CN203039385U - Storage-battery equilibrium apparatus for electric bicycle - Google Patents

Abstract

The utility model discloses an electric bicycle storage battery equalization device. The electric bicycle storage battery includes a battery pack, the storage battery pack is provided with a structure connected to an external power source, the equalization device is provided with a voltage equalization module and a control module, and the voltage equalization module is connected to the storage battery pack; The voltage equalization module is connected with the control module through a high-frequency switch. The above technical solution adopts the battery balancing device, so that each single battery can be charged and discharged in a balanced manner, which ensures that the parameters of each single battery in the battery pack are consistent to a large extent, and greatly prolongs the service life of the battery pack. Improve the overall performance of the battery pack, reduce the user's burden of maintaining the battery to the greatest extent and reduce the early scrapping rate of the battery pack, thereby reducing the cost of using the electric bicycle.

Description

A battery balancing device for an electric bicycle

technical field

The utility model belongs to the technical field of power batteries and relates to the battery technology of electric bicycles. More specifically, the utility model relates to a battery balancing device for an electric bicycle.

Background technique

Batteries have been widely used in various fields, especially the improved lead-acid batteries that have appeared in recent years, which are widely used in electric bicycles due to their high cost performance.

Electric bicycles need to charge and discharge the battery frequently, which puts forward higher requirements on the performance of the battery, and also pushes the performance of the battery to the limit.

Because the voltage of a single battery is generally very small, in many applications, it is not enough for a single battery, but it is necessary to connect the single batteries in series to meet the voltage requirements of the equipment. Therefore, batteries are generally used after connecting multiple batteries in series.

Even if the consistency of the screened batteries before grouping is good, there will be differences after a period of use. During the discharge process, the voltage of the single battery is low, and it loses the ability to discharge. At this time, it becomes an electrical appliance, and other batteries that still have capacity are connected in series to charge it. The entire storage battery pack cannot work normally, and at the same time it has a great impact on the battery life of the opposite pole.

During the charging process, the battery that is discharged first will be fully charged first, so that overcharging will occur, so that the entire battery pack cannot be fully charged normally. As the number of charge-discharge cycles increases, the discharge capacity of the battery gradually decreases. In fact, the actual discharge capacity of a group of batteries is determined by the lead-acid battery with the smallest actual capacity. End of life.

At present, the lead-acid battery packs for electric bicycles on the market are generally not equipped with equalization devices, which leads to a great reduction in the battery life and battery life of electric vehicles, thus virtually increasing the use cost of electric bicycles.

Utility model content

The utility model provides an equalizing device for storage batteries of an electric bicycle, the purpose of which is to improve the battery life of battery packs and prolong their service life.

In order to achieve the above object, the technical scheme that the utility model takes is:

The electric bicycle storage battery equalization device provided by the utility model, the electric bicycle storage battery includes a battery pack, and the storage battery pack is provided with a structure connected to an external power supply; the equalization device is provided with a voltage equalization module and a control module, The voltage equalization module is connected with the battery pack; the voltage equalization module is connected with the control module through a high frequency switch.

The voltage equalization module is also connected to the control module through an output voltage feedback module and a photoelectric coupling module.

The voltage balancing module is also connected to the control module through an input voltage feedback module.

The voltage balance module is connected to the control module through the output voltage feedback module and the photoelectric coupling module; the voltage balance module is also connected to the control module through the input voltage feedback module; the input voltage feedback module It is also connected with the optocoupler module.

The control module adopts UC3841B chip.

The input voltage sampling module is an adjustable output voltage regulator composed of TL431 regulator tube.

The utility model adopts the above-mentioned technical scheme. Compared with the electric bicycle in the prior art, since the battery balancing device is adopted, each single battery can be charged and discharged in a balanced and consistent manner, which ensures that each single battery in the battery pack is The parameters of the body battery are consistent, which greatly prolongs the service life of the battery pack, improves the overall performance of the battery pack, and reduces the burden of maintaining the battery for the user to the greatest extent and reduces the early scrapping rate of the battery pack, thereby reducing the use cost of the electric bicycle.

Description of drawings

The following is a brief description of the content expressed in the drawings of this manual and the marks in the drawings:

Fig. 1 is the block diagram of battery equalizing device of the present utility model;

FIG. 2 is a schematic circuit diagram of the battery balancing device in FIG. 1 .

The labels in Figure 1 are:

1. Control module, 2. High frequency switch (Q), 3. Voltage equalization module, 4. Battery pack, 5. External power supply; 6. Photoelectric coupling module (PC817), 7. Output voltage feedback module; 8. Input voltage Sampling module.

Detailed ways

Next, with reference to the accompanying drawings, through the description of the embodiments, the specific implementation of the utility model will be further described in detail, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solutions of the utility model .

The structure of the utility model as shown in Fig. 1 and Fig. 2 is a battery balancing device for an electric bicycle, which is a battery balancing device for an electric bicycle with low price, high efficiency and low maintenance cost. The electric bicycle storage battery includes a storage battery pack 4, and the storage battery pack 4 is provided with a structure connected to an external power supply 5.

The SOC (State of Charge) of the battery is a concentrated reflection of the difference in battery performance. Balancing the SOC of the battery is undoubtedly the most effective balancing measure. However, because the SOC is affected by many factors such as discharge rate, temperature, and cycle times, its The estimation accuracy is not high. Moreover, to estimate and equalize the SOC of each single battery, the circuit is very large, and the cost, volume and quality of the equalization system are unacceptable.

In order to simplify the equalization circuit of the battery pack, it can be realized by simplifying the equalization parameters and reducing the equalization objects. Since the open circuit voltage of the battery has a certain corresponding relationship with its SOC, the SOC of the battery can be balanced indirectly by equalizing the open circuit voltage.

In order to solve the problems existing in the prior art and overcome its defects, and realize the purpose of the invention of improving the endurance of the storage battery pack and prolonging its service life, the technical scheme adopted by the utility model is as follows:

As shown in Figure 1, the electric bicycle storage battery balancing device provided by the utility model is provided with a voltage balancing module 3 and a control module 1, and the voltage balancing module 3 is connected with the battery pack 4; The module 3 is connected with the control module 1 through the high frequency switch 2 .

Commonly used electric bicycle battery packs are composed of 4 single batteries connected in series. The rated voltage of each single battery is 12V, and the total rated voltage is 48V. The centralized equalization of the device means that the whole battery pack shares an equalizer. The structure block diagram of the equalization system is shown in Figure 1, and E1, E2, E3, and E4 in the figure are battery packs. Module 3 is an equalizer module, whose core is a DC-DC converter composed of a high-frequency transformer T. The converter has an input U _s and four outputs U ₁ ~ U ₄ , and the circuit is designed so that U ₁ =U ₂ =U ₃ =U ₄ =U _s /4=12V, U _s is the battery terminal voltage.

The control module 1 controls the conduction of the high-frequency switch by detecting whether there is a low level, and then directly acts on the voltage equalization module 3 to make a corresponding action, so that the battery pack 4 is balanced.

Compared with the electric bicycles in the prior art, due to the use of the battery equalization device, the consistent and balanced charging and discharging of the single cells is done well, and the parameters of the single cells in the battery pack are guaranteed to be consistent to a large extent. Greatly prolong the service life of the battery pack, improve the overall performance of the battery pack, reduce the user's burden of maintaining the battery pack and reduce the early scrapping rate of the battery pack to the greatest extent, thereby reducing the use cost of the electric bicycle. The technical proposal of the utility model has the advantages of low price, high efficiency and low maintenance cost.

The voltage equalization module 3 is also connected to the control module 1 through an output voltage feedback module 7 and a photoelectric coupling module 6 .

The voltage balancing module 3 is also connected to the control module 1 through an input voltage feedback module 8 .

The voltage equalization module 3 is connected to the control module 1 through the output voltage feedback module 7 and the photoelectric coupling module 6; the voltage equalization module 3 is also connected to the control module 1 through the input voltage feedback module 8; The input voltage feedback module 8 is also connected with the photocoupling module 6 .

The control module 1 adopts UC3841B chip.

The input voltage sampling module 8 is an adjustable output voltage regulator composed of a TL431 regulator tube. It is used to generate a reference voltage and provide a regulated power supply to the chip.

Analyze the working principle of the present utility model below:

As shown in Figure 1, when the external power supply 5 charges the battery pack module 4, U _s increases; when the battery pack 4 supplies power to the load, U _s decreases. The four outputs in the storage battery pack 4 are respectively connected to four single storage batteries. When the external power supply 5 charges the storage battery pack 4, each battery cell has two charging currents, i _s (external power supply charging current) and i _i (i = 1, 2, 3, 4, equalizer module 3 charging current to battery pack 4).

By detecting the current cell voltage of the battery and comparing the reference voltage with the photoelectric coupling module 6 (PC817), the output signal is sent to the control module 1, and the control module 1 controls the high-frequency switch 2 to turn on and off according to whether there is an input signal to control Whether the balancing module 3 needs to charge the single battery.

时，均衡器模块3向该单体蓄电池充电，将有i_i和i_s一起对单体蓄电池组充电；若单体蓄电池的端电压高

时，二极管截止（即i_i=0），只有i_s对这些蓄电池组充电。这样端电压低的蓄电池组充电电流大，其端电压上升得快一些，过程持续到蓄电池组间电压相同为止，达到了均衡控制的目的。The terminal voltage of the battery cell is compared with the reference voltage provided by the input voltage sampling module 8 through the output voltage feedback module 7; If it is not turned on, the voltage equalization module 3 does not charge the respective connected battery cells. If the terminal voltage of the single battery is not equal to the reference voltage, that is, the terminal voltage of the single battery is low

, the equalizer module 3 charges the single battery, and i _i and i _s will charge the single battery group together; if the terminal voltage of the single battery is high

When , the diode is cut off (that is, i _i =0), only i _s charges these battery packs. In this way, the battery pack with low terminal voltage has a large charging current, and its terminal voltage rises faster, and the process continues until the voltage between the battery packs is the same, achieving the purpose of balanced control.

It can be seen from FIG. 2 that when the external power supply 5 is cut off, the voltage equalizer module 3 is coupled through a high-frequency transformer to realize the automatic transfer of energy between the cells, thereby gradually reducing the inconsistency of the cells in the battery pack 4. Balances voltage by transferring energy from cells with higher voltage to cells with lower voltage.

When charging, the voltage equalization module 3 is turned on immediately at the beginning of charging, so that the voltages of all the single storage batteries are first balanced to the same level, and then the voltages of all the single storage batteries rise with the same slope until they are fully charged. The same is true for the discharge process. The voltage equalization module 3 is turned on at the beginning of the discharge, so that the slopes of each monomer are kept consistent, so that the battery pack 4 quickly reaches a balanced state.

In the technical solution of the utility model, the battery balancing device has the characteristics of low switching frequency, small conduction loss, simple structure, easy to realize fast and efficient energy transfer, etc., and at the same time has the characteristics of low cost, low maintenance, and easy to promote in the market .

The utility model has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited by the above-mentioned methods, as long as various insubstantial improvements are made by adopting the method concept and technical solutions of the utility model, or Directly applying the ideas and technical solutions of the utility model to other occasions without improvement is within the protection scope of the utility model.

Claims (6)

1. An electric bicycle battery balancing device, the electric bicycle battery includes a battery pack (4), and the battery pack (4) is provided with a structure connected to an external power supply (5), characterized in that: the The equalization device is provided with a voltage equalization module (3) and a control module (1), and the voltage equalization module (3) is connected to the battery pack (4); (2) Connect with the control module (1). 2. The battery equalization device for electric bicycles according to claim 1, characterized in that: said voltage equalization module (3) is also connected to said control module through output voltage feedback module (7), photoelectric coupling module (6) (1) Connection. 3. The electric bicycle storage battery balancing device according to claim 1, characterized in that: said voltage balancing module (3) is also connected to said control module (1) through an input voltage feedback module (8). 4. The battery equalization device for electric bicycles according to claim 1, characterized in that the voltage equalization module (3) communicates with the control module ( 1) connection; the voltage equalization module (3) is also connected to the control module (1) through the input voltage feedback module (8); the input voltage feedback module (8) is also connected to the photoelectric coupling module (6 )connect. 5. The electric bicycle battery balancing device according to any one of claims 1 to 4, characterized in that: the control module (1) uses a UC3841B chip. 6. The electric bicycle storage battery balancing device according to claim 4, characterized in that: the input voltage sampling module (8) is an adjustable output voltage regulator composed of TL431 voltage regulator tubes.

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