A power distribution method for a group charging system of a battery swap station

Abstract

The present invention discloses a power distribution method for a group charging system of a battery swap station, and the steps are as follows: S1. Determine the battery model in the group charging system, and obtain the charging current according to the battery capacity and the charging current characteristics at different SOC stages; S2. Determine the number of batteries in the battery swap station as N, and the time interval for each battery replacement as Ts; when the battery is replaced, the position where the battery is located is not charged; S3. Determine the battery replacement sequence 1 to N, and start charging the batteries in the battery swap station in sequence from 1 to N according to the replacement sequence, and determine the start time interval; S4. In the case of continuous battery replacement, find the maximum value of the charging current and define it as the maximum current demand; S5. According to the maximum current demand and the maximum output current of a single AC / DC module at the rated voltage of the battery, obtain the number of modules; S6. According to the number of AC / DC modules, configure the corresponding DC contactor matrix to achieve DC group charging that matches the power demand for continuous charging of N battery packs in the battery swap station.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle charging and battery swapping technology, specifically to a charging power calculation method, and more particularly to a power distribution method for a group charging system of a battery swap station. Background Art

[0002] A multi-charger system, also known as a group charging system, refers to a charging station with multiple charging ports. This system supports simultaneous charging of multiple vehicles, not only improving charging efficiency but also saving labor costs. Power distribution is crucial for group charging systems.

[0003] For example, CN111137168A provides a battery charging method and system for battery swap stations. This system, which addresses the differences in peak and valley electricity prices, restricts charging scheduling at existing battery swap stations to peak and valley periods. This effectively utilizes valley electricity periods and addresses the high electricity costs of electric vehicles. Another example is CN115663318A, which provides a charging method for new energy vehicles at battery swap stations. This method is a control method for charging battery packs at existing battery swap station chargers, enabling AC / DC modules to simultaneously charge multiple battery packs.

[0004] However, the applicant believes that the existing group charging system has the following two problems: 1) The battery charging AC / DC module of the battery charger at the battery swap station cannot dynamically switch the power output between each battery pack; 2) The power configuration of the charger at the current battery swap station is based on the maximum power configuration of the battery pack, resulting in an excessively high total power demand of the battery swap station and excessively high investment costs for the charger equipment and transformers. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a power distribution method for a group charging system of a battery swap station to solve the problems mentioned in the above background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A power distribution method for a group charging system of a battery swap station, characterized by the following steps:

[0008] S1. Determine the battery model in the group charging system. Based on the battery capacity and charging current characteristics at different SOC stages, calculate the charging current C = f(t), where t is time and C is current.

[0009] S2. Determine the number of batteries in the battery swap station as N, and the time interval between each battery swap is Ts; when the battery is swapped, the battery compartment is not charged, that is, C = 0, T c <t≤T c +T S , get the current of K charging cycles

[0010] S3. Determine the battery replacement sequence 1 to N. The batteries in the battery swap station start charging in the order of replacement from 1 to N. The start time interval is Ts; that is, the charging current of each battery in the battery swap station

[0011] S4. In the case of continuous battery replacement, the total current of N batteries is in, The maximum value is the maximum current demand I dmand ;

[0012] S5. According to the maximum current requirement I dmand And the maximum output current I of a single AC / DC module at the rated voltage of the battery max , thus calculating the number of modules

[0013] S6. According to the number of AC / DC modules N x , configure the corresponding DC contactor matrix to achieve DC group charging that matches the power demand and continuously charge N battery packs in the battery swap station.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention calculates the charging curve of the entire station that meets continuous battery replacement based on the battery charging curve and the battery replacement sequence, obtains the maximum charging current requirement, and finally obtains the total power configuration of the battery replacement station according to the current output capacity of the charging module, thereby utilizing group charging technology to meet the power switching requirements of different batteries.

[0016] By calculating the charging current demand under continuous battery swapping at the battery swap station, group charging technology is used to reduce the total power of the battery swap station and the investment cost of charger equipment and transformers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A system flow chart of an embodiment of the present invention.

[0019] Figure 2 1 is the capacity of a single battery and the current curve at different SOC stages in an embodiment of the present invention.

[0020] Figure 3 This is the current curve of the embodiment of the present invention during continuous battery replacement. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the present invention, the present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0023] Example 1:

[0024] like Figure 1 As shown, this embodiment provides a power distribution method for a group charging system of a battery swap station, and the steps are as follows:

[0025] S1. Determine the battery model in the group charging system. Based on the battery capacity and charging current characteristics at different SOC stages, calculate the charging current C = f(t), where t is time and C is current.

[0026] S2. Determine the number of batteries in the battery swap station as N, and the time interval between each battery swap is Ts; when the battery is swapped, the battery compartment is not charged, that is, C = 0, T c <t≤T c +T S , get the current of K charging cycles

[0027] S3. Determine the battery replacement sequence 1 to N. The batteries in the battery swap station start charging in the order of replacement from 1 to N. The start time interval is Ts; that is, the charging current of each battery in the battery swap station

[0028] S4. In the case of continuous battery replacement, the total current of N batteries is in, The maximum value is the maximum current demand I dmand ;

[0029] S5. According to the maximum current requirement I dmand And the maximum output current I of a single AC / DC module at the rated voltage of the battery max , thus calculating the number of modules

[0030] S6. According to the number of AC / DC modules N x , configure the corresponding DC contactor matrix to achieve DC group charging that matches the power demand and continuously charge N battery packs in the battery swap station.

[0031] This method uses the battery charging curve and battery swap sequence to derive a charging curve for the entire station that meets the requirements for continuous battery swapping. This curve then determines the maximum charging current requirement, ultimately determining the total power configuration of the station based on the current output capacity of the charging modules. This allows for power switching to meet the varying charging requirements of different batteries using group charging technology. By calculating the charging current requirements for continuous battery swapping at a station, group charging technology can be used to reduce the station's total power, minimizing the investment in chargers and transformers.

[0032] It effectively solves the problem that the AC / DC module of the battery charging machine at the battery swap station cannot dynamically switch the power output between each battery pack, and solves the problem that the power configuration of the charger at the current battery swap station is based on the maximum power configuration of the battery pack, resulting in excessively high total power demand of the battery swap station and excessively high investment costs for charger equipment and transformers.

[0033] Take a battery as an example, and get the charging current C=f(t) from SOC 15% to 100%. Figure 2 (The X-axis is time, the left Y-axis is current, and the right Y-axis is percentage.) A charging curve at 25-50°C was selected for analysis. The SOC ranged from 15% to 85%, with constant power charging at a rate of 1C and a current of 268A. The charging efficiency increased by 1.7% per minute, and the charging time was approximately 41 minutes. At 85% to 98% with primary current limiting, charging at a rate of 0.8C and a current of 214A increased the charging efficiency by 1.3% per minute, and the charging time was approximately 10 minutes. At 98% to 100% with secondary current limiting and a current of 20A, the charging efficiency increased by 0.12% per minute, and the charging time was approximately 16 minutes. The battery fully charged from 15% to 100% SOC in a total of approximately 66 minutes.

[0034] Figure 3Taking 8 batteries and a 7-minute battery replacement interval as an example, the calculated total current curve is at the bottom. Among them, after battery pack No. 1 is fully charged after a cycle of 66 minutes, it starts to replace the battery and enters the second charging cycle about 7 minutes later; battery pack No. 2 starts the cycle charging 7 minutes later than battery pack No. 1, and battery packs No. 3 to No. 8 are delayed by 7 minutes in turn. The 8 battery packs basically cycle for about 1 hour. The battery voltage takes the median value of 609V, corresponding to the maximum output current of 49.3A for the 30kW module. When the total module power is about 1200kW, the maximum output current of the module is about 1971A. It can be seen that during the periodic charging process of the 8 battery packs, the peak current is 2036A only at minutes 50-51 and 124-125, which exceeds the total output current of the module. Therefore, this system meets the requirements.

[0035] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to enumerate all implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A power distribution method for a battery swap station group charging system, characterized in that: Here are the steps: S1. Determine the battery model in the group charging system. Based on the battery capacity and charging current characteristics at different SOC stages, calculate the charging current C = f(t), where t is time and C is current. S2. Determine the number of batteries in the battery swap station as N, and the time interval between each battery replacement is Ts; the battery compartment where the battery is located is not charged when the battery is replaced; S3. Determine the battery replacement order 1 to N. The batteries in the battery swap station start charging in the order of replacement from 1 to N, and determine the start time interval Ts; S4. Under the condition of continuous battery replacement, find the maximum value of the charging current and define it as the maximum current demand I dmand ; S5. According to the maximum current requirement I dmand And the maximum output current I of a single AC / DC module at the rated voltage of the battery max , get the number of modules N x ; S6. According to the number of AC / DC modules N x , configure the corresponding DC contactor matrix to achieve DC group charging that matches the power demand and continuously charges N battery packs in the battery swap station; In step S2, C=0, Tc<t≤Tc+Ts, and the current of K charging cycles is obtained. 。 2. A power distribution method for a battery swap station group charging system according to claim 1, characterized in that: In S3, the charging current of each battery in the battery swap station is 。 3. The power distribution method for a battery swap station group charging system according to claim 1, characterized in that: The total charging current of N batteries in S4 is 。

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