CN102270871A - Power battery pack air pressure control rechargeable power balance system - Google Patents

Abstract

The invention provides a pneumatic-control charging-type electric quantity equalizing system for a power battery pack, which comprises a battery pack manager and a plurality of electric quantity equalizers. The system is characterized in that a plurality of pneumatic switches are added, the equalizing charge current of each electric quantity equalizer is more than 10 A, the output ends of the individual electric quantity equalizers are correspondingly connected in parallel at the two ends of the unit batteries in the battery pack, and the output end of the battery pack manager is correspondingly connected with the control ends of the electric quantity equalizers through the normally-closed contacts of the individual pneumatic switches. By use of the system, the equalizing speed and efficiency are increased, the unit batteries are fully charged, and the electric quantities of the unit batteries are relatively equalized, so that the charging efficiency is not reduced. The electric quantity of an over-discharged unit battery is supplemented in time during discharging, and an under-voltage alarm is given when the voltage of the whole battery pack drops to a preset value. The service life of the whole battery pack is dependent on low-life unit batteries in the battery pack, and since the unit batteries can be fully charged each time and not over-discharged, the service life of the battery pack is increased.

Description

Power battery pack air pressure control rechargeable power balance system

technical field

The invention provides a power battery pack air pressure control charging type power balance system, which belongs to the technical field of power battery packs.

Background technique

At present, the power battery pack of a pure electric vehicle is composed of multiple batteries connected in series. Due to the dispersion of battery cells, the performance varies greatly. The life of the entire battery pack depends on a single low-life battery. This power battery system solution mainly has the following disadvantages: 1. The life of the battery pack is much lower than the cycle life of a single battery. 2. The battery pack is generally charged in series as a whole. The charging and discharging control detects the voltage of the whole or the battery cell. When the cell is overcharged or over-discharged, only an alarm signal is issued. The system cannot perform effective power balance and cannot play the role of the battery and the battery pack maximum potency. 3. The power balance system configured by the battery pack is a small current (less than 5 amps) discharge type (energy consumption) structure. This equalizer cannot meet the power balance requirements of the power battery pack of a pure electric vehicle above 100 amperes. 4. The balance control of the battery pack is generally controlled by the voltage of the battery cells. When the temperature changes, the voltage control balance system has poor power balance effect.

Contents of the invention

The purpose of the present invention is to provide a power battery pack air pressure control rechargeable power balance system that can overcome the above-mentioned defects, effectively perform high-current power balance, have a long battery life, and be suitable for pure electric vehicles with 100 ampere hours or more. Its technical solution is:

A power battery pack air pressure control charging type power balance system, including a battery pack manager and a plurality of power equalizers, is characterized in that: a plurality of air pressure switches are added, and the balanced charging current of each power balancer is above 10 amps. The output end of each power balancer corresponds to the two ends of the battery cells connected in parallel in the battery pack, and the output end of the battery pack manager is connected to the control end of the power balancer via the normally closed contact of each air pressure switch.

In the power battery pack air pressure control charging type power balance system, the air pressure sensing plug of each air pressure switch is correspondingly sealed and installed in the housing of each battery cell, and the power balancer adopts an isolated DC-DC controllable balanced charging type The module has a balanced current of more than 10 amps, including high-frequency rectifier diodes, isolated high-frequency transformers, PWM controllers, light-controlled switches and constant current and voltage-limiting control units, wherein the incoming power supply is connected to the input terminal of the PWM controller through the light-controlled switch. The output terminal of the PWM controller is connected to the primary coil of the isolated high-frequency transformer, the secondary coil of the isolated high-frequency transformer is connected to both ends of the battery cell through a high-frequency rectifier diode, and the control terminal of the PWM controller is connected to the constant current and voltage limiting control unit. The output end of the high-frequency rectifier diode and the control end of the light control switch are connected to the output end of the battery pack manager through the normally closed contact of the air pressure switch.

Its working principle is: each cell balancer is controlled by the air pressure switch and the battery pack manager. When charging the power battery pack, first use the charger to charge the whole battery pack in series, when the battery pack manager detects that one of the battery cells reaches the set voltage, stop the series charging of the battery pack by the charger, and then manage the battery pack The power balancer connected in parallel with each battery cell is activated by the controller selection control, and the other undervoltage battery cells are charged in parallel until the internal gas evolution pressure of the battery cell reaches the set value of the air pressure switch. The closed contact is disconnected, and the parallel charging is stopped. Finally, each battery cell is fully charged, and the parallel charging electric energy is obtained from the electric energy of the total voltage of the battery pack. During the discharge of the power battery pack, if one or more of the battery cells reaches the over-discharge voltage, the battery pack manager also selects and controls the power balancer connected in parallel with each battery cell, and the over-discharged battery cell The modules are charged in parallel, and the charging power comes from the total voltage of the battery pack. When the total voltage of the module or system is lower than the set value, the system discharges and stops working.

Compared with the prior art, the present invention has the advantages of:

1. The current of the power balancer is generally selected to be more than 10 amps, and the electric energy mobile charging equalization is used instead of the resistance energy consumption discharge equalization to improve the equalization speed and efficiency.

2. When charging, due to the combination of series charging and parallel charging, it can ensure that each battery cell can be fully charged, and the balanced charging power is controlled by the pressure of gas evolution inside the battery cell, ensuring that the battery cell power is relatively balanced, without It will reduce the charging efficiency; when discharging, it can replenish the power of the over-discharged battery in time, and when the overall voltage of the battery pack drops to the set value, it will alarm for insufficient power.

3. The life of the entire battery pack depends on a single low-life battery. Since a single battery can be fully charged every time and cannot be over-discharged, the life of the battery pack will also increase accordingly.

Description of drawings

Fig. 1 is the wiring diagram of embodiment;

Fig. 2 is a working principle diagram of the electric balancer in the embodiment of the present invention;

Fig. 3 is a schematic diagram of the mechanical connection between the air pressure switch and the battery cell in the embodiment of the present invention.

In the figure: 1. Battery pack manager 2. Power balancer 3. Air pressure switch 4. Battery cell 5. Housing 6. High frequency rectifier diode 7. Isolated high frequency transformer 8. PWM controller 9. Light control switch 10 , Constant current and voltage limiting control unit

Detailed ways

In the embodiment shown in Figures 1-3: it includes a battery pack manager 1, a plurality of power equalizers 2 and a plurality of air pressure switches 3, and the air pressure sensing plug of each air pressure switch 3 is correspondingly sealed and installed on each battery cell In the housing 5 of the body 4, each power equalizer 2 adopts an isolated DC-DC controllable equalizing charging module, and the equalizing current is above 10 amps, including a high-frequency rectifier diode 6, an isolated high-frequency transformer 7, and a PWM controller 8 , light-controlled switch 9 and constant-current-voltage-limiting control unit 10, wherein the incoming line power is connected to the input end of PWM controller 8 through light-controlled switch 9, and the output end of PWM controller 8 is connected to the primary coil of isolated high-frequency transformer 7, isolated The secondary coil of the high-frequency transformer 7 is connected to the two ends of the battery cell 4 through the high-frequency rectifier diode 6, and the control terminal of the PWM controller 8 is connected to the output terminal of the high-frequency rectifier diode 6 through the constant current and voltage limiting control unit 10. The control end of the switch 9 is correspondingly connected to the output end of the battery pack manager 1 via the normally closed contact of the air pressure switch 3 .

Claims (2)

1. A power battery pack air pressure control charging type power balance system, including a battery pack manager (1) and a plurality of power balancers (2), characterized in that: a plurality of air pressure switches (3) are added, each power The balanced charging current of the equalizer (2) is above 10 amps, and the output terminals of each power equalizer (2) correspond to the two ends of the battery cells (4) connected in parallel in the battery pack, and the battery pack manager (1 ) output end is connected to the control end of the electric balancer (2) correspondingly through the normally closed contact of each air pressure switch (3). 2. The power battery pack air pressure control rechargeable power balance system according to claim 1, characterized in that: the air pressure sensing plug of each air pressure switch (3) is correspondingly sealed and installed on the shell of each battery cell (4) Inside the body (5), the power equalizer (2) adopts an isolated DC-DC controllable equalizing charging module, with an equalizing current of more than 10 amps, including a high-frequency rectifier diode (6), an isolated high-frequency transformer (7), and a PWM control device (8), light control switch (9) and constant current voltage limiting control unit (10), wherein the incoming power supply is connected to the input end of the PWM controller (8) through the light control switch (9), and the PWM controller (8) The output terminal of the isolated high-frequency transformer (7) is connected to the primary coil of the isolated high-frequency transformer (7), and the secondary coil of the isolated high-frequency transformer (7) is connected to the two ends of the battery cell (4) through the high-frequency rectifier diode (6), and the PWM controller (8 ) is connected to the output terminal of the high-frequency rectifier diode (6) through the constant current and voltage limiting control unit (10), and the control terminal of the light control switch (9) is connected to the battery pack through the normally closed contact of the air pressure switch (3). output of manager(1).

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