CN112083323A

CN112083323A - Relay adhesion detection circuit and detection method thereof

Info

Publication number: CN112083323A
Application number: CN202010717768.6A
Authority: CN
Inventors: 张伟峰; 程亚兵; 刘林; 余翠羊
Original assignee: Zhejiang Qualtech Co ltd
Current assignee: Zhejiang Qualtech Co ltd
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2020-12-15
Anticipated expiration: 2040-07-23
Also published as: CN112083323B

Abstract

The invention relates to a relay adhesion detection circuit and a detection method thereof, wherein the circuit comprises an isolation power supply, a detection unit, a control unit and a judgment unit, wherein the isolation power supply is respectively connected with the judgment unit and the detection unit, and the detection unit is used for detecting whether a main relay and a negative relay are closed and whether the residual voltage of a load capacitor is discharged or not; the judging unit is used for analyzing whether the main relay and the negative relay are closed or not according to the level signal detected by the detecting unit so as to obtain an analysis result; and the control unit is used for feeding back the analysis result to the specified equipment. According to the invention, the adhesion detection is carried out in a level detection mode, so that the accuracy of the adhesion detection of the relay is improved, and the cost is reduced.

Description

Relay adhesion detection circuit and detection method thereof

Technical Field

The invention relates to a relay, in particular to a relay adhesion detection circuit and a detection method thereof.

Background

The relay of the high-voltage main loop of the electric automobile controls the discharge of a battery system, and the reliable work of the relay is directly related to the safety problem of the electric automobile. The safety accident may be caused when the electric automobile works in the relay adhesion state. If false alarm occurs in the adhesion detection of the relay, the electric automobile cannot be started. Therefore, the BMS (Battery Management System) needs to reliably detect the relay adhesion state.

The mainstream relay of present BMS glues detection scheme is that the physical quantity that utilizes the detection is mainly exactly Voltage and electric current, judge different measured values under the different scenes, come to draw the adhesion fault conclusion, current mainstream relay glues detection scheme and can't detect the adhesion state of RTN (feedback Voltage Input, RETURN Input Voltage RTN) end relay under the external machine that charges need to charge and discharge under-process detection insulation's the condition, and can all meet load capacitance's residual Voltage problem at normal testing process, need wait for the electric capacity short time and release, the accuracy of detection has been reduced, and the components and parts that constitute detection circuitry are comparatively complicated, and the cost is higher.

Therefore, it is necessary to design a new circuit to improve the accuracy of the relay adhesion detection and reduce the cost.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a relay adhesion detection circuit and a detection method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme: a relay adhesion detection circuit comprises an isolation power supply, a detection unit, a control unit and a judgment unit, wherein the isolation power supply is respectively connected with the judgment unit and the detection unit, and the detection unit is used for detecting whether a main relay and a negative relay are closed and whether residual voltage of a load capacitor is released or not; the judging unit is used for analyzing whether the main relay and the negative relay are closed or not according to the level signal detected by the detecting unit so as to obtain an analysis result; and the control unit is used for feeding back to the specified equipment according to the analysis result.

The further technical scheme is as follows: the detection unit comprises a first detection subunit and a second detection subunit which are connected between the negative relay and the charger, and the first detection subunit and the second detection subunit are respectively connected with the control unit.

The further technical scheme is as follows: the first detection subunit comprises a triode QSS1 and clamping diodes DSS66 and DSS4, wherein the negative electrode of the clamping diode DSS66 is connected with the positive electrode of the clamping diode DSS4, and the negative electrode of the clamping diode DSS4 is connected between a negative relay and a charger; the positive electrode of the clamping diode DSS66 is connected with the emitting electrode of the transistor QSS1, and the collecting electrode of the transistor QSS1 is connected with the judging unit through an anti-reverse diode DSS 3; the collector of the transistor QSS1 is connected to the isolated power supply.

The further technical scheme is as follows: the first detection subunit further comprises clamping diodes DSS1 and DSS2, the anode of the clamping diode DSS1 is connected with the judging unit through a resistor RSS68 and a resistor RSS15, the cathode of the clamping diode DSS1 is connected with the anode of the clamping diode DSS2, the cathode of the clamping diode DSS2 is grounded, the cathode of the clamping diode DSS4 is connected with a resistor RSS36 and a resistor RSS35, and a photocoupler USS1 is connected between the resistor RSS35 and the isolation power supply.

The further technical scheme is as follows: a resistor RSS16 and a resistor RSS67 are connected between the collector of the transistor QSS1 and the isolated power supply.

The further technical scheme is as follows: a filter resistor RSS66 with one end grounded is further connected between the reverse connection prevention diode DSS3 and the judgment unit.

The further technical scheme is as follows: the second detection subunit comprises a triode QSS2, and the base electrode of the triode QSS2 is connected between the negative relay and the charger; the collector of the transistor QSS2 is connected with the judging unit and the isolating unit, and the emitter of the transistor QSS2 is grounded through a clamping diode DSS 11.

The further technical scheme is as follows: the base electrode of the triode QSS2 is respectively connected with a resistor RSS25, an anti-reverse diode DSS65 and an anti-reverse diode DSS27, wherein the resistor RSS25 is connected with the negative electrode of the anti-reverse diode DSS65, the positive electrode of the anti-reverse diode DSS65 is connected with the negative electrode of the anti-reverse diode DSS27, and the positive electrode of the anti-reverse diode DSS27 is connected between the negative relay and the charger.

The further technical scheme is as follows: an anti-reverse diode DSS34 and an anti-reverse diode DSS7 are also connected between the collector of the triode QSS2 and the isolation unit.

The invention also provides a detection method of the relay adhesion detection circuit, which comprises the following steps:

the detection unit detects whether the main and negative relays are closed and whether the residual voltage of the load capacitor is released or not;

the judging unit analyzes whether the main relay and the negative relay are closed or not according to the level signal detected by the detecting unit to obtain an analysis result;

and the control unit feeds back the analysis result to the specified equipment.

Compared with the prior art, the invention has the beneficial effects that: the invention discloses a relay adhesion detection device, which is characterized in that an isolation power supply, a detection unit, a judgment unit and a control unit are arranged, the detection unit is provided with a first detection subunit and a second detection subunit, the first detection subunit and the second detection subunit are used for detecting whether a main negative relay is closed or not and whether residual voltage of a load capacitor is discharged or not in real time, level signals under different conditions are detected, when the first detection subunit and the second detection subunit detect that the main negative relay is closed or not, if one detection subunit detects that the level is low, the main negative relay is opened, adhesion detection is carried out in a level detection mode, the accuracy of relay adhesion detection is improved, and the cost is reduced.

The invention is further described below with reference to the accompanying drawings and specific embodiments.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic block diagram of a relay sticking detection circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a specific circuit of a detecting unit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a specific circuit of a first detecting subunit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a second detecting subunit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and the detailed description.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be connected or detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above should not be understood to necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by one skilled in the art.

According to the specific embodiment shown in fig. 1-4, the relay adhesion detection circuit provided by the embodiment can be applied to the relay adhesion condition detection process in the battery box, the adhesion condition of the main and negative relays is judged under different conditions of whether the residual voltage of the load capacitor C1 is released or not, the detection circuit is formed by adopting simpler and lower-cost components, the adhesion state of the relay is judged by utilizing resistance voltage division and a level detection mode, the accuracy of relay adhesion detection is improved, and the cost is reduced.

Referring to fig. 1, the relay adhesion detection circuit includes an isolation power supply 30, a detection unit 40, a control unit 10 and a determination unit 50, where the isolation power supply 30 is connected to the determination unit 50 and the detection unit 40, respectively, and the detection unit 40 is configured to detect level signals of different situations, such as whether a main relay and a negative relay are closed and whether a residual voltage of a load capacitor is completely discharged; a judging unit 50, configured to analyze whether the main and negative relays are closed according to the level signal detected by the detecting unit 40, so as to obtain an analysis result; and the control unit 10 is used for feeding back the analysis result to the specified equipment.

Referring to fig. 1, a battery module, a main positive relay S1A, a pre-charging relay S3A, a main negative relay S2A and an external auxiliary equipment charger are arranged in the internal structure of the battery box, and two ends of the charger are also connected in parallel with a load capacitor C1, wherein two stages of the battery module are respectively connected with the main positive relay S1A and the main negative relay S2A correspondingly, and the pre-charging relay S3A is connected in parallel with the main positive relay S1A; when the main positive relay S1A and the main negative relay S2A are closed and the battery charger charges the battery module, whether the main negative relay S2A is closed or not needs to be effectively judged; at this time, the level condition of the RTN side is detected by the detection unit 40 to be fed back to the judgment unit 50 for analysis, the detection unit 40 obtains different level detection values under different conditions of whether the main and negative relays S2A are closed and whether the residual voltage of the load capacitor C1 is discharged, the different level detection values are input to the judgment unit 50, the judgment unit 50 detects and analyzes the different level values, a judgment is made and reported to the control unit 10 through communication modes such as IIC, and the isolation power supply 30 and the communication isolation mainly isolate the high-voltage detection module from other low-voltage functional modules, so as to protect the operation of the whole system.

In the present embodiment, a communication isolation unit 20 is connected between the determination unit 50 and the control unit 10, and is used for isolating the high-voltage module from the low-voltage module, so as to protect the operation of the whole system.

In this embodiment, the determining unit 50 includes a power supply module, a communication module, a GPIO input/output module, a voltage AD collecting module, and a current collecting module; the power supply module supplies power to the whole judging unit 50 normally, the GPIO input/output module is used for judging the high and low levels of the detection points input by the judging unit 50, the communication module is used for feeding back and summarizing the detected high and low levels, executing a judgment strategy designed by a pre-program to obtain a judgment result, and reporting the judgment result to the control unit 10 through data communication.

In an embodiment, referring to fig. 2, the detecting unit 40 includes a first detecting subunit and a second detecting subunit, which are connected between the negative relay and the charger, and the first detecting subunit and the second detecting subunit are respectively connected to the control unit 10. The closing condition of the main and negative relays S2A is comprehensively judged by using the level signals detected by the first and second detecting subunits, and since the residual voltage of the load capacitor C1 has a condition of complete or incomplete discharging, two detecting subunits need to be arranged for comprehensive detection to cope with detection and judgment of whether the main and negative relays S2A are closed or not under different conditions.

In an embodiment, referring to fig. 2 and fig. 3, the first detecting subunit includes a transistor QSS1 and clamping diodes DSS66 and DSS4, wherein a cathode of the clamping diode DSS66 is connected to an anode of the clamping diode DSS4, and a cathode of the clamping diode DSS4 is connected between the negative relay and the charger; the positive electrode of the clamping diode DSS66 is connected with the emitting electrode of the transistor QSS1, and the collecting electrode of the transistor QSS1 is connected with the judging unit 50 through an anti-reverse diode DSS 3; the collector of transistor QSS1 is connected to isolated power supply 30.

In this embodiment, the isolation power supply 30 needs to selectively output positive and negative voltages, the isolation power supply 30 outputs negative voltage mainly to form a loop with the detection unit 40, and the loop side of the negative voltage needs to add a resistor with a large resistance value to suggest hundreds of megabits and optical relay control, so that the optical relay switch S4A is connected to one end of the isolation power supply 30 connected to the charger, and the on or off of the optical relay switch S4A determines whether the detection unit 40 can form a loop.

In an embodiment, referring to fig. 2 and fig. 3, the first detecting subunit further includes clamping diodes DSS1 and DSS2, an anode of the clamping diode DSS1 is connected to the determining unit 50 through a resistor RSS68 and a resistor RSS15, a cathode of the clamping diode DSS1 is connected to an anode of the clamping diode DSS2, a cathode of the clamping diode DSS2 is grounded, a cathode of the clamping diode DSS4 is connected to a resistor RSS36 and a resistor RSS35, and a photocoupler USS1 is connected between the resistor RSS35 and the isolation power supply 30.

The clamping diode is arranged in the first detection subunit, so that the detection unit 40 can be prevented from being damaged by back pressure formed in the moment of cutting off the relay and the like, the clamping judgment on the detection unit 40 can be realized, and the safety of the whole detection unit 40 is improved.

In one embodiment, referring to fig. 3, a resistor RSS16 and a resistor RSS67 are connected between the collector of the transistor QSS1 and the isolated power supply 30.

In addition, a filter resistor RSS66 with one end grounded is connected between the reverse connection prevention diode DSS3 and the determination unit 50. The anti-reverse diode DSS3 may function to prevent the occurrence of a situation where a connection error of the isolated power supply 30 causes damage to the device.

In an embodiment, referring to fig. 2 and fig. 4, the second detecting subunit includes a transistor QSS2, and a base of the transistor QSS2 is connected between the negative relay and the charger; the collector of the transistor QSS2 is connected to the determination unit 50 and the isolation unit, and the emitter of the transistor QSS2 is grounded through a clamping diode DSS 11.

Whether the transistor QSS2 is conducted or not is determined by the voltage between the negative relay and the charger.

In addition, the base of the triode QSS2 is connected with a resistor RSS25, an anti-reverse diode DSS65 and an anti-reverse diode DSS27 respectively, wherein the resistor RSS25 is connected with the negative electrode of the anti-reverse diode DSS65, the positive electrode of the anti-reverse diode DSS65 is connected with the negative electrode of the anti-reverse diode DSS27, and the positive electrode of the anti-reverse diode DSS27 is connected between the negative relay and the charger.

In an embodiment, referring to fig. 4, an anti-reverse diode DSS34 and an anti-reverse diode DSS7 are further connected between the collector of the transistor QSS2 and the isolation unit.

The clamp diode DSS11 is further connected to a resistor RSS86, a resistor RSS87, and an inductor FSS 20.

Specifically, RTN1 ckq1 and RTN1 ckq2 are level input detection points, that is, points at which the detection unit 40 is connected to the determination unit 50. Since there is residual voltage of the load capacitor C1 on the RTN side, taking the characteristic of the diode as 0.7V as an example, if the voltage on the RTN1 side is greater than 0.7V, the current passes through the resistors RSS16 and RSS67, then passes through the transistor QSS1, the clamp diode DSS66, the clamp diode DSS4, the resistor RSS36, and the resistor RSS35, then passes through the photocoupler USS1, and then returns to the negative electrode of the isolation power supply 30, this loop is always on, at this time, the loop detected at the RTN1 ckq1 is high level, at this time, if the main negative relay S2A is closed, the transistor dssqss 2, the clamp diode 11, GNV and RT1, the anti-reverse diode DS27, DS65, and the resistor RSS25 form a loop that is in a clamp state, and the loop detected at the RTN1 ckq2 is high level; if the main negative relay S2A is turned off, a loop formed by the isolation power supply 30, the resistor RSS74, the resistor RSS69, the reverse connection prevention diode DSS34, the reverse connection prevention diode DSS7, the transistor QSS2, the clamping diode DSS11, the inductor FSS20, the resistor RSS87 and the resistor RSS86 is conducted, and a low level is detected at the RTN1 CkeckQ 2.

If the voltage on the side of the RTN1 is less than 0.7V, a loop formed by the isolation power supply 30, the resistor RSS74, the resistor RSS69, the reverse-connection prevention diode DSS34, the reverse-connection prevention diode DSS7, the transistor QSS2, the clamp diode DSS11, the inductor FSS20, the resistor RSS87 and the resistor RSS86 is always kept in a non-conducting state, a high level is detected at the RTN1 ckq2, at this time, if the main negative relay S2A is closed, the GNV is equal to the RTN1, the loop formed by the transistor QSS1, the resistor RSS17, the clamp diode DSS1, the clamp diode DSS2, the GNV and RT1, the clamp diode DS4 and the clamp diode 66 is in a clamping state, and a high level is detected at the RTN1 ckq 1; if the main negative relay S2A is turned off, the current passes through the resistors RSS16 and RSS67, then passes through the transistor QSS1, the clamping diode DSS66, the clamping diode DSS4, the resistor RSS36, and the resistor RSS35, then passes through the photocoupler USS1, and returns to the negative electrode of the isolation power supply 30, the loop is turned on, and the low level is detected at the RTN1 ckq 1.

In summary, when both RTN1 ckq1 and RTN1 ckq2 detect a high level, the main negative relay S2A is in a closed state; when one of the RTN1 ckq1 and RTN1 ckq2 detects a low level, the main negative relay S2A is in an off state, and according to this principle, the determination unit 50 can determine the state of the main negative relay S2A according to the high and low of the received two level signals.

In the present embodiment, the communication isolation unit 20 includes a communication isolation chip, which is model number but not limited to VK 3366.

In this embodiment, the control unit 10 includes a master control chip, which is, but not limited to, an NJM2295A model.

The utility model provides a foretell relay adhesion detection circuitry, through setting up isolation power 30, detecting element 40, judge unit 50 and the control unit 10, detecting element 40 sets up first detection subelement and second detection subelement, utilize first detection subelement and second detection subelement real-time detection main negative relay whether closed and the residual voltage of load capacitance whether the level signal under the different situation of completion of releasing, it is high level signal to detect both, then show that main negative relay is closed, as long as one of them detects the subelement and detects the low level, then show that main negative relay breaks off, adopt the level detection mode to carry out adhesion detection, realize improving the accuracy that the relay adhesion detected, and reduce cost.

In one embodiment, there is also provided a method for detecting a relay adhesion detection circuit, including:

the detection unit 40 detects level signals under different conditions that whether the main and negative relays are closed and whether the residual voltage of the load capacitor is discharged;

the judging unit 50 analyzes whether the main and negative relays are closed or not according to the level signal detected by the detecting unit 40 to obtain an analysis result;

the control unit 10 feeds back to the designated device according to the analysis result.

It should be noted that, as can be clearly understood by those skilled in the art, the specific implementation process of the detection method for a relay adhesion detection circuit described above may refer to the corresponding description in the foregoing embodiment of the relay adhesion detection circuit, and for convenience and brevity of description, no further description is provided herein.

The technical contents of the present invention are further illustrated by the examples only for the convenience of the reader, but the embodiments of the present invention are not limited thereto, and any technical extension or re-creation based on the present invention is protected by the present invention. The protection scope of the invention is subject to the claims.

Claims

1. A relay adhesion detection circuit is characterized by comprising an isolation power supply, a detection unit, a control unit and a judgment unit, wherein the isolation power supply is respectively connected with the judgment unit and the detection unit, and the detection unit is used for detecting whether a main relay and a negative relay are closed and whether the residual voltage of a load capacitor is discharged or not; the judging unit is used for analyzing whether the main relay and the negative relay are closed or not according to the level signal detected by the detecting unit so as to obtain an analysis result; and the control unit is used for feeding back to the specified equipment according to the analysis result.

2. The relay adhesion detection circuit according to claim 1, wherein the detection unit comprises a first detection subunit and a second detection subunit, which are connected between the negative relay and the charger, and the first detection subunit and the second detection subunit are respectively connected with the control unit.

3. The relay adhesion detection circuit according to claim 2, wherein the first detection subunit comprises a transistor QSS1 and clamping diodes DSS66, DSS4, wherein the negative pole of the clamping diode DSS66 is connected with the positive pole of the clamping diode DSS4, and the negative pole of the clamping diode DSS4 is connected between the negative relay and the charger; the positive electrode of the clamping diode DSS66 is connected with the emitting electrode of the transistor QSS1, and the collecting electrode of the transistor QSS1 is connected with the judging unit through an anti-reverse diode DSS 3; the collector of the transistor QSS1 is connected to the isolated power supply.

4. The relay adhesion detection circuit according to claim 3, wherein the first detection subunit further comprises clamp diodes DSS1, DSS2, an anode of the clamp diode DSS1 is connected to the determination unit through a resistor RSS68 and a resistor RSS15, a cathode of the clamp diode DSS1 is connected to an anode of the clamp diode DSS2, a cathode of the clamp diode DSS2 is grounded, a cathode of the clamp diode DSS4 is connected to a resistor RSS36 and a resistor RSS35, and a photocoupler USS1 is connected between the resistor RSS35 and the isolation power supply.

5. The relay sticking detection circuit as claimed in claim 4, wherein a resistor RSS16 and a resistor RSS67 are connected between the collector of the transistor QSS1 and the isolated power supply.

6. The relay adhesion detection circuit according to claim 5, wherein a filter resistor RSS66 with one end grounded is further connected between the reverse connection prevention diode DSS3 and the determination unit.

7. The relay sticking detection circuit as claimed in any one of claims 2 to 5, wherein the second detection subunit comprises a transistor QSS2, and the base of the transistor QSS2 is connected between the negative relay and the charger; the collector of the transistor QSS2 is connected with the judging unit and the isolating unit, and the emitter of the transistor QSS2 is grounded through a clamping diode DSS 11.

8. The relay adhesion detection circuit according to claim 7, wherein a resistor RSS25, a reverse connection prevention diode DSS65 and a reverse connection prevention diode DSS27 are respectively connected to the base of the transistor QSS2, wherein the resistor RSS25 is connected to the negative pole of the reverse connection prevention diode DSS65, the positive pole of the reverse connection prevention diode DSS65 is connected to the negative pole of the reverse connection prevention diode DSS27, and the positive pole of the reverse connection prevention diode DSS27 is connected between the negative relay and the charger.

9. The relay sticking detection circuit as claimed in claim 8, wherein an anti-reverse diode DSS34 and an anti-reverse diode DSS7 are further connected between the collector of the transistor QSS2 and the isolation unit.

10. A detection method of a relay adhesion detection circuit is characterized by comprising the following steps:

and the control unit feeds back the analysis result to the specified equipment.