CN221039346U

CN221039346U - Integrated circuit for sampling pre-charging and relay adhesion detection

Info

Publication number: CN221039346U
Application number: CN202322788482.9U
Authority: CN
Inventors: 姜梦征; 顾永; 王文涌; 秦晓冬; 韦创创
Original assignee: Anhui Daheng New Energy Technology Co ltd
Current assignee: Anhui Daheng New Energy Technology Co ltd
Priority date: 2023-10-18
Filing date: 2023-10-18
Publication date: 2024-05-28
Anticipated expiration: 2033-10-18

Abstract

The utility model discloses a comprehensive circuit for sampling, pre-charging and relay adhesion detection, and relates to the field of new energy storage inverters, wherein the comprehensive circuit for sampling, pre-charging and relay adhesion detection comprises a power supply circuit, a voltage acquisition circuit, a pre-charging control circuit, a charging and discharging control circuit, a communication circuit and a load circuit; the power supply circuit is electrically connected with the voltage acquisition circuit, the voltage acquisition circuit is electrically connected with the pre-charge control circuit, the pre-charge control circuit is electrically connected with the charge and discharge control circuit, the charge and discharge control circuit is electrically connected with the communication circuit, and the communication circuit is electrically connected with the load circuit. The utility model compares whether the voltage values of each path reach the expected value and the difference between the voltage values, and completes the real-time monitoring of the voltage, the pre-charging of the load end capacitor and the detection of whether the relay group in the charge and discharge control circuit and the pre-charging control circuit relay group are adhered or not respectively in the process, thereby ensuring the safe power supply of other related systems.

Description

Integrated circuit for sampling pre-charging and relay adhesion detection

Technical Field

The utility model relates to the field of new energy storage inverters, in particular to a comprehensive circuit for sampling pre-charging and relay adhesion detection.

Background

The energy storage inverter is a converter for converting direct current electric energy (a battery and an accumulator jar) into constant frequency and constant voltage or frequency and voltage-regulating alternating current. The energy storage inverter is mainly applied to an energy storage link of power grid access, can realize bidirectional conversion and flow of electric energy according to requirements, and is an important component of energy storage solutions in various scenes. Specifically, the battery pack monitoring device can sample the battery packs, monitor the working parameters such as voltage, current and the like of each battery pack in real time, and is internally provided with the relay group so as to control the charging and discharging of the battery packs.

The traditional circuit is generally designed by adopting separate modules, communication between modules depends on a bus, the structure is complex, the cost is high, an automatic sequential work flow cannot be realized, only a single point can be sampled and detected, a plurality of relays cannot be monitored in real time, faults are difficult to find, the detection time is too long when the detection points are too many, real-time monitoring requirements are difficult to meet, the traditional circuit is complex in structure and difficult to maintain, the service life and reliability are low, module expansion is difficult to carry out, and the circuit needs to be redesigned once functions are required to be increased, so that the universality and expansibility are poor.

For the problems in the related art, no effective solution has been proposed at present.

Disclosure of utility model

Aiming at the problems in the related art, the utility model provides a comprehensive circuit for sampling pre-charging and relay adhesion detection, which aims to overcome the technical problems in the prior related art.

For this purpose, the utility model adopts the following specific technical scheme:

The integrated circuit for sampling, pre-charging and relay adhesion detection comprises a power supply circuit, a voltage acquisition circuit, a pre-charging control circuit, a charging and discharging control circuit, a communication circuit and a load circuit;

the power supply circuit is electrically connected with the voltage acquisition circuit, the voltage acquisition circuit is electrically connected with the pre-charge control circuit, the pre-charge control circuit is electrically connected with the charge and discharge control circuit, the charge and discharge control circuit is electrically connected with the communication circuit, and the communication circuit is electrically connected with the load circuit.

Further, the power supply circuit comprises a battery pack xN, a diode D1, a diode D2, a capacitor C1, a capacitor C2 and an inductor L;

The diode D1 is connected with the cathode of the diode D2 and the first pin of the flyback power supply circuit respectively, the anode of the diode D2 is connected with one end of an external power supply, the other end of the external power supply is connected with the cathode of the battery xN and the second pin of the flyback power supply circuit respectively, the third pin of the flyback power supply circuit is connected with one end of the capacitor C1 and one end of the inductor L respectively, the other end of the capacitor C1 is grounded, the inductor L is connected with the first pin of the isolation voltage reduction circuit, the second pin of the isolation voltage reduction circuit is connected with the fourth pin of the flyback power supply circuit and grounded, one end of the capacitor C2 is connected with the cathode of the battery xN, and the other end of the capacitor C2 is grounded.

Further, the pre-charge control circuit comprises a relay YC+, a relay YC-, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10 and a resistor R11;

The relay YC+ is respectively connected with one end of a resistor R6, one end of a resistor R7 and one end of a resistor R8, and the other end of the resistor R6 is respectively connected with the other end of the resistor R7 and the other end of the resistor R8;

The relay YC-is connected to one end of the resistor R9, one end of the resistor R10, and one end of the resistor R11, respectively, and the other end of the resistor R9 is connected to the other end of the resistor R10 and the other end of the resistor R11, respectively.

Further, the charge-discharge control circuit comprises a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a diode D3, a triode Q1, a triode Q2, a capacitor CD1, a capacitor CD2 and a relay K;

The second pin of relay K is connected with one end of electric capacity CD1, one end of electric capacity CD2 and the one end of diode D3 respectively and connects +12V, the other end of electric capacity CD1 and the other end of electric capacity CD2 are all grounded, the other end of diode D3 is connected with triode Q2's collecting electrode and relay K's first pin respectively, triode Q2's base is connected with resistance R16's one end and resistance R17's one end respectively, resistance R17's the other end is connected with triode Q2's generating electrode and is grounded, resistance R16's the other end is connected with resistance R15's one end and triode Q1's generating electrode respectively, resistance R15's the other end is connected with resistance R14's one end and is grounded, resistance R14's the other end is connected with R12 and triode Q1's base respectively, triode Q1's collecting electrode is connected with resistance R13's one end, resistance R13's the other termination +5V.

Further, the communication circuit comprises a signal integration circuit and a signal transmission circuit.

Further, the signal integrating circuit comprises a chip U1, a capacitor C1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5;

The first pin of chip U1 is grounded, the second pin of chip U1 is connected with the one end of resistance R1, the one end of resistance R1 connects +5V, the third pin of chip U1 is grounded, the eighth pin of chip U1 is connected with the one end of electric capacity C1 and connects +5V, the other end ground connection of electric capacity C1, the ninth pin of chip U1 is connected with the one end of resistance R3 and the one end of resistance R5 respectively, the other end of resistance R5 terminates signal SDA1, the tenth pin of chip U1 is connected with the one end of resistance R2 and the one end of resistance R4 respectively, the other end of resistance R2 is connected with the other end of resistance R3 and connects +5V, the one end of resistance R4 connects signal SCL1.

Further, the signal transmission circuit comprises a chip U2, a capacitor C3, a resistor R18 and a resistor R19;

The first pin of chip U2 connects +5V, and the fourth pin and the fifth pin of chip U2 all ground connection, and the sixth pin of chip U2 is connected with resistance R19's one end respectively and connects signal SCL2, and resistance R19's the other end is connected with resistance R18's one end, and resistance R18's the other end is connected with chip U2's seventh pin and connects signal SDA2, and the one end of electric capacity C2 connects +5V, and electric capacity C2's the other end ground connection, electric capacity C3's one end connects +3.3V, electric capacity C3's the other end ground connection.

The beneficial effects of the utility model are as follows:

1. The integrated circuit for sampling, pre-charging and relay adhesion detection provided by the utility model uses a small amount of electronic components, so that the circuit is simple in structure, economical and reliable, meanwhile, the electronic components with good reliability are adopted, the specific long-term service life is long, and the functions of sampling, pre-charging, charging and discharging control and relay adhesion detection can be completed, so that the sequential execution of the processes of sampling, controlling and the like can be realized, the time is saved, the working efficiency is improved, problems can be found in time by detecting the state of the relay, and the damage under various abnormal conditions is further prevented.

2. According to the utility model, three paths of voltages are sampled at the same time, and under the condition of response of different control circuits, whether each path of voltage value reaches the expected value or not and the difference between the voltage values are compared, and the voltage real-time monitoring, the pre-charging of the load end capacitor and the detection of whether the relay group in the charge and discharge control circuit and the relay group of the pre-charge control circuit are adhered or not are completed in the process, so that the safe power supply of other related systems is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a functional block diagram of an integrated circuit for sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 2 is a functional block diagram of a communication circuit in a combined circuit for sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 3 is a circuit diagram of a power supply circuit in a combined circuit of sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 4 is a circuit diagram of a voltage acquisition circuit in a combined circuit of sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 5 is a circuit diagram of a precharge control circuit in a combined circuit of sample precharge and relay adhesion detection according to an embodiment of the present utility model;

FIG. 6 is a circuit diagram of a charge-discharge control circuit in a combined circuit of sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 7 is a circuit diagram of a signal integration circuit in a combined circuit for sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

FIG. 8 is a circuit diagram of a signal transmission circuit in a combined circuit of sample pre-charge and relay adhesion detection in accordance with an embodiment of the present utility model;

Fig. 9 is a diagram of a precharge and charge-discharge control circuit in a combined circuit for sampling precharge and relay adhesion detection according to an embodiment of the present utility model.

In the figure:

1. a power supply circuit; 2. a voltage acquisition circuit; 3. a precharge control circuit; 4. a charge-discharge control circuit; 5. a communication circuit; 501. a signal integration circuit; 502. a signal transmission circuit; 6. and a load circuit.

Detailed Description

For the purpose of further illustrating the various embodiments, the present utility model provides the accompanying drawings, which are a part of the disclosure of the present utility model, and which are mainly used for illustrating the embodiments and for explaining the principles of the operation of the embodiments in conjunction with the description thereof, and with reference to these matters, it will be apparent to those skilled in the art to which the present utility model pertains that other possible embodiments and advantages of the present utility model may be practiced.

According to an embodiment of the utility model, an integrated circuit for sampling pre-charge and relay adhesion detection is provided.

The utility model will be further described with reference to the accompanying drawings and the specific embodiments, as shown in fig. 1, a comprehensive circuit for sampling, pre-charging and relay adhesion detection according to an embodiment of the utility model includes a power supply circuit 1, a voltage acquisition circuit 2, a pre-charging control circuit 3, a charging and discharging control circuit 4, a communication circuit 5 and a load circuit 6.

The power supply circuit 1 is electrically connected with the voltage acquisition circuit 2, the voltage acquisition circuit 2 is electrically connected with the pre-charge control circuit 3, the pre-charge control circuit 3 is electrically connected with the charge and discharge control circuit 4, the charge and discharge control circuit 4 is electrically connected with the communication circuit 5, and the communication circuit 5 is electrically connected with the load circuit 6.

In one embodiment, the power supply circuit 1 includes a battery set xN, a diode D1, a diode D2, a capacitor C1, a capacitor C2, and an inductance L.

Specifically, the power supply circuit 1 provides power for all circuits and supplies power for other subsequent power utilization circuits, and comprises a battery power supply circuit and a protection circuit, wherein the battery power supply circuit comprises a plurality of battery packs xN connected in series or externally connected with power supply signals, and the protection circuit comprises a diode D1, a diode D2, a capacitor C1, a capacitor C2 and an inductor L; the diode D1 and the diode D2 can prevent the voltage crosstalk between power supplies; the capacitor C1 and the capacitor C2 can increase the voltage wave resistance; the inductance L can increase the current ripple resistance.

Specifically, as shown in fig. 3, the first stage voltage provides power to the input; the second-stage voltage is an output voltage obtained by transforming the first-stage voltage by the flyback power supply circuit; the third-stage voltage is an isolated step-down circuit, and the second-stage voltage is transformed into a voltage suitable for power supply of a specific chip.

Specifically, the power supply circuit 1 processes an input power supply, and designs a mode of supplying power by two paths of power supplies (a plurality of battery packs xN are connected in series or externally connected with power supply signals) in an energy storage project, and uses battery voltage as an example of power supply of a control system, controls the input direction of the input source by using a unidirectional diode to prevent crosstalk between the two paths of power supplies, and then performs voltage isolation and voltage conversion by an isolation voltage reduction circuit to provide the power supply for a back-end circuit.

Specifically, the positive electrode of the power supply V0 is connected with the negative electrode of the diode D1/diode D2, current can flow to the primary winding of the transformer in the flyback power supply circuit through the positive electrode of the diode D1/diode D2, the voltage V1 is output after being converted by the transformer, the purpose of transforming by using the flyback power supply circuit is that the voltage can be regulated and controlled through a voltage chip, and a threshold voltage can be set, namely, the input voltage can be started or closed when the input voltage is larger than a certain value or smaller than a certain value; more importantly, the power supply chip can obtain more stable output voltage under different input voltage values by arranging the output feedback circuit.

Specifically, the types of the diode D1 and the diode D2 are US5M.

Specifically, since the voltage signal values applied to the control chip, the signal transmission chip and the relay control end are different, the output of the flyback power supply circuit is set to be relatively high +12v, namely V1, and then V1 is subjected to isolation voltage reduction circuit to obtain independent +5v voltage V2 for supplying power to the signal transmission circuit 502.

Specifically, as shown in fig. 4, three resistor voltage dividing circuits are formed by ra_1-ra_ M, rb _1-rb_ M, rc _1-rc_m in the voltage acquisition circuit 2, and v_a, v_b, and v_c in the voltage acquisition circuit 2 are the obtained sampling voltages.

In one embodiment, the precharge control circuit 3 includes a relay yc+, a relay YC-, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11.

The relay yc+ is connected to one end of the resistor R6, one end of the resistor R7, and one end of the resistor R8, respectively, and the other end of the resistor R6 is connected to the other end of the resistor R7 and the other end of the resistor R8, respectively.

Specifically, as shown in fig. 5, the pre-charging control unit module includes six groups of pre-charging resistors and two groups of pre-charging relays, the relay yc+ and the relay YC-are pre-charging relays, the pre-charging relay number is HF49/12, the pre-charging control circuit 3 can be controlled to be turned on or off, and the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10 and the resistor R11 are pre-charging resistors.

Specifically, the pre-charging relay in the pre-charging control circuit 3 has the advantages of high voltage withstand, small rated power of the coil, small volume, high switching speed and the like; the pre-charge resistor is selected from cement resistors with the specification of 10w and 300 omega, and the resistor is capable of bearing high temperature and high pressure, resisting corrosion and has higher power capacity.

In one embodiment, the charge-discharge control circuit 4 includes a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a diode D3, a transistor Q1, a transistor Q2, a capacitor CD1, a capacitor CD2, and a relay K.

Specifically, as shown in fig. 6, the resistors R12, R13, R14, R15, R16, and R17 are used as current limiting resistors in the charge/discharge control circuit 4; the capacitor CD1 and the capacitor CD2 are used as filter capacitors, the capacitor CD1 filters high-frequency clutter, and the capacitor CD2 filters low-frequency clutter; the triode Q1 and the triode Q2 (the triode Q1 and the triode Q2 are N-channel triodes) are used as amplifying devices, and the control of higher voltage input by using the output pin of the control chip is completed.

Specifically, the relay in the charge-discharge control circuit 4 is a high-power relay contactor, an EVHC50 direct current contactor is selected, withstand voltage among contacts, among contacts and among coils reaches 3000v, withstand current reaches 50A, and the ceramic arc-extinguishing chamber is designed, so that adhesion is effectively prevented, and the service life of the relay is greatly prolonged.

In one embodiment, the communication circuit 5 includes a signal integration circuit 501 and a signal transmission circuit 502.

In one embodiment, the signal integration circuit 501 includes a chip U1, a capacitor C1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5.

In one embodiment, as shown in fig. 2, the signal transmission circuit 502 includes a chip U2, a capacitor C3, a resistor R18, and a resistor R19.

Specifically, as shown in fig. 7-8, the chip U1 is a signal integration chip, the model of the chip U1 is UCC28C44, the chip U2 is a signal isolation chip, and the model of the chip U2 is NSI8100N; the resistor R1, the resistor R2, the resistor R3, the resistor R18 and the resistor R19 are pull-up resistors, and the resistor R4 and the resistor R5 are current limiting resistors; the capacitor C1, the capacitor C2, and the capacitor C3 have the effect of a filter capacitor.

Specifically, the communication circuit 5 includes a signal integrating circuit 501 and a signal transmitting circuit 502 (the signal transmitting circuit 502 includes a communication signal conversion and a signal isolation conversion), and in order to prevent common mode interference, a power supply part required by the control chip is derived from a power supply source but is different from a reference ground of the power supply part of the power supply source. Therefore, the bus reference ground is used in sampling, and the bus reference ground is required to be converted to interact with the control chip, and on the other hand, as can be seen from fig. 5, the communication signal conversion chip (the model of the communication signal conversion chip is SGM58031XMS 10G/TR) can also save the number of communication conversion signals and reduce the number of channels occupied by the control chip.

Table 1: relationship between relay adhesion detection and sampling precharge is schematically shown

Specifically, a voltage reduction chip is used for converting V2 into +3.3V power supply for supplying power to a control chip, and the control chip compares the voltage difference Vab of BAT+ and BAT-through the collected voltage value; the pressure difference Vdb of PACK+ and BAT-; the pressure difference Vdc of PACK+ and PACK-; judging whether the relay state is normal or not, as shown in table 1, the implementation steps specifically include:

Step one: when the system does not receive an output instruction, namely, no output is performed, the Vab, vdc and Vdb voltage values are read, and if the Vab value is the power supply voltage value within the allowable error range and the Vdc and Vdb are 0, the positive relay HK+ is normal.

Step two: the main control unit sends suction instructions to the positive and negative pre-charging relays YC+ and YC-, and a capacitance pool charging formula is as follows:

T＝RC*Ln[(Vbat-V0)/(Vbat-Vp)]；

Wherein: t is the precharge time, R is the precharge resistor, C is the load terminal capacitance, vbat is the battery pack voltage, V0 is the voltage before the load terminal closes the high voltage, and Vp is the load terminal voltage at the end of the precharge. Typically, vp is chosen to be 90% or 95% of the total voltage Vbat, expressed as:

T＝RC*Ln10；

After the charging is finished, the positive and negative pre-charging relays are disconnected, then the voltage values of Vab, vdc and Vdb are read, if the voltage value of the Vab is that the voltage value of the power supply is within an error range, the voltage value of the Vdc and Vdb are equal, the voltage value of the Vdc and Vdb is slightly smaller than the voltage value of the Vab, and the voltage value of the positive and negative pre-charging relays YC+ and YC-are normal.

Step three: the main control unit sends an actuation instruction to the negative relay HK-and then reads the voltage values of Vab, vdc and Vdb, if the Vab value is that the voltage value of the power supply is within the error range, the Vdc and Vdb are equal, the value is slightly smaller than Vab and gradually decays, and then the positive and negative pre-charge relays YC+ and the relays YC-are normal.

Step four: the main control unit sends an actuation instruction to the positive relay HK+ and then reads the voltage values of Vab, vdc and Vdb, if the voltage value of the Vab is within the error range, the voltage value of the power supply is equal to Vab, and the Vdc and Vdb are kept stable.

Specifically, in practical application, the acquisition of the Vab, vdc and Vdb pressure values needs to be kept at a higher frequency; and in the second step and the third step, the main control unit issues the command for not too long in interval between the end of the pre-charging and the suction of the negative relay HK-in the two steps.

Specifically, as shown in fig. 9, the positive electrode bat+ of the power supply is connected to the first end of the fuse F1 at the same time, and the other end point a of the fuse is connected to the first end of the positive electrode relay hk+ and the first end of the positive electrode precharge relay yc+; the other end of the precharge relay YC+ is connected with a precharge resistor, and the precharge resistor at the positive electrode end is formed by connecting three cement electric groups (a resistor R7, a resistor R8 and a resistor R9) in parallel; the purpose of using three cement electric groups in parallel connection is to equally divide large current generated during pre-charging, so that the excessive power born by the pre-charging resistor during pre-charging is avoided, and different resistance values and numbers are considered according to actual conditions in practical application.

The other end of the pre-charging resistor is connected to the positive electrode of a load (the capacitor pool in the present case), namely the point D, meanwhile, the positive electrode relay HK+ second end is also connected to the point D, the negative electrode C point of the load is connected to the negative electrode terminal pre-charging resistor, meanwhile, the negative electrode C point of the load is also connected with the negative electrode relay HK-first end, and the negative electrode terminal pre-charging resistor is connected to the negative electrode pre-charging relay YC-first end; the second end of the negative electrode pre-charging relay YC-is connected to the first end of the negative electrode fuse F2, namely the point B, and the second end of the negative electrode relay HK-is also connected to the point B; and finally, the second end of the negative fuse F2 is connected to the positive electrode of the power supply, so that a connection loop of the whole system is completed.

In summary, by means of the technical scheme, the integrated circuit for sampling, pre-charging and relay adhesion detection provided by the utility model uses a small amount of electronic components, so that the circuit is simple in structure, economical and reliable, meanwhile, the electronic components with good reliability are adopted, the specific long-term service life is high, and the functions of sampling, pre-charging, charging and discharging control and relay adhesion detection can be completed, so that the sequential execution of the processes of sampling, controlling and the like can be realized, the time is saved, the working efficiency is improved, the problems can be found in time by detecting the state of the relay, and further, the damage under various abnormal conditions can be prevented; according to the utility model, three paths of voltages are sampled at the same time, and under the condition of response of different control circuits, whether each path of voltage value reaches the expected value or not and the difference between the voltage values are compared, and the voltage real-time monitoring, the pre-charging of the load end capacitor and the detection of whether the relay group in the charge and discharge control circuit and the relay group of the pre-charge control circuit are adhered or not are completed in the process, so that the safe power supply of other related systems is ensured.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "configured," "connected," "secured," "screwed," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intermediaries, or in communication with each other or in interaction with each other, unless explicitly defined otherwise, the meaning of the terms described above in this application will be understood by those of ordinary skill in the art in view of the specific circumstances.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims

1. The integrated circuit for sampling, pre-charging and relay adhesion detection is characterized by comprising a power supply circuit (1), a voltage acquisition circuit (2), a pre-charging control circuit (3), a charging and discharging control circuit (4), a communication circuit (5) and a load circuit (6);

The power supply circuit (1) is electrically connected with the voltage acquisition circuit (2), the voltage acquisition circuit (2) is electrically connected with the pre-charging control circuit (3), the pre-charging control circuit (3) is electrically connected with the charging and discharging control circuit (4), the charging and discharging control circuit (4) is electrically connected with the communication circuit (5), and the communication circuit (5) is electrically connected with the load circuit (6).

2. The integrated circuit for sampling pre-charge and relay adhesion detection according to claim 1, wherein the power supply circuit (1) comprises a battery set xN, a diode D1, a diode D2, a capacitor C1, a capacitor C2 and an inductance L;

The battery pack xN is connected in series, the positive electrode of the battery pack xN is connected with the positive electrode of the diode D1, the negative electrode of the diode D1 is connected with the negative electrode of the diode D2 and the first pin of the flyback power supply circuit respectively, the positive electrode of the diode D2 is connected with one end of an external power supply, the other end of the external power supply is connected with the negative electrode of the battery pack xN and the second pin of the flyback power supply circuit respectively, the third pin of the flyback power supply circuit is connected with one end of the capacitor C1 and one end of the inductor L respectively, the other end of the capacitor C1 is grounded, the inductor L is connected with the first pin of the isolation voltage reduction circuit, the second pin of the isolation voltage reduction circuit is connected with the fourth pin of the flyback power supply circuit and grounded, one end of the capacitor C2 is connected with the negative electrode of the battery pack xN, and the other end of the capacitor C2 is grounded.

3. The integrated circuit for sampling pre-charge and relay adhesion detection according to claim 2, wherein the pre-charge control circuit (3) comprises a relay yc+, a relay YC-, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, and a resistor R11;

The relay yc+ is respectively connected with one end of the resistor R6, one end of the resistor R7 and one end of the resistor R8, and the other end of the resistor R6 is respectively connected with the other end of the resistor R7 and the other end of the resistor R8;

The relay YC-is connected to one end of the resistor R9, one end of the resistor R10, and one end of the resistor R11, and the other end of the resistor R9 is connected to the other end of the resistor R10 and the other end of the resistor R11, respectively.

4. A combined circuit for sampling, pre-charging and relay adhesion detection according to claim 3, wherein the charge-discharge control circuit (4) comprises a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a diode D3, a triode Q1, a triode Q2, a capacitor CD1, a capacitor CD2 and a relay K;

The second pin of relay K is connected with one end of electric capacity CD1 respectively the one end of electric capacity CD2 and the one end of diode D3 is connected in parallel +12V, the other end of electric capacity CD1 and the other end of electric capacity CD2 all ground connection, the other end of diode D3 respectively with triode Q2's collecting electrode and relay K's first pin is connected, triode Q2's base respectively with resistance R16's one end and resistance R17's one end is connected, resistance R17's the other end with triode Q2's generating electrode is connected and ground connection, resistance R16's the other end respectively with resistance R15's one end and triode Q1's generating electrode is connected, resistance R15's the other end with resistance R14's one end is connected and ground connection, resistance R14's the other end respectively with R12 and triode Q1's base, triode Q1's one end is connected with resistance R13's generating electrode is connected and is grounded, another +5V of resistance R13.

5. The integrated circuit for sample pre-charging and relay adhesion detection according to claim 4, wherein the communication circuit (5) comprises a signal integration circuit (501) and a signal transmission circuit (502).

6. The integrated circuit for sampling precharge and relay adhesion detection according to claim 5, wherein the signal integration circuit (501) comprises a chip U1, a capacitor C1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5;

The first pin of chip U1 is grounded, the second pin of chip U1 with resistance R1's one end is connected, resistance R1's one end connects +5V, chip U1's third pin is grounded, chip U1's eighth pin with electric capacity C1's one end is connected and is connected +5V, electric capacity C1's the other end ground connection, chip U1's ninth pin respectively with resistance R3's one end and resistance R5's one end is connected, resistance R5's the other end termination signal SDA1, chip U1's tenth pin respectively with resistance R2's one end and resistance R4's one end is connected, resistance R2's the other end with resistance R3's the other end is connected and is connected +5V, resistance R4's one end is connected signal SCL1.

7. The integrated circuit for sample pre-charge and relay adhesion detection of claim 6, wherein the signal transmission circuit (502) comprises a chip U2, a capacitor C3, a resistor R18, and a resistor R19;

The first pin of chip U2 connects +5V, the fourth pin and the fifth pin of chip U2 all ground connection, the sixth pin of chip U2 respectively with resistance R19's one end is connected and connects signal SCL2, resistance R19's the other end with resistance R18's one end is connected, resistance R18's the other end with chip U2's seventh pin is connected and connects signal SDA2, capacitance C2's one end connects +5V, capacitance C2's the other end ground connection, capacitance C3's one end connects +3.3V, capacitance C3's the other end ground connection.