Hall sensor correction method and energy storage system

Abstract

The invention 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 steps that after a loop to be measured is converted into an open-circuit state from a closed-circuit state, in the environment temperature decreasing process, the loop to be measured is corrected; collecting measured values of a target Hall sensor at a plurality of moments and a first environment temperature; the target Hall sensor is used for measuring the physical quantity of the loop to be measured; updating a null drift correction table of the target Hall sensor based on the measured values of the multiple moments and the first environment temperature; the null drift correction table comprises a plurality of preset second environment temperatures and first null drift correction values corresponding to the second environment temperatures; and when the loop to be measured is in a closed state, correcting the target Hall sensor based on the null drift correction table. According to the invention, the Hall sensor can be corrected through the newest zero drift corresponding to the current temperature all the time, so that the accuracy of the measurement result of the Hall sensor under the abnormal temperature is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of Hall sensor calibration, and in particular relates to a Hall sensor calibration method and an energy storage system. Background Art

[0002] The Hall sensor detects the current by measuring the magnetic field generated by the current, thereby realizing non-contact measurement of the current. In practical applications, due to environmental magnetic fields, stray magnetic fields, etc., the measurement results of the Hall sensor usually have errors. Therefore, the Hall sensor needs to be calibrated before use.

[0003] The current correction scheme for the Hall sensor usually adopts a linear correction method, that is, the correction relationship in the form of a linear function is determined by the actual current value obtained at room temperature and the collected value of the Hall sensor. The slope of the linear function is the linear error coefficient of the Hall sensor, and the intercept of the linear function is the zero drift of the Hall sensor. However, the inventors found that when the Hall sensor works at abnormal temperatures, the existing linear correction method will still produce a large error, that is, the Hall sensor has a temperature drift effect. At the same time, the inventors also found that at different temperatures, the Hall sensor will have different degrees of zero drift; however, the relationship between the zero drift of the Hall sensor and the temperature is not obvious, which makes it difficult to calibrate the measurement results of the Hall sensor at abnormal temperatures. Summary of the invention

[0004] In order to overcome the problems existing in the related art, the embodiments of the present invention provide a Hall sensor calibration method and an energy storage system to solve the problem that the measurement results of the Hall sensor at abnormal temperatures are difficult to calibrate.

[0005] The present invention is achieved through the following technical solutions:

[0006] In the first aspect, an embodiment of the present invention provides a Hall sensor calibration method, comprising: when a circuit to be measured is converted from a path state to an open circuit state, in the process of the ambient temperature dropping, collecting the measurement values ​​of the target Hall sensor at multiple times and a first ambient temperature; the target Hall sensor is used to measure the physical quantity of the circuit to be measured, and when the circuit to be measured is in a path state, the ambient temperature rises; after the circuit to be measured is converted from a path state to an open circuit state, the ambient temperature drops; based on the measurement values ​​at the multiple times and the first ambient temperature, updating the zero drift correction table of the target Hall sensor; the zero drift correction table includes multiple preset second ambient temperatures and first zero drift correction values ​​corresponding to each second ambient temperature; when the circuit to be measured is in a path state, calibrating the target Hall sensor based on the zero drift correction table.

[0007] In combination with the first aspect, in some embodiments, updating the zero drift correction table of the target Hall sensor based on the measurement values ​​at the multiple moments and the first ambient temperature includes:

[0008] Based on the measurement values ​​at the multiple moments and the first ambient temperature, determining an average value of the measurement values ​​corresponding to each third ambient temperature; the third ambient temperature is an ambient temperature at the intersection of the multiple preset second ambient temperatures and the first ambient temperature at the multiple moments;

[0009] Based on the average value of the measurement 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.

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

[0011] Determine a third zero drift correction value corresponding to the target Hall sensor at the current moment based on the zero drift correction table and the ambient temperature monitored at the current moment;

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

[0013] In combination with the first aspect, in some embodiments, the circuit to be tested 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 target Hall sensor and temperature probe are provided in the high-voltage box; the target Hall sensor is used to measure the current in the circuit where the battery cluster connected to the corresponding high-voltage box is located, and the temperature probe is used to collect the ambient temperature.

[0014] In combination with the first aspect, in some embodiments, when the circuit to be tested is converted from a path state to an open circuit state, in the process of the ambient temperature dropping, the measured values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected, including: when the energy storage system is converted from a charge and discharge state to a static state, if it is monitored that there is no circulation between the battery clusters, in the process of the ambient temperature dropping, the measured values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected;

[0015] When the circuit to be tested is in a conducting state, the target Hall sensor is calibrated based on the zero drift correction table, including: when the energy storage system is in a charging and discharging state, the target Hall sensor is calibrated based on the zero drift correction table.

[0016] In combination with the first aspect, in some embodiments, the battery cluster includes a plurality of single batteries; before detecting that there is no circulating current between the battery clusters, the method further includes:

[0017] Obtain the cluster-end cumulative total voltage of each battery cluster, and determine the maximum and minimum values ​​of all cluster-end cumulative total voltages; the cluster-end cumulative total voltage of each battery cluster is the sum of the voltages of all series-connected single cells in the 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 circulation between the battery clusters;

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

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

[0021] Based on a plurality of preset measured currents and test values ​​obtained by testing each measured current under a plurality of fourth ambient temperatures by a sample Hall sensor, a 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 value changing with the test value;

[0022] Based on the linear error coefficients corresponding to the respective fourth ambient temperatures, determining a relationship between the linear error coefficients and the ambient temperature;

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

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

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

[0027] In combination 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 energy storage converter includes a current detection device, and the current detection device is used to collect bus current; before the monitoring that there is no circulating current between the battery clusters, the method further includes:

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

[0029] When it is monitored that the bus current changes from non-zero to zero, it is determined that the energy storage system is converted from a charging and discharging state to a static state.

[0030] In a second aspect, an embodiment of the present invention provides an energy storage system, comprising a plurality of battery clusters connected in parallel, a plurality of high-voltage boxes respectively connected to each battery cluster, an energy storage converter connected in series with the plurality of battery clusters connected in parallel, and a data processing device;

[0031] The high voltage box is provided with a target Hall sensor and a temperature probe;

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

[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, and the current detection device is used to collect bus current;

[0035] The data processing device is connected to the target Hall sensor, and is used to calibrate the measurement value of the target Hall sensor according to the Hall sensor calibration method as described in any one of the first aspects above.

[0036] Compared with the related art, the embodiments of the present invention have the following beneficial effects:

[0037] According to the Hall sensor calibration method provided by the embodiment of the present invention, when the circuit to be measured is converted from a path state to an open circuit state, the physical quantity required to be measured by the target Hall sensor will actually become zero. At this time, the ambient temperature of the target Hall sensor will gradually drop as the circuit to be measured is disconnected. The measurement value and ambient temperature of the target Hall sensor are collected during this cooling process, which is equivalent to obtaining the latest zero drift corresponding to each temperature during the cooling process. The zero drift correction table is updated according to these latest zero drift values, so that when the target Hall sensor is zero-drift corrected according to the zero drift correction table at different temperatures, it can be corrected with the latest zero drift corresponding to the current temperature, thereby improving the accuracy of the measurement results of the Hall sensor at abnormal temperatures.

[0038] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 is a flow chart of a Hall sensor calibration method provided by an embodiment of the present invention;

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

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

[0043] Figure 4 is a curve diagram showing the temperature change over time of a certain target Hall sensor during a state switching process provided by an embodiment of the present invention;

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

[0045] Figure 6 It is a schematic diagram of the structure of a battery management system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are provided to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.

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

[0048] In addition, in the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0049] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and specific implementation methods.

[0050] Figure 1 is a flow chart of a Hall sensor calibration method provided by an embodiment of the present invention. The method can be applied to Figure 2 See the example scenario shown. Figure 2 The scenario includes a circuit to be tested 210 and a target Hall sensor 220, and the target Hall sensor 220 can be used to measure the physical quantity of the circuit to be tested 210. In the embodiment of the present invention, there is usually no temperature control device around the circuit to be tested 210.

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

[0052] S101, when the circuit to be tested 210 is converted from a circuit state to an open circuit state, in the process of the ambient temperature decreasing, the measured values ​​of the target Hall sensor 220 at multiple times and the first ambient temperature are collected.

[0053] In the embodiment of the present invention, the connection state of the circuit to be tested 210 refers to a state in which the current in the circuit is not zero, and the open circuit state refers to a state in which the current in the circuit is zero.

[0054] It should be noted that when the circuit 210 to be tested is in a through state, the ambient temperature rises; after the circuit 210 to be tested is converted from a through state to an open state, the ambient temperature drops. It should be understood that when the circuit 210 to be tested is turned on, the wires, devices, etc. in the circuit 210 to be tested will dissipate heat, causing the temperature around the circuit 210 to be tested to rise, that is, the ambient temperature of the target Hall sensor 220 will rise. When the circuit 210 to be tested is converted from a through state to an open state, there is no more current in the wires and devices, and electrical energy is no longer converted into heat energy, and the temperature around the circuit 210 to be tested will gradually drop.

[0055] In this embodiment, the physical quantity measured by the target Hall sensor 220 may be current, magnetic field strength, etc. When the circuit 210 to be measured is converted from the passage state to the open circuit state, the current in the circuit 210 to be measured is actually 0, and the magnetic field generated by the current of the circuit 210 to be measured will also disappear, that is, the physical quantity required to be measured by the target Hall sensor 220 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 and temperature drift of components inside the sensor, and temperature drift is the main cause of zero drift. However, the inventors of the present invention have found that the relationship between the zero drift of the Hall sensor and the temperature is difficult to accurately express in a certain way. Based on this, the inventors of the present invention consider collecting the measured values ​​of the target Hall sensor 220 at different temperatures during the above-mentioned ambient temperature drop, 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 can be provided near the target Hall sensor 220. After the circuit 210 to be tested is changed from a pass 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 corresponding to each temperature during the process of ambient temperature dropping.

[0057] S102 , updating the zero drift correction table of the target Hall sensor 220 based on the measurement values ​​at multiple moments and the first ambient temperature.

[0058] The zero drift correction table includes a plurality of 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 correspondence table between ambient temperature and zero drift correction value. The multiple preset second ambient temperatures may 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°C to 80°C, then the multiple preset second ambient temperatures may be 20°C, 25°C, 30°C, 35°C, 40°C, ..., 65°C, 70°C, 75°C, 80°C; or, the multiple preset second ambient temperatures may be 20°C, 21°C, 22°C, 23°C, 24°C, ..., 77°C, 78°C, 79°C, 80°C. In actual applications, the value of the second ambient temperature may be determined according to actual application requirements such as calculation requirements and accuracy requirements, and this application does not limit 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 210 to be tested 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 210 to be tested 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 drift values; when the ambient temperature drops to room temperature (or normal temperature), stop collecting; and determine the first zero drift correction value in the initial zero drift correction table based on the measurement values ​​collected at multiple second ambient temperatures.

[0061] After the target Hall sensor 220 is put into use, every time the circuit 210 to be tested is converted from the on-state to the open-circuit state, the zero drift of the target Hall sensor 220 can be collected by using the subsequent cooling process, so as to update the first zero drift correction value in the zero drift correction table. It should be noted that, on the one hand, in practical applications, after the circuit 210 to be tested is converted from the on-state to the open-circuit state, it may remain in the open-circuit state for a long time. In this case, the ambient temperature will usually drop from the highest temperature to room temperature (or normal temperature), and then maintain room temperature (or normal temperature) until the circuit 210 to be tested is turned on again. In this case, the zero drift at all the second ambient temperatures can be collected, so that the entire zero drift correction table can be updated. On the other hand, in actual applications, after the circuit to be tested 210 is converted from a conductive state to an open state, it may be turned on again soon. That is to say, when the ambient temperature has not dropped to room temperature (or normal temperature), the circuit to be tested 210 is turned on again. In this case, only part of the zero drift corresponding to the second ambient temperature can be collected, so only part 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: Determine an average value of the measurement values ​​corresponding to each third ambient temperature based on the measurement values ​​at multiple moments and the first 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 the first ambient temperature at multiple moments. When collecting the measured values ​​and the first ambient temperature at multiple moments, the first ambient temperature may be continuous. For example, the first ambient temperature can be 78.5°C, 78°C, 77.5°C, 77°C...56.5°C. If the second ambient temperature in this embodiment is 20°C, 25°C, 30°C...75°C, 80°C, it is necessary to filter out the value of the second ambient temperature from the first ambient temperature, that is, the third ambient temperature. The third ambient temperature includes 75°C, 70°C, 65°C, and 60°C. 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 expression, and its actual temperature value is consistent with the temperature value in the second ambient temperature.

[0065] In this embodiment, among the measurement values ​​and the first ambient temperature collected at multiple moments, there may be multiple consecutive moments where the first ambient temperature is the same, but the measurement values ​​are different, that is, the zero drift at the same temperature may fluctuate. At this time, the measurement values ​​at the temperature can be averaged to determine the average zero drift corresponding to the temperature.

[0066] S1022: Determine a second zero drift correction value corresponding to each third ambient temperature based on an average value of the measurement values ​​corresponding to each third ambient temperature, and update a first zero drift correction value corresponding to each third ambient temperature in a zero drift correction table.

[0067] For example, in step S1021, it is determined that the average value of the current measurement value corresponding to the third ambient temperature of 55°C is 0.01 A. Then in step S1022, it can be determined that the second zero drift correction value corresponding to the third ambient temperature of 55°C is -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 to be tested is in a connection state, calibrating the target Hall sensor based on the zero drift correction table.

[0069] In some embodiments, step S103 may include: determining a third zero drift correction value corresponding to the target Hall sensor at the current moment based on the zero drift correction table and the ambient temperature monitored at the current moment; and correcting the zero drift of the target Hall sensor at the current moment 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 performing zero drift correction on the target Hall sensor 220 , and the “third” here is only used to distinguish the expression.

[0071] The Hall sensor correction method provided in the above embodiment collects the measurement value of the target Hall sensor when the measured physical quantity is actually zero and the ambient temperature drops, thereby obtaining the latest zero drift corresponding to each temperature in the cooling process, and updating the zero drift correction table according to these latest zero drift values. When the target Hall sensor performs zero drift correction according to the zero drift correction table at different temperatures, it can be corrected with the latest zero drift corresponding to the current temperature, thereby effectively improving the accuracy of the measurement results of the Hall sensor at abnormal temperatures.

[0072] Next, the Hall sensor calibration method provided by the present invention is described with a specific embodiment.

[0073] In this specific embodiment, the circuit to be tested is a circuit in the energy storage system, and the physical quantity includes current. Figure 3 The energy storage system 300 in this embodiment includes a plurality of battery clusters 310 connected in parallel and a plurality of high-voltage boxes 320 connected to each battery cluster; a target Hall sensor 220 and a temperature probe 321 are provided in the high-voltage box 320; the target Hall sensor 220 is used to measure the current in the circuit where the battery cluster 310 connected to the corresponding high-voltage box 320 is located, and the temperature probe 321 is used to collect the ambient temperature. Figure 3 As shown, the battery cluster 310 includes a plurality of single cells 311. The energy storage system 300 also includes an energy storage converter 330 connected in series with the plurality of parallel battery clusters 310. The energy storage converter 330 includes a current detection device 331, which is used to collect 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 electric energy.

[0074] In this embodiment, the high-voltage box 320 is generally not provided with 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 transferred to the high-voltage box 320, causing the ambient temperature of the target Hall sensor 220 to increase. Accordingly, when the energy storage system 300 no longer dissipates heat, the ambient temperature of the target Hall sensor 220 will no longer continue to increase. If the loop where each battery cluster 310 is located is converted from a state where current flows to a state where current does not flow, the ambient temperature of the target Hall sensor 220 will gradually decrease. Figure 4 FIG. 2 is a graph showing the temperature variation over time of a certain target Hall sensor 220 during state switching.

[0075] In this embodiment, the implementation process of step S101 may be: when the energy storage system 300 is converted from the charging and discharging state to the static state, if it is monitored that there is no circulation between the battery clusters 310, then in the process of the ambient temperature dropping, 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 can realize the bidirectional flow of electric energy through the energy storage converter (PCS) in the charging and discharging state, and can be charged or discharged according to the needs of the power grid. Therefore, when the energy storage system 300 is in the charging state or the discharging state, there is current flow in the circuit where each battery cluster 310 is located. The static state of the energy storage system 300 refers to the state in which the energy storage system 300 remains stationary and does not perform energy conversion during the period when there is no charging or discharging activity. In this state, the energy storage system will not exchange energy with the power grid or the load, and the battery cluster 310 maintains the current state of charge.

[0077] In the above embodiment, after collecting the measurement values ​​at multiple times and the first ambient temperature, the second zero drift correction value corresponding to the third ambient temperature can be determined, so as to update the zero drift correction table. Here, it should be noted that the zero drift of the Hall sensor is mainly affected by temperature, but the inventor of the present invention also found that after the Hall sensor is put into use, as the use time increases, its zero drift may also change due to the aging of the device itself, and the aging of the device will also be affected by the operation of the equipment in the use scenario. Therefore, in the embodiment of the present invention, the method of online acquisition of the initial zero drift correction value and online update of the zero drift correction table is adopted to fully consider the influence of the use environment on the zero drift of the Hall sensor, so that each time the Hall sensor is zero drift corrected, a zero drift correction value that can accurately correct the zero drift amount of the Hall sensor in the latest state is used.

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

[0079] The cluster-end cumulative total pressure of each battery cluster 310 is obtained, and the maximum and minimum values ​​of the cumulative total pressures of all cluster ends are determined; the cluster-end cumulative total pressure of each battery cluster 310 is the sum of the voltages of all the single cells 311 connected in series in the battery cluster 310; if the difference between the maximum and minimum values ​​is less than the preset voltage difference, it is determined that there is no circulation between the battery clusters 310; if the difference is greater than or equal to the preset voltage difference, it is determined that there is circulation between the battery clusters 310.

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

[0081] In the above embodiment, when confirming whether there is a circulation between the battery clusters 310, it is necessary to ensure that no "cell voltage acquisition failure" occurs in the energy storage system 300 to avoid misjudgment due to inaccurate reading of the cluster-end accumulated total voltage value.

[0082] Optionally, the static state of the energy storage system 300 can be determined by the bus current. Before monitoring that there is no circulating current between the battery clusters, the above-mentioned Hall sensor calibration method can also include: obtaining the bus current collected by the current detection device 331; when monitoring that the bus current changes from non-zero to zero, determining that the energy storage system 300 is converted from the charging and discharging state to the static state.

[0083] The implementation process of step S103 may be: 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 correction 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, and the data processing device includes a Hall calibration module for storing a zero drift correction table of each target Hall sensor 200, and determining a 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 is converted from the charging and discharging state to the static state and there is no circulation between the battery clusters 310, the measurement value of the target Hall sensor 220 during the ambient temperature drop is collected, so as to determine the zero drift amount at different temperatures and update the zero drift correction table. When the energy storage system 300 is in the charging and discharging state, the correction value of the target Hall sensor 200 is determined based on the latest zero drift correction table, so that the current value of each battery cluster 310 during charging and discharging can be accurately obtained.

[0086] It should be noted that the above 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 is used to control the on and off of the corresponding battery cluster 310. The current measured by the target Hall sensor 220 may be the current passing through the high voltage box relay. Before the high voltage box relay is closed (before power-on), the current therein must be 0, and at this time, the target Hall sensor 220 can be directly zeroed.

[0087] In some embodiments, in order to improve the accuracy of the Hall sensor, in addition to performing zero drift correction on it, temperature drift correction can also be performed on it at the same time. The above-mentioned Hall sensor correction method can also include:

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

[0089] Among them, the brand and model of the sample Hall sensor are the same as those of the target Hall sensor 220. The fourth ambient temperature refers to the temperature value set when considering the temperature drift correction. The fourth ambient temperature can be the same as the second ambient temperature, that is, a plurality of 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 completely the same as the second ambient temperature can also be preset as required. For example, the second ambient temperature includes 20°C, 30°C, 40°C...80°C, and the fourth ambient temperature includes 20°C, 25°C, 30°C...80°C. It should be understood that the values ​​of the second ambient temperature and the fourth ambient temperature are determined according to the working environment and device performance of the target Hall sensor 220, and the values ​​can be temperatures above zero or temperatures below zero. The present invention does not specifically limit its value range.

[0090] In this embodiment, when temperature drift correction and zero drift correction are performed on the target Hall sensor 220 at the same time, a Hall correction function may be used:

[0091] y=kx+b

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

[0093] It has been found through research that temperature drift is in accordance with a linear relationship, that is, temperature and the linear error coefficient k are in accordance with a linear relationship. The linear error coefficient k used for temperature drift correction can be determined offline, so the temperature drift law of the target Hall sensor 220 can be determined using the manufacturer's test data or the test data of the self-tested sample device. In other words, the multiple measured currents in step S104, and the test values ​​obtained by testing each measured current by the sample Hall sensor at multiple fourth ambient temperatures, can be the test data of the Hall sensor manufacturer or the self-test test data. In actual applications, which data to use can be reasonably selected according to actual conditions.

[0094] S105: Determine a relationship between the linear error coefficient and the ambient temperature based on the linear error coefficient corresponding to each fourth ambient temperature.

[0095] The relationship is:

[0096] k=mT+n

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

[0098] According to 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 of the target Hall sensor monitored at the current moment and the relationship, correct 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 according to the real-time ambient temperature, so as to accurately correct the temperature drift of the target Hall sensor 220. In other embodiments, the change of the ambient temperature can also be monitored in real time, and the temperature value in the above relationship is updated whenever the ambient temperature changes to a preset temperature difference. The temperature change refers to the difference between the currently collected ambient temperature and the ambient temperature in the current relationship.

[0101] Exemplarily, the preset temperature difference is first set to 5°C. At the first moment, the ambient temperature in the relationship is updated to 35°C, then the linear error coefficient k=35m+n; the ambient temperature collected at the second moment is 36°C, the temperature change is 1°C, which is less than the preset temperature difference, then when the temperature drift correction is performed at the second moment, the linear error coefficient k used is still 35m+n; if the ambient temperature collected at the third moment is 40°C, the temperature change reaches 5°C, therefore, the ambient temperature in the relationship should be updated at the third moment, and the linear error coefficient k=40m+n.

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

[0103] S1031, determining a Hall correction function corresponding to the target Hall sensor 220 based on the currently monitored ambient temperature, the above relationship and the zero drift correction table.

[0104] The Hall correction function is a linear function that takes the uncalibrated measurement value of the target Hall sensor 220 as input and the corrected value of the target Hall sensor 220 as output. The slope of the Hall correction function is a relationship, 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 Tis the zero drift correction value determined based on the zero drift correction table.

[0106] In a first possible implementation, the zero drift correction value b T Based on the ambient temperature T introduced in the Hall correction function. Step S1031 may include: if the current ambient temperature T(t) is different from the ambient temperature T introduced in the Hall correction function currently used p When the temperature difference reaches the preset temperature difference, the ambient temperature T introduced into the Hall correction function is p Updated to the fifth ambient temperature T q , and according to the fifth ambient temperature T q 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 It is the current ambient temperature T(t), or it is the temperature among the fourth ambient temperatures that is closest to the current ambient temperature T(t).

[0107] In a second possible implementation, the zero drift correction value b T Based on the current ambient temperature T(t), step S1031 may include: if the current ambient temperature T(t) is equal to the ambient temperature T introduced in the Hall correction function currently used, p When the temperature difference reaches the preset temperature difference, the ambient temperature T introduced into the Hall correction function is p Updated to the fifth ambient temperature T q , and determine the zero drift correction value b in the Hall correction function according to the current ambient temperature T(t) and the zero drift correction table T Among them, the fifth ambient temperature T q It is the current ambient temperature T(t), or it is the temperature among the fourth ambient temperatures that is closest to the current ambient temperature T(t).

[0108] In a third possible implementation, the ambient temperature T p And zero drift correction value b T are determined based on the current ambient temperature T(t). Step S1031 may include: converting the ambient temperature T in the Hall correction function p Update to 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 above, the fifth ambient temperature is the temperature value updated in the temperature drift correction, and the updated temperature value may be the current ambient temperature T(t). For example, the preset temperature difference is 5°C, and the ambient temperature T in the original Hall correction function is pThe ambient temperature T in the Hall correction function needs to be changed to 40℃. The ambient temperatures collected at the following collection moments are 41℃, 43℃, and 46℃, respectively. When 46℃ is detected, the ambient temperature T in the Hall correction function needs to be changed to 41℃, 43℃, and 46℃, respectively. p Updated to 46°C. The fifth ambient temperature can also be a temperature value in the fourth ambient temperature. For example, the preset temperature difference is 5°C, and the fourth ambient temperature includes 15°C, 20°C, 25°C...80°C; the ambient temperature T in the original Hall correction function p The ambient temperature T in the Hall correction function needs to be changed to 40℃. The ambient temperatures collected at the following collection moments are 41℃, 43℃, and 46℃, respectively. When 46℃ is detected, the ambient temperature T in the Hall correction function needs to be changed to 41℃, 43℃, and 46℃, respectively. p Updated to 45℃.

[0110] It should be understood that in practical applications, a suitable Hall correction function update scheme can be selected according to the computing power of the data processing device and the accuracy requirement 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 embodiment, for zero drift correction, the present invention collects the zero drift of the target Hall sensor 220 online under specific conditions, and timely updates its zero drift correction table based on this, thereby fully improving the accuracy of zero drift correction. For temperature drift correction, the present invention also fully considers the impact of different temperatures and temperature changes on temperature drift, and uses a linear relationship to perform temperature drift correction. 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 collected in real time by the temperature probe 321, thereby improving the accuracy of the current measurement result.

[0113] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean 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 embodiment of the present invention.

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

[0115] The target Hall sensor 220 and the temperature probe 321 are disposed in the high voltage box 320 .

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

[0117] The 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 bus current.

[0119] The data processing device 510 is connected to the target Hall sensor 220 and is used to calibrate the measurement value of the target Hall sensor 220 according to the Hall sensor calibration method in the above embodiment.

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

[0121] The energy storage system 300 in the above embodiment can measure more accurate current data when correcting the measured value of the target Hall sensor 220 according to the Hall sensor correction method in the above embodiment, so that the energy storage system 300 can be managed more effectively.

[0122] The embodiment of the present invention also provides a battery management system. 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, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 610 executes the computer program, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0123] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory 620 and executed by the processor 610 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to 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 appreciate that Figure 5 This is only an example of the battery management system 600 and does not constitute a limitation of the battery management system 600. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the battery management system 600 may also include input and output devices, network access devices, buses, etc.

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

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

[0127] For the convenience and simplicity of description, only the division of the above functional modules / units is used as an example for illustration. In actual applications, the above functions can be assigned to different functional modules / units as needed. The above modules / units can be implemented in the form of hardware, software, or a combination of hardware and software.

[0128] The embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the methods in the above method embodiments are implemented.

[0129] The embodiment of the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the methods in the above method embodiments are implemented.

[0130] The computer program includes computer program code, which may be in source code form, object code form, executable file or some intermediate form, etc. Computer readable media may include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0131] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. If there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment according to their internal logical relationship.

[0132] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A Hall sensor calibration method, characterized in that: include: When the circuit to be tested is converted from a connection state to an open state, in the process of the ambient temperature dropping, the measured values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected; the target Hall sensor is used to measure the physical quantity of the circuit to be tested, and when the circuit to be tested is in the connection state, the ambient temperature rises; after the circuit to be tested is converted from the connection state to the open state, the ambient temperature drops; Based on the measurement values ​​at the multiple moments and the first ambient temperature, updating the zero drift correction table of the target Hall sensor; The zero drift correction table includes a plurality of preset second ambient temperatures and first zero drift correction values ​​corresponding to each second ambient temperature; When the circuit to be tested is in a conducting state, the target Hall sensor is calibrated based on the zero drift correction table.

2. The Hall sensor calibration method according to claim 1, characterized in that: The updating of the zero drift correction table of the target Hall sensor based on the measurement values ​​at the multiple moments and the first ambient temperature includes: Based on the measurement values ​​at the multiple moments and the first ambient temperature, determining an average value of the measurement values ​​corresponding to each third ambient temperature; the third ambient temperature is an ambient temperature at the intersection of the multiple preset second ambient temperatures and the first ambient temperature at the multiple moments; Based on the average value of the measurement 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.

3. The Hall sensor calibration method according to claim 1, characterized in that: The calibrating the target Hall sensor based on the zero drift correction table includes: Determine a third zero drift correction value corresponding to the target Hall sensor at the current moment based on the zero drift correction table and the ambient temperature monitored at the current moment; Based on the third zero drift correction value, the zero drift of the target Hall sensor at the current moment is corrected.

4. The Hall sensor calibration method according to claim 1, characterized in that: The circuit to be tested is a circuit in an energy storage system, and the physical quantity includes current; Among them, the energy storage system includes multiple parallel battery clusters and multiple high-voltage boxes respectively connected to each battery cluster; the target Hall sensor and temperature probe are arranged in the high-voltage box; the target Hall sensor is used to measure the current in the circuit where the battery cluster connected to the corresponding high-voltage box is located, and the temperature probe is used to collect the ambient temperature.

5. The Hall sensor calibration method according to claim 4, characterized in that: After the circuit to be tested is converted from a circuit state to an open circuit state, during the process of the ambient temperature decreasing, the measured values ​​of the target Hall sensor at multiple times and the first ambient temperature are collected, including: When the energy storage system is converted from a charging and discharging state to a static state, if it is monitored that there is no circulation between the battery clusters, then 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; When the circuit to be tested is in a connection state, calibrating the target Hall sensor based on the zero drift correction table includes: When the energy storage system is in a charging and discharging state, the target Hall sensor is calibrated based on the zero drift correction table.

6. The Hall sensor calibration method according to claim 5, characterized in that: The battery cluster includes a plurality of single cells; Before detecting that there is no circulating current between the battery clusters, the method further includes: Obtain the cluster-end cumulative total voltage of each battery cluster, and determine the maximum and minimum values ​​of all cluster-end cumulative total voltages; the cluster-end cumulative total voltage of each battery cluster is the sum of the voltages of all series-connected single cells in the 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 circulation between the battery clusters; If the difference is greater than or equal to the preset pressure difference, it is determined that there is a circulating current between the battery clusters.

7. The Hall sensor calibration method according to claim 5, characterized in that: The method further comprises: Based on a plurality of preset measured currents and test values ​​obtained by testing each measured current under a plurality of fourth ambient temperatures by a sample Hall sensor, a 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 value changing with the test value; Based on the linear error coefficients corresponding to the respective fourth ambient temperatures, determining a relationship between the linear error coefficients and the ambient temperature; Based on the ambient temperature of the target Hall sensor currently monitored and the relationship, the temperature drift of the target Hall sensor is corrected.

8. The Hall sensor calibration method according to claim 7, characterized in that: The calibrating the target Hall sensor based on the zero drift correction table includes: Based on the ambient temperature monitored at the current moment, the relational expression and the zero drift correction table, determining a Hall correction function corresponding to the target Hall sensor; wherein the Hall correction function is a linear function that takes the measured value of the target Hall sensor when it is not calibrated as input and takes the corrected value of the target Hall sensor after correction 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, a correction value corresponding to the measurement value of the target Hall sensor at the current moment is determined.

9. The Hall sensor calibration method according to claim 5, characterized in that: The energy storage system further comprises an energy storage converter connected in series with the plurality of parallel battery clusters, wherein the energy storage converter comprises a current detection device, and the current detection device is used to collect bus current; Before detecting that there is no circulating current between the battery clusters, the method further includes: Obtaining the bus current collected by the current detection device; When it is monitored that the bus current changes from non-zero to zero, it is determined that the energy storage system is converted from a charging and discharging state to a static state.

10. An energy storage system, characterized in that: It includes a plurality of battery clusters connected in parallel, a plurality of high-voltage boxes respectively connected to each battery cluster, an energy storage converter connected in series with the plurality of battery clusters connected in parallel, and a data processing device; The high voltage box is provided with a target Hall sensor and a temperature probe; The target Hall sensor is used to measure the current in the loop where the battery cluster connected to the corresponding high-voltage box is located; 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, and the current detection device is used to collect bus current; The data processing device is connected to the target Hall sensor and is used to calibrate the measurement value of the target Hall sensor according to the Hall sensor calibration method according to any one of claims 4 to 9.

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