A low-side parallel contactor adhesion detection circuit for a battery system

Abstract

The present invention discloses a low-side parallel contactor adhesion detection circuit of a battery system, the battery system includes multiple battery packs connected in parallel; the circuit includes multiple battery pack detection modules and a BMS main control chip; each battery pack is connected to a battery pack detection module respectively; the negative terminal B of each battery pack is connected to the negative terminal P of the battery system through a contactor KL respectively; the positive terminals B+ of multiple battery packs are connected to the positive terminal P+ of the battery system after the convergence connection; each battery pack detection module is used to output the contact detection signal VPF of the connected battery pack to the BMS main control chip; the BMS main control chip is used to determine whether there is an adhesion fault at the contactor KL contact connected to each battery pack. The present invention can detect the contact adhesion fault of the low-side contactor in the parallel battery pack, and can accurately locate the adhesion fault contactor in the parallel circuit online.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a low-side parallel contactor adhesion detection circuit for a battery system. Background Art

[0002] The Battery Management System (BMS) is a battery protection device and a bridge between the battery and the load terminal. It provides overcharge, over-discharge, over-temperature and other protection functions for the battery according to the actual use status of the battery monitored online to ensure the safe use of the battery. The battery management system BMS is widely used in many fields such as electric vehicles, communication base stations, robots, etc.

[0003] When a DC contactor is used as a switch for a high-voltage power circuit in a power battery system, contactor adhesion failures often occur, causing the BMS to be unable to disconnect the physical connection between the battery system and the external load or charging device, which seriously threatens the personal safety of the operator.

[0004] When the power battery system is composed of multiple battery packs in parallel, and each battery pack requires an independent low-side contactor as the switch of its own high-voltage power circuit, if a contact adhesion failure occurs in the low-side contactor of one of the battery packs, the voltage at both ends of the battery system will always exist, and the high voltage cannot be powered off. At this time, the BMS will issue a contact adhesion failure alarm message, but it cannot locate the specific faulty contactor.

[0005] The reason for the above problems is that the existing technical solution only detects the battery pack voltage and the battery system voltage, and then compares whether the voltages between the two are equal to determine whether the contactor contacts are sticking. If they are equal, it is determined that the contactor contacts are sticking, and if they are not equal, the contactor contacts are not sticking. This method can only determine whether the contactor has a contact adhesion failure, but cannot determine which battery pack's low-side contactor in the high-voltage power circuit has a contact adhesion failure.

[0006] Therefore, there is an urgent need to develop a technology that can detect contact adhesion failures of low-side contactors in parallel battery packs and accurately locate adhesion-faulty contactors in parallel circuits online. Summary of the invention

[0007] The purpose of the present invention is to provide a low-side parallel contactor adhesion detection circuit for a battery system in view of the technical defects in the prior art.

[0008] To this end, the present invention provides a low-side parallel contactor adhesion detection circuit for a battery system, the battery system comprising a plurality of battery packs connected in parallel to each other;

[0009] The low-side parallel contactor adhesion detection circuit of the battery system specifically includes multiple battery pack detection modules and a BMS main control chip;

[0010] Wherein, each battery pack is connected to a battery pack detection module respectively;

[0011] The negative terminal B- of each battery pack is connected to the negative terminal P- of the battery system through a contactor KL;

[0012] After the positive terminals B+ of the multiple battery packs are connected in a busbar, they are all connected to the positive terminal P+ of the battery system;

[0013] For each battery pack detection module, it includes a first power input terminal and a second power input terminal, and includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal VPF;

[0014] Wherein, each battery pack detection module has a first power input terminal connected to a DC power supply VDD1;

[0015] The second power input terminal of each battery pack detection module is connected to a DC power supply VDD2;

[0016] Each battery pack detection module has a first input terminal connected to the positive terminal P+ of the battery system;

[0017] The second input terminal of each battery pack detection module is respectively connected to the negative terminal B- of a battery pack;

[0018] The third input terminal of each battery pack detection module is connected to the negative terminal P- of the battery system;

[0019] The fourth input terminal of each battery pack detection module is connected to the switch signal output terminal SW of the BMS main control chip;

[0020] The output terminal VPF of each battery pack detection module is connected to the input terminal of the BMS main control chip;

[0021] Each battery pack detection module is used to detect the signal input status of its first input terminal, the second input terminal and the third input terminal, and correspondingly output the contact detection signal VPF of the battery pack to the BMS main control chip;

[0022] Among them, the BMS main control chip has multiple output terminals KC, which are respectively connected to the signal input terminals of the contactors KL connected to the multiple battery packs, and are used to send multiple switch control signals KC to the contactors KL connected to the multiple battery packs, respectively, to control the on and off of the multiple contactors KL accordingly;

[0023] The BMS main control chip is used to determine whether there is a sticking fault in the contacts of the contactor KL connected to each battery pack.

[0024] Preferably, the BMS main control chip is used to receive the contact detection signal VPF sent by the battery pack detection module, and after controlling the on and off of the contactors KL connected to multiple battery packs through its output terminal KC, it determines whether there is a sticking fault in the contacts of the contactor KL connected to each battery pack according to the switch control signal KC of the contactor KL connected to each battery pack and the level state of the contact detection signal VPF of each battery pack.

[0025] Preferably, the BMS main control chip is used for, when the output terminals KC1 and KC2 of the BMS main control chip output low-level or high-level control signals to the signal input terminals of the contactors KL1 and KL2, the output terminals SW1 and SW2 of the BMS main control chip output switch control signals, and respectively alternately control the switch K1 in the first detection module and the switch K2 in the second detection module to close, so that the first detection module and the second detection module start to detect whether the contacts of the contactors KL1 and KL2 are adhered.

[0026] Preferably, for the BMS main control chip, when the switch control signal output by its output terminal KC to the signal input terminal of the contactor KL connected to any battery pack changes from a high level to a low level, if the level of the contact detection signal VPF sent by the battery pack detection module connected to the battery pack is a high level, it is judged that the contacts of the contactor KL connected to the battery pack have a sticking fault.

[0027] Preferably, the battery system comprises a first battery pack and a second battery pack;

[0028] Wherein, the first battery pack and the second battery pack are connected in parallel;

[0029] Wherein, the negative terminal B1- of the first battery pack is connected to the negative terminal P- of the battery system through the contactor KL1;

[0030] The negative terminal B2- of the second battery group is also connected to the negative terminal P- of the battery system through the contactor KL2;

[0031] The positive terminal B1+ of the first battery group and the positive terminal B2+ of the second battery group are both connected to the positive terminal P+ of the battery system after the currents are converged and intersected;

[0032] The low-side parallel contactor adhesion detection circuit of the battery system specifically includes a first detection module, a second detection module and a BMS main control chip;

[0033] Wherein, the first detection module has a first power input terminal connected to a DC power supply VDD1;

[0034] A first detection module, a second power input terminal of which is connected to a DC power supply VDD2;

[0035] A first detection module, a first input terminal of which is connected to the positive terminal P+ of the battery system;

[0036] A first detection module, a second input terminal of which is connected to the negative terminal B1- of the first battery pack;

[0037] A first detection module, a third input terminal of which is connected to the negative terminal P- of the battery system;

[0038] A second detection module, wherein a fourth input terminal thereof is connected to a switch signal output terminal SW1 of a BMS main control chip;

[0039] A first detection module, whose output terminal VPF1 is connected to a first input terminal of a BMS main control chip;

[0040] The first detection module is used to detect the signal input status of the first input terminal, the second input terminal and the third input terminal, and correspondingly output a contact detection signal VPF1 to the BMS main control chip;

[0041] A second detection module, wherein a first power input terminal thereof is connected to a DC power supply VDD1;

[0042] A second detection module, wherein a second power input terminal thereof is connected to a DC power supply VDD2;

[0043] A second detection module, a first input terminal of which is connected to the positive terminal P+ of the battery system;

[0044] A second detection module, a second input terminal of which is connected to the negative terminal B2- of the second battery pack;

[0045] A second detection module, a third input terminal of which is connected to the negative terminal P- of the battery system;

[0046] A second detection module, wherein a fourth input terminal thereof is connected to a switch signal output terminal SW2 of the BMS main control chip;

[0047] A second detection module, whose output terminal VPF2 is connected to the second input terminal of the BMS main control chip;

[0048] The second detection module is used to detect the signal input status of the first input terminal, the second input terminal and the third input terminal, and output a contact detection signal VPF2 to the BMS main control chip accordingly;

[0049] The BMS main control chip, whose output terminal KC1 is connected to the signal input terminal of the contactor KL1, is used to send a switch control signal KC1 to the contactor KL1 to control the on and off of the contactor KL1;

[0050] The BMS main control chip, whose output terminal KC2 is connected to the signal input terminal of the contactor KL2, is used to send a switch control signal KC2 to the contactor KL2 to control the on and off of the contactor KL2;

[0051] The BMS main control chip is used to receive the contact detection signal VPF1 sent by the first detection module and the contact detection signal VPF2 sent by the second detection module, and after controlling the on and off of the contactors KL1 and KL2 respectively through its output terminals KC1 and KC2, it is judged whether there is a sticking fault in the contact of the contactor KL1 according to the level state of the contact detection signal VPF1 and the switch control signal KC1, and it is judged whether there is a sticking fault in the contact of the contactor KL2 according to the level state of the contact detection signal VPF2 and the switch control signal KC2.

[0052] Preferably, the first detection module includes: resistors R1-R14, diodes D1-D3, a voltage regulator D4, switch tubes Q1-Q2 and an optical coupler Q3, wherein:

[0053] The first pin of the resistor R1 is used as the first input terminal of the first detection module and is connected to the positive terminal P+ of the battery system;

[0054] The second pin of resistor R1 is connected to the V0 terminal;

[0055] The V0 terminal is also connected to the first pin of the resistor R4 and the first pin of the resistor R8 respectively;

[0056] The first pin of the resistor R2 is used as the third input terminal of the first detection module and is connected to the negative terminal P- of the battery system;

[0057] The second pin of resistor R2 is connected to the V5 terminal;

[0058] The V5 terminal is also connected to the first pin of the voltage regulator tube D4 and the cathode of the diode D1 respectively;

[0059] The anode of the diode D1 is connected to one end of the switch K1;

[0060] The second pin of the voltage regulator tube D4 is connected to the anode of the diode D3 and the first pin of the resistor R3 respectively;

[0061] The cathode of the diode D3, serving as the second input terminal of the first detection module, is connected to the negative terminal B1- of the first battery pack;

[0062] The second pin of resistor R4 is connected to the V4 terminal;

[0063] The V4 terminal is also connected to the other end of the switch K1 and the first pin of the resistor R5;

[0064] The signal input terminal of the switch K1 serves as the fourth input terminal of the first detection module;

[0065] The second pin of resistor R5 is connected to the V1 terminal;

[0066] The V1 terminal is also connected to the cathode of the diode D2 and the first pin of the resistor R6 respectively;

[0067] The second pin of resistor R6 is connected to the V6 terminal;

[0068] The V6 terminal is also connected to the second pin of the resistor R3, the second pin of the resistor R11, the second pin of the resistor R9 and the emitter E of the switch tube Q2;

[0069] The second pin of resistor R8 is connected to the V2 terminal;

[0070] The V2 terminal is also connected to the first pin of the resistor R7, the emitter E of the switch tube Q1 and the first pin of the resistor R9 respectively;

[0071] The base B of the switch tube Q1 is connected to the second pin of the resistor R7 and the anode of the diode D2 respectively;

[0072] The collector C of the switch tube Q1 is connected to the first pin of the resistor R10;

[0073] The second pin of resistor R10 is connected to the V3 terminal;

[0074] The V3 terminal is also connected to the first pin of the resistor R11 and the base B of the switch tube Q2;

[0075] The collector C of the switch tube Q2 is connected to the second pin of the optocoupler Q3;

[0076] The first pin of resistor R12 is connected to the 12V DC power supply VDD1;

[0077] The second pin of the resistor R12 is connected to the first pin of the optocoupler Q3;

[0078] The second pin of the optocoupler Q3 is connected to the collector C of the switch tube Q2;

[0079] The third pin of the optocoupler Q3 is connected to the second pin of the resistor R13;

[0080] The 4th pin of the optocoupler Q3 is connected to the VPF1 terminal and the 1st pin of the resistor R14 respectively;

[0081] Among them, the VPF1 terminal serves as the output terminal of the first detection module;

[0082] The first pin of the resistor R13 is connected to the 5V DC power supply VDD2;

[0083] The second pin of the resistor R14 is connected to the ground terminal GND.

[0084] Preferably, the second detection module includes: resistors R21-R34, diodes D21-D23, a voltage regulator tube 24, switch tubes Q21-Q22 and an optical coupler Q23, wherein:

[0085] The first pin of the resistor R21 is used as the first input terminal of the second detection module and is connected to the positive terminal P+ of the battery system;

[0086] The second pin of resistor R21 is connected to the V20 terminal;

[0087] The V20 terminal is also connected to the first pin of the resistor R24 ​​and the first pin of the resistor R28 respectively;

[0088] The first pin of the resistor R22 is used as the third input terminal of the second detection module and is connected to the negative terminal P- of the battery system;

[0089] The second pin of resistor R22 is connected to the V25 terminal;

[0090] The V25 terminal is also connected to the first pin of the voltage regulator tube D24 and the cathode of the diode D21 respectively;

[0091] The anode of the diode D21 is connected to one end of the switch K2;

[0092] The signal input terminal of the switch K2 serves as the fourth input terminal of the second detection module;

[0093] The second pin of the voltage regulator tube D24 is connected to the anode of the diode D23 and the first pin of the resistor R23 respectively;

[0094] The cathode of the diode D23 is connected to the negative terminal B2- of the second battery group;

[0095] The second pin of resistor R24 ​​is connected to the V24 terminal;

[0096] The V24 terminal is also connected to the other end of the switch K2 and the first pin of the resistor R25;

[0097] The second pin of resistor R25 is connected to the V21 terminal;

[0098] The V21 terminal is also connected to the cathode of the diode D22 and the first pin of the resistor R26 respectively;

[0099] The second pin of resistor R26 is connected to the V26 terminal;

[0100] The V26 terminal is also connected to the second pin of the resistor R23, the second pin of the resistor R31, the second pin of the resistor R29 and the emitter E of the switch tube Q22;

[0101] The second pin of resistor R28 is connected to the V22 terminal;

[0102] The V22 terminal is also connected to the first pin of the resistor R27, the emitter E of the switch tube Q21 and the first pin of the resistor R29 respectively;

[0103] The base B of the switch tube Q21 is connected to the second pin of the resistor R27 and the anode of the diode D22 respectively;

[0104] The collector C of the switch tube Q21 is connected to the first pin of the resistor R30;

[0105] The second pin of resistor R30 is connected to the V23 terminal;

[0106] The V23 terminal is also connected to the first pin of the resistor R31 and the base B of the switch tube Q22;

[0107] The collector C of the switch tube Q22 is connected to the second pin of the optocoupler Q23;

[0108] The first pin of the resistor R32 is connected to the 12V DC power supply VDD1;

[0109] The second pin of the resistor R32 is connected to the first pin of the optocoupler Q23;

[0110] The second pin of the optocoupler Q23 is connected to the collector C of the switch tube Q22;

[0111] The third pin of the optocoupler Q23 is connected to the second pin of the resistor R33;

[0112] The 4th pin of the optocoupler Q23 is connected to the VPF2 terminal and the 1st pin of the resistor R34 respectively;

[0113] Among them, the VPF2 terminal serves as the output terminal of the second detection module;

[0114] The first pin of the resistor R33 is connected to the 5V DC power supply VDD2;

[0115] The second pin of the resistor R34 is connected to the ground terminal GND.

[0116] Preferably, when the output terminals KC1 and KC2 of the BMS main control chip output low-level control signals to the signal input terminals of contactors KL1 and KL2 respectively, the BMS main control chip is used to determine that the contacts of contactor KL1 are disconnected and there is no adhesion fault based on the low-level KC1 and the low-level VPF1, and is used to determine that the contacts of contactor KL2 are disconnected and there is no adhesion fault based on the low-level KC2 and the low-level VPF2.

[0117] Preferably, when the output terminals KC1 and KC2 of the BMS main control chip output high-level control signals to the signal input terminals of contactors KL1 and KL2 respectively, the BMS main control chip is used to determine that the contact of contactor KL1 has been closed based on the high-level KC1 and the high-level VPF1, and is used to determine that the contact of contactor KL2 has been closed based on the high-level KC2 and the high-level VPF2.

[0118] Preferably, when the control signal output by the output terminal KC1 of the BMS main control chip to the signal input terminal of the contactor KL1 changes from a high level to a low level, and the control signal output by the output terminal KC2 of the BMS main control chip to the signal input terminal of the contactor KL2 also changes from a high level to a low level, the BMS main control chip is used to judge whether the contacts of the contactor KL1 are stuck based on the low level KC1 and the high level VPF1, and is used to judge whether the contacts of the contactor KL2 are stuck based on the low level KC2 and the high level VPF2.

[0119] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides a low-side parallel contactor adhesion detection circuit for a battery system, which can detect contact adhesion failures of the low-side contactors in parallel battery packs, and can accurately locate adhesion failure contactors in parallel circuits online, which has great practical significance.

[0120] For the present invention, the hardware circuit design is scientific, the electronic components are of commonly used models, easy to select, and the price is also very low;

[0121] In addition, for the present invention, the power consumption of the hardware circuit is relatively low, so surface-mount low-power electronic components can be used, so the circuit board occupies a small space, greatly reducing the material cost.

[0122] In addition, the present invention can detect the contact adhesion fault of the contactor in the parallel battery pack by combining software and hardware, and can locate the faulty contactor online without offline manual troubleshooting.

[0123] Therefore, the technical solution of the present invention has strong practical value and market promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0124] Figure 1 A schematic block diagram of a low-side parallel contactor adhesion detection circuit for a battery system provided by the present invention;

[0125] Figure 2 A schematic diagram of a first detection module in a low-side parallel contactor adhesion detection circuit for a battery system provided by the present invention;

[0126] Figure 3A schematic diagram of a second detection module in a low-side parallel contactor adhesion detection circuit of a battery system provided by the present invention. DETAILED DESCRIPTION

[0127] In order to make the technical means implemented by the present invention easier to understand, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the relevant application, rather than to limit the application. It is also necessary to explain that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings.

[0128] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0129] See also Figures 1 to 3 The present invention provides a low-side parallel contactor adhesion detection circuit in a battery system, which can detect the adhesion fault of the parallel contactor on the low-side branch in the high-voltage circuit of the battery system and can determine the specific faulty contactor.

[0130] For the low-side parallel contactor adhesion detection circuit of the battery system provided by the present invention, the battery system includes a plurality of battery packs connected in parallel to each other (which may be any plurality greater than or equal to two, and each battery pack includes a plurality of batteries connected in series and / or in parallel);

[0131] The low-side parallel contactor adhesion detection circuit of the battery system specifically includes a plurality of battery pack detection modules and a BMS main control chip 300;

[0132] Wherein, each battery pack is connected to a battery pack detection module respectively;

[0133] The negative terminal B- of each battery pack is connected to the negative terminal P- of the battery system through a contactor KL;

[0134] After the positive terminals B+ of the multiple battery packs are connected in a busbar, they are all connected to the positive terminal P+ of the battery system;

[0135] For each battery pack detection module, it includes a first power input terminal and a second power input terminal, and includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal VPF;

[0136] Wherein, each battery pack detection module has a first power input terminal connected to a DC power supply VDD1;

[0137] The second power input terminal of each battery pack detection module is connected to a DC power supply VDD2;

[0138] Each battery pack detection module has a first input terminal connected to the positive terminal P+ of the battery system;

[0139] The second input terminal of each battery pack detection module is respectively connected to the negative terminal B- of a battery pack;

[0140] The third input terminal of each battery pack detection module is connected to the negative terminal P- of the battery system;

[0141] The fourth input terminal of each battery pack detection module is connected to the switch signal output terminal SW of the BMS main control chip 300;

[0142] Each battery pack detection module has an output terminal VPF connected to an input terminal of the BMS main control chip 300;

[0143] Each battery pack detection module is used to detect the signal input status of its first input terminal, the second input terminal and the third input terminal, and correspondingly output the contact detection signal VPF (high level or low level contact detection signal VPF) of the battery pack (i.e. the battery pack connected to the second input terminal) to the BMS main control chip 300;

[0144] Among them, the BMS main control chip 300 has multiple output terminals KC, which are respectively connected to the signal input terminals of the contactors KL connected to the multiple battery packs, and are used to send multiple switch control signals KC to the contactors KL connected to the multiple battery packs, respectively, to control the on and off of the multiple contactors KL accordingly;

[0145] The BMS main control chip 300 is used to determine whether the contacts of the contactor KL connected to each battery pack have a sticking fault (i.e., whether there is a sticking fault). Specifically, it is used to receive the contact detection signal VPF sent by the battery pack detection module, and after controlling the on and off of the contactors KL connected to multiple battery packs through its output terminal KC, it determines whether the contacts of the contactor KL connected to each battery pack have a sticking fault (i.e., whether there is a sticking fault) according to the switch control signal KC of the contactor KL connected to each battery pack and the level state of the contact detection signal VPF of each battery pack.

[0146] Among them, the BMS main control chip 300 is used to output switch control signals at the output ends SW1 and SW2 of the BMS main control chip 300 before the contactors KL1 and KL2 are allowed to close and after they have been disconnected (that is, when the output ends KC1 and KC2 of the BMS main control chip 300 output low-level or high-level control signals to the signal input ends of the contactors KL1 and KL2), and alternately control the closure of the switch K1 in the first detection module and the switch K2 in the second detection module, so that the first detection module 100 and the second detection module 200 start to detect whether the contacts of the contactors KL1 and KL2 are adhered, wherein the switches K1 and K2 cannot be closed at the same time.

[0147] In the present invention, in a specific implementation, for the BMS main control chip 300, when the switch control signal output by its output terminal KC to the signal input terminal of the contactor KL connected to any battery pack changes from a high level to a low level, if the level of the contact detection signal VPF sent by the battery pack detection module connected to the battery pack is a high level, it is determined that the contacts of the contactor KL connected to the battery pack have a adhesion fault (adhesion).

[0148] It should be noted that, in the present invention, two parallel battery packs and two parallel contactors are used as an example to explain the technical solution. The details are as follows:

[0149] In the present invention, in a specific implementation, the battery system includes a first battery pack and a second battery pack;

[0150] Wherein, the first battery pack and the second battery pack are connected in parallel;

[0151] Wherein, the negative terminal B1- of the first battery pack is connected to the negative terminal P- of the battery system through the contactor KL1;

[0152] The negative terminal B2- of the second battery group is also connected to the negative terminal P- of the battery system through the contactor KL2;

[0153] The positive terminal B1+ of the first battery group and the positive terminal B2+ of the second battery group are both connected to the positive terminal P+ of the battery system after the currents are converged and intersected;

[0154] The low-side parallel contactor adhesion detection circuit of the battery system specifically includes a first detection module 100, a second detection module 200 and a BMS main control chip 300;

[0155] Wherein, the first detection module 100 has a first power input terminal connected to a DC power source VDD1;

[0156] The first detection module 100 has a second power input terminal connected to a DC power source VDD2;

[0157] A first detection module 100, a first input terminal of which is connected to the positive terminal P+ of the battery system;

[0158] A first detection module 100, a second input terminal of which is connected to the negative terminal B1- of the first battery pack;

[0159] The first detection module 100 has a third input terminal connected to the negative terminal P- of the battery system;

[0160] The second detection module 100 has a fourth input terminal connected to the switch signal output terminal SW1 of the BMS main control chip 300;

[0161] The first detection module 100, whose output terminal VPF1 is connected to the first input terminal of the BMS main control chip 300;

[0162] The first detection module 100 is used to detect the signal input status of the first input terminal, the second input terminal and the third input terminal, and output a contact detection signal VPF1 to the BMS main control chip 300 accordingly;

[0163] The second detection module 200 has a first power input terminal connected to a DC power source VDD1;

[0164] The second detection module 200 has a second power input terminal connected to a DC power source VDD2;

[0165] A second detection module 200, a first input terminal of which is connected to the positive terminal P+ of the battery system;

[0166] A second detection module 200, a second input terminal of which is connected to the negative terminal B2- of the second battery pack;

[0167] A second detection module 200, a third input terminal of which is connected to the negative terminal P- of the battery system;

[0168] The second detection module 200 has a fourth input terminal connected to the switch signal output terminal SW2 of the BMS main control chip 300;

[0169] The second detection module 200, whose output terminal VPF2 is connected to the second input terminal of the BMS main control chip 300;

[0170] The second detection module 200 is used to detect the signal input status of the first input terminal, the second input terminal and the third input terminal, and output a contact detection signal VPF2 to the BMS main control chip 300 accordingly;

[0171] The BMS main control chip 300 has an output terminal KC1 connected to a signal input terminal of the contactor KL1, and is used to send a switch control signal KC1 to the contactor KL1 to control the on and off of the contactor KL1;

[0172] The BMS main control chip 300, whose output terminal KC2 is connected to the signal input terminal of the contactor KL2, is used to send a switch control signal KC2 to the contactor KL2 to control the on and off of the contactor KL2;

[0173] The BMS main control chip 300 is used to receive the contact detection signal VPF1 sent by the first detection module 100 and the contact detection signal VPF2 sent by the second detection module 200, and after controlling the on and off of the contactors KL1 and KL2 respectively through its output terminals KC1 and KC2, it is used to determine whether there is a sticking fault in the contact of the contactor KL1 (i.e., whether there is a sticking fault) according to the level state of the contact detection signal VPF1 and the switch control signal KC1, and to determine whether there is a sticking fault in the contact of the contactor KL2 (i.e., whether there is a sticking fault) according to the level state of the contact detection signal VPF2 and the switch control signal KC2.

[0174] In the present invention, it should be noted that the DC power supplies VDD1 and VDD2 should be isolated power supplies.

[0175] In the present invention, it should be noted that both the contactor KL1 and the contactor KL2 are DC contactors.

[0176] It should be noted that the first battery pack, the second battery pack, the contactor KL1 and the contactor KL2 do not belong to the scope of the technical solution of the present invention. They are existing electronic components or devices. In order to facilitate the description of the invention, they need to be reflected in the schematic diagram. Therefore, their working principles and the control methods of the contactors KL1 and KL2 are not explained in detail.

[0177] In order to more clearly understand the technical solution of the present invention, the working principle of the present invention is described below:

[0178] 1. When the output terminals KC1 and KC2 of the BMS main control chip 300 respectively output low-level control signals to the signal input terminals of the contactors KL1 and KL2, the contacts of the contactors KL1 and KL2 are disconnected, and the negative terminal P- of the battery system is not connected to the negative terminal B1- of the first battery pack and the negative terminal B2- of the second battery pack. The first detection module 100 is only provided with input signals by the first input terminal P+ and the second input terminal B1-, so that the output terminal VPF1 of the first detection module 100 is low level; similarly, the second detection module 200 is also only provided with input signals by the first input terminal P+ and the second input terminal B2-, so that the output terminal VPF2 of the second detection module 200 is low level;

[0179] The low level KC1 and the low level VPF1 enable the BMS main control chip 300 to determine that the contactor KL1 contact is disconnected and there is no adhesion fault.

[0180] That is to say, the BMS main control chip 300 is used to determine that the contact of the contactor KL1 is disconnected and there is no adhesion fault according to the low level KC1 and the low level VPF1.

[0181] The low level KC2 and the low level VPF2 enable the BMS main control chip 300 to determine that the contactor KL2 contact is disconnected and there is no adhesion fault.

[0182] That is to say, the BMS main control chip 300 is used to determine that the contact of the contactor KL2 is disconnected and there is no adhesion fault according to the low level KC2 and the low level VPF2.

[0183] 2. When the output terminals KC1 and KC2 of the BMS main control chip 300 respectively output high-level control signals to the signal input terminals of the contactors KL1 and KL2, the contacts of the contactors KL1 and KL2 are closed, and the negative terminal P- of the battery system is connected to the negative terminal B1- of the first battery pack and the negative terminal B2- of the second battery pack. The first detection module 100 is provided with input signals by the first input terminal P+, the second input terminal B1- and the third input terminal P-, so that the output terminal VPF1 of the first detection module 100 changes from a low level to a high level; similarly, the second detection module 200 is provided with input signals by the first input terminal P+, the second input terminal B2- and the third input terminal P-, so that the signal of the output terminal VPF2 of the second detection module 200 changes from a low level to a high level;

[0184] The high level KC1 and the high level VPF1 enable the BMS main control chip 300 to determine that the contact of the contactor KL1 is closed.

[0185] That is, the BMS main control chip 300 is used to determine that the contact of the contactor KL1 has been closed according to the high level KC1 and the high level VPF1.

[0186] The high level KC2 and the high level VPF2 enable the BMS main control chip 300 to determine that the contact of the contactor KL2 has been closed.

[0187] That is, the BMS main control chip 300 is used to determine that the contact of the contactor KL2 has been closed according to the high level KC2 and the high level VPF2.

[0188] 3. When the control signal outputted by the output terminal KC1 of the BMS main control chip 300 changes from a high level to a low level, but the contact of the contactor KL1 is not disconnected, so that the negative terminal P- of the battery system is still connected to the negative terminal B1- of the first battery pack and the negative terminal B2- of the second battery pack, the first detection module 100 continues to provide input signals from the first input terminal P+, the second input terminal B1- and the third input terminal P-, so that the output terminal VPF1 of the first detection module 100 continues to maintain a high level;

[0189] The low level KC1 and the high level VPF1 enable the BMS main control chip 300 to determine that the contact of the contactor KL1 is stuck.

[0190] That is to say, the BMS main control chip 300 is used to determine whether the contact of the contactor KL1 is stuck according to the low level KC1 and the high level VPF1. In the case that the contact of the contactor KL1 is stuck, the control signal output by the output terminal KC2 of the BMS main control chip 300 also changes from high level to low level, and the contact of the contactor KL2 changes from closed to open, disconnecting the connection between the negative terminal P- of the battery system and the negative terminal B2- of the second battery pack. Then, the second detection module 200 provides input signals from the first input terminal P+ and the second input terminal B2-, so that the signal of the output terminal VPF2 of the second detection module 200 changes from low level to high level;

[0191] The low level KC2 and the high level VPF2 enable the BMS main control chip 300 to determine that the contact of the contactor KL2 is disconnected and there is no adhesion fault.

[0192] That is to say, the BMS main control chip 300 is used to determine the contact adhesion of the contactor KL2 according to the low level KC2 and the high level VPF2. It should be noted that, for the present invention, the first detection module 100 or the second detection module 200 of the present invention supports expansion and can be applied to the adhesion detection of the low-side contactor in multiple parallel battery packs, that is, using multiple first detection modules 100 or the second detection modules 200, the contactors connected to the corresponding multiple battery packs can be detected respectively.

[0193] In the present invention, in specific implementation, the circuit structure of the battery pack detection module can be adopted Figure 2 The circuit of the first detection module 100 shown in FIG. Figure 3 The circuit of the second detection module 200 is shown.

[0194] In the present invention, the specific implementation is as follows: Figure 2 As shown, the first detection module 100 includes:

[0195] Resistors R1~R14, diodes D1~D3, voltage regulator D4, switch tubes Q1~Q2 and optocoupler Q3, where:

[0196] The first pin of the resistor R1 is used as the first input terminal of the first detection module 100 and is connected to the positive terminal P+ of the battery system;

[0197] The second pin of the resistor R1 is connected to the V0 terminal (i.e., a wiring terminal);

[0198] The V0 terminal is also connected to the first pin of the resistor R4 and the first pin of the resistor R8 respectively;

[0199] The first pin of the resistor R2 is used as the third input terminal of the first detection module 100 and is connected to the negative terminal P- of the battery system;

[0200] The second pin of resistor R2 is connected to the V5 terminal;

[0201] The V5 terminal is also connected to the first pin of the voltage regulator tube D4 and the cathode of the diode D1 respectively;

[0202] The anode of the diode D1 is connected to one end of the switch K1;

[0203] The signal input terminal of the switch K1 serves as the fourth input terminal of the first detection module 100;

[0204] The second pin of the voltage regulator tube D4 is connected to the anode of the diode D3 and the first pin of the resistor R3 respectively;

[0205] The cathode of the diode D3, serving as the second input terminal of the first detection module 100, is connected to the negative terminal B1- of the first battery pack;

[0206] The second pin of resistor R4 is connected to the V4 terminal;

[0207] The V4 terminal is also connected to the other end of the switch K1 and the first pin of the resistor R5;

[0208] The second pin of resistor R5 is connected to the V1 terminal;

[0209] The V1 terminal is also connected to the cathode of the diode D2 and the first pin of the resistor R6 respectively;

[0210] The second pin of resistor R6 is connected to the V6 terminal;

[0211] The V6 terminal is also connected to the second pin of the resistor R3, the second pin of the resistor R11, the second pin of the resistor R9 and the emitter E of the switch tube Q2;

[0212] The second pin of resistor R8 is connected to the V2 terminal;

[0213] The V2 terminal is also connected to the first pin of the resistor R7, the emitter E of the switch tube Q1 and the first pin of the resistor R9 respectively;

[0214] The base B of the switch tube Q1 is connected to the second pin of the resistor R7 and the anode of the diode D2 respectively;

[0215] The collector C of the switch tube Q1 is connected to the first pin of the resistor R10;

[0216] The second pin of resistor R10 is connected to the V3 terminal;

[0217] The V3 terminal is also connected to the first pin of the resistor R11 and the base B of the switch tube Q2;

[0218] The collector C of the switch tube Q2 is connected to the second pin of the optocoupler Q3;

[0219] The first pin of the resistor R12 is connected to a 12V DC isolated power supply (DC power supply VDD1);

[0220] The second pin of the resistor R12 is connected to the first pin of the optocoupler Q3;

[0221] The second pin of the optocoupler Q3 is connected to the collector C of the switch tube Q2;

[0222] The third pin of the optocoupler Q3 is connected to the second pin of the resistor R13;

[0223] The 4th pin of the optocoupler Q3 is connected to the VPF1 terminal and the 1st pin of the resistor R14 respectively;

[0224] Among them, the VPF1 terminal serves as the output terminal of the first detection module 100;

[0225] The first pin of the resistor R13 is connected to a 5V DC power supply (DC power supply VDD2);

[0226] The second pin of the resistor R14 is connected to the ground terminal GND.

[0227] In specific implementation, the switch K1 is a relay switch.

[0228] It should be noted that the reverse withstand voltage capability of the diode D3 is considered according to the battery system voltage.

[0229] In the present invention, the specific implementation is as follows: Figure 3 As shown, the second detection module 200 includes: resistors R21-R34, diodes D21-D23, a voltage regulator tube 24, switch tubes Q21-Q22 and an optical coupler Q23, wherein:

[0230] The first pin of the resistor R21 is used as the first input terminal of the second detection module 200 and is connected to the positive terminal P+ of the battery system;

[0231] The second pin of the resistor R21 is connected to the V20 terminal (i.e., a wiring terminal);

[0232] The V20 terminal is also connected to the first pin of the resistor R24 ​​and the first pin of the resistor R28 respectively;

[0233] The first pin of the resistor R22 is used as the third input terminal of the second detection module 200 and is connected to the negative terminal P- of the battery system;

[0234] The second pin of resistor R22 is connected to the V25 terminal;

[0235] The V25 terminal is also connected to the first pin of the voltage regulator tube D24 and the cathode of the diode D21 respectively;

[0236] The anode of the diode D21 is connected to one end of the switch K2;

[0237] The signal input terminal of the switch K2 serves as the fourth input terminal of the second detection module 200;

[0238] The second pin of the voltage regulator tube D24 is connected to the anode of the diode D23 and the first pin of the resistor R23 respectively;

[0239] The cathode of the diode D23 is connected to the negative terminal B2- of the second battery group;

[0240] The second pin of resistor R24 ​​is connected to the V24 terminal;

[0241] The V24 terminal is also connected to the other end of the switch K2 and the first pin of the resistor R25;

[0242] The second pin of resistor R25 is connected to the V21 terminal;

[0243] The V21 terminal is also connected to the cathode of the diode D22 and the first pin of the resistor R26 respectively;

[0244] The second pin of resistor R26 is connected to the V26 terminal;

[0245] The V26 terminal is also connected to the second pin of the resistor R23, the second pin of the resistor R31, the second pin of the resistor R29 and the emitter E of the switch tube Q22;

[0246] The second pin of resistor R28 is connected to the V22 terminal;

[0247] The V22 terminal is also connected to the first pin of the resistor R27, the emitter E of the switch tube Q21 and the first pin of the resistor R29 respectively;

[0248] The base B of the switch tube Q21 is connected to the second pin of the resistor R27 and the anode of the diode D22 respectively;

[0249] The collector C of the switch tube Q21 is connected to the first pin of the resistor R30;

[0250] The second pin of resistor R30 is connected to the V23 terminal;

[0251] The V23 terminal is also connected to the first pin of the resistor R31 and the base B of the switch tube Q22;

[0252] The collector C of the switch tube Q22 is connected to the second pin of the optocoupler Q23;

[0253] The first pin of the resistor R32 is connected to a 12V DC isolated power supply (DC power supply VDD1);

[0254] The second pin of the resistor R32 is connected to the first pin of the optocoupler Q23;

[0255] The second pin of the optocoupler Q23 is connected to the collector C of the switch tube Q22;

[0256] The third pin of the optocoupler Q23 is connected to the second pin of the resistor R33;

[0257] The 4th pin of the optocoupler Q23 is connected to the VPF2 terminal and the 1st pin of the resistor R34 respectively;

[0258] Among them, the VPF2 terminal serves as the output terminal of the second detection module 200;

[0259] The first pin of the resistor R33 is connected to a 5V DC power supply (DC power supply VDD2);

[0260] The second pin of the resistor R34 is connected to the ground terminal GND;

[0261] In specific implementation, the switch K2 is a relay switch.

[0262] It should be noted that the reverse withstand voltage capability of the diode D23 is considered according to the battery system voltage.

[0263] In the present invention, in specific implementation, the working principles of the first detection module 100 and the second detection module 200 are described below:

[0264] First of all, it should be noted that before the contactors KL1 and KL2 are allowed to close and after they have been disconnected (that is, when the output terminals KC1 and KC2 of the BMS main control chip 300 output low-level or high-level control signals to the signal input terminals of the contactors KL1 and KL2), the output terminals SW1 and SW2 of the BMS main control chip 300 output switch control signals, which alternately control the closure of the switch K1 in the first detection module and the switch K2 in the second detection module, respectively, so that the first detection module 100 and the second detection module 200 can start to detect whether the contacts of the contactors KL1 and KL2 are adhered, wherein the switches K1 and K2 cannot be closed at the same time, and when one is closed, the other is disconnected.

[0265] After the contact sticking detection is completed, the output terminals SW1 and SW2 of the BMS main control chip 300 output control signals to respectively control the switches K1 and K2 to be disconnected.

[0266] 1. When the output terminals KC1 and KC2 of the BMS main control chip 300 output low-level control signals to the signal input terminals of the contactors KL1 and KL2, the contacts of the contactors KL1 and KL2 are disconnected, and the negative terminal P- of the battery system is not connected to the negative terminal B1- of the first battery pack and the negative terminal B2- of the second battery pack;

[0267] In this case, the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be closed, and the output terminal SW2 sends a switch control signal to control the switch K2 to be opened. The first detection module 100 is only provided with input signals by the first input terminal P+ and the second input terminal B1-, so that the voltage at the V0 terminal is equal to the P+ input voltage minus the voltage drop of the resistor R1, and after voltage division by the resistors R4, R5 and R6, the voltage at the V1 terminal is greater than the sum of the base and emitter conduction voltages of the switch tube Q1 and the conduction voltage of the diode D2, so that the switch tube Q1 is turned off, and then the switch tube Q2 is also turned off, so the optocoupler Q3 is turned off, and the VPF1 terminal is grounded through the resistor R14 as a low-level signal.

[0268] Similarly, the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be disconnected, and the output terminal SW2 sends a switch control signal to control the switch K2 to be closed. The second detection module 200 only provides input signals from the first input terminal P+ and the second input terminal B2-, so that the voltage at the V20 terminal is equal to the P+ input voltage minus the voltage drop of the resistor R21, and after voltage division through the resistors R24, R25 and R26, the voltage at the V21 terminal is greater than the sum of the base and emitter conduction voltages of the switch tube Q21 and the conduction voltage of the diode D22, so that the switch tube Q21 is turned off, and then the switch tube Q22 is also turned off, so the optocoupler Q23 is turned off, and the VPF2 terminal is grounded through the resistor R34 as a low-level signal;

[0269] The low level KC1 and the low level VPF1 enable the BMS main control chip 300 to determine that the contactor KL1 contact is disconnected and there is no adhesion fault;

[0270] The low level KC2, the low level VK2 and the low level VPF2 enable the BMS main control chip 300 to determine that the contactor KL2 contact is disconnected and there is no adhesion fault;

[0271] It should be noted that when the switch tube Q1 is turned off, due to the voltage-dividing effect of the resistors R8 and R9 on the V0 terminal, the voltage at the V2 terminal can be reduced to a low voltage, making the switch tube Q1 easy to select;

[0272] It should be noted that when the switch tube Q21 is turned off, due to the voltage-dividing effect of the resistors R28 and R29, the voltage at the V22 terminal can be reduced to a low voltage, making it easier to select the switch tube Q21;

[0273] 2. When the output terminals KC1 and KC2 of the BMS main control chip 300 output high-level control signals, the contacts of the contactors KL1 and KL2 are closed, and the negative terminal P- of the battery system is connected to the negative terminal B1- of the first battery pack and the negative terminal B2- of the second battery pack;

[0274] In this case, if the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be closed, and the output terminal SW2 sends a switch control signal to the switch K2 to control the switch K2 to be opened, the first detection module 100 provides input signals from the first input terminal P+, the second input terminal B1- and the third input terminal P-; since the resistance value of the resistor R2 is less than the sum of the resistance values ​​of the resistors R5 and R6, the voltage at the V4 terminal is reduced, and after the voltage is divided by the resistors R5 and R6, the voltage at the V1 terminal is also reduced and is less than the sum of the base and emitter conduction voltages of the switch tube Q1 and the conduction voltage of the diode D2, so that the switch tube Q1 is turned from off to on, and then the switch tube Q2 is also turned from off to on, so the optocoupler Q3 is turned from off to on, and the resistor R13 and the resistor R14 divide the voltage by DC 5V, so that the signal at the VPF1 terminal is changed from low level to high level.

[0275] Similarly, if the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be disconnected, and the output terminal SW2 sends a switch control signal to the switch K2 to control the switch K2 to be closed, the second detection module 200 provides input signals from the first input terminal P+, the second input terminal B2- and the third input terminal P-; since the resistance value of the resistor R22 is less than the sum of the resistance values ​​of the resistors R25 and R26, the voltage at the V24 terminal is reduced, and after voltage division by the resistors R25 and R26, the voltage at the V1 terminal is also reduced and is less than the sum of the base and emitter conduction voltages of the switch tube Q21 and the conduction voltage of the diode D22, so that the switch tube Q21 is turned from off to on, and then the switch tube Q22 is also turned from off to on, so the optocoupler Q23 is turned from off to on, and the resistor R33 and the resistor R34 divide the voltage by DC 5V, so that the signal at the VPF2 terminal is changed from low level to high level.

[0276] The high level KC1 and the high level VPF1 make the BMS main control chip 300 determine that the contactor KL1 is closed;

[0277] The high level KC2 and the high level VPF2 make the BMS main control chip 300 determine that the contactor KL2 is closed;

[0278] 3. When the control signal outputted from the output terminal KC1 of the BMS main control chip 300 to the signal input terminal of the contactor KL1 changes from a high level to a low level, but the contact of the contactor KL1 is not disconnected, so that the negative terminal P- of the battery system and the negative terminal B1- of the first battery pack remain connected; at the same time, the control signal outputted from the output terminal KC2 of the BMS main control chip 300 also changes from a high level to a low level, and the contact of the contactor KL2 changes from closed to open, disconnecting the connection between the negative terminal P- of the battery system and the negative terminal B2- of the second battery pack;

[0279] In this case, the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be closed, and the output terminal SW2 sends a switch control signal to the switch K2 to control the switch K2 to be opened, and the first detection module 100 continues to provide input signals from the first input terminal P+, the second input terminal B1- and the third input terminal P-, so that the voltage at the V1 terminal is still less than the sum of the base and emitter conduction voltages of the switch tube Q1 and the conduction voltage of the diode D2, so that the switch tube Q1, the switch tube Q2 and the optocoupler Q4 remain in the on state, and the signal at the VPF1 terminal continues to maintain a high level state.

[0280] The low level KC1 and the high level VPF1 make the BMS main control chip 300 determine that the contact of the contactor KL1 is adhered and not disconnected;

[0281] After the BMS main control chip 300 determines that the contact of the contactor KL1 is stuck, the output terminal SW1 of the BMS main control chip 300 sends a switch control signal to the switch K1 to control the switch K1 to be disconnected, and the output terminal SW2 sends a switch control signal to the switch K2 to control the switch K2 to be closed. Since the contactor KL2 is disconnected, the connection between the negative terminal P- of the battery system and the negative terminal B2- of the second battery pack is disconnected, and the second detection module 200 provides an input signal from the first input terminal P+ and the second input terminal B2-, so that the voltage at the V21 terminal is greater than the sum of the base and emitter conduction voltages of the switch tube Q21 and the conduction voltage of the diode D22, so that the switch tube Q21, the switch tube Q22 and the optocoupler Q23 are turned from on to off, and the signal at the VPF2 terminal is changed from a high level to a low level.

[0282] The low level KC2 and the low level VPF2 enable the BMS main control chip 300 to determine that the contactor KL2 contact is disconnected and no adhesion fault occurs.

[0283] It should be noted that, under normal circumstances, the voltage at the V25 terminal is less than the voltage regulation value of the voltage regulator D22. When a reverse high voltage appears at the third input terminal P-, the voltage at the V25 terminal is greater than the voltage regulation value of the voltage regulator D22.

[0284] In the present invention, it should be noted that the BMS main control chip 300 can be a brand, series and model commonly used at present, such as NXP's MC9S12 series, Infineon's TC2 series TC265, etc. The model of the BMS main control chip 300 is not within the protection scope of the present invention.

[0285] To sum up, compared with the prior art, the present invention provides a low-side parallel contactor adhesion detection circuit for a battery system, which can detect contact adhesion failures of low-side contactors in parallel battery packs and can accurately locate adhesion failure contactors in parallel circuits online, which has great practical significance.

[0286] For the present invention, the hardware circuit design is scientific, the electronic components are of commonly used models, easy to select, and the price is also very low;

[0287] In addition, for the present invention, the power consumption of the hardware circuit is relatively low, so surface-mount low-power electronic components can be used, so the circuit board occupies a small space, greatly reducing the material cost.

[0288] In addition, the present invention can detect the contact adhesion fault of the contactor in the parallel battery pack by combining software and hardware, and can locate the faulty contactor online without offline manual troubleshooting.

[0289] Therefore, the technical solution of the present invention has strong practical value and market promotion value.

[0290] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-side parallel contactor adhesion detection circuit for a battery system, characterized in that: The battery system includes a plurality of battery packs connected in parallel; The low-side parallel contactor adhesion detection circuit of the battery system specifically comprises a plurality of battery pack detection modules and a BMS main control chip (300); Wherein, each battery pack is connected to a battery pack detection module respectively; The negative terminal B- of each battery pack is connected to the negative terminal P- of the battery system through a contactor KL; After the positive terminals B+ of the multiple battery packs are connected in a busbar, they are all connected to the positive terminal P+ of the battery system; For each battery pack detection module, it includes a first power input terminal and a second power input terminal, and includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal VPF; Wherein, each battery pack detection module has a first power input terminal connected to a DC power supply VDD1; The second power input terminal of each battery pack detection module is connected to a DC power supply VDD2; Each battery pack detection module has a first input terminal connected to the positive terminal P+ of the battery system; The second input terminal of each battery pack detection module is respectively connected to the negative terminal B- of a battery pack; The third input terminal of each battery pack detection module is connected to the negative terminal P- of the battery system; Each battery pack detection module has a fourth input terminal connected to a switch signal output terminal SW of a BMS main control chip (300); Each battery pack detection module has an output terminal VPF connected to an input terminal of a BMS main control chip (300); Each battery pack detection module is used to detect the signal input status of its first input terminal, the second input terminal and the third input terminal, and correspondingly output a contact detection signal VPF of the battery pack to the BMS main control chip (300); The BMS main control chip (300) has a plurality of output terminals KC, which are respectively connected to the signal input terminals of the contactors KL connected to the plurality of battery packs, and are used to respectively send a plurality of switch control signals KC to the contactors KL connected to the plurality of battery packs, and correspondingly control the on and off of the plurality of contactors KL; A BMS main control chip (300) is used to determine whether there is a sticking fault at the contact of the contactor KL connected to each battery pack; The BMS main control chip (300) is used to receive a contact detection signal VPF sent by a battery pack detection module, and after controlling the on and off of contactors KL connected to multiple battery packs through its output terminal KC, determine whether there is a sticking fault in the contact of the contactor KL connected to each battery pack according to the switch control signal KC of the contactor KL connected to each battery pack and the level state of the contact detection signal VPF of each battery pack; The battery system includes a first battery pack and a second battery pack; Wherein, the first battery pack and the second battery pack are connected in parallel; Wherein, the negative terminal B1- of the first battery pack is connected to the negative terminal P- of the battery system through the contactor KL1; The negative terminal B2- of the second battery group is also connected to the negative terminal P- of the battery system through the contactor KL2; The positive terminal B1+ of the first battery group and the positive terminal B2+ of the second battery group are both connected to the positive terminal P+ of the battery system after the currents are converged and intersected; The low-side parallel contactor adhesion detection circuit of the battery system specifically comprises a first detection module (100), a second detection module (200) and a BMS main control chip (300); Wherein, the first detection module (100) has a first power input terminal connected to a direct current power source VDD1; A first detection module (100), a second power input terminal of which is connected to a direct current power supply VDD2; A first detection module (100), a first input terminal of which is connected to a positive terminal P+ of a battery system; A first detection module (100), a second input terminal of which is connected to the negative terminal B1- of the first battery pack; A first detection module (100), a third input terminal of which is connected to the negative terminal P- of the battery system; A second detection module (100), a fourth input terminal of which is connected to a switch signal output terminal SW1 of a BMS main control chip (300); A first detection module (100), an output terminal VPF1 of which is connected to a first input terminal of a BMS main control chip (300); The first detection module (100) is used to detect the signal input states of the first input terminal, the second input terminal and the third input terminal thereof, and to output a contact detection signal VPF1 to the BMS main control chip (300) accordingly; A second detection module (200), wherein a first power input terminal thereof is connected to a direct current power source VDD1; A second detection module (200), a second power input terminal of which is connected to a direct current power source VDD2; A second detection module (200), a first input terminal of which is connected to the positive terminal P+ of the battery system; A second detection module (200), a second input terminal of which is connected to the negative terminal B2- of the second battery pack; A second detection module (200), a third input terminal of which is connected to the negative terminal P- of the battery system; A second detection module (200), a fourth input terminal of which is connected to a switch signal output terminal SW2 of a BMS main control chip (300); A second detection module (200), an output terminal VPF2 of which is connected to a second input terminal of a BMS main control chip (300); The second detection module (200) is used to detect the signal input states of the first input terminal, the second input terminal and the third input terminal thereof, and to output a contact detection signal VPF2 to the BMS main control chip (300) accordingly; A BMS main control chip (300), whose output terminal KC1 is connected to the signal input terminal of the contactor KL1, and is used to send a switch control signal KC1 to the contactor KL1 to control the on and off of the contactor KL1; The BMS main control chip (300) has an output terminal KC2 connected to a signal input terminal of the contactor KL2, and is used to send a switch control signal KC2 to the contactor KL2 to control the on and off of the contactor KL2; The BMS main control chip (300) is used to receive a contact detection signal VPF1 sent by the first detection module (100) and a contact detection signal VPF2 sent by the second detection module (200), and after controlling the on and off of contactors KL1 and KL2 respectively through their output terminals KC1 and KC2, determine whether the contact of contactor KL1 has a sticking fault according to the level states of the contact detection signal VPF1 and the switch control signal KC1, and determine whether the contact of contactor KL2 has a sticking fault according to the level states of the contact detection signal VPF2 and the switch control signal KC2; The first detection module (100) comprises: resistors R1-R14, diodes D1-D3, a voltage regulator tube D4, switch tubes Q1-Q2 and an optical coupler Q3, wherein: The first pin of the resistor R1 is used as the first input terminal of the first detection module (100) and is connected to the positive terminal P+ of the battery system; The second pin of resistor R1 is connected to the V0 terminal; The V0 terminal is also connected to the first pin of the resistor R4 and the first pin of the resistor R8 respectively; The first pin of the resistor R2 is used as the third input terminal of the first detection module (100) and is connected to the negative terminal P- of the battery system; The second pin of resistor R2 is connected to the V5 terminal; The V5 terminal is also connected to the first pin of the voltage regulator tube D4 and the cathode of the diode D1 respectively; The anode of the diode D1 is connected to one end of the switch K1; The second pin of the voltage regulator tube D4 is connected to the anode of the diode D3 and the first pin of the resistor R3 respectively; The cathode of the diode D3, serving as the second input terminal of the first detection module (100), is connected to the negative terminal B1- of the first battery pack; The second pin of resistor R4 is connected to the V4 terminal; The V4 terminal is also connected to the other end of the switch K1 and the first pin of the resistor R5; The signal input terminal of the switch K1 serves as the fourth input terminal of the first detection module (100); The second pin of resistor R5 is connected to the V1 terminal; The V1 terminal is also connected to the cathode of the diode D2 and the first pin of the resistor R6 respectively; The second pin of resistor R6 is connected to the V6 terminal; The V6 terminal is also connected to the second pin of the resistor R3, the second pin of the resistor R11, the second pin of the resistor R9 and the emitter E of the switch tube Q2; The second pin of resistor R8 is connected to the V2 terminal; The V2 terminal is also connected to the first pin of the resistor R7, the emitter E of the switch tube Q1 and the first pin of the resistor R9 respectively; The base B of the switch tube Q1 is connected to the second pin of the resistor R7 and the anode of the diode D2 respectively; The collector C of the switch tube Q1 is connected to the first pin of the resistor R10; The second pin of resistor R10 is connected to the V3 terminal; The V3 terminal is also connected to the first pin of the resistor R11 and the base B of the switch tube Q2; The collector C of the switch tube Q2 is connected to the second pin of the optocoupler Q3; The first pin of resistor R12 is connected to the 12V DC power supply VDD1; The second pin of the resistor R12 is connected to the first pin of the optocoupler Q3; The second pin of the optocoupler Q3 is connected to the collector C of the switch tube Q2; The third pin of the optocoupler Q3 is connected to the second pin of the resistor R13; The 4th pin of the optocoupler Q3 is connected to the VPF1 terminal and the 1st pin of the resistor R14 respectively; The VPF1 terminal serves as the output terminal of the first detection module (100); The first pin of the resistor R13 is connected to the 5V DC power supply VDD2; The second pin of the resistor R14 is connected to the ground terminal GND.

2. The low side parallel contactor adhesion detection circuit of the battery system according to claim 1, characterized in that: The BMS main control chip (300) is used for, when the output terminals KC1 and KC2 of the BMS main control chip (300) output low-level or high-level control signals to the signal input terminals of the contactors KL1 and KL2, the output terminals SW1 and SW2 of the BMS main control chip (300) output switch control signals, and respectively alternately control the switch K1 in the first detection module and the switch K2 in the second detection module to be closed, so that the first detection module (100) and the second detection module (200) start to detect whether the contacts of the contactors KL1 and KL2 are adhered.

3. The low side parallel contactor adhesion detection circuit of the battery system according to claim 1, characterized in that: For the BMS main control chip (300), when the switch control signal output by its output terminal KC to the signal input terminal of the contactor KL connected to any battery pack changes from a high level to a low level, if the level of the contact detection signal VPF sent by the battery pack detection module connected to the battery pack is a high level, it is determined that the contact of the contactor KL connected to the battery pack has a sticking fault.

4. The low side parallel contactor adhesion detection circuit of the battery system according to claim 1, characterized in that: The second detection module (200) comprises: resistors R21-R34, diodes D21-D23, a voltage regulator tube 24, switch tubes Q21-Q22 and an optical coupler Q23, wherein: The first pin of the resistor R21 is used as the first input terminal of the second detection module (200) and is connected to the positive terminal P+ of the battery system; The second pin of resistor R21 is connected to the V20 terminal; The V20 terminal is also connected to the first pin of the resistor R24 ​​and the first pin of the resistor R28 respectively; The first pin of the resistor R22 is used as the third input terminal of the second detection module (200) and is connected to the negative terminal P- of the battery system; The second pin of resistor R22 is connected to the V25 terminal; The V25 terminal is also connected to the first pin of the voltage regulator tube D24 and the cathode of the diode D21 respectively; The anode of the diode D21 is connected to one end of the switch K2; The signal input terminal of the switch K2 serves as the fourth input terminal of the second detection module (200); The second pin of the voltage regulator tube D24 is connected to the anode of the diode D23 and the first pin of the resistor R23 respectively; The cathode of the diode D23 is connected to the negative terminal B2- of the second battery group; The second pin of resistor R24 ​​is connected to the V24 terminal; The V24 terminal is also connected to the other end of the switch K2 and the first pin of the resistor R25; The second pin of resistor R25 is connected to the V21 terminal; The V21 terminal is also connected to the cathode of the diode D22 and the first pin of the resistor R26 respectively; The second pin of resistor R26 is connected to the V26 terminal; The V26 terminal is also connected to the second pin of the resistor R23, the second pin of the resistor R31, the second pin of the resistor R29 and the emitter E of the switch tube Q22; The second pin of resistor R28 is connected to the V22 terminal; The V22 terminal is also connected to the first pin of the resistor R27, the emitter E of the switch tube Q21 and the first pin of the resistor R29 respectively; The base B of the switch tube Q21 is connected to the second pin of the resistor R27 and the anode of the diode D22 respectively; The collector C of the switch tube Q21 is connected to the first pin of the resistor R30; The second pin of resistor R30 is connected to the V23 terminal; The V23 terminal is also connected to the first pin of the resistor R31 and the base B of the switch tube Q22; The collector C of the switch tube Q22 is connected to the second pin of the optocoupler Q23; The first pin of the resistor R32 is connected to the 12V DC power supply VDD1; The second pin of the resistor R32 is connected to the first pin of the optocoupler Q23; The second pin of the optocoupler Q23 is connected to the collector C of the switch tube Q22; The third pin of the optocoupler Q23 is connected to the second pin of the resistor R33; The 4th pin of the optocoupler Q23 is connected to the VPF2 terminal and the 1st pin of the resistor R34 respectively; The VPF2 terminal serves as the output terminal of the second detection module (200); The first pin of the resistor R33 is connected to the 5V DC power supply VDD2; The second pin of the resistor R34 is connected to the ground terminal GND.

5. The low side parallel contactor adhesion detection circuit of the battery system according to claim 1, characterized in that: When the output terminals KC1 and KC2 of the BMS main control chip (100) output low-level control signals to the signal input terminals of the contactors KL1 and KL2, respectively, the BMS main control chip (300) is used to determine, based on the low-level KC1 and the low-level VPF1, that the contact of the contactor KL1 is disconnected and there is no adhesion fault, and is used to determine, based on the low-level KC2 and the low-level VPF2, that the contact of the contactor KL2 is disconnected and there is no adhesion fault.

6. The low side parallel contactor sticking detection circuit of the battery system according to claim 1, characterized in that: When the output terminals KC1 and KC2 of the BMS main control chip (100) output high-level control signals to the signal input terminals of the contactors KL1 and KL2, respectively, the BMS main control chip (300) is used to determine that the contact of the contactor KL1 has been closed based on the high-level KC1 and the high-level VPF1, and is used to determine that the contact of the contactor KL2 has been closed based on the high-level KC2 and the high-level VPF2.

7. The low side parallel contactor sticking detection circuit of the battery system according to claim 1, characterized in that: When the control signal outputted from the output terminal KC1 of the BMS main control chip (100) to the signal input terminal of the contactor KL1 changes from a high level to a low level, and the control signal outputted from the output terminal KC2 of the BMS main control chip (100) to the signal input terminal of the contactor KL2 also changes from a high level to a low level, the BMS main control chip (300) is used to judge whether the contact of the contactor KL1 is stuck based on the low level KC1 and the high level VPF1, and is used to judge whether the contact of the contactor KL2 is stuck based on the low level KC2 and the high level VPF2.

Images