CN109814044B - An electric vehicle power battery passive equalization experimental system and its experimental method - Google Patents

Abstract

The invention discloses a passive equalization experiment system for a power battery of an electric automobile, which comprises an electronic controller and an experiment battery pack; the electronic controller is in control connection with the experimental battery pack; the experimental battery pack comprises a plurality of battery modules which are connected in series; the battery module comprises a plurality of single batteries which are connected in parallel; the experimental battery pack comprises a battery pack protection device; the heat dissipation air path is designed in the protection device, so that heat generated in the experiment can be discharged in time, and stable performance of the experiment is ensured.

Description

An electric vehicle power battery passive equalization experimental system and its experimental method

Technical field

The invention relates to the field of electric vehicle battery systems, and in particular to a passive balancing experimental system for electric vehicle power batteries.

Background technique

Electric vehicle power batteries are usually composed of several modules connected in series, and have high requirements for the balance of each module. Battery balancing uses power electronics technology to keep the voltage deviation of each module within a reasonable range to prevent overcharge and overdischarge of a single module. There are two types of battery balancing: active balancing and passive balancing. Active balancing uses energy transfer, while passive balancing uses energy consumption to achieve consistency among modules. In order to ensure the safety and stability of electric vehicles during use, it is necessary to invent a passive balancing experimental system for electric vehicle power batteries based on the principle of passive balancing and with outstanding heat dissipation performance.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a passive equalization experimental system for electric vehicle power batteries based on the principle of passive equalization and with outstanding heat dissipation performance.

Technical solution: In order to achieve the above purpose, the present invention provides an electric vehicle power battery passive equalization experimental system, which includes an electronic controller, a rechargeable battery, a power switch and an experimental battery pack; the electronic controller is connected to the experimental battery pack for control; The electronic controller, rechargeable battery, power switch and experimental battery pack are arranged in series; the experimental battery pack includes a number of battery modules connected in series; the battery module includes a number of single cells connected in parallel; the battery module Also included are discharge resistors and electronic switches connected in series with each other.

Further, the battery module includes a first module, a second module and a third module; the electronic controller is electrically connected with a charging switch, a first module discharge switch, and a second module discharge switch. switch, a third module discharge switch, and a balancing switch; several of the battery module series circuits are also provided with normally open relays; the first module is provided with a first module electronic switch and a first module in parallel Discharge resistor; the second module is provided with a second module electronic switch and a second module discharge resistor in parallel; the third module is provided with a third module electronic switch and a third module discharge resistor in parallel. .

Further, the experimental battery pack includes a battery pack protection device; the battery pack protection device includes a first wiring board and a second wiring board that are electrically connected to each other; a plurality of the single cells are clamped and arranged on the first wiring board , between the second wiring boards; the side of the first wiring board facing away from the single battery is fitted with a first thermal conductive plate; the side of the second wiring board facing away from the single battery is fitted with a third thermal conductive plate. Two thermal conductive plates; a first panel and a second panel are installed at both ends of the first thermal conductive plate along its length direction; a third wiring board is embedded on the first panel; the third wiring board faces the unit One side of the battery is electrically connected to the first wiring board and the second wiring board; a wiring hole is provided on the side of the third wiring board facing away from the single battery.

Further, a ventilation plate is installed on the side of the first heat conduction plate facing away from the first wiring board; a circulation hole is provided inside the ventilation plate along the length direction of the first heat conduction plate; the circulation hole is close to the first panel. An exhaust fan is provided on one end; a first vent is provided on the first panel; the first vent is positioned correspondingly to the exhaust fan; a second vent is provided on the side of the second panel close to the second wiring board; A first protective plate and a second protective plate are connected and installed between the first thermal conductive plate and the second thermal conductive plate; the two ends of the first protective plate along the length direction of the first thermal conductive plate are respectively connected with the first panel and the second thermal conductive plate. The two panels are connected; the two ends of the second protective plate along the length direction of the first thermal conductive plate are respectively connected to the first panel and the second panel.

Further, a plurality of circulation holes in the ventilation plate are spaced apart from each other, specifically including a first circulation hole and a second circulation hole; the air inlet of the exhaust fan corresponds to the first circulation hole; a plurality of the second circulation holes The holes are distributed around the first circulation holes; the second circulation holes are arranged in communication with the first circulation holes.

Further, an air inlet device is provided at the second vent on the second panel; an air hole is provided at the bottom of the air inlet device; a gas channel is provided in the air inlet device; the air hole passes through the gas channel Communicated with the second vent; a filter plate is embedded on the side of the air inlet device; the filter plate is correspondingly arranged on the path of the gas channel; a storage tank is provided on the top of the air inlet device; the top of the storage tank Hinged set with flip lid.

Further, a first inlay groove is provided on the inside of one end of the first protective plate facing the first panel; a second inlay groove is provided on the inside of one end of the second protective plate facing the first panel; the first panel faces the first panel. A first conductive piece and a second conductive piece are provided on one side of the two panels; the first conductive piece is nested and matched with the first inlay groove, and a first temperature sensor is provided on the side facing away from the first inlay groove; The second conductive piece is nested and matched with the second embedding groove, and a second temperature sensor is provided on a side facing away from the second embedding groove.

An experimental method for an electric vehicle power battery passive equalization experimental system: including the following steps:

Step 1, the charging stage of the experimental battery pack; the power switch and charging switch are closed, the electronic controller controls the contact of the normally open relay to close, the rechargeable battery uses a 12V battery to charge the three battery modules, and the voltage value of each battery module is fed back to Electronic controller, when the voltage value of a certain battery module reaches the maximum limit, the electronic controller is triggered to control the contact of the normally open relay to open; a voltmeter is used to monitor the voltage of each module, and it can be manually disconnected as needed Charging switch, exit charging mode;

Step 2, the battery module discharge stage; the power switch is closed, and the first module discharge switch, the second module discharge switch, and the third module discharge switch are partially or fully closed; the electronic controller controls the electronic switch of the corresponding battery module When the module is turned on and the corresponding module discharge resistor generates heat and consumes module power, use a voltmeter to monitor the voltage of each battery module. You can manually disconnect the corresponding module discharge switch as needed to exit the module discharge condition; when a certain When the voltage value of the battery module reaches the minimum limit, the electronic controller will automatically disconnect the corresponding module electronic switch and make the module exit the discharge condition;

Step three, the battery module balancing stage; the power switch and balancing switch are closed, and the electronic controller determines whether balancing is needed based on the voltage value of each battery module. If balancing is required, the electronic controller will control the module corresponding to the battery module with the higher voltage. When the electronic switch is turned on, the corresponding module resistor discharges and generates heat, consuming the module's power until the target value is reached. If balancing is not required, a certain battery module can be discharged first and then the balancing experiment can be performed.

Beneficial effects: An electric vehicle power battery passive equalization experimental system of the present invention includes an electronic controller and an experimental battery pack; the electronic controller is controlled and connected to the experimental battery pack; the experimental battery pack includes a number of battery modules connected in series. group; the battery module includes a number of single cells connected in parallel; the experimental battery pack includes a battery pack protection device; a heat dissipation air path is designed in the protection device, which can discharge the heat generated during the experiment in a timely manner, ensuring that The experiment proceeds smoothly.

Description of the drawings

Figure 1 is a schematic diagram of the experimental system circuit;

Figure 2 is a schematic diagram of the overall structure of the protective device;

Figure 3 is a schematic structural diagram of the air intake device.

Implementation

The present invention will be further described below in conjunction with the accompanying drawings.

An electric vehicle power battery passive equalization experimental system, as shown in Figure 1, includes an electronic controller 1 and an experimental battery pack 10; the electronic controller 1 is controlled and connected to the experimental battery pack 10; the experimental battery pack 10 includes A number of battery modules 20 are connected in series; the battery module 20 includes a number of single cells 201 connected in parallel; the electronic controller 1 specifically adopts a single-chip microcomputer module (such as an STM32 series single-chip microcomputer) purchased on the market, and the batteries can be purchased from the market. The lithium batteries on sale, switches, resistors and other components are common components in circuit construction and will not be described in detail here.

The experimental battery of this experimental device uses a single lithium battery with a nominal voltage of 3.7V. The highest and lowest set limits are 4.2V and 3V. Three single batteries are connected in parallel to form a battery module 20, and then three single batteries are connected in parallel to form a battery module 20. The battery modules 20 are connected in series; this experimental device can visually display the voltage of each module, and has the characteristics of simple structure, safe use and convenient operation.

The passive equalization experimental system also includes a rechargeable battery 2 and a power switch 3; the rechargeable battery 2, the power switch 3 and the experimental battery pack 10 are arranged in series; the battery module 20 also includes a discharge resistor and an electronic switch connected in series with each other.

The battery module 20 includes a first module 61, a second module 62, and a third module 63; the electronic controller 1 is electrically connected to a charging switch 4, a first module discharge switch 5, and a third module 63. The second module discharge switch 6, the third module discharge switch 7, and the balancing switch 8; the series circuits of the battery modules 20 are also provided with normally open relays 9; the first module 61 is provided with a third module in parallel. A module electronic switch 11 and a first module discharge resistor 12; the second module 62 is provided with a second module electronic switch 13 and a second module discharge resistor 14 in parallel; the third module 63 is A third module electronic switch 15 and a third module discharge resistor 16 are arranged in parallel; the experimenter controls the charging switch 4, the first module discharge switch 5, the second module discharge switch 6, and the third module discharge switch 7 and balancing switch 8, and then the electronic controller 1 specifically controls the electronic switches and discharge resistors in each battery module 20.

As shown in Figures 2 and 3, the experimental battery pack 10 includes a battery pack protection device 21; the battery pack protection device 21 includes a first wiring board 22 and a second wiring board 23 that are electrically connected to each other; several The single battery 201 is clamped and arranged between the first wiring board 22 and the second wiring board 23; etched circuits are evenly distributed on the first wiring board 22 and the second wiring board 23, and there are also etched circuits between the two wiring boards. Electrical connection, so that multiple single cells 201 can be connected together; when it is necessary to change the number of battery modules 20 or the number of single cells 201 contained, only the wiring board needs to be replaced, thus eliminating the need for A large amount of wiring time significantly improves the efficiency of the experiment; the first thermal conductive plate 24 is attached to the side of the first wiring board 22 facing away from the single cell 201; the second wiring board 23 faces away from the single cell A second thermal conductive plate 25 is attached to one side of 201; a first panel 26 and a second panel 27 are installed at both ends of the first thermal conductive plate 24 along its length direction; the first panel 26 is embedded with The third wiring board 266; the side of the third wiring board 266 facing the single battery 201 is electrically connected to the first wiring board 22 and the second wiring board 23; the third wiring board 266 faces away from the single battery 201 A wiring hole is provided on one side of the battery; the battery is connected to the corresponding electronic controller 1, various switches and resistors through the third wiring board 266.

A ventilation plate 28 is installed on the side of the first heat conduction plate 24 facing away from the first wiring board 22; a circulation hole 281 is provided inside the ventilation plate 28 along the length direction of the first heat conduction plate 24; the circulation hole 281 is close to An exhaust fan 282 is provided on one end of the first panel 26; a first vent 261 is provided on the first panel 26; the vent 261 is positioned correspondingly to the exhaust fan 282; the second panel 27 is close to the second wiring board A second vent 271 is provided on one side of 23; a first protective plate 29 and a second protective plate 30 are connected between the first thermal conductive plate 24 and the second thermal conductive plate 25; the first protective plate 29 The two ends along the length direction of the first heat conduction plate 24 are connected to the first panel 26 and the second panel 27 respectively; the two ends of the second protective plate 30 along the length direction of the first heat conduction plate 24 are respectively connected to the first panel 26 Connected to the second panel 27; the first panel 26, the second panel 27, the first thermal conductive plate 24, the second thermal conductive plate 25, the first protective plate 29 and the second protective plate 30 together form a closed space, close to the protective Cold air flows into the second vent 271 at the lower end of the device 21. This air flows in the protective device 21 and is finally pumped out from the first vent 261 by the exhaust fan 282. In this way, the air generated during the operation of the experimental system can be discharged in a timely manner. The heat is discharged to ensure the smooth progress of the experiment; at the same time, the first protective plate 29 and the second protective plate 30 are hingedly connected to the first thermal conductive plate 24. When maintenance and replacement are required inside the system, only the protective plates need to be lifted up. Complete the operation, avoiding the traditional process of laborious disassembly and assembly of the structure.

There are multiple circulation holes 281 spaced apart from each other in the ventilation plate 28, specifically including a first circulation hole 288 and a second circulation hole 283; the air inlet of the exhaust fan 282 matches the first circulation hole 288; several of the The second circulation holes 283 are distributed around the first circulation holes 288; the second circulation holes 283 are connected with the first circulation holes 288; this can make the exhaust ports more centralized and improve the utilization efficiency of the exhaust fan 282.

The second vent 271 on the second panel 27 is provided with an air inlet device 31; the bottom of the air inlet device 31 is provided with an air hole; the air inlet device 31 is provided with a gas passage; the air inlet device 31 passes through The gas channel is connected to the second vent 271; a filter plate 312 is embedded on the side of the air inlet device 31; the filter plate 312 is correspondingly arranged on the path of the gas channel; the filter plate 312 can effectively remove suspended particles in the air. The flocculent impurities and dust are intercepted outside to ensure the cleanliness inside the experimental system. When the filter plate needs to be cleaned, the replacement operation can be quickly completed by simply pulling it out; a storage tank is provided at the top of the air inlet device 31; The top of the storage tank is hingedly provided with a flip cover 314, which can place some commonly used tools such as screwdrivers, so that the experimental system has a storage function.

The first protective plate 29 is provided with a first inlay groove 291 on the inner side of one end facing the first panel 26; the second protective plate 30 is provided with a second inlay groove 301 on the inner side of one end facing the first panel 26; A first conductive piece 262 and a second conductive piece 263 are provided on the side of the panel 26 facing the second panel 27; the first conductive piece 262 is nested with the first inlay groove 291 and faces away from the first inlay groove 291. A first temperature sensor is provided on one side of It can be seen that the temperature of the part near the first panel 27 away from the first vent 261 is relatively high. By monitoring the temperature here, the overall heat dissipation condition of the experimental system can be determined.

An experimental method for an electric vehicle power battery passive equalization experimental system: including the following steps:

Step 1, the charging stage of the experimental battery pack 10; the power switch 3 and the charging switch 4 are closed, the electronic controller 1 controls the contact of the normally open relay 9 to close, the rechargeable battery 2 uses a 12V battery to charge the three battery modules 20, each battery The voltage value of the module 20 is fed back to the electronic controller 1. When the voltage value of a certain battery module 20 reaches the highest limit, the electronic controller 1 is triggered to control the contact of the normally open relay 9 to open; a voltmeter is used to measure each The module voltage is monitored, and the charging switch 4 can be manually disconnected as needed to exit the charging mode;

Step two, the battery module 20 is in the discharge stage; the power switch 3 is closed, and the first module discharge switch 5, the second module discharge switch 6, and the third module discharge switch 7 are partially or fully closed; the electronic controller 1 controls the corresponding When the electronic switch of the battery module 20 is turned on and the corresponding module discharge resistor generates heat and consumes the module power, a voltmeter is used to monitor the voltage of each battery module 20. The corresponding module discharge switch can be manually disconnected as needed to exit the module. Group discharge working condition; when the voltage value of a certain battery module 20 reaches the minimum limit value, the electronic controller 1 will also automatically disconnect the corresponding module electronic switch to cause the module to exit the discharge working condition;

Step 3: The battery module 20 is in the balancing stage; the power switch 3 and the balancing switch 8 are closed, and the electronic controller 1 determines whether balancing is needed based on the voltage value of each battery module 20. If balancing is required, the electronic controller 1 will control the battery with the higher voltage. The module electronic switch corresponding to the module 20 is turned on, and the corresponding module resistor discharges and generates heat, consuming the module power until the target value is reached; if balancing is not required, a certain battery module 20 can be discharged first, and then the balancing experiment can be performed.

The above are only the preferred embodiments of the present invention. It should be pointed out that those of ordinary skill in the art can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications can also be made. should be regarded as the protection scope of the present invention.

Claims (5)

1. The passive equalization experiment system for the power battery of the electric automobile is characterized in that: the device comprises an electronic controller (1), a rechargeable battery (2), a power switch (3) and an experimental battery pack (10); the electronic controller (1) is in control connection with the experimental battery pack (10); the electronic controller (1), the rechargeable battery (2) and the power switch (3) are connected in series with the experimental battery pack (10); the experimental battery pack (10) comprises a plurality of battery modules (20) which are connected in series; the battery module (20) comprises a plurality of single batteries (201) which are connected in parallel; the battery module (20) further comprises a discharge resistor and an electronic switch which are connected in series;

the experimental battery pack (10) comprises a battery pack protection device (21); the battery pack protection device (21) comprises a first wiring board (22) and a second wiring board (23) which are electrically connected with each other; the single batteries (201) are clamped and arranged between the first wiring board (22) and the second wiring board (23); a first heat conducting plate (24) is attached to one side, facing away from the single battery (201), of the first wiring board (22); a second heat conducting plate (25) is attached to one side, facing away from the single battery (201), of the second wiring board (23); the first heat-conducting plate (24) is provided with a first panel (26) and a second panel (27) along two ends of the length direction of the first heat-conducting plate; a third wiring board (266) is embedded on the first panel (26); one side of the third wiring board (266) facing the single battery (201) is electrically connected with the first wiring board (22) and the second wiring board (23); a wiring hole is formed in one side, facing away from the single battery (201), of the third wiring board (266);

a ventilation plate (28) is arranged on one side of the first heat conduction plate (24) facing away from the first wiring plate (22); a flow hole (281) is formed in the ventilation plate (28) along the length direction of the first heat conduction plate (24); an exhaust fan (282) is correspondingly arranged at one end of the circulation hole (281) close to the first panel (26); a first ventilation opening (261) is arranged on the first panel (26); the first ventilation opening (261) corresponds to the position of the exhaust fan (282); a second vent (271) is arranged on one side of the second panel (27) close to the second wiring board (23); a first protection plate (29) and a second protection plate (30) are connected and installed between the first heat-conducting plate (24) and the second heat-conducting plate (25); the first protection plate (29) is respectively connected with the first panel (26) and the second panel (27) along the two ends of the first heat conduction plate (24) in the length direction; the second protection plate (30) is respectively connected with the first panel (26) and the second panel (27) along the two ends of the first heat conduction plate (24) in the length direction;

a plurality of flow holes (281) in the ventilation plate (28) are arranged at intervals, and specifically comprise a first flow hole (288) and a second flow hole (283); the air inlet of the exhaust fan (282) is correspondingly matched with the first flow hole (288); a plurality of second flow holes (283) are distributed around the first flow holes (288); the second flow hole (283) is provided in communication with the first flow hole (288).

2. The electric vehicle power battery passive equalization experiment system according to claim 1, wherein: the battery module (20) comprises a first module (61), a second module (62) and a third module (63); the electronic controller (1) is electrically connected with a charging switch (4), a first module discharging switch (5), a second module discharging switch (6), a third module discharging switch (7) and an equalizing switch (8); a normally open relay (9) is also arranged on the series circuit of the plurality of battery modules (20); the first module (61) is provided with a first module electronic switch (11) and a first module discharging resistor (12) in parallel; the second module (62) is provided with a second module electronic switch (13) and a second module discharging resistor (14) in parallel; and a third module electronic switch (15) and a third module discharging resistor (16) are arranged on the third module (63) in parallel.

3. The electric vehicle power battery passive equalization experiment system according to claim 1, wherein: an air inlet device (31) is arranged at a second air vent (271) on the second panel (27); the bottom of the air inlet device (31) is provided with an air hole; a gas channel is arranged in the gas inlet device (31); the air hole is communicated with the second air vent (271) through an air channel; a filter plate (312) is embedded on the side surface of the air inlet device (31); the filter plates (312) are correspondingly arranged on the paths of the gas channels; a storage groove is formed in the top of the air inlet device (31); the top of the storage groove is hinged with a flip cover (314).

4. The electric vehicle power battery passive equalization experiment system according to claim 1, wherein: a first caulking groove (291) is formed in the inner side of one end, facing the first panel (26), of the first protection plate (29); a second caulking groove (301) is formed in the inner side of one end, facing the first panel (26), of the second protection plate (30); a first conductive sheet (262) and a second conductive sheet (263) are arranged on one side of the first panel (26) facing the second panel (27); the first conducting strip (262) is in nested fit with the first caulking groove (291), and a first temperature sensor is arranged on one side, facing away from the first caulking groove (291); the second conducting strip (263) is in nested fit with the second caulking groove (301), and a second temperature sensor is arranged on one side, facing away from the second caulking groove (301).

5. An experimental method of a passive equalization experimental system of an electric automobile power battery according to any one of claims 1-4: comprises the steps of,

step one, a charging stage of an experimental battery pack (10); the power switch (3) and the charging switch (4) are closed, the electronic controller (1) controls the contacts of the normally open relay (9) to be closed, the rechargeable battery (2) charges the 3 battery modules (20) by adopting a 12V storage battery, the voltage value of each battery module (20) is fed back to the electronic controller (1), and when the voltage value of one battery module (20) reaches the highest limit value, the electronic controller (1) is triggered to control the contacts of the normally open relay (9) to be opened; the voltage of each module is monitored by using a voltmeter, a charging switch (4) can be manually disconnected according to the requirement, and the charging working condition is exited;

step two, a discharging stage of the battery module (20); the power switch (3) is closed, and the first module discharging switch (5), the second module discharging switch (6) and the third module discharging switch (7) are partially or completely closed; the electronic controller (1) controls the electronic switch of the corresponding battery module (20) to be turned on, the corresponding module discharging resistor heats and consumes module electric energy, the voltage of each battery module (20) is monitored by using the voltmeter, the corresponding module discharging switch can be manually disconnected according to the requirement, and the module discharging working condition is exited; when the voltage value of a certain battery module (20) reaches the minimum value, the electronic controller (1) also automatically turns off the corresponding module electronic switch to enable the module to exit the discharging working condition;

step three, a battery module (20) balancing stage; the power switch (3) and the equalization switch (8) are closed, the electronic controller (1) determines whether equalization is needed according to the voltage value of each battery module (20), if equalization is needed, the electronic controller (1) can control the corresponding module electronic switch of the battery module (20) with high voltage to be conducted, and the corresponding module resistor discharges, heats and consumes module electric energy until reaching a target value; if no equalization is required, the battery module (20) can be discharged first and then an equalization experiment can be performed.