EMS control method based on online monitoring of energy storage system sensors

Abstract

The present invention discloses an EMS control method based on online monitoring of energy storage system sensors. The energy storage system includes a plurality of energy storage units and a temperature sensor, a voltage sensor and a current sensor arranged on each energy storage unit. The method includes: obtaining the state data of each energy storage unit in the energy storage system in the current control cycle; based on the state data, calculating the SOC change value of the energy storage unit in the current control cycle in combination with the performance data of the energy storage unit; obtaining the SOC measurement value of the energy storage unit in combination with the SOC change value according to the SOC initial value of the energy storage unit in the current control cycle; based on the EMS of the energy storage system, controlling the corresponding energy storage unit to charge and discharge in combination with the SOC measurement value. Accurate SOC measurement values ​​are obtained through the detection data of various sensors in the energy storage system, and targeted charging and discharging are reasonably controlled according to the accurate data of the energy storage unit, and the EMS control strategy is made to have dynamic adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage system control, and in particular to an EMS control method based on online monitoring of energy storage system sensors. Background Art

[0002] With the global emphasis on renewable energy and the growing demand for electricity, energy storage technology has become increasingly prominent in the energy field. Energy storage systems can effectively store electrical energy and play a regulating role when energy supply and demand are unbalanced. For example, they can store electrical energy when there is an excess of renewable energy generation (solar energy, wind energy, etc.) and release electrical energy when energy demand peaks or renewable energy generation is insufficient, thereby improving energy utilization efficiency and enhancing the stability and reliability of the power system. In energy storage systems, energy storage units are core components, and common ones include lithium-ion batteries and lead-acid batteries. In order to achieve efficient operation and precise control of energy storage systems, status monitoring and management of energy storage units are essential. The development of sensor technology enables real-time acquisition of various status data of energy storage units, such as temperature, voltage, and current. These data provide a basic basis for evaluating the performance and status of energy storage units.

[0003] Traditional EMS control methods can, to a certain extent, control charging and discharging based on information such as the SOC (State of Charge) of the energy storage unit, but there are many limitations. Current charging and discharging control strategies often do not fully consider the performance differences of different energy storage units in the energy storage system. Different energy storage units may have large differences in capacity, internal resistance, charging and discharging efficiency, etc. due to manufacturing processes, usage history, etc. During the charging and discharging process, if unified control is performed without distinction, some energy storage units may overwork, while some energy storage units fail to fully function, affecting the performance and life of the entire energy storage system. For example, some energy storage units with a high degree of aging and large internal resistance may generate too much heat during high-power charging and discharging, accelerating their own aging, and may also affect the safety of the entire energy storage system. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide an EMS control method based on online monitoring of energy storage system sensors, obtain accurate SOC measurement values ​​through detection data of various sensors in the energy storage system, perform targeted charging and discharging reasonable control based on accurate data of the energy storage unit, and make the EMS control strategy have dynamic adaptability.

[0005] To solve the above technical problems, a first aspect of an embodiment of the present invention provides an EMS control method based on online monitoring of an energy storage system sensor. The energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor, and a current sensor arranged on each of the energy storage units. The EMS control method includes the following steps:

[0006] Acquire status data of each energy storage unit in the energy storage system in a current control cycle;

[0007] Based on the state data, and in combination with the performance data of the energy storage unit, calculate the SOC change value of the energy storage unit in the current control cycle;

[0008] Obtaining an SOC measurement value of the energy storage unit according to an initial SOC value of the energy storage unit in a current control cycle and in combination with the SOC change value;

[0009] Based on the EMS of the energy storage system, the corresponding energy storage unit is controlled to be charged and discharged in combination with the SOC measurement value.

[0010] Further, the state data includes: real-time temperature value, real-time voltage value and real-time current value;

[0011] The performance data includes: a nominal open circuit voltage, a reference temperature and a maximum available capacity of the energy storage unit.

[0012] Furthermore, the calculation formula of the SOC change value of the energy storage unit is:

[0013]

[0014] Among them, ΔSOC ij is the SOC change value, i is the sequence number of the energy storage unit, j is the sequence number of the control cycle, I discharge_ij (t) is the discharge current of the current control cycle, I charge_ij (t) is the charging current of the current control cycle, t1 is the start time of the current control cycle, t2 is the end time of the current control cycle, Q max is the maximum available capacity of the energy storage unit, OCV nominal is the nominal open circuit voltage of the energy storage unit under standard conditions, V measured_ij is the actual voltage value, R0 is the energy storage unit at the reference temperature T ref The internal resistance value at the time of η1 is the coefficient of linear change of internal resistance with temperature, T ij is the real-time temperature value, T ref is the reference temperature of the energy storage unit, η2 is the coefficient of the quadratic change of internal resistance with temperature, |I avg | is the average charge and discharge current absolute value in the current control cycle, C rate is the charge and discharge rate.

[0015] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0016] Obtaining a polarization voltage change value of the energy storage unit;

[0017] Calculate the SOC change value of the energy storage unit in combination with the polarization voltage change value;

[0018] The calculation formula of the SOC change value of the energy storage unit is:

[0019]

[0020] ΔV polarization_ij =κ×I avg ×Δt;

[0021] Δt=t2-t1;

[0022] Where, ΔV polarization_ij is the polarization voltage change value of the energy storage unit, and κ is a constant related to the battery material and aging state of the energy storage unit.

[0023] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0024] Obtaining a SOH evaluation value of the energy storage unit;

[0025] Calculating the SOC change value of the energy storage unit in combination with the SOH evaluation value;

[0026] The calculation formula of the SOC change value of the energy storage unit is:

[0027]

[0028]

[0029] Among them, SOH ij is the SOH evaluation value of the i-th energy storage unit in the current detection cycle, R ij is the internal resistance value of the i-th energy storage unit in the current detection cycle, R ij_0 is the initial internal resistance of the i-th energy storage unit, Q ij is the capacity value of the i-th energy storage unit in the current detection cycle, Q ij_0 is the initial capacity value of the i-th energy storage unit, ω R and ω Q They are the weight coefficients of internal resistance and capacity when calculating the SOH evaluation value.

[0030] Furthermore, the obtaining of the status data of each energy storage unit in the energy storage system in the current control cycle includes:

[0031] Obtaining the real-time current value at several sampling time points in the current control cycle;

[0032] Perform data interpolation processing on the real-time current value between two adjacent sampling time points based on the spline interpolation method;

[0033] The SOC change value is calculated based on the sampling data and interpolation data of the real-time current value in the current control cycle.

[0034] Further, the controlling the corresponding energy storage unit to charge and discharge in combination with the SOC measurement value includes:

[0035] The energy storage unit whose SOC measurement value is greater than or equal to a first preset threshold is marked as a high-power state, the energy storage unit whose SOC measurement value is greater than or equal to a second preset threshold and less than the first preset threshold is marked as a normal state, and the energy storage unit whose SOC measurement value is less than the second preset threshold is marked as a low-power state;

[0036] When the energy storage system is in the process of discharging, the energy storage unit in a high power state is discharged first;

[0037] When the energy storage system is in the charging process, the energy storage unit in a low power state is charged first.

[0038] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0039] When the discharge power command value of the energy storage system is greater than the sum of the dischargeable powers of the plurality of energy storage units in a high power state, the plurality of energy storage units in a normal state are selected in descending order of SOC measurement values ​​for discharge;

[0040] When the charging power command value of the energy storage system is greater than the sum of the rechargeable powers of the several energy storage units in the low power state, the several energy storage units in the normal state are selected in order from small to large in the SOC measurement value for charging.

[0041] Accordingly, a second aspect of an embodiment of the present invention provides an EMS control device based on online monitoring of an energy storage system sensor, wherein the energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor, and a current sensor disposed on each of the energy storage units, and the EMS control device includes:

[0042] A status data acquisition module, which is used to obtain status data of each energy storage unit in the energy storage system in a current control cycle;

[0043] A first data calculation module, which is used to calculate the SOC change value of the energy storage unit in the current control cycle based on the state data and in combination with the performance data of the energy storage unit;

[0044] A second data calculation module, which is used to obtain the SOC measurement value of the energy storage unit according to the SOC initial value of the energy storage unit in the current control cycle in combination with the SOC change value;

[0045] An energy storage unit control module is used to control the charging and discharging of the corresponding energy storage unit based on the EMS of the energy storage system and in combination with the SOC measurement value.

[0046] Accordingly, a third aspect of an embodiment of the present invention provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the above-mentioned EMS control method based on online monitoring of energy storage system sensors.

[0047] Accordingly, a fourth aspect of an embodiment of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-mentioned EMS control method based on online monitoring of energy storage system sensors.

[0048] The above technical solution of the embodiment of the present invention has the following beneficial technical effects:

[0049] 1. Through multi-sensor data fusion and consideration of multiple influencing factors, the SOC of the energy storage unit is accurately evaluated. Not only the real-time temperature value, real-time voltage value and real-time current value are used for basic calculation, but also the polarization voltage change value and SOH evaluation value are incorporated to correct the SOC change value, thereby effectively overcoming the SOC estimation error caused by a single factor or simple calculation, making the internal power state of the energy storage unit more accurate, and providing a highly reliable basis for the charge and discharge control of the energy storage system, avoiding problems such as over-charging and discharging, energy waste or shortened battery life caused by inaccurate SOC estimation, and improving the stability and economy of the entire energy storage system;

[0050] 2. Based on accurate SOC measurement values, EMS can perform efficient and flexible charge and discharge control according to the power state of the energy storage unit. By dividing the energy storage unit into high power, normal and low power states, and calling the energy storage unit in the corresponding state in a specific order according to different charging and discharging requirements, it realizes the refined management of the energy flow of the energy storage system. When discharging, the energy storage unit in the high power state is used first, which can ensure that the energy storage resources are used to the maximum extent while meeting the load demand. When charging, the energy storage unit in the low power state is charged first, which helps to maintain the power balance of each energy storage unit in the system and reduce the performance inconsistency caused by excessive power differences. When the power of the energy storage unit in the high or low power state is insufficient, it can be reasonably supplemented from the energy storage unit in the normal state, giving full play to the potential of the entire energy storage system, improving the adaptability of the energy storage system to variable loads and complex power grid environments, and ensuring the reliability and continuity of power supply;

[0051] 3. Spline interpolation is used to process the sampled data during the data acquisition process, which effectively improves the continuity and accuracy of the data, thereby improving the accuracy of the SOC calculation and the reliability of the entire control strategy. By interpolating and averaging the data at multiple sampling time points, it can more comprehensively reflect the actual state changes of the energy storage unit in the current control cycle and reduce the calculation deviation caused by data discreteness or sampling errors. On the one hand, accurate SOC calculation provides a guarantee for reasonable charging and discharging control. On the other hand, the actual operating data in the charging and discharging control process can be fed back to further optimize the data processing and SOC calculation model, so that the entire EMS control method can continuously adapt to the performance changes of the energy storage system and the dynamic adjustment of the operating environment, achieve long-term stable and efficient operation results, and reduce system maintenance costs and operating risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart of an EMS control method based on online monitoring of energy storage system sensors provided by an embodiment of the present invention;

[0053] Figure 2 It is a block diagram of an EMS control device module based on online monitoring of energy storage system sensors provided in an embodiment of the present invention.

[0054] Reference numerals:

[0055] 1. Status data acquisition module, 2. First data calculation module, 3. Second data calculation module, 4. Energy storage unit control module. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0057] Please refer to Figure 1 A first aspect of an embodiment of the present invention provides an EMS control method based on online monitoring of an energy storage system sensor. The energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor, and a current sensor disposed on each energy storage unit. The EMS control method includes the following steps:

[0058] Step S100, obtaining status data of each energy storage unit in the energy storage system in the current control cycle.

[0059] Data is acquired by relying on temperature sensors, voltage sensors, and current sensors installed on each energy storage unit. The above sensors need to have sufficient accuracy and reliability to ensure that the collected data can accurately reflect the real-time status of the energy storage unit. The frequency of data collection needs to be determined according to the characteristics and application scenarios of the energy storage unit. For example, in some applications that are sensitive to changes in battery status, such as electric vehicle energy storage systems, a higher acquisition frequency (several times per second or even higher) may be required to capture the rapid changes of the battery during the charging and discharging process in a timely manner; and for some large-scale power grid energy storage systems, their status changes are relatively slow, and the acquisition frequency can be appropriately reduced (once every few seconds), but it is also necessary to ensure that key status change information can be monitored.

[0060] After acquiring the raw state data, preliminary preprocessing includes: checking the integrity of the data to ensure that there is no missing or erroneous data. For possible noise data (such as abnormal sensor readings due to electromagnetic interference, etc.), filtering algorithms can be used for processing. For example, a simple moving average filter can be used to remove high-frequency noise, or a more complex Kalman filter algorithm can be used to remove noise while also estimating and predicting the state of the data, thereby improving data availability.

[0061] Specifically, the status data includes: real-time temperature value, real-time voltage value and real-time current value, and the performance data includes: nominal open circuit voltage, reference temperature and maximum available capacity of the energy storage unit.

[0062] Step S200, based on the state data and in combination with the performance data of the energy storage unit, calculate the SOC change value of the energy storage unit in the current control cycle.

[0063] When calculating the SOC change value, multiple factors should be considered comprehensively. Charging current and discharging current are key factors that directly affect the SOC change. The increase or decrease in power can be calculated by integrating the charging current and discharging current within the control cycle. In addition, many factors such as the internal resistance, open circuit voltage and temperature of the battery need to be considered. Among them, the internal resistance will cause the battery to have a voltage drop during the charging and discharging process, and its size is related to the temperature. This voltage drop will affect the actual voltage value used for power calculation, and then affect the calculation of the SOC change value; the open circuit voltage also has a certain functional relationship with the battery's SOC, and can also be further refined into a function related to SOC and temperature to improve the accuracy of SOC calculation.

[0064] The charge and discharge rate should also be taken into account when calculating the SOC change value. A higher charge and discharge rate will lead to an increase in the polarization phenomenon inside the battery, which will reduce the actual available capacity of the battery at this rate. It is necessary to consider the correction of the charge and discharge rate to the SOC change value calculation. In addition, different types of batteries have different tolerances to charge and discharge rates. It is necessary to accurately determine the calculation parameters of this part based on the specific characteristics of the battery. As the battery ages, its response to the charge and discharge rate will also change, and the relevant parameters need to be updated and optimized regularly.

[0065] Step S300, obtaining the SOC measurement value of the energy storage unit according to the SOC initial value of the energy storage unit in the current control cycle and the SOC change value.

[0066] Specifically, the SOC initial value is the state of charge of the energy storage unit at the beginning of the current control cycle, and the SOC change value reflects the change in SOC caused by charging or discharging operations during this control cycle. By adding these two values, the SOC measurement value can be obtained, which represents the state of charge of the energy storage unit at the end of the current control cycle.

[0067] The initial SOC value is an important basis for calculating the measured SOC value. When the energy storage system is started for the first time or restarted after a long period of inactivity, the initial SOC value can be determined by some specific methods, such as the open circuit voltage method (after the battery has been inactive for a long enough time, its open circuit voltage is measured, and the initial SOC value is determined based on the pre-established open circuit voltage-SOC curve) or the capacity calibration method (the battery is fully charged and discharged to determine its actual capacity, thereby obtaining the initial SOC value).

[0068] During the normal operation of the energy storage system, the initial SOC value is the SOC measurement value obtained in the previous control cycle. In addition, in order to improve the accuracy of the SOC measurement value, the initial SOC value needs to be calibrated regularly, for example, the open circuit voltage method or other more accurate methods are used to correct the initial SOC value every certain number of charge and discharge cycles or time intervals to compensate for the SOC calculation deviation caused by factors such as aging and self-discharge during battery use.

[0069] After obtaining the SOC measurement value, its rationality should be judged, and the SOC measurement value should be within a reasonable range of 0 to 1. If the calculated SOC measurement value exceeds this range, it needs to be corrected accordingly. At the same time, the SOC measurement value can also be compared with historical data or the SOC value predicted based on the energy storage system operation mode. If the deviation is too large, there may be problems such as data collection errors, abnormal battery performance, or inaccurate calculation model, which require further investigation and correction. For example, you can check whether the sensor is working properly, whether the battery has a fault (such as short circuit, open circuit, etc.), or adjust and optimize the parameters in the calculation model.

[0070] Step S400, based on the EMS of the energy storage system and in combination with the SOC measurement value, the corresponding energy storage unit is controlled to charge and discharge.

[0071] When controlling the charging and discharging of energy storage units, not only the SOC measurement value and state priority should be considered, but also the chargeable and dischargeable power of the energy storage unit. When the discharge power command value of the energy storage system is greater than the sum of the dischargeable powers of several energy storage units in a high-power state, the energy storage units in a normal state are selected for discharge in order from large to small SOC measurement values, and the discharge power of each energy storage unit involved in the discharge should be reasonably allocated to avoid excessive discharge of a certain energy storage unit. Similarly, when charging, when the charging power command value is greater than the sum of the chargeable powers of several energy storage units in a low-power state, the energy storage units in a normal state are selected for charging in order from small to large SOC measurement values, and the charging power is controlled to prevent overcharging. In addition, the energy balance and power balance of the entire energy storage system need to be considered to ensure that the energy storage system can operate stably and efficiently under different operating conditions and achieve good energy interaction with the external power grid or load.

[0072] In a specific implementation of the embodiment of the present invention, the calculation formula of the SOC change value of the energy storage unit is:

[0073]

[0074] Among them, ΔSOC ij is the SOC change value, i is the sequence number of the energy storage unit, j is the sequence number of the control cycle, I discharge_ij(t) is the discharge current of the current control cycle, I charge_ij (t) is the charging current of the current control cycle, t1 is the start time of the current control cycle, t2 is the end time of the current control cycle, Q max is the maximum available capacity of the energy storage unit, OCV nominal is the nominal open circuit voltage of the energy storage unit under standard conditions, V measured_ij is the actual voltage value, R0 is the energy storage unit at the reference temperature T ref The internal resistance value at the time of η1 is the coefficient of linear change of internal resistance with temperature, T ij is the real-time temperature value, T ref is the reference temperature of the energy storage unit, η2 is the coefficient of the quadratic change of internal resistance with temperature, |I avg | is the average charge and discharge current absolute value in the current control cycle, C rate is the charge and discharge rate.

[0075] Among them, the discharge current I discharge_ij (t) flows out of the battery, which will reduce the battery power. Its integral over time It directly reflects the amount of power reduction during the discharge process. charge_ij (t) flows into the battery to increase the charge, It is the embodiment of charging power. It determines the net change in charge, which in turn affects the SOC. For example, if the discharge current is large and lasts for a long time, while the charging current is small or there is no charging process, the SOC will drop significantly. Based on the measurement of high-precision current sensors (the sensors should have wide range, low noise, fast response and other characteristics), it can adapt to the accurate measurement of current at different charge and discharge rates. For the measured current data, filtering may be required to remove noise interference. At the same time, factors such as the zero drift and gain error of the current sensor should be considered, and regular calibration should be performed to ensure the accuracy of current measurement.

[0076] The maximum available capacity of a battery is affected by many factors, including battery materials, manufacturing process, use environment, and aging. For example, as the number of cycles of lithium-ion batteries increases, changes in the electrode material structure and loss of active substances will cause the capacity to gradually decay. max There is also a significant impact. At low temperatures, the rate of chemical reactions inside the battery decreases, reducing the available capacity; high temperatures may trigger side reactions, which also damage the capacity. New batteries can be tested through standard capacity tests to determine the initial Q maxDuring use, the capacity needs to be re-evaluated regularly (such as every certain number of cycles or running time). A full charge and discharge test can be used, but this method is time-consuming and may cause certain damage to the battery. Alternatively, a partial discharge test combined with an open circuit voltage method, internal resistance measurement and other indirect methods can be used to estimate the capacity change, thereby updating Q. max value to ensure that the SOC calculation is based on accurate capacity parameters.

[0077] The nominal open circuit voltage of the energy storage unit has a specific functional relationship with SOC, which is nonlinear. The nominal open circuit voltage OCV under standard conditions (specific temperature, pressure, etc.) nominal Different battery systems (such as lead-acid batteries, lithium-ion batteries, etc.) have different OCVs. nominal Curve shape. For example, when the SOC of a lithium-ion battery is in the middle range, the open circuit voltage changes relatively slowly, while when the SOC is close to the two ends (extremely low or extremely high), the voltage changes more sharply. In practical applications, temperature and battery aging will change the OCV-SOC relationship. When the temperature rises or falls, the balance of the chemical reaction inside the battery moves, and the open circuit voltage will change accordingly. A three-dimensional temperature-OCV-SOC model can be established to adjust the OCV according to the current temperature. nominal For aged batteries, the OCV-SOC curve will shift and deform due to changes in the structure and performance of the electrode materials. It is necessary to establish an aging model based on long-term experimental data to correct the OCV nominal Compensation is performed to improve the SOC calculation accuracy.

[0078] The actual measured voltage V measured_ij and open circuit voltage OCV nominal , internal resistance voltage drop and polarization voltage. When calculating SOC, use V measured_ij With OCV nominal The difference between the two values ​​and the internal resistance model are used to infer the change in the internal state of the battery and then correct the SOC. measured_ij Lower than OCV nominal When the difference is large, it may be due to the large current discharge causing the internal resistance voltage drop and polarization voltage to increase. At this time, it is necessary to comprehensively consider these factors to accurately calculate the SOC, rather than simply judging the SOC based on the voltage value.

[0079] The internal resistance of the energy storage resistor battery is R0+η1×(T ij -T ref )+η2×(T ij -T ref ) 2 , R0 is the reference temperature T refThe basic internal resistance under the temperature reflects the inherent resistance characteristics of the battery at a specific standard temperature. η1 and η2 respectively reflect the degree of linear and quadratic change of the internal resistance with temperature. For example, for some batteries, within a certain temperature range, the internal resistance may first decrease with increasing temperature (η1 plays a leading role), but when the temperature continues to rise, the internal resistance will increase again due to intensified side reactions and other reasons (η2 has a prominent influence). The internal resistance of the battery at different temperatures is experimentally measured, and the values ​​of R0, η1 and η2 are determined by data fitting method. In the SOC calculation, according to the current battery temperature T ij Substitute the model to calculate the actual internal resistance, and then calculate the internal resistance voltage drop (I×R), which is used to correct the SOC calculation based on voltage measurement. At the same time, as the battery ages, the internal resistance will change, and these parameters need to be re-measured regularly to ensure the accuracy of the internal resistance model.

[0080] Measure the current battery temperature T through the temperature sensor ij , the sensor should have good thermal response characteristics and accuracy, and be able to accurately reflect the temperature changes inside the battery. Temperature affects almost all performance of the battery, including chemical reaction rate, ion diffusion rate, internal resistance, open circuit voltage and capacity. In the SOC calculation, temperature mainly affects the SOC calculation result indirectly by affecting the internal resistance and open circuit voltage. For example, at low temperatures, the internal resistance of the battery increases, and the internal resistance voltage drop increases under the same current, resulting in a decrease in the measured voltage. If the temperature correction is not considered, the SOC will be misjudged as low; at high temperatures, the capacity may decay due to side reactions, affecting the benchmark capacity parameters for the SOC calculation. Reference temperature T ref It is the reference temperature for establishing the internal resistance model and other temperature-related models. It is usually selected in the middle of the normal operating temperature range of the battery or a specific standard temperature (such as 25°C). In practical applications, all temperature-related parameter corrections are relative to T ref This is done to ensure the consistency and accuracy of SOC calculation under different temperature environments.

[0081] The average absolute value of the charge and discharge current in the time period |I avg_ij |Reflects the average intensity of the charge and discharge current during the time period in which the SOC change is calculated, which is related to the battery capacity Q max Combined, through The influence of charge and discharge rate on the actual available capacity and SOC change of the battery is taken into account in the form of . A large average current means a higher charge and discharge rate, which will lead to increased polarization inside the battery, reducing the actual available capacity at this rate, thus affecting the accuracy of SOC calculation. For example, when discharging at a high rate, the battery voltage drops rapidly. If the SOC is calculated only by conventional methods, the remaining battery capacity will be overestimated.

[0082] Charge and discharge rate C rateDefines the multiple of the battery's charge and discharge rate relative to its rated capacity. Different batteries have different tolerances to charge and discharge rates, and their effects on battery performance vary. Determine C rate The parameters need to be tested through a large number of experiments to test the battery's performance indicators such as capacity retention rate, voltage change, internal resistance change at different rates, and establish C rate The relationship model with the above performance data is used for correction in SOC calculation. At the same time, as the battery ages, its response characteristics to the charge and discharge rate will change, and C needs to be updated regularly. rate Related parameters.

[0083] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0084] Step S511, obtaining the polarization voltage change value of the energy storage unit.

[0085] During the charging and discharging process of the energy storage unit, due to the complex electrochemical process inside the battery, the reaction rate on the electrode surface and the diffusion rate of ions in the electrolyte cannot reach a state of equilibrium instantly, resulting in polarization, causing the actual battery voltage to deviate from its open circuit voltage. This deviation value is the polarization voltage change value.

[0086] The polarization voltage change value can be estimated based on the relationship between the polarization voltage, the charge and discharge current, and the time. polarization_ij and the average charge and discharge current I avg_ij The polarization voltage change is related to the time interval Δt (where κ is a constant related to the battery material and aging state). By monitoring the charge and discharge current in real time and setting an appropriate time interval, combined with a predetermined κ value, the polarization voltage change can be estimated.

[0087] Step S512, calculating the SOC change value of the energy storage unit in combination with the polarization voltage change value.

[0088] When accurately calculating the SOC of an energy storage unit, polarization voltage is a factor that cannot be ignored. This is because the calculation of SOC is usually based on battery voltage, current and other parameters to indirectly infer the state of charge inside the battery. The polarization voltage will cause the measured battery terminal voltage to deviate from its open circuit voltage that truly reflects the SOC. If the influence of the polarization voltage is not considered, directly calculating the SOC based on the measured voltage will result in a large error. For example, at the beginning of a large current discharge, the battery terminal voltage will drop rapidly due to the presence of the polarization voltage. If the SOC is judged only based on the voltage after the drop at this time, it will be mistakenly believed that the SOC has dropped too fast, but in fact the actual amount of charge inside the battery has not decreased that much.

[0089] Accordingly, the calculation formula for the SOC change value of the energy storage unit is:

[0090]

[0091] ΔV polarization_ij =κ×I avg ×Δt;

[0092] Δt = t2 - t1;

[0093] Where, ΔV polarization_ij is the polarization voltage change value of the energy storage unit, and κ is a constant related to the battery material and aging state of the energy storage unit.

[0094] Polarization voltage change ΔV polarization_ij It is the voltage deviation caused by the non-equilibrium state of the electrode reaction during the battery charging and discharging process. Correct the SOC calculation. Polarization phenomena include ohmic polarization, concentration polarization, and electrochemical polarization. For example, during high current charging and discharging, ohmic polarization causes an instantaneous voltage drop, concentration polarization causes a voltage change because the ion diffusion rate cannot keep up with the electrode reaction rate, causing the ion concentration on the electrode surface to change, and electrochemical polarization is related to the electrode reaction kinetics. These polarization phenomena have a comprehensive impact on the actual voltage of the battery, which in turn affects the SOC judgment.

[0095] κ is a constant related to battery materials and aging status. Different battery materials (such as different positive electrode materials in lithium-ion batteries) have different polarization characteristics and different κ values. As the battery ages, changes in the electrode material structure and interface properties will intensify polarization and the κ value will also change. To determine the κ value, experiments are required to measure the changes in polarization voltage at different aging stages and under different current conditions, and fit the relationship model between the κ value and the battery status to accurately correct the polarization effect in the SOC calculation.

[0096] Indicates the proportion of the polarization voltage change value in the actual measured voltage. Subtracting this proportion from 1 is equivalent to restoring the SOC change corresponding to the real voltage after removing the polarization effect. For example, if the polarization voltage change value causes the measured voltage to decrease by a certain proportion After correction, the SOC change value will be calculated based on the situation after removing the 10% voltage deviation, making the SOC calculation closer to the actual charge change inside the battery.

[0097] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0098] Step S521, obtaining the SOH evaluation value of the energy storage unit.

[0099] The SOH evaluation value reflects the degree of aging and performance degradation of the battery in the energy storage unit during use. For example, the SOH of a brand new battery is 100%. As the number of charge and discharge cycles increases and time passes, due to factors such as the loss of electrode materials, the decomposition of electrolytes, and the increase of internal resistance, its maximum available capacity will gradually decrease, and the SOH will also decrease accordingly. When the SOH decreases to a certain level, the performance of the battery will decrease significantly, such as the reduction of the energy storage time of the energy storage power station, and it may even affect the safety and reliability of the battery.

[0100] Step S522, calculating the SOC change value of the energy storage unit in combination with the SOH evaluation value.

[0101] Accordingly, the calculation formula for the SOC change value of the energy storage unit is:

[0102]

[0103] Among them, SOH ij is the SOH evaluation value of the i-th energy storage unit in the current detection cycle, R ij is the internal resistance value of the i-th energy storage unit in the current detection cycle, R ij_0 is the initial internal resistance of the i-th energy storage unit, Q ij is the capacity value of the i-th energy storage unit in the current detection cycle, Q ij_0 is the initial capacity value of the i-th energy storage unit, ω R and ω Q They are the weight coefficients of internal resistance and capacity when calculating the SOH evaluation value.

[0104] Will Conduct R The power operation makes the influence of internal resistance change on SOH subject to the weight ω R When ω R When ω is larger, the influence of internal resistance change on SOH is more significant. R = 0.8, a relatively small change in the internal resistance increase may result in a large decrease in SOH because The part will decrease rapidly with the increase of internal resistance. This exponential form can more flexibly reflect the importance of internal resistance change to battery health status assessment under different weights.

[0105] Similarly, the capacity change and the weight ω are converted by exponential operation Q Combined. When ω Q When ω is larger, the impact of capacity decay on SOH is dominant. For example, in some application scenarios with extremely high requirements for battery life, such as mobile energy storage equipment, ω may be set QFor a larger value, even if the internal resistance changes slightly, the SOH will drop significantly as long as the capacity decays to a certain extent, because It accounts for a larger proportion in the SOH calculation formula.

[0106] ω R and ω Q It is used to reflect the relative importance of internal resistance increase and capacity decay in evaluating the battery state of health (SOH). R =ω Q = 0.5, which means that the increase in internal resistance and capacity attenuation are considered to have equal impact on battery performance. For example, in some application scenarios, such as uninterruptible power supply (UPS) systems that require extremely high battery output power stability, the increase in internal resistance may cause output voltage fluctuations and affect the normal operation of the equipment. In this case, ω may be appropriately increased. R The value of makes the internal resistance factor play a more important role in SOH evaluation.

[0107] The size of the weight coefficient directly determines the contribution of the internal resistance change and capacity change to the calculation of SOH. R =0.7,ω R =0.3, when evaluating the impact of battery aging on performance, the factor of increased internal resistance will be given a greater weight. Even if the capacity decay is relatively small, if the internal resistance increases significantly, the SOH will decrease faster. This is reflected in the application scenario, and more attention is paid to the impact of internal resistance changes on battery performance. This may be because this scenario is more sensitive to the battery's charge and discharge efficiency or output voltage stability.

[0108] Specifically, the step S100 of obtaining the status data of each energy storage unit in the energy storage system in the current control cycle includes:

[0109] Step S110, obtain the real-time current value at several sampling time points in the current control cycle. In the refined management and efficient operation of the energy storage system, it is necessary to grasp the status data of each energy storage unit in real time and accurately. For the key status indicator of current, several sampling time points will be strategically selected according to system characteristics and operation requirements during the current control cycle. In the fast charging scenario of electric vehicles with high power requirements, the current changes rapidly, and a sampling point may be set every millisecond or even shorter to ensure accurate and timely data collection. In a relatively stable distributed energy storage system, when used for routine tasks such as peak shaving and valley filling, the rhythm of current changes slows down, and the sampling interval may be extended to once per second or several seconds, which can not only meet the basic needs of status monitoring, but also avoid massive redundant data.

[0110] Step S120 , performing data interpolation processing on the real-time current value between two adjacent sampling time points based on a spline interpolation method.

[0111] In a complex charging and discharging process, the current may change nonlinearly, such as rising rapidly at the beginning of charging and then gradually stabilizing. If we only rely on discrete sampling points, we cannot accurately capture this continuous change process, and spline interpolation can construct a continuous current function between adjacent sampling points, which is more in line with the actual current change. The interpolation data obtained by spline interpolation makes the current data in the SOC change value calculation formula closer to the actual continuously changing current. The interpolated data can more accurately reflect the current changes in the entire control cycle, and the SOC change value obtained by integral calculation is closer to the actual charge change, thereby significantly improving the calculation accuracy.

[0112] Step S130, calculating the SOC change value based on the sampling data and interpolation data of the real-time current value in the current control cycle.

[0113] The current data after spline interpolation can better describe the dynamic characteristics of the energy storage unit during the charging and discharging process. For energy storage systems with frequent dynamic changes, such as battery energy storage systems during frequent acceleration and deceleration of electric vehicles, the interpolation data can timely reflect the rapid changes in current, so that the calculation of the SOC change value can keep up with the actual state changes of the energy storage unit, and enhance the description of the dynamic process of the energy storage system. More accurate SOC change value calculation helps to optimize the control and management of the energy storage system. For example, in the application scenario where the energy storage system participates in the frequency modulation of the power grid, accurate SOC calculation can enable the system to better perform charging and discharging scheduling according to the power grid demand, avoid excessive charging and discharging or unreasonable power output due to SOC calculation errors, extend the service life of the energy storage system, and improve the overall performance and reliability of the system.

[0114] In addition, controlling the corresponding energy storage unit to charge and discharge in combination with the SOC measurement value in step S400 includes:

[0115] Step S410, marking an energy storage unit whose SOC measurement value is greater than or equal to a first preset threshold as a high-power state, marking an energy storage unit whose SOC measurement value is greater than or equal to a second preset threshold and less than the first preset threshold as a normal state, and marking an energy storage unit whose SOC measurement value is less than the second preset threshold as a low-power state.

[0116] According to the SOC measurement value, the energy storage unit is divided into a high power state (the SOC measurement value is greater than or equal to the first preset threshold), a normal state (the SOC measurement value is greater than or equal to the second preset threshold and less than the first preset threshold) and a low power state (the SOC measurement value is less than the second preset threshold). This classification method helps to determine the priority of different energy storage units in the charging and discharging process. During the discharge process, energy storage units in a high power state are preferentially discharged because these units have a higher residual power, can provide more power output, and have a relatively small impact on the battery life during the discharge process. During the charging process, energy storage units in a low power state are charged first to restore their power as soon as possible to avoid damage to the battery caused by excessive discharge. For energy storage units in a normal state, when energy storage units in a high power or low power state cannot meet the charging and discharging power requirements, they participate in charging and discharging in sequence according to the order of SOC measurement values ​​to fully utilize the energy of the entire energy storage system.

[0117] High power state: The energy storage unit in this state means that it stores a lot of electricity and has a strong discharge capacity. From the perspective of battery health, the internal structure of the battery, such as the electrode material, is relatively stable at this time. Discharging at a reasonable discharge rate will cause relatively little loss to the battery. However, if the high power state is maintained for a long time and the discharge is not used reasonably, some energy may be wasted due to factors such as self-discharge, or in some battery systems (such as lithium-ion batteries), maintaining an excessively high SOC for a long time may cause the side reactions inside the battery to intensify, affecting the battery life.

[0118] Normal state: In normal state, the SOC of the energy storage unit is in a moderate range. It has a certain discharge capacity and a certain amount of power absorption space when charging is needed. The energy storage unit in this state can be used as a flexible resource in the energy storage system. According to the overall charging and discharging demand and the number and power of energy storage units in high and low power states, it participates in the charging and discharging process in a timely manner to balance the energy of the energy storage system.

[0119] Low power state: When the energy storage unit is in a low power state, it means that the remaining power is low and it is in urgent need of power replenishment. If the discharge continues, it may cause the battery to be over-discharged, damage the battery electrode material, affect the reversibility of the battery, and in severe cases may even cause irreversible damage to the battery and shorten the battery life. Therefore, it is necessary to charge it as soon as possible to restore its power reserve and ensure the normal operation of the energy storage system and the health of the battery.

[0120] The specific values ​​of the first preset threshold and the second preset threshold need to be determined by comprehensively considering many factors. On the one hand, it is necessary to base on the characteristics of the energy storage unit itself, such as the battery type (different types of batteries have different optimal charge and discharge ranges, for example, the SOC range of lithium-ion batteries and lead-acid batteries has different effects on their performance), the rated capacity of the battery, and the designed charge and discharge depth limit. On the other hand, it is also necessary to combine the application scenarios of the energy storage system. For example, when used as a power source for electric vehicles, in order to ensure that the vehicle has sufficient mileage and avoid excessive charging and discharging of the battery to affect its life, the threshold of the high power state may be set relatively high to ensure that the vehicle has sufficient power reserves during driving; in the application scenario where grid energy storage is used for peak shaving and valley filling, the setting of the threshold may focus more on considering the grid load characteristics and the scheduling strategy of the energy storage system, so that the energy storage unit can participate in the power regulation of the grid in the appropriate power range.

[0121] Step S420: When the energy storage system is in the discharge process, the energy storage units in a high power state are discharged first.

[0122] From the perspective of battery use, when the battery is discharged at a high level, the internal electrochemical process is relatively stable, the structural changes of the electrode materials and the loss of active substances are relatively small, which can reduce the irreversible damage of the battery during the discharge process and help extend the cycle life of the battery. For example, during the discharge process of lithium-ion batteries, the electrode reaction kinetics in the high SOC stage is relatively more favorable, and the ion diffusion process is relatively smooth, so the performance and life of the battery can be better guaranteed.

[0123] As the discharge process progresses, the SOC of the energy storage unit in a high power state will gradually decrease. When its SOC approaches the threshold of the normal state, it is necessary to dynamically adjust the discharge strategy and timely transfer part of the discharge task to other energy storage units that are still in a high power state or normal state to maintain the continuous and stable discharge capacity of the energy storage system. At the same time, the changes in external load demand must also be considered. If the load power suddenly increases or decreases, the discharge power distribution of the energy storage unit and the combination of units involved in the discharge must also be adjusted accordingly.

[0124] Step S430: When the energy storage system is in the charging process, the energy storage units in the low power state are charged first.

[0125] When a battery in a low-power state begins to charge, its internal electrochemical polarization and other phenomena are relatively weak, and it can accept the injection of electrical energy at a relatively high efficiency. For example, in the early stage of charging a lithium-ion battery, the battery voltage is low, the resistance of ions embedded in the electrode material during the charging process is relatively small, and the charging efficiency is high. Therefore, charging the energy storage unit in a low-power state first can make full use of the efficient charging characteristics of this stage and improve the charging efficiency of the entire energy storage system.

[0126] Although charging of energy storage units in low-power state is prioritized, in actual energy storage systems, the charging power limit of the entire system and the conditions of other energy storage units in normal or high-power states must also be considered. If charging power resources are limited, power must be allocated reasonably to ensure that energy storage units in low-power state are charged as quickly as possible while also taking into account the power maintenance or replenishment needs of other units to avoid the situation where some energy storage units cannot be charged for a long time and affect the overall performance.

[0127] Furthermore, the EMS control method based on online monitoring of the energy storage system sensor also includes:

[0128] Step S441, when the discharge power command value of the energy storage system is greater than the sum of the dischargeable powers of several energy storage units in a high power state, several energy storage units in a normal state are selected in descending order of SOC measurement values ​​for discharge.

[0129] During the operation of the energy storage system, when faced with a large discharge power demand, the energy storage unit in a high power state alone may not be able to meet it. At this time, it is necessary to supplement the discharge capacity from the energy storage unit in the normal state. The selection is in order from large to small according to the SOC calibration value, because the normal state energy storage unit with a higher SOC is relatively closer to the high power state, and its remaining power is larger. While meeting the power demand, it can reduce the impact of deep discharge of the battery, thereby better protecting the health of the battery and maintaining the continuous discharge capacity of the energy storage system. For example, if there are multiple normal state energy storage units, and the SOCs are 60%, 50%, and 40% respectively, the unit with a 60% SOC is preferentially discharged, which can reduce the discharge pressure on the 50% and 40% SOC units while providing power, and prevent them from entering a low power state too early.

[0130] In the process of selecting normal state energy storage units for discharge in sequence, as the discharge progresses, the SOC of these units will gradually decrease, and the dischargeable power will also change. It is necessary to monitor the status of each unit involved in the discharge in real time. When the SOC of a unit drops to a certain level or its dischargeable power cannot meet the requirements, the discharge strategy should be adjusted in time. It may be necessary to continue to supplement from the remaining normal state units, or appropriately reduce the discharge power command value according to the situation to ensure the stable discharge of the entire energy storage system and avoid damage to certain units due to excessive discharge.

[0131] Step S442: when the charging power command value of the energy storage system is greater than the sum of the chargeable powers of several energy storage units in a low power state, several energy storage units in a normal state are selected in order of SOC measurement values ​​from small to large for charging.

[0132] When the charging power demand is large and the energy storage units in the low power state cannot absorb all of them, select the energy storage units in the normal state for charging. The selection is in the order of SOC calibration values ​​from small to large, because the energy storage units in the normal state with lower SOC are relatively closer to the low power state, and their power absorption space is larger. Charging them first can make more efficient use of charging power resources, make the power distribution in the energy storage system more balanced, and avoid overcharging of high SOC normal state units. For example, there are several normal state energy storage units with SOCs of 70%, 60%, and 50%. Giving priority to charging the unit with 50% SOC can increase its power faster, and can better balance the charging progress of each unit when the charging power is limited.

[0133] During the charging process of the energy storage units in normal state, it is necessary to ensure the charging balance of the entire energy storage system. Not only should we pay attention to the SOC changes of a single unit, but also consider the SOC differences between units. When the SOC of a unit rises rapidly and approaches a high power state, it may be necessary to appropriately reduce its charging power and allocate more power to other normal state units with lower SOCs to maintain a relative balance of SOC among the units in the system. In addition, it is also necessary to combine with the overall management strategy of the energy storage system. For example, according to external factors such as the load of the power grid and the power generation of renewable energy, the charging power distribution of each energy storage unit is dynamically adjusted to achieve efficient and safe charging of the energy storage system under different working conditions.

[0134] Accordingly, please refer to Figure 2 A second aspect of an embodiment of the present invention provides an EMS control device based on online monitoring of an energy storage system sensor, wherein the energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor, and a current sensor disposed on each energy storage unit, and the device includes:

[0135] A state data acquisition module 1 is used to acquire the state data of each energy storage unit in the energy storage system in the current control cycle;

[0136] A first data calculation module 2, which is used to calculate the SOC change value of the energy storage unit in the current control cycle based on the state data and in combination with the performance data of the energy storage unit;

[0137] A second data calculation module 3, which is used to obtain the SOC measurement value of the energy storage unit according to the SOC initial value of the energy storage unit in the current control cycle and the SOC change value;

[0138] The energy storage unit control module 4 is used to control the charging and discharging of the corresponding energy storage unit based on the EMS of the energy storage system and in combination with the SOC measurement value.

[0139] Accordingly, a third aspect of an embodiment of the present invention provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the above-mentioned EMS control method based on online monitoring of energy storage system sensors.

[0140] Accordingly, a fourth aspect of an embodiment of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-mentioned EMS control method based on online monitoring of energy storage system sensors.

[0141] The embodiment of the present invention aims to protect an EMS control method and device based on online monitoring of energy storage system sensors. The energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor, and a current sensor arranged on each energy storage unit. The method includes the following steps: obtaining the status data of each energy storage unit in the energy storage system in the current control cycle; based on the status data, calculating the SOC change value of the energy storage unit in the current control cycle in combination with the performance data of the energy storage unit; according to the SOC initial value of the energy storage unit in the current control cycle, combining the SOC change value to obtain the SOC measurement value of the energy storage unit; based on the EMS of the energy storage system, controlling the corresponding energy storage unit to charge and discharge in combination with the SOC measurement value. The above technical solution has the following effects:

[0142] 1. Through multi-sensor data fusion and consideration of multiple influencing factors, the SOC of the energy storage unit is accurately evaluated. Not only the real-time temperature value, real-time voltage value and real-time current value are used for basic calculation, but also the polarization voltage change value and SOH evaluation value are incorporated to correct the SOC change value, thereby effectively overcoming the SOC estimation error caused by a single factor or simple calculation, making the internal power state of the energy storage unit more accurate, and providing a highly reliable basis for the charge and discharge control of the energy storage system, avoiding problems such as over-charging and discharging, energy waste or shortened battery life caused by inaccurate SOC estimation, and improving the stability and economy of the entire energy storage system;

[0143] 2. Based on accurate SOC measurement values, EMS can perform efficient and flexible charge and discharge control according to the power state of the energy storage unit. By dividing the energy storage unit into high power, normal and low power states, and calling the energy storage unit in the corresponding state in a specific order according to different charging and discharging requirements, it realizes the refined management of the energy flow of the energy storage system. When discharging, the energy storage unit in the high power state is used first, which can ensure that the energy storage resources are used to the maximum extent while meeting the load demand. When charging, the energy storage unit in the low power state is charged first, which helps to maintain the power balance of each energy storage unit in the system and reduce the performance inconsistency caused by excessive power differences. When the power of the energy storage unit in the high or low power state is insufficient, it can be reasonably supplemented from the energy storage unit in the normal state, giving full play to the potential of the entire energy storage system, improving the adaptability of the energy storage system to variable loads and complex power grid environments, and ensuring the reliability and continuity of power supply;

[0144] 3. Spline interpolation is used to process the sampled data during the data acquisition process, which effectively improves the continuity and accuracy of the data, thereby improving the accuracy of the SOC calculation and the reliability of the entire control strategy. By interpolating and averaging the data at multiple sampling time points, it can more comprehensively reflect the actual state changes of the energy storage unit in the current control cycle and reduce the calculation deviation caused by data discreteness or sampling errors. On the one hand, accurate SOC calculation provides a guarantee for reasonable charging and discharging control. On the other hand, the actual operating data in the charging and discharging control process can be fed back to further optimize the data processing and SOC calculation model, so that the entire EMS control method can continuously adapt to the performance changes of the energy storage system and the dynamic adjustment of the operating environment, achieve long-term stable and efficient operation results, and reduce system maintenance costs and operating risks.

[0145] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0146] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0147] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0148] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An EMS control method based on online monitoring of energy storage system sensors, characterized in that: The energy storage system includes a plurality of energy storage units, and also includes a temperature sensor, a voltage sensor and a current sensor arranged on each of the energy storage units. The EMS control method includes the following steps: Acquire status data of each energy storage unit in the energy storage system in a current control cycle; Based on the state data, and in combination with the performance data of the energy storage unit, calculate the SOC change value of the energy storage unit in the current control cycle; Obtaining an SOC measurement value of the energy storage unit according to an initial SOC value of the energy storage unit in a current control cycle and in combination with the SOC change value; Based on the EMS of the energy storage system, the corresponding energy storage unit is controlled to be charged and discharged in combination with the SOC measurement value.

2. The EMS control method based on online monitoring of energy storage system sensors according to claim 1 is characterized in that: The state data includes: real-time temperature value, real-time voltage value and real-time current value; The performance data includes: a nominal open circuit voltage, a reference temperature and a maximum available capacity of the energy storage unit.

3. The EMS control method based on online monitoring of energy storage system sensors according to claim 2 is characterized in that: The calculation formula of the SOC change value of the energy storage unit is: Among them, ΔSOC ij is the SOC change value, i is the sequence number of the energy storage unit, j is the sequence number of the control cycle, I discharge_ij (t) is the discharge current of the current control cycle, I charge_ij (t) is the charging current of the current control cycle, t1 is the start time of the current control cycle, t2 is the end time of the current control cycle, Q max is the maximum available capacity of the energy storage unit, OCV nominal is the nominal open circuit voltage of the energy storage unit under standard conditions, V measured_ij is the actual voltage value, R0 is the energy storage unit at the reference temperature T ref The internal resistance value at the time of η1 is the coefficient of linear change of internal resistance with temperature, T ij is the real-time temperature value, T ref is the reference temperature of the energy storage unit, η2 is the coefficient of the quadratic change of internal resistance with temperature, |I avg | is the average charge and discharge current absolute value in the current control cycle, C rate is the charge and discharge rate.

4. The EMS control method based on online monitoring of energy storage system sensors according to claim 3 is characterized in that: Also includes: Obtaining a polarization voltage change value of the energy storage unit; Calculating the SOC change value of the energy storage unit in combination with the polarization voltage change value; The calculation formula of the SOC change value of the energy storage unit is: ΔV polarization_ij =κ×I avg ×Δt; Δt=t2-t1; Where, ΔV polarization_ij is the polarization voltage change value of the energy storage unit, and κ is a constant related to the battery material and aging state of the energy storage unit.

5. The EMS control method based on online monitoring of energy storage system sensors according to claim 3 is characterized in that: Also includes: Obtaining a SOH evaluation value of the energy storage unit; Calculating the SOC change value of the energy storage unit in combination with the SOH evaluation value; The calculation formula of the SOC change value of the energy storage unit is: Among them, SOH ij is the SOH evaluation value of the i-th energy storage unit in the current detection cycle, R ij is the internal resistance value of the i-th energy storage unit in the current detection cycle, R ij_0 is the initial internal resistance of the i-th energy storage unit, Q ij is the capacity value of the i-th energy storage unit in the current detection cycle, Q ij_0 is the initial capacity value of the i-th energy storage unit, ω R and ω Q They are the weight coefficients of internal resistance and capacity when calculating the SOH evaluation value.

6. The EMS control method based on online monitoring of energy storage system sensors according to any one of claims 1 to 5, characterized in that: The obtaining of the status data of each energy storage unit in the energy storage system in the current control cycle includes: Obtain the real-time current value at several sampling time points in the current control cycle; Perform data interpolation processing on the real-time current value between two adjacent sampling time points based on the spline interpolation method; The SOC change value is calculated based on the sampling data and interpolation data of the real-time current value in the current control cycle.

7. The EMS control method based on online monitoring of energy storage system sensors according to any one of claims 1 to 5, characterized in that: The controlling the corresponding energy storage unit to charge and discharge in combination with the SOC measurement value includes: The energy storage unit whose SOC measurement value is greater than or equal to a first preset threshold is marked as a high-power state, the energy storage unit whose SOC measurement value is greater than or equal to a second preset threshold and less than the first preset threshold is marked as a normal state, and the energy storage unit whose SOC measurement value is less than the second preset threshold is marked as a low-power state; When the energy storage system is in the process of discharging, the energy storage unit in a high power state is discharged first; When the energy storage system is in the charging process, the energy storage unit in a low power state is charged first.

8. The EMS control method based on online monitoring of energy storage system sensors according to claim 7 is characterized in that: Also includes: When the discharge power command value of the energy storage system is greater than the sum of the dischargeable powers of the plurality of energy storage units in a high power state, the plurality of energy storage units in a normal state are selected in descending order of SOC measurement values ​​for discharge; When the charging power command value of the energy storage system is greater than the sum of the rechargeable powers of the several energy storage units in the low power state, the several energy storage units in the normal state are selected in order from small to large in the SOC measurement value for charging.

9. An electronic device, characterized in that: include: at least one processor; And a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the EMS control method based on online monitoring of energy storage system sensors as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that: Computer instructions are stored thereon, and when the instructions are executed by the processor, the EMS control method based on online monitoring of energy storage system sensors as described in any one of claims 1-8 is implemented.

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