CN212905117U - Current detection circuit, system and car - Google Patents

Abstract

The utility model discloses a current detection circuit, system and car. The current detection circuit includes: n first detection ends and N second detection ends; the first detection end is used for being electrically connected with the anode of a battery in the battery pack, and the second detection end is used for being electrically connected with the cathode of the first battery; the N first connecting ends are in one-to-one correspondence with the N first detection ends, and the second connecting ends are electrically connected with the second detection ends; n first switches in one-to-one correspondence with the N first detection ends and N second switches in one-to-one correspondence with the N first connection ends; the first switch is connected between the corresponding first detection end and the current detection unit, and the second switch is connected between the corresponding first connection end and the current detection unit; and the first end of the q-th third switch is electrically connected with the q-th first detection end, and the second end of the q-th third switch is electrically connected with the q-th first connection end. The utility model discloses utilize simple circuit to realize the detection of electric current.

Description

Current detection circuit, system and car

Technical Field

The embodiment of the utility model provides a relate to the current detection technique, especially relate to a current detection circuit, system and car.

Background

With the increasing requirement on environmental protection, new energy automobiles are more and more widely applied due to the advantages of environmental protection, no pollution and the like.

The BATTERY management system (BATTERY MANAGEMENT SYSTEM, BMS) plays an important role in new energy vehicles, mainly for improving the utilization rate of the BATTERY pack, wherein one important role is to prevent the BATTERY pack from being over-discharged. When a device on the BMS fails, it may cause leakage of the battery, affect the life span of the battery, and even cause an accident. However, current BMS only does the earth leakage detection when leaving the factory, just no longer detects after assembling to the car, just can do the earth leakage detection until when breaking down to need unpack the group battery during the detection, then establish ties the ampere meter and go into, how many battery festivals just need to cluster how many times of ampere meters, and the testing process is not only troublesome but also has the potential safety hazard.

SUMMERY OF THE UTILITY MODEL

The utility model provides a current detection circuit, system and car to utilize simple circuit to realize the detection of electric current.

In a first aspect, an embodiment of the present invention provides a current detection circuit, the current detection circuit includes: n first detection ends and N second detection ends; n is an integer of 3 or more; the kth first detection end is used for being electrically connected with the positive electrode of the kth battery in the battery pack, k is more than or equal to 1 and less than or equal to N, and the second detection end is used for being electrically connected with the negative electrode of the first battery in the battery pack; the N first connecting ends are in one-to-one correspondence with the N first detection ends, and the second connecting end is electrically connected with the second detection end; the N first switches are in one-to-one correspondence with the N first detection ends, and the N second switches are in one-to-one correspondence with the N first connection ends; the first switch is connected between the corresponding first detection end and the current detection unit, and the second switch is connected between the corresponding first connection end and the current detection unit; and the first end of the q-th third switch is electrically connected with the q-th first detection end, the second end of the q-th third switch is electrically connected with the q-th first connection end, and q is more than or equal to 1 and less than or equal to N-1.

Optionally, the current detection circuit comprises N coils and N control switches; the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N control switches correspond to the N coils one by one, the first ends of the coils are electrically connected with the first ends of the control switches, and the second ends of the coils are electrically connected with the reference voltage input end; and the second end of the control switch is electrically connected with the control signal input end.

Optionally, the current detection circuit further comprises: the device comprises a decoder, N coils and a plurality of control switches; the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N coils correspond to the N output ends of the decoder one by one, the first ends of the coils are electrically connected with the output end of the decoder, and the second ends of the coils are electrically connected with the reference voltage input end; the control switches are in one-to-one correspondence with the input ends of the decoder, the first ends of the control switches are electrically connected with the input ends of the decoder, and the second ends of the control switches are electrically connected with the input ends of the control signals; and the pull-up resistors are in one-to-one correspondence with the control switches, the first ends of the pull-up resistors are electrically connected with the first ends of the control switches, and the second ends of the pull-up resistors are electrically connected with the reference voltage input end.

Optionally, a main power switch is further included, the main power switch being connected between the reference voltage input and the pull-up resistor.

Optionally, the N first connection ends and the second connection end are integrated on a connector.

Optionally, the current detection unit is an ammeter.

Optionally, the current detection unit is a detection resistor and a voltmeter connected in parallel.

In a second aspect, an embodiment of the present invention further provides a current detection system, where the current detection system includes the current detection circuit, the battery pack, and the battery management system BMS of the first aspect; the battery pack is electrically connected with a plurality of first detection ends and second detection ends of the current detection circuit, and the battery management system is electrically connected with the first connection end and the second connection end.

Optionally, the current detection circuit further comprises: the device comprises a decoder, N coils and a plurality of control switches; the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N coils correspond to the N output ends of the decoder one by one, the first ends of the coils are electrically connected with the output end of the decoder, and the second ends of the coils are electrically connected with the reference voltage input end; the control switches are in one-to-one correspondence with the input ends of the decoder, the first ends of the control switches are electrically connected with the input ends of the decoder, and the second ends of the control switches are electrically connected with the input ends of the control signals; a plurality of pull-up resistors in one-to-one correspondence with the plurality of control switches, wherein a first end of each pull-up resistor is electrically connected with a first end of each control switch, and a second end of each pull-up resistor is electrically connected with the reference voltage input end; the reference voltage input end is electrically connected with the battery management system.

In a third aspect, the embodiment of the present invention further provides an automobile, including the current detection system of the second aspect.

In the technical scheme of the embodiment, the adopted current detection circuit comprises N first detection ends and N second detection ends; the kth first detection end is used for being electrically connected with the positive electrode of the kth battery in the battery pack, k is more than or equal to 1 and less than or equal to N, and the second detection end is used for being electrically connected with the negative electrode of the first battery in the battery pack; the N first connecting ends are in one-to-one correspondence with the N first detection ends, and the second connecting ends are electrically connected with the second detection ends; n first switches in one-to-one correspondence with the N first detection ends and N second switches in one-to-one correspondence with the N first connection ends; the first switch is connected between the corresponding first detection end and the current detection unit, and the second switch is connected between the corresponding first connection end and the current detection unit; and the first end of the q-th third switch is electrically connected with the q-th first detection end, the second end of the q-th third switch is electrically connected with the q-th first connection end, and q is more than or equal to 1 and less than or equal to N-1. The circuit structure is simple, the needed components and parts are fewer, and when the battery pack is detected to have leakage current, the switch can be closed for several times to detect whether each battery in the battery pack leaks current, so that the current detection time is greatly saved.

Drawings

Fig. 1 is a schematic circuit structure diagram of a current detection circuit according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a circuit structure of a current detection circuit electrically connected to a battery pack and a BMS according to an embodiment of the present invention;

fig. 3 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;

fig. 5 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;

fig. 6 is a schematic circuit structure diagram of another current detection circuit according to an embodiment of the present invention;

fig. 7 is a schematic circuit structure diagram of a current detection system according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an automobile according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic circuit structure diagram of a current detection circuit according to an embodiment of the present invention, referring to fig. 1, the current detection circuit is used to be electrically connected to a battery pack, wherein the battery pack includes N batteries connected in series, and a cathode of a j-th battery is electrically connected to an anode of a j-1 th battery; 1< j is less than or equal to N; the current detection circuit comprises N first detection terminals A1 and a second detection terminal A2; n is an integer of 3 or more; the kth first detection end A1 is used for being electrically connected with the positive electrode of the kth battery in the battery pack, k is more than or equal to 1 and less than or equal to N, and the second detection end A2 is used for being electrically connected with the negative electrode of the first battery in the battery pack; n first connection terminals B1 corresponding to the N first detection terminals a1 one to one and a second connection terminal B2 electrically connected to the second detection terminal a 2; n first switches 101 one-to-one corresponding to the N first detection terminals a1 and N second switches 102 one-to-one corresponding to the N first connection terminals B1; the first switch 101 is connected between the corresponding first detection end a1 and the current detection unit 103, and the second switch 102 is connected between the corresponding first connection end B1 and the current detection unit 103; n-1 third switches 401, wherein a first terminal of the q-th third switch 401 is electrically connected to a q-th first detection terminal A1, and a second terminal of the q-th third switch 401 is electrically connected to a q-th first connection terminal B1.

Specifically, there are various capacitors, resistors, and transistors for equalization in the BMS, and when the components are damaged, the corresponding battery may leak electricity, and the current detection circuit may be used to detect a leakage current between the battery pack and the BMS; the number of the first detecting terminals a1 and the first connecting terminals B1 can be set according to the number of the battery in the battery pack, how many batteries are contained in the battery pack, how many first detecting terminals a1 and how many first connecting terminals B1 are set, the first detecting terminals a1 can be used for connecting the batteries, the first connecting terminals B1 can be used for connecting the BMS, fig. 2 is a schematic diagram of a circuit structure in which a current detecting circuit is electrically connected with the battery pack and the BMS, which is described in detail with reference to fig. 2, the working principle of the present invention is described in detail with N being 3, that is, the battery pack contains three batteries as an example, and at this time, the battery pack contains a first battery 3001, a second battery 3002 and a third battery 3003; the corresponding current detection circuit includes N, i.e., 3 first detection terminals (a first detection terminal a11, a second first detection terminal a12, and a third first detection terminal a13, respectively); n, i.e., 3 first connection terminals (a first connection terminal B11, a second first connection terminal B12, and a third first connection terminal B13); n, i.e., 3 first switches (first switch 1011, second first switch 1012, and third first switch 1013); n, i.e., 3 second switches (a first second switch 1021, a second switch 1022, and a third second switch 1023); n-1, i.e., 2 third switches (first third switch 4011 and second third switch 4012); electrically connected to the structure shown in fig. 2, after the first detection terminal a1 is connected to the battery and the first connection terminal B1 is connected to the BMS 400, a current loop may be formed through the second connection terminal a2 and the second detection terminal B2, when a leakage current of the battery pack needs to be detected, the corresponding first switch 101, second switch 102 and third switch 401 may be closed, a leakage current generated from the battery pack due to a leakage current of some cells in the BMS may flow back to the battery pack through the corresponding first switch 101, current detection unit, second switch 102, BMS, first connection terminal B1 and third switch 401 to generate a current loop, or flow back to the battery pack through the corresponding first switch 101, current detection unit, second switch 102, first connection terminal, BMS, second connection terminal and second detection terminal, the current detection unit 103 may detect a leakage current in the loop, and when the leakage current is 0, it is stated that the battery pack has no leakage phenomenon, and when the leakage current that current detection unit 103 detected out is great, the device that shows to have the damage in the BMS can in time send out warning information, reminds maintainer to maintain BMS or group battery. As shown in fig. 2, the BMS generally includes a first capacitor 4001, a first diode 4002, a first resistor 4003, an equalizing transistor 4005, a second diode 4004 and a second capacitor 4006, which are electrically connected to the structure shown in fig. 2, when it is required to detect whether the third battery 3003 leaks current, the third first switch 1013, the third second switch 1023 and the second third switch 4012 are closed, and the remaining first switch, the second switch and the third switch are opened, if the corresponding first capacitor 4001 in the BMS is damaged, the current generated by the third battery 3003 flows from the positive electrode through the third first detection terminal a13, the third first switch 1013, the current detection unit, the third second switch 1023, the third first connection terminal B13, the corresponding first capacitor 4001 in the BMS, the second first connection terminal B12, the second third connection terminal 4012, the second first detection terminal a12 and the negative electrode of the third switch 3003, a current loop is generated, if the current detection unit detects that the loop current is not 0, it indicates that there is a leakage between the third battery and the BMS, and the leakage may be caused by at least one of the first capacitor 4001, the first diode 4002, the second capacitor 4006 and the equalizing transistor 4005 corresponding to the BMS, wherein the second capacitor 4006 is electrically connected with the total negative pole in the BMS; when it is necessary to detect whether the first battery 3001 leaks electricity, the detection may be performed by closing the first switch 1011 and the first second switch 1021, and the detection principle is the same as above, and will not be described herein again. When the first battery needs to be detected whether the electricity leaks, only the first switch 101 and the second switch 102 corresponding to the first battery need to be closed, and whether the electricity leaks is judged according to the current information output by the current detection unit 103, so that whether each battery in the battery pack leaks can be detected by closing the switches for several times, and the time for detecting the current is greatly saved.

In the technical scheme of the embodiment, the adopted current detection circuit comprises N first detection ends and N second detection ends; n is an integer of 3 or more; the kth first detection end is used for being electrically connected with the positive electrode of the kth battery in the battery pack, k is more than or equal to 1 and less than or equal to N, and the second detection end is used for being electrically connected with the negative electrode of the first battery in the battery pack; the N first connecting ends are in one-to-one correspondence with the N first detection ends, and the second connecting ends are electrically connected with the second detection ends; n first switches in one-to-one correspondence with the N first detection ends and N second switches in one-to-one correspondence with the N first connection ends; the first switch is connected between the first detection end and the current detection unit, and the second switch is connected between the first connection end and the current detection unit; and the first end of the q-th third switch is electrically connected with the q-th first detection end, the second end of the q-th third switch is electrically connected with the q-th first connection end, and q is more than or equal to 1 and less than or equal to N-1. The circuit structure is simple, the needed components and parts are fewer, and when the battery pack is detected to have leakage current, the switch can be closed for several times to detect whether each battery in the battery pack leaks current, so that the current detection time is greatly saved.

Optionally, fig. 3 is a schematic circuit structure diagram of another current detection circuit provided by an embodiment of the present invention, referring to fig. 3, the current detection circuit further includes: n coils 105 and N control switches 106; the N coils 105 correspond to the N first switches 101 one by one, the N coils 105 correspond to the N second switches 102 one by one, and the kth coil 105 is used for controlling the states of the kth first switch 101 and the kth second switch 102; the q +1 th coil 105 is used to control the state of the q-th third switch; the N control switches 106 correspond to the N coils 105 one by one, a first end of each coil 105 is electrically connected with a first end of the corresponding control switch 106, and a second end of each coil 105 is electrically connected with a reference voltage input end VCC; a second terminal of the control switch 106 is electrically connected to the control signal input terminal VSS.

Specifically, the coil 105 and the corresponding first switch 101, second switch 102, and third switch 401 are a three-pole single-throw relay 200, and since the first coil only corresponds to the first second switch and the first switch, the first coil, the first second switch, and the first switch are a double-pole single-throw relay 501, and the reference signal input terminal VCC is different from the signal level input by the control signal input terminal VSS, when the control switch 106 is closed, the two ends of the corresponding coil 105 generate current in the coil 105 due to different voltages, and when there is current in the coil 105, the corresponding first switch, second switch, and third switch are closed, so that the current detection unit 103 and the corresponding battery form a loop; because the voltage of the battery pack controlled by the BMS is high, if the first switch 101, the second switch 102 and the third switch are closed manually, the danger is high, in the embodiment, the first switch 101, the second switch 102 and the third switch are controlled by the coil 105, and the first switch 101, the second switch 102 and the third switch can be controlled to be closed by a small current flowing in the coil 105, so that the large voltage can be controlled by a small voltage, the safety is greatly improved, and when the leakage of a certain battery needs to be detected, the control switch corresponding to the coil corresponding to the battery can be closed.

Optionally, fig. 4 is a schematic circuit structure diagram of another current detection circuit provided in the embodiment of the present invention, referring to fig. 4, the current detection circuit further includes: a decoder 104, N coils 105, and a plurality of control switches 106; the N coils 105 correspond to the N first switches 101 one by one, the N coils 105 correspond to the N second switches 102 one by one, and the coils 105 are used for controlling the states of the first switches 101 and the second switches 102; the kth coil is used for controlling the states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N coils 105 correspond to the N output ends of the decoder 104 one by one, a first end of each coil 105 is electrically connected with the output end of the decoder 104, and a second end of each coil 105 is electrically connected with a reference voltage signal input end VCC; the control switches 106 correspond to the input ends of the decoder 104 one by one, a first end of the control switch 106 is electrically connected with the input end of the decoder 104, and a second end of the control switch 106 is electrically connected with the control signal input end VSS; and a plurality of pull-up resistors 107 in one-to-one correspondence with the plurality of control switches 106, wherein a first end of the pull-up resistor 107 is electrically connected with a first end of the control switch 106, and a second end of the pull-up resistor 107 is electrically connected with a reference voltage input terminal VCC.

Illustratively, the decoder 104 may be, for example, a 74HC154, and its output terminal outputs a high level by default, the reference signal input terminal VCC also inputs a high level, the reference signal input terminal VCC may input a high level, such as a 5V input signal, and the control signal input terminal VSS may input a low level signal, such as ground; when an output terminal of the decoder 104 is active, the output terminal outputs a low level, so that a voltage difference exists between the output terminal and the reference signal input terminal VCC across the coil 105, a current is generated in the coil 105, and then the corresponding first switch 101 and the corresponding second switch 102 are controlled to be closed, or the corresponding first switch, the corresponding second switch, and the corresponding third switch are controlled to be closed. It should be noted that, in some other embodiments, the decoder output may also be set to output a low level by default, and the reference signal input VCC may also be set to input a low level at this time. When the control switch 106 is closed, the corresponding input terminal of the decoder 104 may be conducted with the control signal input terminal VSS, so that a low level signal is input to the input terminal, and a high level signal is input to the input terminal corresponding to the control switch 106 that is not conducted under the action of the pull-up resistor 107, so that a control signal is input to the corresponding input terminal of the decoder 104, and the corresponding output terminal is controlled to output an effective signal; the decoder 104 only outputs a valid signal at any time at one output end, so that at most one first switch 101 is ensured to be switched on at any time, and the corresponding batteries are prevented from being short-circuited when the first switches 101 are switched on; meanwhile, the number of the input ends of the decoder 104 is less than that of the output ends of the decoder 104, so that fewer control switches 106 are required, which is beneficial to simplifying the circuit.

With continued reference to fig. 4, the decoder 104 further includes an enable signal terminal, when an active signal is input at the enable signal terminal, the decoder 104 starts to operate, and when an active signal is not input at the enable terminal, the decoder 104 does not operate, at this time, an enable switch 201 and an enable pull-up resistor 108 may be disposed in the current detection circuit, and are electrically connected to the structure shown in fig. 3, when the enable switch 201 is closed, an active signal (e.g., high level) is input at the enable signal input terminal, so as to control the decoder 104 to operate, and when the enable switch 201 is opened, an inactive signal (e.g., low level) is input at the enable signal input terminal, and the decoder 104 does not operate.

Optionally, with continued reference to fig. 4, the current detection circuit further comprises a main power switch 109, the main power switch 109 being connected between the reference voltage input VCC and the pull-up resistor 107.

Specifically, the second end of the pull-up resistor 107 is electrically connected to the first end of the main power switch 109, and the second end of the main power switch 109 is electrically connected to the reference voltage input VCC, so that the current detection circuit can operate only when the main power switch 109 is closed, and the current detection circuit does not operate when the main power switch 109 is opened, thereby avoiding power consumption waste and energy saving caused by no need of detecting leakage current.

Alternatively, with continued reference to fig. 4, N first connection terminals B1 and second connection terminals B2 are integrated on the connector 110.

Specifically, the first and second connection terminals B1 and B2 may be detachably connected to the BMS, and may be easily detachably connected to the BMS by integrating the first and second connection terminals B1 and B2 into the connector 110, and may also protect the first and second connection terminals B1 and B2, reducing the risk of corrosion.

Optionally, fig. 5 is a schematic circuit structure diagram of another current detection circuit provided in the embodiment of the present invention, and referring to fig. 5, the current detection unit 103 is an ammeter.

Specifically, the ammeter has characteristics such as current detection efficiency is high, and the accuracy is high, and the current detection unit adopts the ammeter, and circuit structure is comparatively simple, detects comparatively accurately. In some other embodiments, as shown in fig. 6, fig. 6 is a schematic circuit structure diagram of another current detection circuit provided in an embodiment of the present invention, and the current detection unit 103 includes a detection resistor 111 and a voltmeter connected in parallel; the voltage value detected by the voltmeter is divided by the resistance value of the detection resistor 111, and the current value in the circuit can be obtained in the same manner.

Fig. 7 is a schematic circuit structure diagram of a current detection system according to an embodiment of the present invention, and referring to fig. 7, the current detection system includes a current detection circuit, a battery pack, and a battery management system BMS 400 according to any embodiment of the present invention; the battery pack is electrically connected to a plurality of first detection terminals B1 and second detection terminals B2 of the current detection circuit, and the battery management system 400 is electrically connected to the first connection terminal B1 and the second connection terminal B2.

Specifically, the battery pack includes a plurality of batteries 300 connected in series, the negative electrode of the first battery serves as the negative electrode of the battery pack, the positive electrode of the last battery serves as the positive electrode of the battery pack, the negative electrode of the second battery is connected with the positive electrode of the first battery, the negative electrode of the third battery is connected with the positive electrode of the second battery, … …, each first detection end a1 is electrically connected with the positive electrode of each battery in a one-to-one correspondence manner, the second detection end a2 is electrically connected with the negative electrode of the first battery, each first connection end B1 and second connection end B2 are electrically connected with corresponding ports on the BMS, the detection process of the leakage current refers to the description of the current detection circuit in the present application, and is not repeated herein, and therefore, the current detection circuit provided by the embodiments of the present invention has the same beneficial effects, and is not repeated herein.

Optionally, the current detection circuit further comprises: a decoder 104, N coils 105, and a plurality of control switches 106; the N coils 105 correspond to the N first switches 101 one by one, the N coils 105 correspond to the N second switches 102 one by one, and the kth coil is used for controlling the states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N coils 105 correspond to the N output ends of the decoder 104 one by one, a first end of each coil 105 is electrically connected with the output end of the decoder 104, and a second end of each coil 105 is electrically connected with a reference voltage input end VCC; the control switches 106 correspond to the input ends of the decoder 104 one by one, a first end of the control switch 106 is electrically connected with the input end of the decoder 104, and a second end of the control switch 106 is electrically connected with the control signal input end VSS; a plurality of pull-up resistors 107 in one-to-one correspondence with the plurality of control switches 106, a first end of the pull-up resistor 107 being electrically connected to a first end of the control switch 106, a second end of the pull-up resistor 107 being electrically connected to a reference voltage input terminal VCC; the reference voltage input terminal VCC is electrically connected to the battery management system 400.

Specifically, the BMS may input a reference voltage signal to the reference voltage input terminal VCC to control the current detection circuit to normally operate, and the current detection circuit does not need to additionally set a power supply, thereby simplifying the circuit. It is understood that the reference voltage input VCC may also be connected to an external power source, such as a button cell. Meanwhile, the reference voltage input terminal VCC may also be electrically connected to a power supply terminal of the decoder 104, thereby supplying power required for the operation of the decoder 104.

Fig. 8 is the utility model provides a structural schematic diagram of a car, refer to fig. 8, the utility model provides a car includes the utility model discloses the current detection system that arbitrary embodiment provided also consequently has the same beneficial effect, no longer gives details here. The automobile can be a car, a pick-up truck, a passenger car or a truck and the like with a battery pack and a BMS, typically a new energy automobile.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. A current detection circuit is used for being electrically connected with a battery pack, wherein the battery pack comprises N batteries which are connected in series, and the cathode of the j battery is electrically connected with the anode of the j-1 battery; 1< j is less than or equal to N; characterized in that, the current detection circuit includes:

n first detection ends and N second detection ends; n is an integer of 3 or more; the kth first detection end is used for being electrically connected with the positive electrode of the kth battery in the battery pack, k is more than or equal to 1 and less than or equal to N, and the second detection end is used for being electrically connected with the negative electrode of the first battery in the battery pack;

the N first connecting ends are in one-to-one correspondence with the N first detection ends, and the second connecting end is electrically connected with the second detection end;

the N first switches are in one-to-one correspondence with the N first detection ends, and the N second switches are in one-to-one correspondence with the N first connection ends;

the first switch is connected between the corresponding first detection end and the current detection unit, and the second switch is connected between the corresponding first connection end and the current detection unit;

and the first end of the q-th third switch is electrically connected with the q-th first detection end, the second end of the q-th third switch is electrically connected with the q-th first connection end, and q is more than or equal to 1 and less than or equal to N-1.

2. The current sensing circuit of claim 1, wherein the current sensing circuit comprises N coils and N control switches;

the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch;

the N control switches correspond to the N coils one by one, the first ends of the coils are electrically connected with the first ends of the control switches, and the second ends of the coils are electrically connected with the reference voltage input end;

and the second end of the control switch is electrically connected with the control signal input end.

3. The current sensing circuit of claim 1, further comprising:

the device comprises a decoder, N coils and a plurality of control switches;

the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch;

the N coils correspond to the N output ends of the decoder one by one, the first ends of the coils are electrically connected with the output end of the decoder, and the second ends of the coils are electrically connected with the reference voltage input end;

the control switches are in one-to-one correspondence with the input ends of the decoder, the first ends of the control switches are electrically connected with the input ends of the decoder, and the second ends of the control switches are electrically connected with the input ends of the control signals;

and the pull-up resistors are in one-to-one correspondence with the control switches, the first ends of the pull-up resistors are electrically connected with the first ends of the control switches, and the second ends of the pull-up resistors are electrically connected with the reference voltage input end.

4. The current sensing circuit of claim 3, further comprising a main power switch connected between the reference voltage input and the pull-up resistor.

5. The current sensing circuit of claim 1, wherein the N first connection terminals and the second connection terminals are integrated on a connector.

6. The current detection circuit according to claim 1, wherein the current detection unit is an ammeter.

7. The current detection circuit according to claim 1, wherein the current detection unit is a detection resistor and a voltmeter connected in parallel.

8. A current sensing system, characterized in that it comprises a current sensing circuit according to any one of claims 1 to 7, a battery pack and a battery management system BMS;

the battery pack is electrically connected with a plurality of first detection ends and second detection ends of the current detection circuit, and the battery management system is electrically connected with the first connection end and the second connection end.

9. The current sensing system of claim 8, wherein the current sensing circuit further comprises: the device comprises a decoder, N coils and a plurality of control switches; the N coils correspond to the N first switches one to one, the N coils correspond to the N second switches one to one, and the kth coil is used for controlling states of the kth first switch and the kth second switch; the (q + 1) th coil is used for controlling the state of the (q) th third switch; the N coils correspond to the N output ends of the decoder one by one, the first ends of the coils are electrically connected with the output end of the decoder, and the second ends of the coils are electrically connected with the reference voltage input end; the control switches are in one-to-one correspondence with the input ends of the decoder, the first ends of the control switches are electrically connected with the input ends of the decoder, and the second ends of the control switches are electrically connected with the input ends of the control signals; a plurality of pull-up resistors in one-to-one correspondence with the plurality of control switches, wherein a first end of each pull-up resistor is electrically connected with a first end of each control switch, and a second end of each pull-up resistor is electrically connected with the reference voltage input end;

the reference voltage input end is electrically connected with the battery management system.

10. An automobile characterized by comprising the current detection system according to claim 8 or 9.

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