CN110556599A - Method for maintaining deteriorated battery in service process of energy storage battery pack - Google Patents

Abstract

The invention discloses a maintenance method for a deteriorated battery during service of an energy storage battery pack. The process is as follows: prepare a series of energy packs with different electric capacities; Analyze one or several degraded batteries in the energy storage battery pack, and obtain the electric capacity data that needs to be supplemented by the degraded battery; if the electric capacity to be supplemented by the degraded battery reaches 5% of its rated electric capacity, then Replace; if the capacity of the deteriorated battery to be supplemented is less than 5% of its rated capacity, during the periodic maintenance of the energy storage battery pack, connect the deteriorated battery in parallel with the energy pack or combination of energy packs with the corresponding capacity. The energy package combination is formed by connecting different energy packages in parallel. The invention adopts the method of supplementing the energy pack to make the residual energy of each single battery tend to be consistent, so that each single battery is basically emptied and fully charged at the same time, and the energy storage efficiency of the system is improved.

Description

A maintenance method for deteriorating batteries during service of an energy storage battery pack

technical field

The invention relates to a maintenance method for a deteriorated battery during service of an energy storage battery pack.

Background technique

In the production process of the battery, due to factors such as manufacturer's technology and management, the performance of the actual product has a certain discreteness. Before being used in series, the batteries with similar performance are generally combined by screening (so-called group pairing), so that the average discharge capacity of the combined battery pack reaches the minimum average discharge capacity value of the single battery, so as to ensure the performance and life of the battery pack. However, after several charge-discharge cycles, this consistency no longer exists, which is manifested in the large difference in residual energy between single cells. The main reason is the inconsistent internal resistance of the battery and the self-discharge of the battery. The change of battery internal resistance is related to the usage (temperature, vibration, current, separator performance), the internal resistance difference of each battery is inevitable, the internal resistance is inconsistent, the thermal power loss is different, and the battery self-discharge is also Each is different, which eventually leads to inconsistency in the remaining energy of the single battery.

In large-scale energy storage battery systems, the differences in battery performance are more obvious. In actual use, large-scale battery pack applications are equipped with battery management system BMS. Through BMS, real-time data such as voltage and temperature of battery packs and single cells can be collected, and battery pack thermal management, SOC diagnosis, and energy can be performed through analysis and calculation. Balance and other operations to improve the overall efficiency of the battery pack.

At present, there are two main types of balancing methods suitable for large-scale, high-capacity battery packs: rechargeable, which uses auxiliary power to supplement low energy and align with high energy. Discharge type, discharge high energy to make it align with low energy. Due to the high hardware requirements of charging type equalization, and the low efficiency of battery replenishment at the end of charging, the actual effect is not as ideal as that of charging type. Most of the existing battery equalization uses discharge type. However, there is a waste of energy in the discharge type, and the waste is even worse when there are particularly deteriorated single cells in the battery pack.

SUMMARY OF THE INVENTION

In view of the above technical problems existing in the prior art, the purpose of the present invention is to provide a maintenance method for the deteriorated battery during the service of the energy storage battery pack.

The maintenance method for the deteriorated battery during the service process of the energy storage battery pack is characterized by comprising the following steps:

1) Prepare a series of energy packs with different capacitances;

2) During a maintenance cycle of the energy storage battery pack, analyze one or several degraded batteries in the running energy storage battery pack through the battery management system, and obtain the electric capacity data that needs to be supplemented by the degraded battery;

3) If the capacity of the deteriorated battery to be supplemented reaches 5% of its rated capacity, the deteriorated battery shall be replaced; if the capacity of the deteriorated battery to be supplemented is less than 5% of its rated capacity, the battery shall be replaced in the energy storage battery pack. During periodic maintenance, the corresponding energy pack or combination of energy packs is connected in parallel to the degraded battery. The electric capacity that needs to be supplemented by the degraded battery is equal to the electric capacity of the energy pack or combination of energy packs. The combination of energy packs is composed of several energy packs. Packages are connected in parallel.

The method for maintaining a deteriorated battery during service of an energy storage battery pack is characterized in that in step 1) the process of preparing a series of energy packs with different electric capacities is: taking the rated electric capacity of a single battery in the energy storage battery pack 1/10000 of the 1/10000 is recorded as C, and the C is recorded as the minimum capacitance; a series of energy packs with capacitances of 1C, 2C, 5C, 10C, 20C, 50C, and 100C are prepared.

The maintenance method for the deteriorated battery during the service of the energy storage battery pack is characterized in that in step 1), the energy pack is connected by a super capacitor, a jack connector arranged at both ends of the super capacitor, and a jack connector arranged on the jack. It consists of inserts on the device.

Compared with the prior art, the beneficial effects obtained by the present invention are:

(1) In a conventional energy storage system, the discharge of the battery pack is limited to the battery with the lowest voltage in the series battery pack, and the charging is limited to the battery with the highest voltage. When charging, there is always something that is not fully charged, and there is always something that cannot be emptied when discharging. This results in the "effective energy storage" of the battery being always lower than the "theoretical maximum energy storage". The invention adopts the method of supplementing the energy pack to make the residual energy of each single battery tend to be consistent, so that each single battery is basically emptied and fully charged at the same time, and the energy storage efficiency of the system is improved.

(2) By adopting the method of the present invention, the failure of the battery pack caused by the backward or different performance of a single (or several) batteries can be well avoided, and the cycle life of the battery pack can be extended to the greatest extent.

Description of drawings

1 is a schematic structural diagram of a battery pack and an energy pack;

Fig. 2 is the structural representation of the energy pack;

In the picture: 1-battery pack, 2-energy pack, 201-supercapacitor, 202-jack connector, 203-insert, 3-degraded battery.

Detailed ways

The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

Example 1:

A maintenance method for a deteriorated battery during service of an energy storage battery pack, comprising the following steps:

1) Prepare a series of energy packs with different capacities; the minimum capacity of the energy pack is 1/10000 of the rated capacity of a single battery in the energy storage battery pack, denoted as C. Based on this, a series of energy packs with capacitances of 1C, 2C, 5C, 10C, 20C, 50C, and 100C are configured. The schematic diagram of the structure of the energy pack is shown in Figure 2: the energy pack 2 is composed of a supercapacitor 201, a jack connector 202 arranged at both ends of the supercapacitor 201, and a plug 203 arranged on the jack connector, including different supercapacitors. The energy packs 2 of 201 can be connected to each other, and the energy packs 2 can be connected to each other in parallel to form a combination of energy packs with different capacitances.

2) During a maintenance cycle of the energy storage battery pack, use the battery management system to analyze one or several degraded batteries in the running energy storage battery pack, and obtain the capacity data that needs to be supplemented by the degraded batteries (via After analyzing the actual electric capacity of the deteriorated battery, the electric capacity that needs to be supplemented by the deteriorated battery = rated electric capacity - the actual electric capacity obtained by the analysis);

3) If the capacity of the deteriorated battery to be supplemented reaches 5% of its rated capacity (that is, the capacity of the deteriorated battery to be supplemented reaches 500C), replace the deteriorated battery; 5% of the capacity, then when the energy storage battery pack performs periodic maintenance, the degraded battery is connected in parallel with the corresponding energy pack or combination of energy packs. .

In each maintenance cycle, the degraded battery is supplemented with energy packs by the above method. For example, when the capacity of the degraded battery to be supplemented is 102C, the corresponding energy pack combination for parallel connection of the degraded battery is composed of a 100C energy pack and a 2C energy pack. The energy packs are connected in parallel with each other.

Among them, if the electric capacity that needs to be supplemented reaches more than 500C, that is, the difference between the degraded battery and other batteries in the battery pack is 5%, and further use of the degraded battery will damage the performance of the entire battery pack. At this time, the degraded battery should be dealt with. Just replace the battery with a new one.

The content described in this specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms stated in the embodiments.

Claims (3)

1. A method for maintaining a degraded battery in the service process of an energy storage battery pack is characterized by comprising the following steps:

1) Preparing a series of energy packs with different capacitances;

2) In a maintenance cycle of the energy storage battery pack, analyzing one or more deteriorated batteries in the running energy storage battery pack through a battery management system to obtain electric capacity data which need to be supplemented by the deteriorated batteries;

3) If the capacity of the degraded battery which needs to be supplemented reaches 5% of the rated capacity, the degraded battery is replaced; if the electric capacity which needs to be supplemented by the degraded battery is less than 5% of the rated electric capacity of the degraded battery, when the energy storage battery pack is periodically maintained, the degraded battery is connected in parallel with a corresponding energy packet or energy packet combination, the electric capacity which needs to be supplemented by the degraded battery is equal to the electric capacity of the energy packet or the energy packet combination, and the energy packet combination is formed by connecting a plurality of energy packets in parallel.

2. The method of claim 1, wherein the step 1) of preparing a series of energy packs of different capacities comprises: recording 1/10000 of the rated capacity of a single battery in the energy storage battery pack as C, wherein the C is the minimum capacity; a series of energy packs with the capacitance of 1C, 2C, 5C, 10C, 20C, 50C and 100C are prepared.

3. the method according to claim 1, wherein in step 1), the energy pack comprises a super capacitor, receptacle connectors arranged at two ends of the super capacitor, and tabs arranged on the receptacle connectors.