A method for equalizing control of an energy storage battery pack

Abstract

The present application relates to the field of energy storage battery, for solving the problem that multiple battery units in the battery pack exist energy loss when being balanced by equalizer, causing energy waste and shortening battery life, specifically a kind of energy storage battery pack equalization control method;The present application monitors multiple battery units in energy storage battery, and each battery unit is labeled by monitoring, and the energy storage battery is divided into two aspects of electric quantity and battery hardware to control the battery, so that the energy storage battery is charged and discharged during the operation, according to the label classification result of battery unit, the separate control of energy storage battery is realized, so that the electric quantity balance, working condition balance and life balance of battery unit are realized in the charging and discharging process of energy storage battery and the outside world, the equalizer is not needed to flow in the energy storage battery to balance the energy storage battery, the energy loss and battery life attenuation of energy storage battery caused by equalizer are avoided.

Description

Technical Field

[0001] This invention relates to the field of energy storage batteries, specifically to a method for equalization control of energy storage battery packs. Background Technology

[0002] In practice, due to the low voltage and capacity of individual batteries, a large number of individual batteries often need to be connected in series and parallel to form a group to provide the required high voltage and high capacity. This is especially true for large energy storage modules, which generally require many battery cells to form a large-capacity energy storage module. After the batteries are assembled, the performance of individual cells is inconsistent due to differences in manufacturing process and degradation rate. At the same time, the differences in internal chemical composition and usage environment between individual cells in the battery pack cause inconsistencies between individual cells. Inconsistencies can lead to overcharging or over-discharging of some individual cells during the charging and discharging process, causing the battery pack capacity to be affected by the "weakest link effect" of these cells. More seriously, if such inconsistencies are not addressed, the lifespan of the battery pack and even the safety of the entire system cannot be effectively guaranteed.

[0003] Currently, the solution to the inconsistency of battery cells in a battery pack is generally to use an equalizer. The equalizer can balance the performance and capacity differences between multiple battery packs by allowing current to flow between them. However, during the current flow, it is actually a process of one battery cell charging another. Since the battery heats up during charging and discharging, some electrical energy is converted into heat energy. As a result, the electrical energy gained by the charged battery cell during the current flow is less than the electrical energy lost by the discharging battery cell, resulting in energy loss. At the same time, the battery has a limited lifespan of charge and discharge cycles, and the current flow will continuously increase the battery's lifespan.

[0004] To address the aforementioned technical problems, this application proposes a solution. Summary of the Invention

[0005] This invention monitors multiple battery cells in an energy storage battery and tags each monitored cell. This allows for individual control of the energy storage battery during charging and discharging operations based on the cell tag classification results. This achieves balanced control of the battery cells during charging and discharging with the external environment, eliminating the need for an equalizer to manage the flow of electrical energy within the battery for balancing. This avoids energy loss and battery life degradation caused by equalizers, and solves the problem of energy loss, waste, and shortened battery life that occurs when multiple battery cells in a battery pack are balanced by an equalizer. Therefore, this invention proposes a balanced control method for energy storage battery packs.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for equalization control of an energy storage battery pack includes the following steps:

[0008] Step 1: Monitor multiple battery cells in the energy storage battery pack and use the equalization control system to ensure that the multiple battery cells in the energy storage battery pack have the same charge during the discharge state.

[0009] Step 2: During the charging process of the energy storage battery pack, monitor the power of multiple battery cells and control the power of multiple battery cells to be the same.

[0010] Step 3: During the operation of the energy storage battery pack, each battery cell is numbered, and the equivalent charge-discharge value of each battery cell is statistically analyzed based on the number. The usage frequency of the battery cells is then classified based on the equivalent charge-discharge value.

[0011] Step 4: Implement different charge and discharge control strategies for different graded battery cells to change the operating power of different graded battery cells during operation.

[0012] Step 5: During battery pack operation, the operating status of each battery cell is individually monitored. A temperature control evaluation signal is generated based on the monitoring results, and the output of the battery cells is distributed according to the temperature control evaluation signal to achieve balanced control of the temperature control system of the battery cells.

[0013] In a preferred embodiment of the present invention, the equalization control system includes a charge-discharge control unit, a charge-discharge monitoring unit, a lifespan statistics unit, a temperature control monitoring unit, and a data central control platform;

[0014] The charge and discharge monitoring unit monitors the power of different battery cells in the battery pack and classifies the battery cells by labeling them based on the power monitoring results.

[0015] The lifespan statistics unit obtains the charging and discharging data of the battery unit through the data control platform, analyzes the charging and discharging data to obtain the equivalent charging and discharging value, generates a battery lifespan tag based on the equivalent charging and discharging value, and sends the battery lifespan tag to the data control platform.

[0016] The temperature control monitoring unit performs data statistics on the operating status of the battery cells in the battery pack, obtains operating condition characteristic values, generates temperature control tags based on the operating condition characteristic values, and sends the temperature control tags to the data control platform.

[0017] The charge / discharge control unit classifies and controls the charging and discharging of battery cells according to their different classification labels.

[0018] In a preferred embodiment of the present invention, when the charging and discharging monitoring unit monitors the energy storage battery pack, it counts the current power of each battery cell and records the counted current power as a percentage.

[0019] The charging and discharging monitoring unit divides the current battery percentage into X levels, where the range of each level is [missing information]. The charge and discharge monitoring unit compares the current charge percentage of each battery cell, records battery cells belonging to the same level range as a set, and assigns a corresponding level label to each set.

[0020] In a preferred embodiment of the present invention, when the lifespan statistics unit acquires the charging and discharging data of the battery unit, it selects a charging and discharging unit, collects the start and end times of charging, calculates the difference between the times, and records it as one charging process. At the same time, it records the amount of electricity at the start and end of charging.

[0021] The lifespan statistics unit collects the time when the battery cell starts discharging and ends discharging, calculates the difference between the times, and records it as one discharge process. At the same time, it records the amount of electricity at the start and end of the discharge.

[0022] The lifespan statistics unit calculates the difference between the amount of electricity at the start of charging and the amount of electricity at the end of charging, and records it as the charging amount; it also calculates the difference between the amount of electricity at the start of discharging and the amount of electricity at the end of discharging, and records it as the discharging amount.

[0023] The lifetime statistics unit performs formula analysis on the charging and discharging processes to obtain the charging equivalent value C and the discharging equivalent value F;

[0024] The lifetime statistics unit performs an arithmetic mean on the charging equivalent value C and the discharging equivalent value F, and records the result of the arithmetic mean as the equivalent charge and discharge value.

[0025] In a preferred embodiment of the present invention, the temperature control monitoring unit detects the operating parameters of each battery cell, including the operating percentage and the operating temperature. The temperature control monitoring unit calculates the ratio of the operating temperature to the operating percentage and records it as a characteristic value of the operating condition.

[0026] The temperature control monitoring unit performs threshold analysis on the operating condition characteristic values ​​and generates temperature control tags based on the analysis results. The temperature control tags include high temperature tags and normal tags.

[0027] In a preferred embodiment of the present invention, the method for the temperature control monitoring unit to obtain the operating percentage is as follows:

[0028] The temperature control monitoring unit advances forward a selected time length from the current time, using the selected time length as the detection cycle, and calculates the ratio of battery running time to battery non-running time within the detection cycle to obtain the battery's operating percentage.

[0029] In a preferred embodiment of the present invention, the lifespan statistics unit obtains the equivalent charge-discharge value, compares the equivalent charge-discharge value with a set threshold, and generates a lifespan compliance label and a lifespan non-compliance label based on the comparison result.

[0030] In a preferred embodiment of the present invention, the charging and discharging control unit obtains the temperature control tag, battery life tag, and battery gear tag of the battery cell through the data central control platform.

[0031] During the charging process, the charging and discharging control unit performs charging operations according to the battery level label, from low to high, and during the discharging process, it performs discharging operations according to the battery level label, from high to low, and so on.

[0032] During the charging and discharging process, the charging and discharging control unit prioritizes charging and discharging the battery cells corresponding to the lifespan compliance label and the normal label.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. In this invention, when monitoring the energy storage battery, multiple battery cells within the energy storage battery are monitored, and each monitored battery cell is tagged. This allows the energy storage battery to be controlled separately based on the tag classification results during charging and discharging operations. This achieves balanced control of the battery cells during the charging and discharging process of the energy storage battery with the external environment, eliminating the need for an equalizer to balance the energy flow within the energy storage battery. This avoids energy loss and battery life degradation caused by the equalizer.

[0035] 2. In this invention, when the energy storage battery is tagged, the battery is controlled by dividing it into two aspects: energy capacity and battery hardware. This enables the energy storage battery to achieve energy balance during charging and discharging, as well as operating condition balance and lifespan balance during charging and discharging, ensuring a high degree of uniformity in the overall performance of multiple battery cells in the energy storage battery. Attached Figure Description

[0036] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0037] Figure 1 This is a system block diagram of the present invention;

[0038] Figure 2 This is a system flowchart of the present invention. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] Please see Figure 1 - Figure 2 As shown, a method for balancing control of an energy storage battery pack includes the following steps:

[0042] Step 1: Monitor multiple battery cells in the energy storage battery pack and use the equalization control system to ensure that the multiple battery cells in the energy storage battery pack have the same charge during the discharge state.

[0043] Step 2: During the charging process of the energy storage battery pack, monitor the power of multiple battery cells and control the power of multiple battery cells to be the same.

[0044] Step 3: During the operation of the energy storage battery pack, each battery cell is numbered, and the equivalent charge-discharge value of each battery cell is statistically analyzed based on the number. The usage frequency of the battery cells is then classified based on the equivalent charge-discharge value.

[0045] Step 4: Implement different charge and discharge control strategies for different graded battery cells to change the operating power of different graded battery cells during operation.

[0046] Step 5: During battery pack operation, the operating status of each battery cell is individually monitored. A temperature control evaluation signal is generated based on the monitoring results, and the output of the battery cells is distributed according to the temperature control evaluation signal to achieve balanced control of the temperature control system of the battery cells.

[0047] Example 2:

[0048] Please see Figure 1 - Figure 2 As shown, the equalization control system includes a charge / discharge control unit, a charge / discharge monitoring unit, a lifespan statistics unit, a temperature control monitoring unit, and a data control platform.

[0049] The charge / discharge monitoring unit monitors the charge level of different battery cells in the battery pack, calculates the current charge level of each cell, and records the current charge level as a percentage. The charge / discharge monitoring unit divides the current charge percentage into X levels, where each level spans a range of [missing value]. The charge and discharge monitoring unit compares the current charge percentage of each battery cell, records battery cells belonging to the same level range as a set, and assigns a corresponding level label to each set, thereby achieving tag-based classification of battery cells.

[0050] When acquiring the charging and discharging data of the battery cell, the lifespan statistics unit selects one charging and discharging unit to acquire the charging and discharging data of the battery cell, collects the start time and end time of charging, calculates the difference between the time and records it as one charging process, and records the amount of electricity at the start time and end time of charging.

[0051] The lifespan statistics unit collects the time when the battery cell starts discharging and ends discharging, calculates the difference between the times, and records it as one discharge process. At the same time, it records the amount of electricity at the start and end of the discharge.

[0052] The lifespan statistics unit calculates the difference between the charge level at the start of charging and the charge level at the end of charging, and records it as the charge amount; it also calculates the difference between the charge level at the start of discharging and the charge level at the end of discharging, and records it as the discharge amount.

[0053] The lifespan statistics unit will count the number of charging processes and number each charging process as i, record the time difference corresponding to each charging process as ti, and record the charging amount of each charging process as Qi. The lifespan statistics unit will count the number of discharging processes and number each discharging process as y, record the time difference corresponding to each discharging process as ty, and record the charging amount of each discharging process as Qy.

[0054] The lifetime statistics unit performs formula analysis on the charging process to obtain the charging equivalent value C. Where Q0 is the maximum capacity of the battery cell;

[0055] The lifetime statistics unit performs formula analysis on the discharge process to obtain the equivalent discharge value F. ;

[0056] The lifetime statistics unit performs an arithmetic mean on the charging equivalent value C and the discharging equivalent value F, and records the result of the arithmetic mean as the equivalent charge and discharge value.

[0057] The lifespan statistics unit obtains the equivalent charge-discharge value and compares it with a set threshold. If the equivalent charge-discharge value is less than the set threshold, a lifespan compliance label is generated. If the equivalent charge-discharge value is greater than or equal to the set threshold, a lifespan non-compliance label is generated, and the battery lifespan label is sent to the data control platform.

[0058] The temperature control monitoring unit detects the operating parameters of each battery cell, including the percentage of battery cell in operation and the operating temperature.

[0059] The temperature control monitoring unit advances the selected time length backward from the current time, and uses the selected time length as the detection cycle. It calculates the ratio of battery running time to battery non-running time within the detection cycle to obtain the battery's operating percentage.

[0060] The temperature control monitoring unit directly collects the temperature of each battery cell through distributed thermal sensors to obtain the operating temperature of each battery cell. The temperature control monitoring unit calculates the ratio of the operating temperature to the operating percentage and records it as the operating condition characteristic value.

[0061] The temperature control monitoring unit performs threshold analysis on the operating condition characteristic values. If the operating condition characteristic value is greater than the set threshold, a high temperature tag is generated. If the operating condition characteristic value is not greater than the set threshold, a normal tag is generated. Both the high temperature tag and the normal tag are temperature control tags. The temperature control monitoring unit sends the temperature control tags to the data control platform.

[0062] The charge / discharge control unit classifies and controls the charging and discharging of battery cells according to their different classification labels, specifically as follows:

[0063] The charging and discharging control unit obtains the battery cell's temperature control label, battery life label, and battery level label through the data control platform;

[0064] During the discharge process, if only a single battery cell or a portion of the battery cells need to be powered, the charging and discharging control unit will perform the discharge operation according to the battery level label, from high to low.

[0065] During the charging and discharging process, the charging and discharging control unit sets a first charging and discharging power threshold for battery cells that simultaneously generate lifespan compliance labels and normal labels, and sets a second power threshold for battery cells that generate lifespan non-compliance labels or high temperature labels. The first power threshold is greater than the second power threshold. During the operation of the charging and discharging control unit, the ratio of the actual charging and discharging power to the power threshold is recorded as the charging and discharging power ratio.

[0066] During the charging process, all battery cells that need to be charged are controlled at the same charging power ratio;

[0067] If all battery cells need to supply power during the discharge process, all battery cells will be controlled to the same discharge power ratio.

[0068] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for equalization control of an energy storage battery pack, characterized in that, The method comprises the following steps: Step 1: monitoring a plurality of battery units in the energy storage battery pack, and controlling the plurality of battery units in the energy storage battery pack in the discharging state to have the same electric quantity through an equalization control system; Step 2: monitoring the electric quantity of the plurality of battery units during the charging process of the energy storage battery pack, and controlling the electric quantity of the plurality of battery units to be the same; Step 3: numbering each battery unit during the operation of the energy storage battery pack, counting the equivalent charge and discharge values of each battery unit according to the number, and grading the use frequency of the battery unit according to the equivalent charge and discharge values; Step 4: adopting different charging and discharging control strategies for different battery units after grading, and changing the operation power of the battery units in different grades during operation; Step 5: detecting the operation state of each battery unit during the operation of the battery pack, generating a temperature control evaluation signal according to the detection result, and distributing the output of the battery unit according to the temperature control evaluation signal, and performing equalization control on the temperature control system of the battery unit; The equalization control system in the step 1 comprises a charging and discharging control unit, a charging and discharging monitoring unit, a service life counting unit, a temperature control monitoring unit, and a data central control platform; The charging and discharging monitoring unit monitors the electric quantity of different battery units in the battery pack, and classifies the battery units according to the monitoring result; The service life counting unit obtains the charging and discharging data of the battery unit through the data central control platform, analyzes the charging and discharging data, obtains the equivalent charge and discharge values, generates a battery service life label according to the equivalent charge and discharge values, and sends the battery service life label to the data central control platform; The temperature control monitoring unit statistically obtains the working condition characteristic value of the battery unit in the battery pack, and generates a temperature control label according to the working condition characteristic value, and sends the temperature control label to the data central control platform; The charging and discharging control unit controls the charging and discharging of the battery unit according to different classification labels of the battery unit; The temperature control monitoring unit detects the operation parameters of each battery unit, the detected operation parameters include the operation proportion and the operation temperature, the temperature control monitoring unit calculates the ratio of the operation temperature and the operation proportion, and records as the working condition characteristic value; The temperature control monitoring unit performs threshold analysis on the operation working condition characteristic value, generates a temperature control label according to the analysis result, and the temperature control label includes a high temperature label and a normal label.

2. The energy storage battery pack equalization control method of claim 1, wherein, The charging and discharging monitoring unit statistically obtains the current electric quantity of each battery unit when monitoring the energy storage battery pack, and records the current electric quantity in the form of percentage; The charge and discharge monitoring unit divides the current percentage of electricity into X gears, wherein the interval span of each gear is The charge and discharge monitoring unit compares the current percentage of electricity of each battery unit, records the battery units belonging to the same gear interval as a set, and gives each set a corresponding gear label.

3. The energy storage battery pack equalization control method of claim 1, wherein, When the service life counting unit obtains the charging and discharging data of the battery unit, it selects a charging and discharging unit, collects the start charging time and the end charging time, calculates the difference between the times, and records as a charging process, and records the electric quantity at the start charging time and the end charging time; The service life counting unit collects the start discharging time and the end discharging time of the battery unit, calculates the difference between the times, and records as a discharging process, and records the electric quantity at the start discharging time and the end discharging time; The life statistics unit calculates the difference between the electric quantity at the beginning of charging and the electric quantity at the end of charging, records it as the charging quantity, calculates the difference between the electric quantity at the beginning of discharging and the electric quantity at the end of discharging, and records it as the discharging quantity; The life statistics unit carries out formula analysis on the charging process and the discharging process to obtain the charging equivalent value C and the discharging equivalent value F; The life statistics unit carries out arithmetic average on the charging equivalent value C and the discharging equivalent value F, and records the result of the arithmetic average as the equivalent charging and discharging value.

4. The energy storage battery pack equalization control method of claim 1, wherein, The temperature control monitoring unit obtains the operation proportion by the following method: The temperature control monitoring unit advances the current time by a selected time length, takes the selected time length as a detection period, carries out ratio calculation on the battery operation time and the battery non-operation time in the detection period, and obtains the operation proportion of the battery.

5. The energy storage battery pack equalization control method of claim 1, wherein, The life statistics unit obtains the equivalent charging and discharging value, compares the equivalent charging and discharging value with a set threshold, and generates a life up-to-standard label and a life not up-to-standard label according to the comparison result.

6. The energy storage battery pack equalization control method of claim 1, wherein, The charging and discharging control unit obtains the temperature control label, the battery life label and the gear label of the battery unit through the data central control platform; The charging and discharging control unit carries out charging work according to the gears from low to high according to the battery gear label in the charging process, and carries out discharging work according to the gears from high to low according to the battery gear label in the discharging process; The charging and discharging control unit preferentially carries out charging and discharging work on the battery units corresponding to the life up-to-standard label and the normal label in the process of charging and discharging.

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