the linear error coefficients corresponding to each fourth ambient temperature, determine the relationship between the linear error coefficients and the ambient temperature.

[0095] The relation is as follows:

[0096] k = mT + n

[0097] Where T is the ambient temperature, m is the slope, and n is the intercept.

[0098] Based on the linear error coefficient k corresponding to each fourth ambient temperature, the values ​​of m and n can be determined, thereby determining the relationship between the linear error coefficient k and the ambient temperature T.

[0099] S106, based on the ambient temperature and relationship of the target Hall sensor monitored at the current moment, corrects the temperature drift of the target Hall sensor.

[0100] In some embodiments, the linear error coefficient k in the Hall correction function y = kx + b can be updated in real time based on the real-time ambient temperature, thereby accurately correcting the temperature drift of the target Hall sensor 220. In other embodiments, changes in ambient temperature can be monitored in real time, and the temperature value in the above formula can be updated whenever the ambient temperature change reaches a preset temperature difference. Temperature change refers to the difference between the currently collected ambient temperature and the ambient temperature in the current formula.

[0101] For example, the preset temperature difference is first set to 5℃. At the first moment, the ambient temperature in the equation is updated to 35℃, so the linear error coefficient k = 35m + n. At the second moment, the ambient temperature is 36℃, and the temperature change is 1℃, which is less than the preset temperature difference. Therefore, when performing temperature drift correction at the second moment, the linear error coefficient k used is still 35m + n. If the ambient temperature is 40℃ at the third moment, and the temperature change reaches 5℃, then the ambient temperature in the equation should be updated at the third moment, and the linear error coefficient k = 40m + n.

[0102] Based on the above embodiments, step S103 can be implemented through steps S1031 to S1032:

[0103] S1031, based on the ambient temperature monitored at the current moment, the above relationship and the zero drift correction table, determine the Hall correction function corresponding to the target Hall sensor 220.

[0104] The Hall correction function is a linear function that takes the measurement value of the target Hall sensor 220 when it is not calibrated as input and the calibration value of the target Hall sensor 220 after calibration as output. The slope of the Hall correction function is a relational expression, and the intercept of the Hall correction function is the first zero drift correction value.

[0105] In the above embodiment, the Hall correction function corresponding to the target Hall sensor 220 is y = (mT+n)x+b T Among them, b TThe zero drift correction value is determined based on the zero drift correction table.

[0106] In the first possible implementation, the zero drift correction value b T The ambient temperature T is determined based on the Hall correction function. Step S1031 may include: if the current ambient temperature T(t) is different from the ambient temperature T input into the currently used Hall correction function... p If the temperature difference reaches the preset temperature difference, then the ambient temperature T will be substituted into the Hall correction function. p Updated to the fifth ambient temperature T q And according to the fifth ambient temperature T q Using the zero-drift correction table, determine the zero-drift correction value b in the Hall correction function. T Among them, the fifth ambient temperature T q The current ambient temperature T(t) is either the current ambient temperature or the temperature in the fourth ambient temperature range that is closest to the current ambient temperature T(t).

[0107] In the second possible implementation, the zero drift correction value b T Determined based on the current ambient temperature T(t). Step S1031 may include: if the current ambient temperature T(t) is different from the ambient temperature T input into the currently used Hall correction function... p If the temperature difference reaches the preset temperature difference, then the ambient temperature T will be substituted into the Hall correction function. p Updated to the fifth ambient temperature T q Based on the current ambient temperature T(t) and the zero-drift correction table, determine the zero-drift correction value b in the Hall correction function. T Among them, the fifth ambient temperature T q The current ambient temperature T(t) is either the current ambient temperature or the temperature in the fourth ambient temperature range that is closest to the current ambient temperature T(t).

[0108] In the third possible implementation, the ambient temperature T is substituted into the relation. p and zero drift correction value b T All are determined based on the current ambient temperature T(t). Step S1031 may include: adjusting the ambient temperature T in the Hall correction function. p Update the current ambient temperature T(t), and determine the zero-drift correction value b in the Hall correction function based on the current ambient temperature T(t) and the zero-drift correction table. T .

[0109] In the first and second implementations described above, the fifth ambient temperature is the updated temperature value in the temperature drift correction, which can be the current ambient temperature T(t). For example, if the preset temperature difference is 5℃, the ambient temperature T in the original Hall correction function... pThe initial ambient temperature was 40℃. The subsequent ambient temperatures collected at various time points were 41℃, 43℃, and 46℃. Therefore, when 46℃ is detected, the ambient temperature T in the Hall correction function needs to be adjusted. p Updated to 46℃. The fifth ambient temperature can also be a temperature value from the fourth ambient temperature range. For example, with a preset temperature difference of 5℃, the fourth ambient temperature range includes 15℃, 20℃, 25℃...80℃; the ambient temperature T in the original Hall correction function... p The initial ambient temperature was 40℃. The subsequent ambient temperatures collected at various time points were 41℃, 43℃, and 46℃. Therefore, when 46℃ is detected, the ambient temperature T in the Hall correction function needs to be adjusted. p Updated to 45℃.

[0110] It should be understood that in practical applications, a suitable Hall correction function update scheme can be selected based on the computing power of the data processing device and the accuracy requirements of the current measurement.

[0111] S1032, based on the Hall correction function, determine the correction value corresponding to the measurement value of the target Hall sensor 220 at the current moment.

[0112] In the above embodiments, for zero drift correction, this invention significantly improves the accuracy of zero drift correction by online acquisition of the zero-point drift of the target Hall sensor 220 under specific conditions and timely updating its zero drift correction table accordingly. For temperature drift correction, this invention also fully considers the impact of different temperatures and temperature changes on temperature drift, and performs temperature drift correction using a linear relationship. When the energy storage system 300 is in a charging or discharging state, the temperature drift and zero drift of the corresponding target Hall sensor 220 are corrected based on the ambient temperature acquired in real time by the temperature probe 321, thereby improving the accuracy of current measurement results.

[0113] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0114] This invention also provides an energy storage system, see [link to relevant documentation]. Figure 5 The energy storage system 300 includes multiple parallel battery clusters 310, multiple high-voltage boxes 320 connected to each battery cluster 310, an energy storage converter 330 connected in series with the multiple parallel battery clusters 310, and a data processing device 510.

[0115] The high-pressure box 320 is equipped with a target Hall sensor 220 and a temperature probe 321.

[0116] The target Hall sensor 220 is used to measure the current in the circuit where the battery cluster 310 is connected to the corresponding high voltage box 320.

[0117] Temperature probe 321 is used to collect the ambient temperature of the environment where the target Hall sensor 220 is located.

[0118] The energy storage converter 330 includes a current detection device 331, which is used to collect the bus current.

[0119] The data processing device 510 is connected to the target Hall sensor 220 and is used to correct the measured value of the target Hall sensor 220 according to the Hall sensor correction method in the above embodiments.

[0120] It is understood that the data processing device 510 can be a separate module or unit, or it can be a sub-module unit in the battery management system (BMS) of the energy storage system 300.

[0121] When the energy storage system 300 in the above embodiments corrects the measured value of the target Hall sensor 220 according to the Hall sensor correction method in the above embodiments, it can obtain more accurate current data, thereby enabling more effective management of the energy storage system 300.

[0122] This invention also provides a battery management system. See [link to relevant documentation]. Figure 6 The battery management system 600 includes a processor 610 and a memory 620. The memory 620 stores a computer program. When the processor 610 executes the computer program, it implements the steps in the various method embodiments described above. Alternatively, when the processor 610 executes the computer program, it implements the functions of each module / unit in the various device embodiments described above.

[0123] For example, a computer program may be divided into one or more modules / units, which are stored in memory 620 and executed by processor 610 to perform the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the battery management system 600.

[0124] The battery management system 600 may include, but is not limited to, a processor 610 and a memory 620. Those skilled in the art will understand that... Figure 5 This is merely an example of the battery management system 600 and does not constitute a limitation on the battery management system 600. It may include more or fewer components than shown, or combine certain components, or different components. For example, the battery management system 600 may also include input / output devices, network access devices, buses, etc.

[0125] The processor 610 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0126] The memory 620 can be an internal storage unit of the battery management system 600, such as the hard disk or memory of the battery management system 600. The memory 620 can also be an external storage device of the battery management system 600, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the battery management system 600. Furthermore, the memory 620 can include both internal storage units and external storage devices of the battery management system 600. The memory 620 is used to store computer programs and other programs and data required by the battery management system 600. The memory 620 can also be used to temporarily store data that has been output or will be output.

[0127] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0128] This invention also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the methods described in the above-described method embodiments.

[0129] This invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the methods described in the above-described method embodiments.

[0130] Computer programs include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. Computer-readable media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0131] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0132] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A Hall sensor calibration method, characterized in that, include: When the circuit under test changes from a closed state to an open state, the target Hall sensor collects measurement values ​​and the first ambient temperature at multiple moments during the process of the ambient temperature decreasing; the target Hall sensor is used to measure the physical quantity of the circuit under test. When the circuit under test is in a closed state, the ambient temperature rises; after the circuit under test changes from a closed state to an open state, the ambient temperature falls back. Based on the measured values ​​at the multiple times and the first ambient temperature, the zero-drift calibration table of the target Hall sensor is updated; The zero-drift correction table includes multiple preset second ambient temperatures and first zero-drift correction values ​​corresponding to each of the second ambient temperatures. When the circuit under test is in a closed state, the target Hall sensor is calibrated based on the zero drift calibration table; The update of the zero-drift calibration table of the target Hall sensor based on the measured values ​​at the multiple times and the first ambient temperature includes: Based on the measured values ​​at the multiple times and the first ambient temperature, the average value of the measured values ​​corresponding to each third ambient temperature is determined; the third ambient temperature is the ambient temperature in the intersection of the multiple preset second ambient temperatures and the multiple first ambient temperatures at the multiple times. Based on the average value of the measured values ​​corresponding to each third ambient temperature, the second zero drift correction value corresponding to each third ambient temperature is determined, and the first zero drift correction value corresponding to each third ambient temperature in the zero drift correction table is updated. The circuit under test is a circuit in an energy storage system, and the physical quantity includes current; wherein, the energy storage system includes multiple parallel battery clusters and multiple high-voltage boxes respectively connected to each battery cluster; the high-voltage box is equipped with the target Hall sensor and a temperature probe; the target Hall sensor is used to measure the current in the circuit of the battery cluster connected to the corresponding high-voltage box, and the temperature probe is used to collect the ambient temperature; When the circuit under test changes from a closed state to an open state, during the process of ambient temperature decrease, the measured values ​​of the target Hall sensor and the first ambient temperature are collected at multiple moments, including: When the energy storage system changes from a charging / discharging state to a stationary state, if no circulating current is detected between the battery clusters, the target Hall sensor's measurement values ​​and the first ambient temperature are collected at multiple moments during the process of the ambient temperature decreasing. When the circuit under test is in a closed state, the target Hall sensor is calibrated based on the zero-drift calibration table, including: When the energy storage system is in a charging or discharging state, the target Hall sensor is calibrated based on the zero-drift calibration table.

2. The Hall sensor calibration method as described in claim 1, characterized in that, The calibration of the target Hall sensor based on the zero-drift calibration table includes: Based on the zero-drift correction table and the ambient temperature monitored at the current moment, determine the third zero-drift correction value of the target Hall sensor at the current moment; Based on the third zero-drift correction value, the zero-point drift of the target Hall sensor at the current moment is corrected.

3. The Hall sensor calibration method as described in claim 1, characterized in that, The battery cluster comprises multiple individual battery cells; Before detecting no circulating current between the individual battery clusters, the method further includes: Obtain the total cumulative voltage at the cluster end of each battery cluster, and determine the maximum and minimum values ​​among all the total cumulative voltages at the cluster ends; the total cumulative voltage at the cluster end of each battery cluster is the sum of the voltages of all individual cells connected in series in that battery cluster; If the difference between the maximum value and the minimum value is less than the preset pressure difference, it is determined that there is no circulating current between the battery clusters. If the difference is greater than or equal to the preset pressure difference, then it is determined that there is circulating current between the battery clusters.

4. The Hall sensor calibration method as described in claim 1, characterized in that, The method further includes: Based on multiple preset measured currents and the test values ​​obtained by the sample Hall sensor testing each measured current at multiple fourth ambient temperatures, the linear error coefficient corresponding to each fourth ambient temperature is determined; wherein, the sample Hall sensor has the same brand and model as the target Hall sensor, and the linear error coefficient is the slope of a linear function of the measured current changing with the test value. Based on the linear error coefficients corresponding to each fourth ambient temperature, the relationship between the linear error coefficients and the ambient temperature is determined. Based on the ambient temperature of the target Hall sensor monitored at the current moment and the relationship formula, the temperature drift of the target Hall sensor is corrected.

5. The Hall sensor calibration method as described in claim 4, characterized in that, The calibration of the target Hall sensor based on the zero-drift calibration table includes: Based on the ambient temperature monitored at the current moment, the relational expression, and the zero-drift correction table, the Hall correction function corresponding to the target Hall sensor is determined; wherein, the Hall correction function is a linear function that takes the measurement value of the target Hall sensor when it is not calibrated as input and the calibration value of the target Hall sensor after calibration as output, the slope of the Hall correction function is the relational expression, and the intercept of the Hall correction function is the first zero-drift correction value; Based on the Hall correction function, the correction value corresponding to the measurement value of the target Hall sensor at the current moment is determined.

6. The Hall sensor calibration method as described in claim 1, characterized in that, The energy storage system also includes an energy storage converter connected in series with the plurality of parallel battery clusters. The energy storage converter includes a current detection device for collecting bus current. Before detecting no circulating current between the individual battery clusters, the method further includes: Obtain the bus current collected by the current detection device; When the bus current is detected to change from non-zero to zero, it is determined that the energy storage system has changed from a charging / discharging state to a static state.

7. An energy storage system, characterized in that, It includes multiple parallel battery clusters, multiple high-voltage boxes connected to each battery cluster, an energy storage converter connected in series with the multiple parallel battery clusters, and a data processing device. The high-pressure box is equipped with a target Hall sensor and a temperature probe; The target Hall sensor is used to measure the current in the circuit where the battery cluster is connected to the corresponding high-voltage box; The temperature probe is used to collect the ambient temperature of the environment where the target Hall sensor is located; The energy storage converter includes a current detection device, which is used to collect the bus current. The data processing device is connected to the target Hall sensor and is used to correct the measured value of the target Hall sensor according to the Hall sensor correction method as described in any one of claims 4 to 6.

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