Battery pack multi-branch parallel connection circulation-free circuit

Abstract

The utility model discloses a circulation-free circuit with multiple parallel branches of a battery pack, which belongs to the technical field of batteries and comprises a battery management system (BMS) control box, a battery pack module, a switch module and a high-voltage battery (HVB) insulation detection module. The high-voltage battery (HVB) insulation detection module comprises a direct-current charging positive contactor module, a direct-current charging negative contactor module, a Hall sensor module, a battery assembly negative contactor, a current relay normally-open type, a pre-charging contactor and a pre-charging resistor, the total cathode of the battery pack module is connected with the direct current charging negative contactor module, the battery assembly negative contactor and the pre-charging contactor through the Hall sensor module; the direct current charging positive contactor module is connected with the switch module through the current relay normally-open type and Hall sensor module. Through the circulation-free circuit provided by the utility model, a current loop can be prevented from being formed among multiple branches of the battery pack when a manual service switch (MSD) of the high-voltage distribution box is inserted back.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the battery technical field, specifically, the utility model relates to a kind of battery pack multi-branch parallel loop-free circuit. BACKGROUND

[0002] At present, new energy electric vehicles generally adopt higher voltage platform, and the voltage in high-voltage circuit is as high as several hundred volts. During vehicle use, it is strictly prohibited to operate under voltage when some faults need to be checked or repaired. In order to protect the safety of the operator, a manual maintenance switch (MSD) is installed on the high-voltage distribution box of the vehicle. When troubleshooting or repairing, the high-voltage circuit can be physically disconnected by pulling out the manual maintenance switch (MSD), thereby protecting the safety of the operator. When the troubleshooting or repair is completed, the operator restores the voltage of the vehicle high-voltage circuit to normal by inserting the manual maintenance switch (MSD).

[0003] However, when a battery cell or module fails and needs to be repaired or replaced during vehicle use, due to the connection method of the entire battery pack, which is connected in series first and then in parallel, after replacing the battery, the new and old battery packs are prone to capacity differences, which can cause a certain voltage difference. If the voltage difference is too large, and the maintenance personnel do not measure the loop voltage value or use the voltage maintenance device to reduce the voltage difference in the parallel circuit to below the safety value, and then recklessly insert the manual maintenance switch (MSD) of the high-voltage distribution box, the high-voltage branch will charge the low-voltage branch at the moment of connection, forming a current loop. When the voltage difference is large, due to the small internal resistance of the battery, a large circulating current will be generated at this time, which can cause a safety accident.

[0004] In patent CN118722329A, a method, device and control device for monitoring the circulating current in the battery pack after the vehicle is powered off are disclosed. The method includes: obtaining a first cell parameter set at the first wake-up after power-off and a second cell parameter set at the measurement, wherein at least one cell parameter is included in the cell parameter set; obtaining the first change rate of the cell parameter from the first cell parameter set and the second cell parameter set, the first change rate being the average rate of change of the cell parameter from the first wake-up to the measurement; correcting the first change rate of at least one cell parameter to obtain the second change rate of the corresponding cell parameter; and determining whether a circulating current is generated according to the size of the second change rate of the cell parameter.

[0005] However, the above-mentioned patent disclosed technology cannot avoid the formation of a current loop at the moment of connection when the manual maintenance switch (MSD) of the high-voltage distribution box is inserted. UTILITY MODEL CONTENTS

[0006] The utility model wants to solve the technical problem of prior art, provide a battery package multi branch parallel's exempt from circulating current circuit to reach the purpose that can avoid the current loop formation between the battery package multi branch when the high voltage distribution box's manual maintenance switch (MSD) is inserted back.

[0007] In order to realize the above-mentioned purpose, the utility model takes the technical scheme for:

[0008] The utility model provides a battery package multi branch parallel's exempt from circulating current circuit, including battery management system (BMS) control box, battery pack module, switch module and high voltage battery (HVB) insulation detection module, high voltage battery (HVB) insulation detection module includes direct current charging positive contactor module, direct current charging negative contactor module, hall sensor module, battery assembly negative contactor, current relay normally open type, precharge contactor and precharge resistance, wherein, battery management system (BMS) control box is connected with battery pack module;The total positive pole of battery pack module is connected with switch module;The total negative pole of battery pack module is connected with direct current charging negative contactor module, battery assembly negative contactor and precharge contactor through hall sensor module;Battery assembly negative contactor is connected with precharge contactor through precharge resistance;Direct current charging positive contactor module is connected with switch module through current relay normally open type and hall sensor module.

[0009] Further, the hall sensor module includes a first hall sensor and a second hall sensor.

[0010] Further, the battery pack module includes a first electric box, a second electric box, a third electric box, and a fourth electric box. The first electric box and the second electric box are connected in series. The third electric box and the fourth electric box are connected in series.

[0011] Further, the switch module includes a first manual service switch (MSD) and a second manual service switch (MSD). The total positive pole after the series connection of the first electric box and the second electric box is connected with the first manual service switch (MSD). The total positive pole after the series connection of the third electric box and the fourth electric box is connected with the second manual service switch (MSD).

[0012] Further, the direct current charging negative contactor module includes a first direct current charging negative contactor and a second direct current charging negative contactor. The total negative pole after the series connection of the first electric box and the second electric box is connected with the first direct current charging negative contactor, the second direct current charging negative contactor, the battery assembly negative contactor, and the precharge contactor through the first hall sensor. The total negative pole after the series connection of the third electric box and the fourth electric box is connected with the first direct current charging negative contactor, the second direct current charging negative contactor, the battery assembly negative contactor, and the precharge contactor.

[0013] Further, the direct current charging positive contactor module comprises a first direct current charging positive contactor and a second direct current charging positive contactor, a first manual service switch (MSD) is connected with the first direct current charging positive contactor and the second direct current charging positive contactor through a second Hall sensor; and a second manual service switch (MSD) is connected with the first direct current charging positive contactor and the second direct current charging positive contactor through a current relay normally open type.

[0014] The circuit of the utility model has the following advantages:

[0015] (1) Through the circulation-free circuit of the utility model, current loop between multiple branches of the battery pack can be avoided when the manual service switch (MSD) of the high-voltage distribution box is inserted back.

[0016] (2) Through the circulation-free circuit of the utility model, damage of related electronic components caused by circulation can be avoided.

[0017] (3) Through the circulation-free circuit of the utility model, the safety of the operator can be protected, and the occurrence of safety accidents can be effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present specification comprises the following drawings, and the shown contents are respectively:

[0019] Figure 1 It is a logic structure block diagram of the circulation-free circuit of the utility model for multiple branches of a battery pack in parallel;

[0020] Figure 2 It is a principle diagram of the circulation-free circuit of the utility model for multiple branches of a battery pack in parallel.

[0021] Explanation of reference signs: 1, battery management system (BMS) control box; 2, battery pack module; 3, switch module; 4, high-voltage battery (HVB) insulation detection module; 11, low-voltage output end of the battery management system (BMS) control box; 12, low-voltage input end of the battery management system (BMS) control box; 21, first electric box; 22, second electric box; 23, third electric box; 24, fourth electric box; 31, first manual service disconnect (MSD); 32, second manual service disconnect (MSD); 41, DC charging positive contactor module; 42, DC charging negative contactor module; 43, Hall sensor module; 44, battery assembly negative contactor; 45, current relay normally open type; 46, pre-charge contactor; 47, pre-charge resistor; 411, first DC charging positive contactor; 412, second DC charging positive contactor; 421, first DC charging negative contactor; 422, second DC charging negative contactor; 431, first Hall sensor; 432, second Hall sensor; 501, total positive pole of the battery pack module; 502, total negative pole of the battery pack module; 5011, total positive pole after series connection of the first electric box and the second electric box; 5012, total positive pole after series connection of the third electric box and the fourth electric box; 5021, total negative pole after series connection of the first electric box and the second electric box; 5022, total negative pole after series connection of the third electric box and the fourth electric box. DETAILED DESCRIPTION

[0022] The specific embodiments of the utility model will be further described below with reference to the drawings and by describing the embodiments, the purpose is to help the technicians in the field to have more complete, accurate and in-depth understanding of the concept and technical scheme of the utility model, and to help them to implement.

[0023] Figure 1 It is a kind of battery pack multi-branch parallel loop-free circuit logic structure diagram of the utility model, including battery management system (BMS) control box 1, battery pack module 2, switch module 3 and high-voltage battery (HVB) insulation detection module 4, high-voltage battery (HVB) insulation detection module 4 includes DC charging positive contactor module 41, DC charging negative contactor module 42, Hall sensor module 43, battery assembly negative contactor 44, current relay normally open type 45, pre-charge contactor 46 and pre-charge resistor 47, wherein, battery management system (BMS) control box 1 is connected with battery pack module 2;The total positive pole 501 of battery pack module 2 is connected with switch module 3;The total negative pole 502 of battery pack module 2 is connected with DC charging negative contactor module 41, battery assembly negative contactor 44 and pre-charge contactor 46 through Hall sensor module 43;Battery assembly negative contactor 44 is connected with pre-charge contactor 46 through pre-charge resistor 47;DC charging positive contactor module 42 is connected with switch module 3 through current relay normally open type 45 and Hall sensor module 43.

[0024] Figure 2 is a kind of battery pack multi-branch parallel loop-free circuit principle diagram of the utility model, Figure 2 In the figure, the Hall sensor module 43( Figure 2 Not marked) includes first Hall sensor 431 and second Hall sensor 432;Battery pack module 2 includes first electric box 21, second electric box 22, third electric box 23 and fourth electric box 24, wherein, first electric box 21 and second electric box 22 are connected in series, third electric box 23 and fourth electric box 24 are connected in series;The total positive pole 501 of battery pack module 2 includes the total positive pole 5011 after first electric box 21 and second electric box 22 are connected in series, the total positive pole 5012 after third electric box 23 and fourth electric box 24 are connected in series, the total negative pole 502 of battery pack module 2 includes the total negative pole 5021 after first electric box 21 and second electric box 22 are connected in series, the total negative pole 5022 after third electric box 23 and fourth electric box 24 are connected in series;Switch module 3 includes first manual maintenance switch (MSD) 31 and second manual maintenance switch (MSD) 32, wherein, the total positive pole 5011 after first electric box 21 and second electric box 22 are connected in series is connected with first manual maintenance switch (MSD) 31, the total positive pole 5012 after third electric box 23 and fourth electric box 24 are connected in series is connected with second manual maintenance switch (MSD) 32;Direct current charging negative contactor module 42 includes first direct current charging negative contactor 421 and second direct current charging negative contactor 422, wherein, the total negative pole 5021 after first electric box 21 and second electric box 22 are connected in series is connected with first direct current charging negative contactor 421, second direct current charging negative contactor 422, battery assembly negative contactor 44 and pre-charging contactor 46 through first Hall sensor 431, the total negative pole 5022 after third electric box 23 and fourth electric box 24 are connected in series is connected with first direct current charging negative contactor 421, second direct current charging negative contactor 422, battery assembly negative contactor 44 and pre-charging contactor 46;Direct current charging positive contactor module 41 includes first direct current charging positive contactor 411 and second direct current charging positive contactor 412, wherein, first manual maintenance switch (MSD) 31 is connected with first direct current charging positive contactor 411 and second direct current charging positive contactor 412 through second Hall sensor 432, second manual maintenance switch (MSD) 32 is connected with first direct current charging positive contactor 411 and second direct current charging positive contactor 412 through current relay normally open type 45.

[0025] In addition, Figure 2 In the figure, the low-voltage output end 11 of battery management system (BMS) control box 1, first electric box 21, second electric box 22, third electric box 23, fourth electric box 24, the low-voltage input end 12 of battery management system (BMS) control box 1 are connected into a loop.

[0026] The following will be combinedFigure 1 and Figure 2 The utility model introduces a kind of working principle of battery multi-branch parallel loop's currentless circuit: Figure 2 Two parallel main circuits are in the middle, and the fuse (not marked in the Figure 2 Back end of one of the main circuits Current relay normally open type 45, after maintenance personnel maintain or replace battery pack, when first manual maintenance switch (MSD) 31 and second manual maintenance switch (MSD) 32 are inserted back normally, because the low voltage of vehicle has been disconnected, so current relay normally open type 45 is still in open state, avoid the battery pack multi-branch parallel loop is connected recklessly when first manual maintenance switch (MSD) 31 and second manual maintenance switch (MSD) 32 are inserted back, further avoid the battery pack multi-branch parallel loop is connected when high voltage branch charges low voltage branch, further can avoid the current between battery pack multi-branch is generated, that is, avoid the situation that current loop is formed when first manual maintenance switch (MSD) 31 and second manual maintenance switch (MSD) 31 of high voltage distribution box are inserted back, effectively avoid the occurrence of safety accident.

[0027] The maximum current that the above-mentioned current relay normally open type 45 can withstand does not exceed the current specified by the main circuit fuse, wherein, in the embodiment, the maximum current that the current relay normally open type 45 can withstand is 120 amperes, but the maximum current is not limited to 120 amperes, and can be set according to specific needs.

[0028] In addition, when the vehicle is under low voltage, the current relay normally open type 45 will be in open state; before the vehicle is powered on high voltage, the battery management system (BMS) control box 1 will detect whether the voltage difference between the battery pack multi-branch is within the safe range, when the battery management system (BMS) control box 1 detects that the voltage difference between the battery pack multi-branch is not greater than the safety threshold of voltage difference, the whole vehicle control current relay normally open type 45 is closed, so that the battery pack multi-branch completes parallel connection. In the embodiment, the above-mentioned safety threshold of voltage difference is 25 millivolts, but the safety threshold of voltage difference is not limited to 25 millivolts, and can be set according to specific conditions.

[0029] In addition, the embodiment is an example of high voltage distribution box with two main circuit outputs, but the technical solution of the utility model is not limited to the principle of high voltage distribution box with two main circuit outputs.

[0030] ​The utility model has been described exemplarily above in combination with the drawings. Apparently, the utility model is not limited by the above-mentioned mode in the specific implementation. As long as various non-essential improvements are made by adopting the method concept and technical scheme of the utility model; or the above-mentioned concept and technical scheme of the utility model are directly applied to other occasions without improvement, all are within the protection scope of the utility model.

Claims

1. A multi-branch parallel-connected circulating current-free circuit for a battery pack, characterized by: It includes a battery management system (BMS) control box, a battery pack module, a switch module and a high-voltage battery (HVB) insulation detection module. The high-voltage battery (HVB) insulation detection module includes a DC charging positive contactor module, a DC charging negative contactor module, a Hall sensor module, a battery assembly negative contactor, a normally open current relay, a pre-charge contactor and a pre-charge resistor. The battery management system (BMS) control box is connected to the battery pack module; the total positive pole of the battery pack module is connected to the switch module; the total negative pole of the battery pack module is connected to the DC charging negative contactor module, the battery assembly negative contactor and the pre-charge contactor through the Hall sensor module; the battery assembly negative contactor is connected to the pre-charge contactor through the pre-charge resistor; the DC charging positive contactor module is connected to the switch module through the normally open current relay and the Hall sensor module.

2. The multi-branch parallel-connected circulating current-free circuit for a battery pack according to claim 1, characterized in that: The Hall sensor module includes a first Hall sensor and a second Hall sensor.

3. The multi-branch parallel-connected circulating current-free circuit for a battery pack according to claim 2, characterized in that: The battery pack module includes a first electrical box, a second electrical box, a third electrical box and a fourth electrical box. The first electrical box and the second electrical box are connected in series; the third electrical box and the fourth electrical box are connected in series.

4. The multi-branch parallel-connected circulating current-free circuit for a battery pack as claimed in claim 3, characterized in that: The switch module includes a first manual maintenance switch (MSD) and a second manual maintenance switch (MSD); the total positive pole of the first electrical box and the second electrical box connected in series is connected to the first manual maintenance switch (MSD); the total positive pole of the third electrical box and the fourth electrical box connected in series is connected to the second manual maintenance switch (MSD).

5. The circulating current-free circuit for multi-branch parallel connection of a battery pack according to claim 3, characterized in that: The DC charging negative contactor module includes a first DC charging negative contactor and a second DC charging negative contactor. The total negative pole after the first electrical box and the second electrical box are connected in series is connected to the first DC charging negative contactor, the second DC charging negative contactor, the battery assembly negative contactor and the pre-charging contactor through the first Hall sensor; the total negative pole after the third electrical box and the fourth electrical box are connected in series is connected to the first DC charging negative contactor, the second DC charging negative contactor, the battery assembly negative contactor and the pre-charging contactor.

6. The circulating current-free circuit for multi-branch parallel connection of a battery pack according to claim 4, characterized in that: The DC charging positive contactor module includes a first DC charging positive contactor and a second DC charging positive contactor. The first manual maintenance switch (MSD) is connected to the first DC charging positive contactor and the second DC charging positive contactor through the second Hall sensor; the second manual maintenance switch (MSD) is connected to the first DC charging positive contactor and the second DC charging positive contactor through the normally open current relay.

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