Energy storage battery pack equalization control method

Abstract

The invention relates to the field of energy storage batteries, is used for solving the problems of electric energy loss, energy waste and short battery life when a plurality of battery units in a battery pack are subjected to series flow equalization through an equalizer, and particularly relates to an equalization control method for an energy storage battery pack. According to the invention, the plurality of battery units in the energy storage battery are monitored, each monitored battery unit is labeled, and the energy storage battery is divided into two aspects of electric quantity and battery hardware to be controlled, so that the energy storage battery can be charged and discharged more accurately when the energy storage battery is charged and discharged. According to label classification results of the battery units, respective control of the energy storage batteries is realized, so that electric quantity balance, working condition balance and service life balance of the battery units are realized in charging and discharging processes of the energy storage batteries and the outside, and an equalizer is not required to carry out electric energy flowing in the energy storage batteries to balance the energy storage batteries. And the energy loss and the service life attenuation of the energy storage battery caused by the equalizer are avoided.

Description

Technical Field

[0001] The present invention relates to the field of energy storage batteries, and in particular to a method for balancing and controlling an energy storage battery group. Background Art

[0002] In actual situations, due to the low voltage and capacity of a single battery, a large number of single batteries are often required to be connected in series and parallel to provide the required high voltage and high capacity. Especially for large energy storage components, many battery cells are generally required to form a large-capacity energy storage component. After the batteries are grouped, the performance of the single cells is inconsistent due to differences in manufacturing process level and decay rate. At the same time, due to the differences in internal chemical composition and use environment between the single batteries in the battery pack, the inconsistency between the single batteries is caused. The inconsistency will cause some single batteries to be overcharged or over-discharged during the charging and discharging process of the battery pack, so that the capacity of the battery pack is affected by the "short board effect" of such batteries. What's more serious is that if such inconsistency is not handled, the service life of the battery pack and even the safety of the entire system cannot be effectively guaranteed; At present, the solution to the inconsistency of battery cells in a battery pack is generally implemented through a balancer. The balancer can balance the performance and power differences between multiple battery packs by connecting the currents between them. However, during the connection process of the battery pack, it is actually a process in which one battery cell charges another battery cell. Since the battery will heat up during the charging and discharging process, part of the electrical energy will be converted into heat energy, resulting in the electrical energy added by the charged battery cell being less than the electrical energy lost by the discharged battery cell during the connection process, causing energy loss. At the same time, the number of charge and discharge times of the battery has a life span, and connection will also continuously increase the battery life loss. In view of the above technical problems, this application proposes a solution. Summary of the invention

[0003] The present invention monitors multiple battery cells in an energy storage battery and labels each monitored battery cell, so that when the energy storage battery is performing charging and discharging operations, the energy storage battery can be controlled separately according to the label classification results of the battery cells, thereby realizing balanced control of the battery cells during the charging and discharging process of the energy storage battery with the outside world. It is not necessary for the equalizer to balance the energy storage battery by flowing electric energy inside the energy storage battery, thus avoiding energy loss and battery life attenuation of the energy storage battery caused by the equalizer, and solving the problem of electric energy loss, energy waste and shortened battery life when multiple battery cells in a battery pack are stream-balanced through an equalizer, and a balanced control method for an energy storage battery pack is proposed.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for balancing and controlling an energy storage battery pack comprises the following steps: Step 1: monitor multiple battery cells in the energy storage battery pack, and control the multiple battery cells of the energy storage battery pack in a discharge state to have the same power through a balancing control system; Step 2: During the charging process of the energy storage battery pack, the power levels of the multiple battery cells are monitored and the power levels of the multiple battery cells are controlled to be the same; Step 3: During the operation of the energy storage battery pack, each battery cell is numbered, the equivalent charge and discharge value of each battery cell is counted according to the number, and the usage frequency of the battery cell is graded according to the equivalent charge and discharge value; Step 4: different charging and discharging control strategies are implemented according to the different battery cells after classification, so as to change the operating power of the battery cells of different classifications during operation; Step 5: During the operation of the battery pack, the operating status of each battery cell is individually detected, a temperature control evaluation signal is generated based on the detection result, and the battery cell output is distributed based on the temperature control evaluation signal to balance the temperature control system of the battery cell.

[0005] As a preferred embodiment of the present invention, the balancing control system includes a charge and discharge control unit, a charge and discharge monitoring unit, a life statistics unit, a temperature control monitoring unit and a data central control platform; The charge and discharge monitoring unit monitors the power of different battery cells in the battery pack, and labels and classifies the battery cells according to the results of the power monitoring; The life statistics unit obtains the charge and discharge data of the battery unit through the data central control platform, analyzes the charge and discharge data to obtain equivalent charge and discharge values, generates a battery life label according to the equivalent charge and discharge values, and sends the battery life label to the data central control platform; The temperature control monitoring unit performs data statistics on the operating status of the battery cells in the battery pack, obtains the operating condition characteristic value, generates a temperature control label according to the operating condition characteristic value, and sends the temperature control label to the data central control platform; The charge and discharge control unit performs charge and discharge classification control on the battery cells according to different classification labels of the battery cells.

[0006] As a preferred embodiment of the present invention, when the charge and discharge monitoring unit monitors the energy storage battery pack, the current power of each battery cell is counted, and the counted current power is recorded in percentage; The charge and discharge monitoring unit divides the current power percentage into X gears, where the interval span of each gear is The charge and discharge monitoring unit compares the current power percentage of each battery cell, records the battery cells belonging to the same gear range as a set, and assigns a corresponding gear label to each set.

[0007] As a preferred embodiment of the present invention, when acquiring the charge and discharge data of the battery unit, the life statistics unit selects a charge and discharge unit, collects the time of starting and ending charging, calculates the difference between the times, and records it as a charging process, and records the power at the start and end of charging at the same time; The life statistics unit collects the time when the battery cell starts discharging and ends discharging, calculates the difference between the times, and records it as a discharging process, and records the amount of electricity when the discharging starts and ends; The life statistics unit calculates the difference between the power at the start of charging and the power at the end of charging, and records it as the charging power, and calculates the difference between the power at the start of discharging and the power at the end of discharging, and records it as the discharging power; The life statistics unit performs formula analysis on the charging process and the discharging process to obtain a charging equivalent value C and a discharging equivalent value F; The life statistics unit performs arithmetic averaging on the charge equivalent value C and the discharge equivalent value F, and records the result of the arithmetic averaging as the equivalent charge and discharge value.

[0008] As a preferred embodiment of the present invention, the temperature control monitoring unit detects the operating parameters of each battery cell, and the detected operating parameters include the operating ratio and the operating temperature. The temperature control monitoring unit calculates the ratio of the operating temperature to the operating ratio and records it as the operating condition characteristic value; The temperature control monitoring unit performs a threshold analysis on the operating condition characteristic value and generates a temperature control label according to the analysis result. The temperature control label includes a high temperature label and a normal label.

[0009] As a preferred embodiment of the present invention, the method for the temperature control monitoring unit to obtain the operation ratio is: The temperature control monitoring unit advances a selected time length from the current time forward, takes the selected time length as a detection period, calculates the ratio of the battery operation time and the battery non-operation time within the detection period, and obtains the battery operation ratio.

[0010] As a preferred implementation of the present invention, the life statistics unit obtains equivalent charge and discharge values, compares the equivalent charge and discharge values ​​with a set threshold, and generates a life standard compliance label and a life standard non-compliance label according to the comparison result.

[0011] As a preferred embodiment of the present invention, the charging and discharging control unit obtains the temperature control label, battery life label and battery gear label of the battery unit through the data central control platform; The charge and discharge control unit performs charging operation according to the battery level from low to high power level according to the battery level label during the charging process, and performs discharging operation according to the battery level from high to low power level according to the battery level label during the discharging process; During the charging and discharging process, the charging and discharging control unit preferentially performs charging and discharging operations on the battery cells corresponding to the life-standard labels and the normal labels.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, when monitoring the energy storage battery, multiple battery cells in the energy storage battery are monitored, and each monitored battery cell is labeled, so that when the energy storage battery is charged and discharged, the energy storage battery can be controlled separately according to the label classification results of the battery cells, so as to achieve balance control of the battery cells during the charging and discharging process of the energy storage battery with the outside world, and there is no need for a balancer to balance the energy storage battery by flowing electric energy inside the energy storage battery, thereby avoiding energy loss and battery life attenuation of the energy storage battery caused by the balancer.

[0013] 2. In the present invention, when the energy storage battery is labeled, the battery is controlled by dividing it into two aspects: power and battery hardware, so that not only the power balance of the energy storage battery can be achieved during the charging and discharging process, but also the working condition balance and life balance of the energy storage battery can be achieved during the charging and discharging process, ensuring that the overall performance of multiple battery cells in the energy storage battery is highly unified. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0015] Figure 1 is a system block diagram of the present invention; Figure 2 It is a system flow chart of the present invention. DETAILED DESCRIPTION

[0016] The technical scheme of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Embodiment 1: See also Figure 1 - Figure 2 As shown, a method for balancing and controlling an energy storage battery pack comprises the following steps: Step 1: monitor multiple battery cells in the energy storage battery pack, and control the multiple battery cells of the energy storage battery pack in a discharge state to have the same power through a balancing control system; Step 2: During the charging process of the energy storage battery pack, the power levels of the multiple battery cells are monitored and the power levels of the multiple battery cells are controlled to be the same; Step 3: During the operation of the energy storage battery pack, each battery cell is numbered, the equivalent charge and discharge value of each battery cell is counted according to the number, and the usage frequency of the battery cell is graded according to the equivalent charge and discharge value; Step 4: different charging and discharging control strategies are implemented according to the different battery cells after classification, so as to change the operating power of the battery cells of different classifications during operation; Step 5: During the operation of the battery pack, the operating status of each battery cell is individually detected, a temperature control evaluation signal is generated based on the detection result, and the battery cell output is distributed based on the temperature control evaluation signal to balance the temperature control system of the battery cell.

[0018] Embodiment 2: See also Figure 1 - Figure 2 As shown, the balancing control system includes a charge and discharge control unit, a charge and discharge monitoring unit, a life statistics unit, a temperature control monitoring unit and a data central control platform; The charge and discharge monitoring unit monitors the power of different battery cells in the battery pack, counts the current power of each battery cell, and records the current power as a percentage. The charge and discharge monitoring unit divides the current power percentage into X gears, where the interval span of each gear is The charge and discharge monitoring unit compares the current power percentage of each battery cell, records the battery cells belonging to the same gear range as a set, and assigns a corresponding gear label to each set to achieve label classification of the battery cells; When acquiring the charge and discharge data of the battery cell, the life statistics unit selects a charge and discharge unit to acquire the charge and discharge data of the battery cell, collects the time of starting and ending charging, calculates the difference between the times, and records it as a charging process, and records the power at the start and end of charging at the same time; The life statistics unit collects the time when the battery cell starts discharging and ends discharging, calculates the difference between the times, and records it as a discharge process. At the same time, it records the amount of electricity when the discharge starts and ends. The life statistics unit calculates the difference between the power at the start of charging and the power at the end of charging, and records it as the charging power; calculates the difference between the power at the start of discharging and the power at the end of discharging, and records it as the discharging power; The life statistics unit counts the number of charging processes, and numbers each charging process as i, records the time difference corresponding to each charging process as ti, and records the charge amount of each charging process as Qi. The life statistics unit counts the number of discharge processes, and numbers each discharge process as y, records the time difference corresponding to each discharge process as ty, and records the charge amount corresponding to each discharge process as Qy. The life statistics unit analyzes the charging process by formula to obtain the charging equivalent value C. , where Q0 is the maximum capacity of the battery cell; The life statistics unit analyzes the discharge process by formula to obtain the discharge equivalent value F. ; The life statistics unit performs arithmetic averaging on the charge equivalent value C and the discharge equivalent value F, and records the result of the arithmetic averaging as the equivalent charge and discharge value; The life statistics unit obtains the equivalent charge and discharge value, and compares the equivalent charge and discharge value with the set threshold. If the equivalent charge and discharge value is less than the set threshold, a life standard tag is generated. If the equivalent charge and discharge value is greater than or equal to the set threshold, a life standard failure tag is generated and the battery life tag is sent to the data control platform. The temperature control monitoring unit detects the operating parameters of each battery cell, including the operating ratio and operating temperature; The temperature control monitoring unit advances the selected time length from the current time forward, takes the selected time length as the detection period, calculates the ratio of the battery operation time and the battery non-operation time within the detection period, and obtains the battery operation ratio; 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 ratio and records it as the operating condition characteristic value. The temperature control monitoring unit performs a threshold analysis on the operating condition characteristic value. 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 tag to the data central control platform. The charge and discharge control unit performs charge and discharge classification control on the battery cells according to the different classification labels of the battery cells, specifically: The charge and discharge control unit obtains the temperature control label, battery life label and battery gear label of the battery unit through the data central control platform; During the discharge process, if only a single battery unit or part of the battery units are needed for power supply, the charge and discharge control unit will perform the discharge operation according to the battery level label from high to low power level; During the charging and discharging process, the charging and discharging control unit sets a first charging and discharging power threshold for the battery cell that generates both a life-span compliance label and a normal label, and sets a second power threshold for the battery cell that generates a life-span non-compliance label or a high-temperature label, wherein 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; During the charging process, all battery cells that need to be charged are controlled at the same charging power ratio; During the discharge process, if all the battery cells are required to supply power, all the battery cells are controlled to have the same discharge power ratio.

[0019] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for balancing and controlling an energy storage battery pack, characterized in that: The following steps are involved: Step 1: monitor multiple battery cells in the energy storage battery pack, and control the multiple battery cells of the energy storage battery pack in a discharge state to have the same power through a balancing control system; Step 2: During the charging process of the energy storage battery pack, the power levels of the multiple battery cells are monitored and the power levels of the multiple battery cells are controlled to be the same; Step 3: During the operation of the energy storage battery pack, each battery cell is numbered, the equivalent charge and discharge value of each battery cell is counted according to the number, and the usage frequency of the battery cell is graded according to the equivalent charge and discharge value; Step 4: different charging and discharging control strategies are implemented according to the different battery cells after classification, so as to change the operating power of the battery cells of different classifications during operation; Step 5: During the operation of the battery pack, the operating status of each battery cell is individually detected, a temperature control evaluation signal is generated based on the detection result, and the battery cell output is distributed based on the temperature control evaluation signal to balance the temperature control system of the battery cell.

2. A method for balancing and controlling an energy storage battery pack according to claim 1, characterized in that: The balancing control system includes a charge and discharge control unit, a charge and discharge monitoring unit, a life statistics unit, a temperature control monitoring unit and a data central control platform; The charge and discharge monitoring unit monitors the power of different battery cells in the battery pack, and labels and classifies the battery cells according to the results of the power monitoring; The life statistics unit obtains the charge and discharge data of the battery unit through the data central control platform, analyzes the charge and discharge data to obtain equivalent charge and discharge values, generates a battery life label according to the equivalent charge and discharge values, and sends the battery life label to the data central control platform; The temperature control monitoring unit performs data statistics on the operating status of the battery cells in the battery pack, obtains the operating condition characteristic value, generates a temperature control label according to the operating condition characteristic value, and sends the temperature control label to the data central control platform; The charge and discharge control unit performs charge and discharge classification control on the battery cells according to different classification labels of the battery cells.

3. The energy storage battery group balancing control method according to claim 1, characterized in that: When the charge and discharge monitoring unit monitors the energy storage battery pack, the current power of each battery cell is counted, and the counted current power is recorded in percentage; The charge and discharge monitoring unit divides the current power percentage into X gears, where the interval span of each gear is The charge and discharge monitoring unit compares the current power percentage of each battery cell, records the battery cells belonging to the same gear range as a set, and assigns a corresponding gear label to each set.

4. A method for controlling energy storage battery group balance according to claim 3, characterized in that: When acquiring the charge and discharge data of the battery cell, the life statistics unit selects a charge and discharge unit, collects the time of starting and ending charging, calculates the difference between the times, and records it as a charging process, and records the power at the start and end of charging at the same time; The life statistics unit collects the time when the battery cell starts discharging and ends discharging, calculates the difference between the times, and records it as a discharging process, and records the amount of electricity when the discharging starts and ends; The life statistics unit calculates the difference between the power at the start of charging and the power at the end of charging, and records it as the charging power, and calculates the difference between the power at the start of discharging and the power at the end of discharging, and records it as the discharging power; The life statistics unit performs formula analysis on the charging process and the discharging process to obtain a charging equivalent value C and a discharging equivalent value F; The life statistics unit performs arithmetic averaging on the charge equivalent value C and the discharge equivalent value F, and records the result of the arithmetic averaging as the equivalent charge and discharge value.

5. The energy storage battery group balancing control method according to claim 1, characterized in that: The temperature control monitoring unit detects the operating parameters of each battery cell, the detected operating parameters include the operating ratio and the operating temperature, and the temperature control monitoring unit calculates the ratio of the operating temperature to the operating ratio and records it as the operating condition characteristic value; The temperature control monitoring unit performs a threshold analysis on the operating condition characteristic value and generates a temperature control label according to the analysis result. The temperature control label includes a high temperature label and a normal label.

6. The energy storage battery group balancing control method according to claim 1, characterized in that: The method for the temperature control monitoring unit to obtain the operation ratio is: The temperature control monitoring unit advances a selected time length from the current time forward, takes the selected time length as a detection period, calculates the ratio of the battery operation time and the battery non-operation time within the detection period, and obtains the battery operation ratio.

7. A method for controlling energy storage battery group balance according to claim 4, characterized in that: The life statistics unit obtains the equivalent charge and discharge value, compares the equivalent charge and discharge value with a set threshold value, and generates a life standard compliance label and a life standard non-compliance label according to the comparison result.

8. The energy storage battery group balancing control method according to claim 1, characterized in that: The charge and discharge control unit obtains the temperature control label, battery life label and battery gear label of the battery unit through the data central control platform; The charge and discharge control unit performs charging operation according to the battery level from low to high power level according to the battery level label during the charging process, and performs discharging operation according to the battery level from high to low power level according to the battery level label during the discharging process; During the charging and discharging process, the charging and discharging control unit preferentially performs charging and discharging operations on the battery cells corresponding to the life-standard labels and the normal labels.

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