CN-120680985-B - Active equalization system for BMS

CN120680985BCN 120680985 BCN120680985 BCN 120680985BCN-120680985-B

Abstract

The invention relates to the technical field of battery management, in particular to an active equalization system for a BMS, which comprises a state evaluation module, a path optimization module, a current equalization module, a loss compensation module and an active equalization module, wherein the state evaluation module is used for performing state evaluation on each electric core in the BMS to generate a state evaluation index of each electric core, the path optimization module is used for optimizing an energy transmission path according to the state evaluation index of each electric core to generate a path optimization result, the current equalization module is used for calculating self-adaptive equalization current based on the state evaluation index of each electric core and the path optimization result, the loss compensation module is used for performing efficiency loss compensation on the BMS based on the self-adaptive equalization current and the path optimization result to determine a corresponding efficiency loss compensation coefficient, and the active equalization module is used for generating an equalization control signal for the BMS based on the efficiency loss compensation coefficient, the path optimization result and a time attenuation factor. The system can improve the accuracy and efficiency of BMS load balancing.

Inventors

CHEN DAJIAO
CUI LIMIN

Assignees

广东宇阳新能源有限公司

Dates

Publication Date: 20260508
Application Date: 20250806

Claims (7)

1. An active equalization system for a BMS, the system comprising: The state evaluation module is used for performing state evaluation on each battery cell in the BMS and generating a state evaluation index of each battery cell; The path optimization module is used for optimizing an energy transmission path according to the state evaluation index of each cell to generate a path optimization result, and is also used for obtaining the difference value between the maximum state evaluation index and the current state index of each path, introducing a dynamic adjustment coefficient to correct the transmission efficiency of each path in real time, comprehensively scoring each path by combining the exponential decay function of the energy transmission distance of each path to obtain a path attenuation item, and determining the path optimization result according to the difference value of each path, the corrected transmission efficiency and the path attenuation item, wherein the path optimization result is expressed as: wherein, the method comprises the steps of, Is the result of the path optimization, Is the maximum state-assessment index of the system, Is the current PSI value for the target cell on the ith path, Is the transmission efficiency of the i-th path, Is the energy transmission distance of the i-th path, Is the dynamic adjustment coefficient of the i-th path, The signal/energy attenuation coefficient of the i-th path; The current balancing module is used for calculating self-adaptive balancing current based on the state evaluation index of each cell and the path optimization result; The loss compensation module is used for carrying out efficiency loss compensation on the BMS based on the self-adaptive equalization current and the path optimization result, and determining a corresponding efficiency loss compensation coefficient; and the active equalization module is used for generating an equalization control signal for the BMS based on the efficiency loss compensation coefficient, the path optimization result and the time attenuation factor.
2. The active equalization system for a BMS of claim 1 wherein the state evaluation module is further configured to: collecting the cell voltage, the voltage change rate and the state of charge of each cell; Square operation is carried out on the ratio of the battery cell voltage to the corresponding reference voltage, and the ratio is used as a first evaluation factor; Performing exponential operation on the absolute value of the voltage change rate to serve as a second evaluation factor; performing nonlinear trigonometric function transformation on the state of charge as a third evaluation factor; the state evaluation index is generated by weighted combination of the first, second and third evaluation factors.
3. The active equalization system for a BMS of claim 1, wherein the current equalization module is further configured to: A base current based on a product of a reference current coefficient and the path optimization result; Acquiring a periodic disturbance term representing a periodic fluctuation component; nonlinear gain adjustment is carried out according to the ratio of the maximum state evaluation index to the minimum state index, and a system unbalanced amplification factor is obtained; and superposing the period disturbance item and the system unbalanced amplification factor on the basic current to obtain the self-adaptive balanced current.
4. The active equalization system for a BMS of claim 3 wherein the loss compensation module is further configured to: Constructing an exponential compensation component related to the self-adaptive equalization current according to the compensation intensity coefficient, the self-adaptive equalization current and the reference current; the path optimization result and the compensation angle parameter are related through a trigonometric function, so that a cosine modulation item is obtained; and adjusting the index compensation component and the cosine modulation term based on the ratio of the average state evaluation index to the maximum state index to obtain the efficiency loss compensation coefficient.
5. The active equalization system for a BMS of claim 4 wherein the active equalization module is further configured to: introducing an inverse trigonometric function to carry out nonlinear mapping on the ratio of the path optimization result to the average state evaluation index to obtain a nonlinear adjustment item; And superposing a time attenuation exponential function and the product of the efficiency loss compensation coefficient and the self-adaptive equalization current on the nonlinear regulation term to obtain the equalization control signal.
6. The active equalization system for a BMS of claim 5 wherein the active equalization module is further configured to: Acquiring the surface temperature distribution of each battery cell in real time through a wireless sensor network; introducing temperature gradient data into a path optimization function, and increasing thermal equilibrium constraint conditions; A temperature compensation term is added to the integrated state index.
7. The method for actively balancing the BMS, which is characterized in that the method comprises the steps of performing state evaluation on each cell in the BMS to generate a state evaluation index of each cell; Optimizing an energy transmission path according to the state evaluation index of each cell to generate a path optimization result, wherein the path optimization result comprises the steps of obtaining the difference value between the maximum state evaluation index and the current state index of each path, introducing a dynamic adjustment coefficient to correct the transmission efficiency of each path in real time, comprehensively scoring each path by combining an exponential decay function of the energy transmission distance of each path to obtain a path attenuation item, and determining the path optimization result according to the difference value of each path, the corrected transmission efficiency and the path attenuation item, wherein the path optimization result is expressed as follows: Wherein, the Is the result of the path optimization, Is the maximum state-assessment index of the system, Is the current PSI value for the target cell on the ith path, Is the transmission efficiency of the i-th path, Is the energy transmission distance of the i-th path, Is the dynamic adjustment coefficient of the i-th path, The signal/energy attenuation coefficient of the i-th path; calculating self-adaptive balanced current based on the state evaluation index of each cell and the path optimization result; Performing efficiency loss compensation on the BMS based on the self-adaptive equalization current and the path optimization result, and determining a corresponding efficiency loss compensation coefficient; And generating an equalization control signal for the BMS based on the efficiency loss compensation coefficient, the path optimization result and the time attenuation factor.

Description

Active equalization system for BMS Technical Field The invention relates to the technical field of battery management, in particular to an active equalization system, an active equalization method, electronic equipment and a non-transitory computer readable storage medium for BMS (battery management system). Background Today, in Battery management systems (Battery MANAGEMENT SYSTEM, BMS), it is often necessary to equalize the voltage differences between the individual cells in order to increase the efficiency of the Battery pack and extend its service life. The active equalization method widely adopted at present mainly comprises the modes of inductive energy transfer, capacitive energy transfer, transformer coupling transfer and the like. However, the traditional inductance or capacitance equalization circuit has a complex structure and high cost, and in a multi-cell system, the energy path scheduling control algorithm is complex, so that the quick and efficient equalization effect is difficult to realize, and on the other hand, part of active equalization methods have extra energy loss in the energy transmission process, so that the efficiency and the response speed cannot be both achieved. Disclosure of Invention Aiming at the technical problems in the prior art, the invention provides an active balancing system for BMS, an active balancing method for BMS, electronic equipment and a non-transitory computer readable storage medium, wherein the accuracy and efficiency of BMS load balancing can be improved. The technical scheme for solving the technical problems is as follows: the present invention provides an active equalization system for a BMS, the system comprising: The state evaluation module is used for performing state evaluation on each battery cell in the BMS and generating a state evaluation index of each battery cell; The path optimization module is used for optimizing the energy transmission path according to the state evaluation index of each cell and generating a path optimization result; The current balancing module is used for calculating self-adaptive balancing current based on the state evaluation index of each cell and the path optimization result; The loss compensation module is used for carrying out efficiency loss compensation on the BMS based on the self-adaptive equalization current and the path optimization result, and determining a corresponding efficiency loss compensation coefficient; and the active equalization module is used for generating an equalization control signal for the BMS based on the efficiency loss compensation coefficient, the path optimization result and the time attenuation factor. Further, the state evaluation module is further configured to: collecting the cell voltage, the voltage change rate and the state of charge of each cell; Square operation is carried out on the ratio of the battery cell voltage to the corresponding reference voltage, and the ratio is used as a first evaluation factor; Performing exponential operation on the absolute value of the voltage change rate to serve as a second evaluation factor; performing nonlinear trigonometric function transformation on the state of charge as a third evaluation factor; the state evaluation index is generated by weighted combination of the first, second and third evaluation factors. Further, the path optimization module is further configured to: obtaining the difference value between the maximum state evaluation index and the current state index of each path; introducing a dynamic adjustment coefficient to correct the transmission efficiency of each path in real time; comprehensively scoring each path by combining an exponential decay function of the energy transmission distance of each path to obtain a path attenuation item; and determining the path optimization result through the difference value of each path, the corrected transmission efficiency and the path attenuation item. Further, the current balancing module is further configured to: A base current based on a product of a reference current coefficient and the path optimization result; Acquiring a periodic disturbance term representing a periodic fluctuation component; nonlinear gain adjustment is carried out according to the ratio of the maximum state evaluation index to the minimum state index, and a system unbalanced amplification factor is obtained; and superposing the period disturbance item and the system unbalanced amplification factor on the basic current to obtain the self-adaptive balanced current. Further, the loss compensation module is further configured to: Constructing an exponential compensation component related to the self-adaptive equalization current according to the compensation intensity coefficient, the self-adaptive equalization current and the reference current; the path optimization result and the compensation angle parameter are related through a trigonometric function, so that a cosine modulation item is obtained; and adjus