CN216013586U

CN216013586U - High limit of battery system and low limit contactor adhesion detection circuitry

Info

Publication number: CN216013586U
Application number: CN202121147658.7U
Authority: CN
Inventors: 张明艳; 邹玉峰
Original assignee: Lishen Qingdao New Energy Co Ltd
Current assignee: Lishen Qingdao New Energy Co Ltd
Priority date: 2021-05-26
Filing date: 2021-05-26
Publication date: 2022-03-11
Anticipated expiration: 2031-05-26

Abstract

The utility model discloses a high-side and low-side contactor adhesion detection circuit of a battery system, which comprises a detection input module, a detection output module, an MCU module and a power module, wherein the battery system P comprises a battery pack B; the positive end B + of the battery pack B is connected with the positive end P + of the battery system through a high-side contactor KL; the negative end B-of the battery pack B is connected with the negative end P-of the battery system through a low-side contactor KL; the positive electrode end BL + of the battery pack BL in the battery pack B is connected with the input end of the detection output module; the detection input module is respectively connected with the battery system P, the high-side contactor KL, the low-side contactor KL and the detection output module; the detection output module is connected with the positive electrode end BL + of the battery pack BL; the detection output module is also respectively connected with the power supply module and the MCU module. The utility model adopts the low-voltage optocoupler and the switch tube, and can realize the contact adhesion detection of the high-low side contactor in each high-voltage loop at the same time.

Description

High limit of battery system and low limit contactor adhesion detection circuitry

Technical Field

The utility model relates to the technical field of battery management, in particular to a high-side and low-side contact adhesion detection circuit of a battery system.

Background

In the field of new energy application, lithium batteries are increasingly used in electronic and electrical products, such as electric vehicles, electric bicycles, electric tools, communication base stations, robots, and the like. In order to enable a lithium battery to be safely and reliably used, a Battery Management System (BMS) is required to monitor the use state of the lithium battery and implement protection functions such as overcharge, overdischarge, and over-temperature.

Taking an electric vehicle as an example, in a vehicle-mounted power battery system (hereinafter referred to as a battery system), a direct current contactor (hereinafter referred to as a contactor) is generally adopted as a switching device of a high-voltage loop of the battery system, and the direct current contactor is a key electrical component in the battery system and is controlled to be switched on and off by a BMS or a vehicle-mounted electronic control system. In practical use, because the impact of heavy current, can take place contactor contact adhesion trouble sometimes for there is high pressure still at power battery system's positive negative pole both ends, will cause very big safety risk to vehicle and operating personnel this moment.

In view of the above problems, some existing technical schemes control the on-off of a low-voltage electronic switch (such as a MOSFET) by using a single chip microcomputer to control the on-off of a high-voltage optocoupler, so as to realize the detection of high voltage at two ends of a power battery system, and the problems existing in the schemes are that: the price of the high-voltage optocoupler is very high, generally, a plurality of contactors in a battery system need to be subjected to adhesion detection, so that the hardware cost of the BMS is greatly increased;

therefore, there is an urgent need to develop a circuit for detecting adhesion of a contactor, which can overcome the disadvantages of the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a high-side and low-side contact adhesion detection circuit of a battery system aiming at the technical defects in the prior art.

Therefore, the utility model provides a high-side and low-side contactor adhesion detection circuit of a battery system, which comprises a detection input module, a detection output module, an MCU module and a power supply module, wherein:

a battery system P including a battery pack B;

the positive end B + of the battery pack B is connected with the positive end P + of the battery system through a high-side contactor KL 1;

the negative end B-of the battery pack B is connected with the negative end P-of the battery system through a low-side contactor KL2, and the negative end B-is also the negative end of the battery pack BL;

the battery pack BL is positioned in the battery pack B and comprises a plurality of batteries preset in the battery pack B;

the positive electrode end BL + of the battery group BL in the battery group B is connected with the input end 1 of the detection output module and is used for providing the voltage and the current of the battery group BL for the detection output module;

the input end 1 of the detection input module is respectively connected with the positive end P + of the battery system P and the contact end 2 of the high-side contactor KL1 and is used for receiving the voltage and the current of the battery pack B;

the input end 2 of the detection input module is respectively connected with the negative end B-of the battery pack B and the contact end 1 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

the input end 3 of the detection input module is respectively connected with the positive terminal B + of the battery pack B and the contact terminal 1 of the high-side contactor KL1 and is used for receiving the voltage and the current of the battery pack B;

the input end 4 of the detection input module is respectively connected with the negative electrode end P-of the battery system P and the contact end 2 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

the output end Z1 of the detection input module is connected with the input end 3 of the detection output module and is used for providing a control signal Z1 for the detection output module, and the control signal Z1 is used for controlling the signal change of the output end TH of the detection output module;

the output end Z3 of the detection input module is connected with the input end 4 of the detection output module and is used for providing a control signal Z3 for the detection output module, and the control signal Z3 is used for controlling the signal change of the output end TH of the detection output module;

the output end Z2 of the detection input module is connected with the input end 5 of the detection output module and is used for providing a control signal Z2 for the detection output module, and the control signal Z2 is used for controlling the signal change of the output end TL of the detection output module;

the output end Z4 of the detection input module is connected with the input end 6 of the detection output module and is used for providing a control signal Z4 for the detection output module, and the control signal Z4 is used for controlling the signal change of the output end TL of the detection output module;

the input end 1 of the detection output module is connected with the positive electrode end BL + of the battery pack BL and is used for receiving the voltage and the current output by the battery pack BL;

the input end 2 of the detection output module is connected with the negative end B-of the battery pack BL and is used for receiving the voltage and the current output by the battery pack BL;

the input end 3 of the detection output module is connected with the output end Z1 of the detection input module and is used for receiving a control signal Z1 output by the detection input module;

the input end 4 of the detection output module is connected with the output end Z3 of the detection input module and is used for receiving the control signal Z3 output by the detection input module;

the input end 5 of the detection output module is connected with the output end Z2 of the detection input module and is used for receiving the control signal Z2 output by the detection input module;

the input end 6 of the detection output module is connected with the output end Z4 of the detection input module and is used for receiving the control signal Z4 output by the detection input module;

the input end 7 of the detection output module is connected with the output end VDD of the power supply module and is used for receiving a direct current power supply VDD;

the output end TH of the detection output module is connected with the input end 1 of the MCU module and used for outputting a high-side contactor detection signal TH to the MCU module;

correspondingly, the MCU module is used for judging whether the contact adhesion fault occurs in the high-side contactor KL1 according to the signal state of the high-side contactor detection signal TH;

the output end TL of the detection output module is connected with the input end 2 of the MCU module and is used for outputting a low-side contactor detection signal TL to the MCU module;

correspondingly, the MCU module is used for judging whether the contact adhesion fault occurs to the low-side contactor KL2 according to the signal state of the detection signal TL;

the input end 3 of the MCU module is connected with the output end VDD of the power supply module and is used for receiving a direct current power supply VDD;

output terminals CK1 and CK2 of the MCU module are respectively used for outputting a high-side contactor control signal CK1 and a low-side contactor control signal CK2, and correspondingly controlling on/off of a high-side contactor KL1 and a low-side contactor KL2, and the control signals CK1 and CK2 are further used for respectively enabling the MCU module to determine whether contact adhesion failure occurs to contacts of KL1 and KL 2.

Preferably, the contact terminal 1 of the high-side contactor KL1 is connected with the positive terminal B + of the battery pack B;

the contact end 2 of the high-side contactor KL1 is connected with the positive end P + of the battery system P;

the contact end 1 of the low-side contactor KL2 is connected with the negative electrode end B-of the battery pack B;

contact terminal 2 of low side contactor KL2 is connected to negative terminal P-of battery system P.

Preferably, the detection input module includes: resistors R1-R4 and diodes D1-D2;

the 1 st pin of the resistor R1, which is used as the input end 1 of the detection input module, is connected with the positive terminal P + of the battery system and the contact terminal 2 of the high-side contactor KL1, and is used for receiving the voltage and current from the battery pack B;

a 2 nd pin of the resistor R1, which is used as an output terminal Z1 of the detection input module, is respectively connected with the 1 st pin of the resistor R2 and the input terminal 3 of the detection output module, and is used for providing a control signal Z1 for the detection output module;

a 2 nd pin of the resistor R2, which is used as an output end Z3 end of the detection input module, is respectively connected with the anode of the diode D1;

the cathode of the diode D1, which is used as the input end 2 of the detection input module, is connected with the cathode end B-of the battery pack B and is used for receiving the voltage and the current from the battery pack B;

the 1 st pin of the resistor R3, which is used as the input end 3 of the detection input module, is connected with the positive terminal B + of the battery pack B and the contact terminal 1 of the high-side contactor KL1, and is used for receiving the voltage and current from the battery pack B;

a 2 nd pin of the resistor R3, which is used as an output terminal Z2 of the detection input module, is respectively connected with the 1 st pin of the resistor R4 and an input terminal 5 of the detection output module, and is used for providing a control signal Z2 for the detection output module;

a 2 nd pin of the resistor R4, which is used as an output end Z3 end of the detection input module, is respectively connected with the anode of the diode D2;

the cathode of diode D2, which serves as the input terminal 4 of the sense input module, is connected to the negative terminal P-of battery system P and to contact terminal 2 of low-side contactor KL2 for receiving voltage and current from battery B.

Preferably, the detection output module includes: resistors R10-R22, diodes D3-D4, switching tubes Q1-Q6 and optical couplers Q4-Q5, wherein:

a 1 st pin of the resistor R10, which is used as an input terminal 1 of the detection output module, is connected to a positive terminal BL + of the battery BL in the battery B for receiving the voltage and current from the battery BL;

the 1 st pin of the resistor R10 is also respectively connected with the 1 st pin of the resistor R13 and the emitter E of the switching tube Q1;

the 2 nd pin of the resistor R10 is respectively connected with the 1 st pin of the resistor R11 and the base B of the switching tube Q1;

the collector C of the switch tube Q1 is connected with the 1 st pin of the resistor R12;

the 2 nd pin of the resistor R11 is connected with the V1 end;

a V1 terminal connected to the drain D of the switch tube Q4, the 1 st pin of the resistor R22 and the gate G of the switch tube Q5;

a grid G of the switching tube Q4, which is used as the input end 3 of the detection output module, is connected with the output end Z1 of the detection input module, and is used for receiving the control signal Z1 output by the detection input module;

the source S of the switching tube Q4 is used as the input end 4 of the detection output module and is connected with the output end Z3 of the detection input module;

the 2 nd pin of the resistor R13 is respectively connected with the 1 st pin of the resistor R21 and the emitter E of the switching tube Q3;

the 2 nd pin of the resistor R21 is respectively connected with the base B of the switch tube and the drain D of the switch tube Q5;

a collector C of the switching tube Q3 connected to an anode of the diode D3;

the cathode of the diode D3 is connected with the cathode of the diode D4, the 1 st pin of the resistor R14 and the emitter E of the switch tube Q2 respectively;

the anode of the diode D4 is respectively connected with the 2 nd pin of the resistor R12 and the 1 st pin of the optocoupler Q7;

a base B of the switching tube Q2, which is respectively connected with the 2 nd pin of the resistor R14 and the 1 st pin of the resistor R15;

the collector C of the switching tube Q2 is connected with the 1 st pin of the optocoupler Q8;

the 2 nd pin of the resistor R15 is connected with the drain D of the switch tube Q6;

a gate G of the switching tube Q6, serving as an input terminal 5 of the detection output module, is connected to the output terminal Z2 of the detection input module, and is configured to receive the control signal Z2 output by the detection output module;

a source S of the switching tube Q6, which is used as an input end 6 of the detection output module and is connected with an output end Z4 of the detection input module;

the No. 2 pin of the optocoupler Q7 and the optocoupler Q8 are both connected with the negative end B-of the battery pack B, and the negative end B-is also the negative end of the battery pack BL;

the 3 rd pin of the optocoupler Q7 is connected with the 1 st pin of the resistor R17;

a 4 TH pin of the optocoupler Q7 is used as an output end TH of the detection output module, connected with a 1 st pin of the resistor R18 and an input end 1 of the MCU module, and used for outputting a high-side contactor detection signal TH for the MCU module;

the 2 nd pin of the resistor R18 is connected with the ground terminal GND;

the 3 rd pin of the optocoupler Q8 is connected with the 1 st pin of the resistor R19;

a 4 th pin of the optocoupler Q8 is used as an output end TL of the detection output module, connected with a 1 st pin of the resistor R20 and an input end 2 of the MCU module, and used for outputting a low-side contactor detection signal TL for the MCU module;

the 2 nd pin of the resistor R20 is connected with the ground terminal GND;

the 2 nd pin of the resistor R17 and the resistor R19, which is the input terminal 7 of the detection output module, is connected to the output terminal VDD of the power module, and is used for receiving the dc power VDD.

Compared with the prior art, the utility model has the advantages that the structural design is scientific, the low-voltage optocoupler and the switching tube are adopted, the contact adhesion detection of the high-low side contactor in each high-voltage loop can be realized simultaneously, the hardware cost of the adhesion detection function can be greatly reduced, the reliability is ensured, and the utility model has great practical significance.

According to the technical scheme, the hardware circuit is scientific in design, the electronic components are of the commonly-used models, the models are easy to select, and the price of the components is low.

In addition, because the hardware circuit of the technical scheme of the utility model has lower power consumption, surface-mounted low-power electronic components can be adopted, so that the circuit board occupies small space and the material cost is greatly reduced. Therefore, the technical scheme of the utility model has strong practical value and market popularization value.

Drawings

Fig. 1 is a block diagram illustrating a high-side and low-side contact adhesion detection circuit of a battery system according to the present invention;

fig. 2 is a schematic diagram of a detection input module in a high-side and low-side contact adhesion detection circuit of a battery system according to the present invention;

fig. 3 is a schematic diagram of a detection output module in the high-side and low-side contact adhesion detection circuit of the battery system according to the present invention.

Detailed Description

In order to make the technical means for realizing the utility model easier to understand, the following detailed description of the present application is made in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant application and are not limiting of the application. It should be noted that, for convenience of description, only the portions related to the present application are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1 to 3, the present invention provides a high-side and low-side contact adhesion detection circuit of a battery system, including a detection input module 100, a detection output module 200, an MCU module 300, and a power module 400, wherein:

a battery system P including a battery B (the battery B includes a plurality of batteries connected in series and/or in parallel);

referring to fig. 1, the positive terminal B + of the battery B is connected to the positive terminal P + of the battery system through a high-side contactor KL 1;

the positive electrode terminal BL + of the battery BL in the battery B is connected to the input terminal 1 of the detection output module 200, and is configured to provide the detection output module 200 with the voltage and current of the battery BL;

it should be noted that the number of the batteries connected in series between the positive terminal BL + and the negative terminal B-of the battery pack BL is much smaller than the number of the batteries connected in series between the positive terminal B + and the negative terminal B-of the battery pack B, for example, in a 90-string battery pack B, the number of the batteries connected in series between BL + and B-is 10 strings, that is, the battery pack BL is a 10-string battery pack.

It should be noted that the number of the batteries in the battery pack BL connected in series needs to be determined according to the maximum withstand voltage of the switching tubes Q1, Q2, and Q3 in the detection output module 200 (fig. 3).

The high-side contactor KL1 is a power switch in the high-side branch of the battery system, and the low-side contactor KL2 is a power switch in the low-side branch of the battery system.

When power supply for a load is needed, for BMSs (battery management systems) respectively connected with the signal input ends of the high-side contact KL1 and the low-side contact KL2, the BMSs send closing control signals to the high-side contact KL1 and the low-side contact KL2 so as to control the closing of the high-side contact KL1 and the low-side contact KL2 (high-voltage power-on); when power supply to the load is not required, the BMS sends an off control signal to the high-side contactor KL1 and the low-side contactor KL2, thereby controlling the high-side contactor KL1 and the low-side contactor KL2 to be turned off (powered down at high voltage).

The input end 1 of the detection input module 100 is respectively connected to the positive terminal P + of the battery system P and the contact terminal 2 of the high-side contactor KL1, and is configured to receive the voltage and the current of the battery pack B;

the input end 2 of the detection input module 100 is respectively connected with the negative end B-of the battery pack B and the contact end 1 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

the input end 3 of the detection input module 100 is respectively connected with the positive terminal B + of the battery pack B and the contact terminal 1 of the high-side contactor KL1, and is used for receiving the voltage and the current of the battery pack B;

the input end 4 of the detection input module 100 is respectively connected with the negative electrode end P-of the battery system P and the contact end 2 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

an output terminal Z1 of the test input module 100 is connected to the input terminal 3 of the test output module 200, and is configured to provide a control signal Z1 to the test output module 200, where the control signal Z1 is configured to control a signal (a test signal for a high-side contactor KL 1) change at the output terminal TH of the test output module 200;

the output terminal Z3 of the detection input module 100 is connected to the input terminal 4 of the detection output module 200, and is configured to provide a control signal Z3 to the detection output module 200, where the control signal Z3 is configured to control a signal (a detection signal for the high-side contactor KL 1) change at the output terminal TH of the detection output module 200;

an output terminal Z2 of the test input module 100, connected to the input terminal 5 of the test output module 200, for providing a control signal Z2 to the test output module 200, where the control signal Z2 is used to control a signal (a test signal for the low-side contactor KL 2) at the output terminal TL of the test output module 200 to change;

an output terminal Z4 of the detection input module 100 is connected to the input terminal 6 of the detection output module 200, and is configured to provide a control signal Z4 to the detection output module 200, where the control signal Z4 is configured to control a signal (a detection signal for the low-side contactor KL 2) change at the output terminal TL of the detection output module 200;

the input end 1 of the detection output module 200 is connected to the positive terminal BL + of the battery BL and is configured to receive the voltage and current output by the battery BL;

the input end 2 of the detection output module 200 is connected to the negative end B of the battery BL (also the negative end of the battery B) and is configured to receive the voltage and the current output by the battery BL;

the input end 3 of the detection output module 200 is connected to the output end Z1 of the detection input module 100, and is configured to receive the control signal Z1 output by the detection input module 100;

the input end 4 of the detection output module 200 is connected to the output end Z3 of the detection input module 100, and is configured to receive the control signal Z3 output by the detection input module 100;

the input end 5 of the detection output module 200 is connected to the output end Z2 of the detection input module 100, and is configured to receive the control signal Z2 output by the detection input module 100;

the input end 6 of the detection output module 200 is connected to the output end Z4 of the detection input module 100, and is configured to receive the control signal Z4 output by the detection input module 100;

the input end 7 of the detection output module 200 is connected to the output end VDD of the power supply module 400 and is used for receiving a direct current power supply VDD;

the output end TH of the detection output module 200 is connected with the input end 1 of the MCU module 300 and is used for outputting a high-side contactor detection signal TH to the MCU module 300;

correspondingly, the MCU module 300 is configured to determine whether a contact adhesion fault occurs in the high-side contactor KL1 according to a signal state of the high-side contactor detection signal TH;

the output end TL of the detection output module 200 is connected to the input end 2 of the MCU module 300, and is configured to output a low-side contactor detection signal TL to the MCU module 300;

correspondingly, the MCU module 300 is configured to determine whether a contact adhesion fault occurs in the low-side contactor KL2 according to the signal state of the detection signal TL;

the input end 3 of the MCU module is connected to the output end VDD of the power module 400, and is configured to receive a dc power VDD;

output ends CK1 and CK2 of the MCU module are respectively used for outputting a high-side contactor control signal CK1 and a low-side contactor control signal CK2 and correspondingly controlling the on-off of a high-side contactor KL1 and a low-side contactor KL2, and the control signals CK1 and CK2 are also used for respectively enabling the MCU module to judge whether contact points of the KL1 and the KL2 are in adhesion fault;

it should be noted that, the MCU module outputs the corresponding CK1 and CK2 control signals according to the original control strategy of the BMS, and the control strategy and how to output the CK1 and CK2 control signals do not belong to the technical solution of the present invention, and therefore, they are not explained in detail herein.

In the utility model, in a specific implementation, a contact terminal 1 of a high-side contactor KL1 is connected with a positive terminal B + of a battery pack B;

Referring to fig. 1, in order to more clearly understand the technical solution of the present invention, the following describes the working principle of the present invention, specifically as follows:

firstly, before high-voltage power-on and after high-voltage power-off:

high-side contactor control signals CK1 and low-side contactor control signals CK2 output by output ends CK1 and CK2 of the MCU module 300 are both low level, contacts of a high-side contactor KL1 and a low-side contactor KL2 are controlled to be disconnected, input ends 1-4 of the detection input module 100 are 0V, output ends Z1-Z4 of the detection input module are all 0V, and therefore TH signals (high-side contactor KL1 detection signals) and TL signals (low-side contactor KL2 detection signals) of output ends TH of the detection output module 200 are controlled to be low level;

at this time, if CK1, CK2, TH and TL are all at low level, the MCU module 300 determines that the contacts of the high-side contactor KL1 and the low-side contactor KL2 are open, and there is no contact adhesion fault; if the contactor control signals CK1, CK2 are both at a low level and either of the contactor detection signals TH, TL is at a high level, it is determined that the contact sticking fault occurs in the corresponding contactor.

Secondly, high-voltage electrifying:

the working principle is explained by taking the sequential control of the closing of the contactors as an example:

when the high voltage is powered on, firstly, the output end CK2 of the MCU module 300 is at a high level, and the low-side contactor KL2 is controlled to be closed, so that the input end 4 of the detection input module 100 is communicated with the negative end B-of the battery B through the negative end P-of the battery system P, and then the voltage of the battery B is present between the input end 3 and the input end 4 of the detection input module 100, so that the voltage between the output ends Z2 and Z4 is changed from a low level to a high level, and the output end TL of the detection output module 200 is changed from a low level to a high level; meanwhile, the output terminal CK1 of the MCU module 300 keeps a low level, and controls the high-side contactor KL1 to be turned off, so that the voltage and current of the battery B are not connected to the input terminal 1 of the detection input module 100, and the output terminals Z1 and Z3 are at a low level, so that the output terminal TH of the detection output module 200 is also at a low level;

at this time, if the low-side contactor control signal CK2 and the low-side contactor detection signal TL are both at a high level and the high-side contactor control signal CK1 and the high-side contactor detection signal TH are both at a low level, the MCU module 300 determines that the low-side contactor KL2 is closed and the high-side contactor KL1 is open, otherwise, it determines that KL1 and/or KL2 are/is malfunctioning.

Then, the output end CK1 of the MCU module 300 is at a high level, and controls the high-side contactor KL1 to close, so that the input end 1 of the detection input module 100 is communicated with the positive end B + of the battery B through the positive end P + of the battery system P, and the voltage of the battery B is between the input end 1 and the input end 2 of the detection input module 100, so that the voltage between the output ends Z1 and Z3 of the detection input module 100 changes from a low level to a high level, and the output end TH of the detection output module 200 changes from a low level to a high level;

at this time, if the high-side contactor control signal CK1 and the high-side contactor detection signal TH are both at a high level, the MCU module 300 determines that the high-side contactor KL1 is closed, otherwise, it determines that the high-side contactor KL1 is malfunctioning.

It should be noted that, the present invention can also support simultaneous closing of KL1 and KL2, and simultaneously detect whether contact adhesion failure occurs in KL1 and KL 2.

Thirdly, powering off under high voltage:

the working principle is explained by taking the example of controlling the contactors to be disconnected according to the sequence:

when the voltage is high, firstly, the output terminal CK1 of the MCU module 300 changes from high level to low level, and controls the high-side contactor KL1 to be turned off, so that the input terminal 1 of the detection input module 100 is disconnected from the positive terminal B + of the battery B, and the voltage and current of the battery B are not connected between the

input terminals

1 and 2 of the detection input module 100, and the output terminal Z1 and the output terminal Z3 of the detection input module 100 change from low level to high level, so that the output terminal TH of the detection output module 200 changes from high level to low level;

at this time, if the high-side contactor control signal CK1 and the high-side contactor detection signal TH are both at low levels, the MCU module 300 determines that the contacts of the high-side contactor KL1 are open and there is no contact adhesion fault; if the high-side contactor detection signal TH is at a high level, it is determined that the contact sticking fault occurs in the high-side contactor KL 1.

Then, the output terminal CK2 of the MCU module 300 changes from high level to low level, and controls the low-side contactor KL2 to open, so that the input terminal 4 of the detection input module 100 is disconnected from the negative terminal P-of the battery system P, and no voltage or current of the battery pack B is connected between the input terminal 3 and the input terminal 4 of the detection input module 100, and the output terminal Z2 and the output terminal Z4 of the detection input module 100 change from low level to high level, so that the output terminal TL of the detection output module 200 changes from high level to low level;

at this time, if the low-side contactor control signal CK2 and the low-side contactor detection signal TL are both at low levels, the MCU module 300 determines that the contacts of the low-side contactor KL2 are open and there is no contact adhesion fault; if the low-side contactor detection signal TL is at a high level, it is determined that the contact sticking fault occurs in the low-side contactor KL 2.

In the present invention, in a specific implementation, referring to fig. 2, the detection input module 100 includes: resistors R1-R4 and diodes D1-D2;

the 1 st pin of the resistor R1, which is used as the input terminal 1 of the detection input module 100, is connected to the positive terminal P + of the battery system and the contact terminal 2 of the high-side contactor KL1, and is used for receiving the voltage and current from the battery pack B;

a 2 nd pin of the resistor R1, which is an output terminal Z1 of the detection input module 100, is respectively connected to the 1 st pin of the resistor R2 and the input terminal 3 of the detection output module 200, and is used for providing a control signal Z1 to the detection output module 200;

a 2 nd pin of the resistor R2, which is an output terminal Z3 terminal of the detection input module 100, is connected to an anode of the diode D1, respectively;

the cathode of the diode D1, which serves as the input terminal 2 of the detection input module 100, is connected to the negative terminal B-of the battery B for receiving the voltage and current from the battery B.

It should be noted that the diode D1 plays a role in preventing reverse connection.

The 1 st pin of the resistor R3, which is used as the input terminal 3 of the detection input module 100, is connected to the positive terminal B + of the battery B and the contact terminal 1 of the high-side contactor KL1, and is used for receiving the voltage and current from the battery B;

a 2 nd pin of the resistor R3, which is an output terminal Z2 of the detection input module 100, is respectively connected to the 1 st pin of the resistor R4 and the input terminal 5 of the detection output module 200, and is used for providing a control signal Z2 to the detection output module 200;

a 2 nd pin of the resistor R4, which is an output terminal Z3 terminal of the detection input module 100, is connected to an anode of the diode D2, respectively;

the cathode of diode D2, which is input terminal 4 of sense input module 100, is connected to the negative terminal P-of battery system P and to contact terminal 2 of low-side contactor KL2 for receiving voltage and current from battery B.

It should be noted that the diode D2 plays a role in preventing reverse connection.

Referring to fig. 2, the working principle of the detection input module 100 of the present invention is described as follows:

firstly, before high-voltage power-on and after high-voltage power-off:

the output terminals CK1 and CK2 of the MCU module 300 are both low level, and control the contacts of the high-side contactor KL1 and the low-side contactor KL2 to be disconnected, so that the voltages at the two ends of the resistor R1 and the resistor R2, and the voltages at the two ends of the resistor R3 and the resistor R4 are both 0V, and thus the voltages at the ends of the Z1 and the Z3 of the detection input module 100 are both low level of 0V;

secondly, high-voltage electrifying:

when the output terminals CK1 and CK2 of the MCU module 300 are both at a high level, the contacts of the high-side contactor KL1 and the low-side contactor KL2 are controlled to be closed, and the resistor R1 and the resistor R2 divide the voltage of the battery pack B, so that the terminal Z1 of the detection input module 100 becomes a high level, and the level voltage amplitude is determined according to the gate voltages of the switching tubes Q6 and Q7 in the detection output module 200.

In the present invention, in a specific implementation, referring to fig. 3, the detection output module 200 includes: resistors R10-R22, diodes D3-D4, switching tubes Q1-Q6 and optical couplers Q4-Q5, wherein:

a 1 st pin of the resistor R10, which is used as an input terminal 1 of the detection output module 100, is connected to a positive terminal BL + of the battery BL in the battery B for receiving the voltage and current from the battery BL;

the 2 nd pin of the resistor R11 is connected with the V1 end;

a gate G of the switching tube Q4, serving as the input end 3 of the detection output module 100, is connected to the output end Z1 of the detection input module 100, and is configured to receive the control signal Z1 output by the detection input module 100;

the control signal Z1 is used to control the signal variation at the output terminal TH of the detection output module 200 (the detection signal for the high-side contactor KL 1);

a source S of the switching tube Q4, serving as the input terminal 4 of the detection output module 100, is connected to the output terminal Z3 of the detection input module 100, and is configured to receive the control signal Z3;

a collector C of the switching tube Q3 connected to an anode of the diode D3;

a gate G of the switching tube Q6, serving as the input terminal 5 of the detection output module 100, is connected to the output terminal Z2 of the detection input module 100, and is configured to receive the control signal Z2 output by the detection output module 200;

a source S of the switching tube Q6, serving as the input terminal 6 of the detection output module 100, is connected to the output terminal Z4 of the detection input module 100, and is configured to receive the control signal Z4;

a 4 TH pin of the optocoupler Q7 is used as an output end TH of the detection output module 200, connected with a 1 st pin of the resistor R18 and an input end 1 of the MCU module 300, and used for outputting a high-side contactor detection signal TH for the MCU module;

the 2 nd pin of the resistor R18 is connected with the ground terminal GND;

a 4 th pin of the optocoupler Q8 is used as an output end TL of the detection output module 200, connected with a 1 st pin of the resistor R20 and an input end 2 of the MCU module 300, and used for outputting a low-side contactor detection signal TL for the MCU module;

the 2 nd pin of the resistor R20 is connected with the ground terminal GND;

the 2 nd pin of the resistor R17 and the resistor R19, which is the input terminal 7 of the detection output module 100, is connected to the output terminal VDD of the power module 400 for receiving the dc power VDD.

Referring to fig. 3, the working principle of the detection output module 200 of the present invention is described as follows:

firstly, before high-voltage power-on and after high-voltage power-off:

the output terminals CK1 and CK2 of the MCU module 300 are both at low level, the control contactors KL1 and KL2 are both disconnected, and the output terminals Z3 and Z4 of the detection input module 100 are not connected to the battery pack negative terminal B-, so that the output terminals Z1 of the detection input module 100 and Z3, Z2 and Z4 are all at low level, and the switching tubes Q4 and Q6 are respectively turned off; when the Q6 is cut off, the switching tube Q2 is cut off, the optocoupler Q8 is cut off, and the output end TL is pulled down to be at a low level by the resistor R20; when the Q4 is cut off, the switching tube Q1 is cut off, the optocoupler Q7 is cut off, and the output end TH is pulled down to be at a low level by the resistor R18; meanwhile, when Q4 is turned off, the voltage of the battery BL at the V1 terminal is divided into high levels by the resistors R10, R11 and R22, so that the switching tubes Q5 and Q3 are turned on;

it should be noted that, considering that the electric quantity of the battery BL is consumed as low as possible, the values of the resistors R10 and R22 are to be as high as possible, such as 1M megaohms.

It should be noted that the voltage at the V1 terminal is determined according to the gate voltage of the switching tube Q5.

At this time, if CK1, CK2, TH and TL are all at low level, the MCU module 300 determines that the contacts of the high-side contactor KL1 and the low-side contactor KL2 are open, and there is no contact adhesion fault; if the contactor control signals CK1 and CK2 are both low level, and any one of the contactor detection signals TH and TL is high level, the MCU module judges that the corresponding contactor has contact adhesion fault.

Secondly, high-voltage electrifying:

when the high voltage is electrified, firstly, the output end CK2 of the MCU module 300 is at a high level, and the low-side contactor KL2 is controlled to be closed, so that the voltage of the battery pack B is between the input end 3 and the input end 4 of the detection input module 100, and the voltage between the output ends Z2 and Z4 is changed from the low level to the high level, that is, the voltage between the input ends 5 and 6 of the detection output module 200 is at the high level, so that the switching tubes Q6 and Q2 are turned on;

because the output end CK1 of the MCU module 300 keeps a low level, the high-side contactor KL1 is controlled to be turned off, so that the output ends Z1 and Z3 of the detection input module 100 are at a low level, and thus the switching tubes Q4 and Q1 are turned off, and the switching tubes Q5 and Q3 are turned on, and the battery pack BL provides a voltage and a current through the turned-on switching tubes Q3 and Q2 to turn on the optocoupler Q8, so that the output end TL of the detection output module 200 is changed from a low level to a high level;

at this time, if CK2 and TL are both high and CK1 and TH are both low, the MCU module 300 determines that the low-side contactor KL2 is closed and the high-side contactor KL1 is open; if TL is at low level, the MCU module judges that the low-side contactor KL1 has a fault and is not closed; if TH is high level, MCU module will judge that high side contactor KL1 takes place contact adhesion trouble.

Secondly, the output end CK1 of the MCU module 300 is at a high level, and controls the high-side contactor KL1 to be closed, so that the voltage of the battery pack B is between the input end 1 and the input end 2 of the detection input module 100, and the voltage between the output ends Z1 and Z3 of the detection input module 100 is changed from a low level to a high level, that is, the voltage between the input end 3 and the input end 4 of the detection output module 200 is at a high level, then the switching tubes Q4 and Q1 are turned on, and the battery pack BL provides voltage and current through the turned-on switching tube Q1, so that the optocoupler Q7 is turned on, and the output end TH of the detection output module 200 is changed from a low level to a high level; meanwhile, the battery pack BL continues to provide voltage and current through the switched-on switching tubes Q1 and Q2, so that the optocoupler Q8 is switched on, and the output end TL of the detection output module 200 continues to maintain a high level;

the switching tube Q4 is turned on, so that the voltage at the V1 end is 0V, and the switching tubes Q5 and Q3 are both turned off;

at this time, if both CK1 and TH are high, the MCU module 300 determines that the high-side contactor KL1 is closed, otherwise, the MCU module 30 determines that KL1 is malfunctioning and not closed.

Thirdly, powering off under high voltage:

when the voltage is low, firstly, the output terminal CK1 of the MCU module 300 is changed from high level to low level, and the high-side contactor KL1 is controlled to be turned off, so that the voltage of the battery pack B is present between the

input terminals

3 and 4 of the detection input module 100, and then the voltage between the output terminals Z1 and Z3 of the detection input module 100 is changed from high level to low level, that is, the voltage between the

input terminals

3 and 4 of the detection output module 200 is low level, so that the switching tubes Q4 and Q1 are changed from on to off, and the switching tubes Q5 and Q3 are changed from off to on; the Q1 is cut off to enable the optocoupler Q7 to be changed from on to off, and the output end TH of the detection output module 200 is changed from high level to low level; the Q3 is conducted (the Q2 is still in a conducting state) so that the battery pack BL can continuously provide voltage and current, the optocoupler Q8 is kept in a conducting state, and the TL end is maintained at a high level;

at this time, if CK1 and TH are both low level and CK2 and TL are both high level, the MCU module 300 determines that the high-side contactor KL1 is open and the low-side contactor KL2 is closed; if TH is high level, the MCU module 300 determines that the contact adhesion fault of the high-side contactor KL1 occurs and the high-side contactor KL1 is not disconnected; if TL is low, the MCU module 300 will determine that the low-side contactor KL2 has failed and is open.

Secondly, the output end CK2 of the MCU module 300 changes from high level to low level, and controls the low-side contactor KL2 to be turned off, so that the voltage of the battery B is between the input end 1 and the input end 2 of the detection input module 100, and the voltage between the output ends Z2 and Z4 of the detection input module 100 changes from high level to low level, that is, the voltage between the input end 5 and the input end 6 of the detection output module 200 is low level, then the switching tubes Q6 and Q2 are turned on and off, and the optocoupler Q7 is turned on and off, so the output end TH of the detection output module 200 changes from high level to low level;

at this time, if both CK2 and TL are at low level, the MCU module 300 determines that the low-side contactor KL2 is open, and if TL is at high level, the MCU module 300 determines that the low-side contactor KL1 has a contact sticking fault without opening.

In the present invention, it should be noted that, in terms of specific implementation, the chip MCU of the MCU module 300 may be of a currently and commonly used brand, series and model, such as MC9S12 series of NXP, and the model of the chip MCU is not within the protection scope of the present invention.

In the present invention, it should be noted that, in terms of specific implementation, the power module 400 is a power circuit commonly used in the existing BMS technical solution, so that a technician can easily obtain and apply the power circuit without innovation.

Therefore, based on the technical scheme, the battery system contactor adhesion detection circuit provided by the utility model has the advantages that the low-voltage type optocoupler and the switching tube are adopted to provide low-voltage hardware signals for the MCU module, and the low-voltage hardware signals and the contactor control signals output by the MCU module form signal combination logic, so that the contact adhesion faults of the high-side contactor and the low-side contactor can be simultaneously detected in a software and hardware combination mode.

It should be noted that the present invention can support the adhesion detection of the high-low side contactor in each high-voltage loop at the same time, and if only the high-side or low-side contactor needs to be detected, the components need to be deleted correspondingly in the schematic diagram (fig. 3) of the present invention. For example, when detecting a high-side contactor KL1, the switching tube Q1, the switching tube Q4, the resistors R10-R12, the resistors R17-R18 and the optocoupler Q7 need to be reserved, and other components are deleted; for another example, for detecting the low-side contactor KL2, the switching tube Q6, the switching tube Q2, the resistors R14 to R15, the resistors R19 to R20, and the optical coupler Q8 need to be reserved, the emitter E of the switching tube Q2 is connected to the input end 1(BL +) of the detection output module, and other components are deleted.

In summary, compared with the prior art, the high-side and low-side contact adhesion detection circuit of the battery system provided by the utility model has a scientific structural design, can realize the simultaneous contact adhesion detection of the high-side and low-side contacts in each high-voltage loop by adopting the low-voltage optocoupler and the switching tube, can greatly reduce the hardware cost of the adhesion detection function, ensures the reliability, and has great practical significance.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A high-side and low-side contact adhesion detection circuit of a battery system, comprising a detection input module (100), a detection output module (200), an MCU module (300) and a power module (400), wherein:

a battery system P including a battery pack B;

the positive electrode end BL + of the battery group BL in the battery group B is connected with the input end 1 of the detection output module (200) and is used for providing the voltage and the current of the battery group BL for the detection output module (200);

the input end 1 of the detection input module (100) is respectively connected with the positive terminal P + of the battery system P and the contact terminal 2 of the high-side contactor KL1 and is used for receiving the voltage and the current of the battery pack B;

the input end 2 of the detection input module (100) is respectively connected with the negative end B-of the battery pack B and the contact end 1 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

the input end 3 of the detection input module (100) is respectively connected with the positive terminal B + of the battery pack B and the contact terminal 1 of the high-side contactor KL1 and is used for receiving the voltage and the current of the battery pack B;

the input end 4 of the detection input module (100) is respectively connected with the negative electrode end P-of the battery system P and the contact end 2 of the low-side contactor KL2 and is used for receiving the voltage and the current of the battery pack B;

the output end Z1 of the detection input module (100) is connected with the input end 3 of the detection output module (200) and is used for providing a control signal Z1 for the detection output module (200), and the control signal Z1 is used for controlling the signal change of the output end TH of the detection output module (200);

the output end Z3 of the detection input module (100) is connected with the input end 4 of the detection output module (200) and is used for providing a control signal Z3 for the detection output module (200), and the control signal Z3 is used for controlling the signal change of the output end TH of the detection output module (200);

the output end Z2 of the detection input module (100) is connected with the input end 5 of the detection output module (200) and is used for providing a control signal Z2 for the detection output module (200), and the control signal Z2 is used for controlling the signal change of the output end TL of the detection output module (200);

the output end Z4 of the detection input module (100) is connected with the input end 6 of the detection output module (200) and is used for providing a control signal Z4 for the detection output module (200), and the control signal Z4 is used for controlling the signal change of the output end TL of the detection output module (200);

the input end 1 of the detection output module (200) is connected with the positive electrode end BL + of the battery pack BL and is used for receiving the voltage and the current output by the battery pack BL;

the input end 2 of the detection output module (200) is connected with the negative end B-of the battery pack BL and is used for receiving the voltage and the current output by the battery pack BL;

the input end 3 of the detection output module (200) is connected with the output end Z1 of the detection input module (100) and is used for receiving a control signal Z1 output by the detection input module (100);

the input end 4 of the detection output module (200) is connected with the output end Z3 of the detection input module (100) and is used for receiving the control signal Z3 output by the detection input module (100);

the input end 5 of the detection output module (200) is connected with the output end Z2 of the detection input module (100) and is used for receiving a control signal Z2 output by the detection input module (100);

the input end 6 of the detection output module (200) is connected with the output end Z4 of the detection input module (100) and is used for receiving the control signal Z4 output by the detection input module (100);

the input end 7 of the detection output module (200) is connected with the output end VDD of the power supply module (400) and is used for receiving a direct current power supply VDD;

the output end TH of the detection output module (200) is connected with the input end 1 of the MCU module (300) and is used for outputting a high-side contactor detection signal TH to the MCU module (300);

correspondingly, the MCU module (300) is used for judging whether the contact adhesion fault occurs in the high-side contactor KL1 according to the signal state of the high-side contactor detection signal TH;

the output end TL of the detection output module (200) is connected with the input end 2 of the MCU module (300) and is used for outputting a low-side contactor detection signal TL to the MCU module (300);

correspondingly, the MCU module (300) is used for judging whether the contact adhesion fault occurs to the low-side contactor KL2 according to the signal state of the detection signal TL;

the input end 3 of the MCU module is connected with the output end VDD of the power supply module (400) and is used for receiving a direct current power supply VDD;

2. The circuit for detecting the adhesion of the high-side and low-side contactors of the battery system according to claim 1, wherein the contact terminal 1 of the high-side contactor KL1 is connected to the positive terminal B + of the battery pack B;

3. The high-side and low-side contact stick detection circuit of a battery system of claim 1, wherein the detection input module (100) comprises: resistors R1-R4 and diodes D1-D2;

the 1 st pin of the resistor R1 is used as an input end 1 of the detection input module (100), is connected with a positive end P + of the battery system and a contact end 2 of the high-side contactor KL1, and is used for receiving voltage and current from the battery pack B;

a 2 nd pin of the resistor R1, which is used as an output terminal Z1 of the detection input module (100), is respectively connected with a 1 st pin of the resistor R2 and an input terminal 3 of the detection output module (200) and is used for providing a control signal Z1 for the detection output module (200);

the 2 nd pin of the resistor R2 is used as the output end Z3 end of the detection input module (100) and is respectively connected with the anode of the diode D1;

the cathode of the diode D1, which is used as the input end 2 of the detection input module (100), is connected with the cathode end B-of the battery pack B and is used for receiving the voltage and the current from the battery pack B;

the 1 st pin of the resistor R3, which is used as the input end 3 of the detection input module (100), is connected with the positive terminal B + of the battery pack B and the contact terminal 1 of the high-side contactor KL1, and is used for receiving the voltage and current from the battery pack B;

a 2 nd pin of the resistor R3, which is used as an output terminal Z2 of the detection input module (100), is respectively connected with a 1 st pin of the resistor R4 and an input terminal 5 of the detection output module (200) and is used for providing a control signal Z2 for the detection output module (200);

the 2 nd pin of the resistor R4 is used as the output end Z3 end of the detection input module (100) and is respectively connected with the anode of the diode D2;

the cathode of diode D2, which serves as input terminal 4 of the detection input module (100), is connected to the negative terminal P-of battery system P and to contact terminal 2 of low-side contactor KL2 for receiving voltage and current from battery B.

4. The high-side and low-side contact sticking detection circuit of a battery system according to claim 1, wherein the detection output module (200) includes: resistors R10-R22, diodes D3-D4, switching tubes Q1-Q6 and optical couplers Q4-Q5, wherein:

a 1 st pin of the resistor R10, which is used as an input end 1 of the detection output module (100), is connected with a positive terminal BL + of a battery pack BL in the battery pack B and is used for receiving the voltage and the current from the battery pack BL;

the 2 nd pin of the resistor R11 is connected with the V1 end;

a grid G of the switching tube Q4, which is used as the input end 3 of the detection output module (100), is connected with the output end Z1 of the detection input module (100), and is used for receiving the control signal Z1 output by the detection input module (100);

the source S of the switching tube Q4 is used as the input end 4 of the detection output module (100) and is connected with the output end Z3 of the detection input module (100);

a collector C of the switching tube Q3 connected to an anode of the diode D3;

a grid G of the switching tube Q6, which is used as an input end 5 of the detection output module (100), is connected with an output end Z2 of the detection input module (100), and is used for receiving a control signal Z2 output by the detection output module (200);

the source S of the switching tube Q6 is used as the input end 6 of the detection output module (100) and is connected with the output end Z4 of the detection input module (100);

a 4 TH pin of the optocoupler Q7 is used as an output end TH of the detection output module (200), connected with a 1 st pin of the resistor R18 and an input end 1 of the MCU module (300) and used for outputting a high-side contactor detection signal TH for the MCU module;

the 2 nd pin of the resistor R18 is connected with the ground terminal GND;

a 4 th pin of the optocoupler Q8 is used as an output end TL of the detection output module (200), connected with a 1 st pin of the resistor R20 and an input end 2 of the MCU module (300) and used for outputting a low-side contactor detection signal TL for the MCU module;

the 2 nd pin of the resistor R20 is connected with the ground terminal GND;

the 2 nd pin of the resistor R17 and the resistor R19 is used as the input end 7 of the detection output module (100), is connected with the output end VDD of the power supply module (400), and is used for receiving the direct current power supply VDD.